[From the U.S. Government Printing Office, www.gpo.gov]
[email protected]@2 Coas,(al Zone 71-formation COASTAL D"'NE Center I 1KFGR%P,4AT,4 [email protected] GEENTER HOWEPA [email protected] Raporl The AMOCO CADIZ Oil Spill GC 1321 A46 1978 k 4w US. DEPARTMENT OF COMMERCE U.S. ENVIRONMENTAL PROTECTION AGENCY National Oceanic and Atmospheric Administration Environmental Research Laboratory COASTAL ZONE INFORMATION CENTER NOAA/EPA Special Report The AMOCO CADIZ Oil Spill A Preliminary Scientific Report Property of CSC Library Edited by Wilmot N. Hess NOAA Environmental Research Laboratories Major Contributors: Environmental Protection Agency U.S. Department of Commerce, NOAA Texas A. & M. University University of New Orleans University of South Carolina U.S. DEPARTMENT OF COMMERCE NOAA COASTAL SERVICES CENTER 2234 SOUTH HOBSON AVENUE CHARLESTON,SC 29405-2413 August 1978 (2nd Printing) U.S. DEPARTMENT OF COMMERCE Juanita Kreps, Secretary National Oceanic and Atmospheric Administration Richard A. Frank, Administrator Environmental Research Laboratories Wilmot N. Hess, Director Boulder, Colorado U.S. ENVIRONMENTAL PROTECTION AGENCY Douglas M. Costle, Administrator Environmental Research Laboratory Eric D. Schneider, Director Narragansett, Rhode Island For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 NOTICE The Environmental Research Laboratories do not approve, recommend, or endorse any proprietary product or proprietary material mentioned in this publication. No reference shall be made to the Environmental Research Laboratories or to this publication furnished by the Environmental Research Labora- tories in any advertising or sales promotion which would in- dicate or imply that the Environmental Research Laboratories approve, recommend, or endorse any proprietary product or proprietary material mentioned herein, or which has as its purpose an intent to cause directly or indirectly the adver- tiqed product to be used or purchased because of this Envi- ronmental Research Laboratories publication. CONTENTS Page Preface v Acknowledgments vi 1. Executive Summary 1 2. Investigations of Physical Processes -7 J. A. Galt (NOAA-PMEL) 3. Chemical Composition of Selected Environmental and Petroleum Samples From the Amoco Cadiz Oil Spill 21 John Calder (NOAA-OCSEAP) James Lake (EPA) John Laseter (U. of New Orleans) 4. Investigations of Beach Processes 85 Erich Gundlach (U. of South Carolina) Miles Hayes (U. of South Carolina) 5. Biological Observations 197 F. A. Cross (NOAA-NMFS) W. P. Davis (EPA) D. E. Hoss (NOAA-NMFS) D. A. Wolfe (NOAA-OCSEAP) Appendix, Ch. 5 216 J. L. Hyland (EPA) 6. Oil Spill Cleanup Activities 229 Roy W. Hann, Jr. (Texas A&M University) Les Rice (Texas A&M University) Marie-Claire Trujillo (Texas A&M University) Harry N. Young, Jr. (Texas A&M University) Appendix A: Chronology 277 Appendix B: Colored Plates 283 iii PREFACE The grounding of the supertanker Amoco Cadiz near the coast of Brittany on March 16, 1978, resulted in the greatest single discharge of petroleum in maritime history, with tragic consequences for the people of France. Strong onshore winds and unusually high spring tides (quite unlike the conditions encountered in the Argo Merchant spill in late 1976) forced the 220,000 ton cargo of the vessel high on the beaches and well into estuaries and marshes along 210 kilometers of the Brittany coast. The effects of the spill, although not totally evaluated to date, were nonetheless devastating in a region heavily dependent on the quality of its coastline and nearshore waters for the maintenance of an active maritime economy and way of life. Few coastal regions of the world are immune from incidents of this nature; lessons learned from the French experience must be immedi- ately translated into effective national and international regulations governing the safe shipment of petroleum and other hazardous substances by sea. In addition, we must establish the means to deal more effec- tively with incidents of this magnitude when they do occur. The French experience, as regrettable as it was, will yield a wealth of information on the effectiveness of various means of containment and cleanup and improve the capability of scientists and engineers around the world to mitigate and assess the environmental consequences of such events in the future. The United States was fortunate to have in place a team of Federal, state and academic scientists tr*ained and equipped to respond on short notice to marine pollutant incidents of this nature. Through the cooperation of the French government, members of the team were able to work closely with their French counterparts to assist in mitigating the effects of the spill, assess the extent of environmental damage, and compile information vital to future United States efforts in this area. This report is a preliminary U.S. contribution to the study of the Amoco Cadiz disaster. A longer-term, international effort is clearly warranted to explore the long-range environmental consequences of the incident, as well as to understand the nature and effectiveness of natural recovery processes. Certainly the United States will continue to support this endeavor. t** Richard A. Frank, Administrator National Oceanic and Atmospheric Administration v ACKNOWLEDGMENTS The United States' scientific team is deeply indebted to Dr. Lucien Laubier, Director of the Centre Oceanologique de Bretagne of the Centre National pour 1'Exploitation des Oceans (COB/CNEXO), for the opportunity to participate with our French counterparts in the study of the Amoco Cadiz incident. Through Dr. Laubier's kind assistance and that of Dr. Allen,'Dr. Cavanie, Dr. Conan, M. de Clarens, Dr. Marchand, Dr. d'Ozouville and other staff members and scientists at COB/CNEXO, scientific advice and laboratory facilities and equipment critical to the United States effort were provided. We are also especially appreciative of the keen insights and valuable assistance offered by Dr. Cabioch, M. Leglise, D. J. Vasserot, and the staff of the Station Biologique Roscoff in aiding our work on the north coast. Considering the devastation of this most diverse and important biological habitat, it is with mixed emotions that we acknowl- edge the major contributions the station is now making to understanding the consequences of world oil pollution. We would like to acknowledge the assistance and fruitful discus- sions provided by Drs. Glemarec and Chasse of the Universit6 de Bretagne Occidental, Col. Ph. Milon and P. Penicand of the Ligue Francaise par la Protection des Oiseaux, and the staff of the Societ6 pour 1'Etude et la Protection de la Nature en Bretagne. Our work was aided in great measure by James Brown at the Depart- ment of State and William Salmon, Ha *rvey Ferguson, and Quincy Lumsden at the U.S. Embassy in Paris. Necessary diplomatic clearances as well as very practical on-scene assistance were provided in an expeditious. manner, under circumstances that were often difficult and sensitive. We would also acknowledge the essential [email protected] provided by our interpreters Catherine Cadon, Brigette de Clarens, Tina Loughlin, Sylvia Walensky, and J. Rubino, without whose assistance communications would*have been impossible at times and difficult at best. Funding in support of this effort was provided by the National Oceanic and Atmospheric Administration, the Environmental Protection Agency, and the Bureau of Land Management. vi THE AMOCO CADIZ OIL SPILL 1. EXECUTIVE SUMMARY This document provides a preliminary account of the United States scientific efforts in response to the Amoco Cadiz oil spill during the period March 19 to May 15, 1978. The To-cument expands on and updates material reported by the National Oceanic and Atmospheric Administration in April 1978 in the document entitled The Amoco Cadiz Oil Spill: A First Report of the SOR Team Activities. It should be emphasized that all material reported herein is indeed preliminary; final assessment of full impact of the incident will require the integration and interpreta- tion of data taken by scientists from several nations. From our knowl- edge of previous spills, we anticipate that final assessment of the full extent of the impact may require a period of several years. At approximately 11:30 p.m. on Thursday, March 16, 1978, the supertanker Amoco Cadiz went aground on a rock outcropping 1.5 km offshore of Portsall-on the northwest-coast of France (see Plates 1-1 through 1-7). The vessel contained a cargo of 216,000 tons of crude oil and 4,000 tons of bunker fuel. At 6:00 a.m. on Friday, March 17, the vessel broke just forward of the wheelhouse and thus started the worst oil spill in maritime history. During the course of the next 15 days, the bunker fuel.and contents of all 13 loaded cargo tanks, which con- tained two varieties of light mideastern crude oil, were released into the ocean. The oil quickly became a water-in-oil emulsion (mousse) of at least 50% water, and heavily impacted nearly 140 km of the Brittany coast from Portsall to Ile de Br6hat. At one time or another oil con- tamination was observed along 393 kin of coastline and at least 60 km offshore (Fig. 1-1). Impacted areas included recreational beaches, mariculture impoundments, and a substantial marine fishery industry. On March 18, Dr. Wilmot N. Hess, Director of the Environmental Research Laboratories (ERL) of the National Oceanic and Atmospheric Administration (NOAA), contacted Dr. Lucien Laubier, Director of the Centre Oceanologique de Bretagne (COB) of the Centre National pour l'Exploitation des Oceans (CNEXO), the French national oceanographic organization. Dr. Hess and Dr. Laubier arranged for participation by United States scientists in a joint Franco-American investigation of physical and chemical manifestations of the spill. On March 24, the agreement was expanded to include.cooperative biological investigations through contacts initiated by Dr. Eric Schneider, Director of the Envi- ronmental Protection Agency's Environmental Research Laboratory in Narragansett, Rhode Island. Since the Argo Merchant oil spill in December 1976, EPA and NOAA have collaborated in development of an interagency oil spill response team, encompassing a variety of scientific disciplines. In the United States this team has three functions: (1) To provide authorities responsible for cleanup with highly- qualified scientific assistance in mitigating the environ- mental and socio-economic impacts of spills of oil and other hazardous substances. (2) To provide scientific assistance in assessing the damage resulting from such spills. (3) To maximize the research advantage offered by the spill situation, especially with respect to improving future re- .sponse capabilities. FRANCE Les Sept. @Ies Br6hat le Grande Perros-Guirec Paumpol Roscoff Lannion Kerfouan o St. Michel-en-Grbve L'Aber W ac'h Plouescat Locquirec Portsall 0 Morlaix L'Aber Benoit COB-CNEXO iie Touessant Brest le Conquet Pie. de St. Mathieu Scale 0 5 10 20 30 40 50 60 70 to Figure 1-1. Coast of Brittany, showing locations of spilled oil. 2 NOAA team members initially arrived on-scene on Sunday, March 19. Initial photographic over-flights and active beach sampling began on Tuesday, March 21, followed by initial chemical sampling by vessel on Friday, March 24. The team was supplemented with EPA biological observ- ers on Sunday, March 26. Routine sampling has continued by all segments of the team until the present time. Throughout the period of investigation, active interaction and coordination with the French scientific community have taken place under the auspices of COB/CNEXO. All sampling has been coordinated with programs organized by CNEXO and other institutions in France, making possible a more thorough evaluation of the effects of the incident than would otherwise have been possible. During the course of the investigation, seven observational objec- tives were established by the U.S. team: (1) Aerial photographic mapping and ground surveys of impacted beaches. (2) Statistical mapping of the distribution of oil on the water surface using vertical photography. (3) Surveys of the concentrations of oil in subsurface water. (4) Evaluation of the effect of weathering on the composition of surface oil as a function of time/distance from the wreck site. (5) Evaluation of the long-term effects of weathering on the composition of oil in sediments from tidal flats and beaches. (6) Evaluation of the biological consequences of the spill. (7) Observation and assessment of cleanup techniques. Given the limitations of our analytical efforts to date, we believe the following preliminary conclusions can be drawn regarding the nature, fate, and effects of the oil spilled from the Amoco Cadiz: (1) According to our best estimate, 64,000 tons of the Amoco Cadiz oil came ashore along 72 km of the shoreline of Brittany during the first two and one-half weeks of the spill. A prevailing westerly wind pushed the oil against west-facing headlands and into shoreline embay- ments as it moved east. Additional wind-induced forcing is hypothesized to have taken place through a sea surface setup along the coast and subsequent development of a significant alongshore current. A wind reversal in early April moved the oil in the opposite direction, contam- inating previously untouched areas and transporting the oil as far southwest as Pointe du Raz (southwest of Brest). At the end of April, 3 the total volume of oil onshore was reduced to 10,000 tons, but by that time 320 km of shoreline had been contaminated. (2) Coastal processes and geomorphology played a major role in the dispersal and accumulation of the oil once it came onshore. For exam- ple, oil accumulated at the heads of crenulate bays and on tombolos (sand spits formed in the lee of offshore islands). Local sinks, such as scour pits around boulders, bar troughs (runnels), marsh pools, and joints and crevasses in rocks, tended to trap oil. The grounded mousse was either eroded away, or buried (up to 70 cm) under new sediment de- posits, in response to the vagaries of the beach cycle. (3) During the initial oiling, the first week after the grounding, oil definitely lifted off with the incoming tide, and was redeposited on the ebb. However, by late April oil/sediment binding was pronounced and considerable sinking'was evident. A significant percentage of the oil spilled by the Amoco Cadiz is now hypothesized to have sunk to'the bottom and thereafter been subjected to bottom transport processes. (4) The distribution of oil.in water in the Aber Wrac'h estuary was uniform vertically, indicating that the benthos was exposed to oil. Six weeks after the grounding, this estuary still contained elevated concentrations of oil in water, particularly at the upper end. (5) Offshore, high concentrations of oil in water were observed under patches of mousse or slick, but, interestingly, near-bottom water usually contained even greater quantities of oil. (6) Chemical analysis of weathered oil samples revealed notable losses of lower molecular weight components, decreases in peak heights of n-alkanes relative to isoprenoids, reductions in resolved vs. unre- solved material in aliphatic and aromatic fractions, and increases in oxygenated material. Mass spectrometric data indicate the presence of photo-oxidation products of dibenzothiophene and its alkyl homologs. There was no mass spectral evidence for photo-oxidation products of the naphthalenes and phenanthrenes. (7) Adverse biological effects of the spill were observed along the northwest coast of Brittany, ranging from Portsall to Perros-Guirec --a distance of about 150 km of coastline.plus numerous rocky outcrop- pings and islands. Biological communities in these habitats were subjected to varying degrees of stress depending upon type of habitat, distance from the spill, and location relative to the configuration of the coastline. (8). Intertidal communities on coastlines facing in a westerly direction, as well as the Aber Benoit estuary and Rulosquet marsh near Ile Grande, were severely impacted. These effects were maximized by spring tides which occurred just after the wreck. Massive mortalities of some intertidal animals occurred near St. Efflam and at Rulosquet 4 marsh over a relatively short time span (a few days), whereas mortal- ities of other populations were observed to occur more gradually (over several weeks). Populations of intertidal crabs, nereid worms, bivalve molluscs, and limpets were much more acutely affected by the spill than were depo�it-feeders (e.g. Arenicola). For epifauna, mortality appeared to be related to physical coating by the oil; the dissolved fraction that penetrated into the interstitial water was probably the primary factor contributing to mortalities of infauna. Acute effects were not observed on attached macroalgae although some evidence was obtained in an independent study that indicates that the fertilization process of exposed plants may be impaired, and that growth of Laminaria may be retarded. (9) The oil spill occurred at a time when many species of marine birds were in the process of migration from wintering to nesting grounds. More than 3,200 dead birds were recovered, representing more than 30 species. About 85% of these deaths, however, were among four species (shag cormorant, guillemot, razorbill, and puffin), the last three of which are considered rare or threatened in France. More chronic impacts on marine birds may result from feeding on contaminated prey. Seagulls were observed feeding on freshly killed intertidal organisms all along the impacted coastline. (10) Mariculture operations for oysters were severely affected in the Aber Benoit and Aber Wrac'h estuaries and the Bay of Morlaix. Large numbers of oysters were either killed or contaminated by the spill. The holding pens of the commercial lobster operation at Roscoff were heavily oiled and probably will be out of operation for a year. The main scallop fishery in Brittany is located east of the impacted area, and adverse effects may be minimal. (11) The transport of oil or its volatile fractions to terrestrial communities may have been substantial. In late March gale force winds and spring tides combined to deposit oil above the high tide mark. More importantly, some of the airborne fractions of the petroleum can adhere to plants and be transported to man via farm crops and livestock. As indicated earlier, U.S. scientific response efforts were con- ducted for the purpose of meeting three objectives: 1) support to operational forces in mitigating impact, 2) assessment of damage, and 3) research for the purpose of improving the effectiveness of future responses. In connection with objective 1, U.S. scientists provided assistance in suggesting alternative measures for dealing with oil contaminated beaches. Assistance in tracking the extent of oil contamination was provided to French authorities on a near-daily basis through frequent photographic overflights. 5 Most of the U.S. scientific activity will contribute to the final assessment of environmental damage in connection with the objective 2 above. U.S. biological observations, when merged with French data on pre-spill conditions, will contribute directly to the assessment of impact. Chemical analyses, coupled with information on the toxicity of crude oil and the expected distribution of biota at the time of the spill, will provide additional evidence of impact in the absence of direct biological observations in the field. Regarding objective 3, major contributions to future U.S. response efforts are anticipated from observations of the clean-up strategies employed by the French and from after-the-fact assessment of each tech- nique and the corresponding long-term impact on the environment. Data collected will also provide new insights concerning oil movement in the marine environment such as the stranding or beaching of oil, sheltering of areas in the lee of headlands, role of longshore drift in oil trans- port and the effect of tidal pumping. These new conceptual understand- ings can be expected to contribute to the next generation of oil spill forecasting models and hydrocarbon impact assessment studies. 6 2. INVESTIGATIONS OF PHYSICAL PROCESSES J. A. Galt* 2.1 Introduction The physical processes that affect the behavior of oil in the marine environment can be divided into two classes. The first class includes those processes that control the movement and mixing of ocean waters independent of the possibility of an added pollutant. These processes are the normal subject of study for physical oceanographers and represent a major research field in their own right. Normally we assume that these processes simply move the oil around and that in a Lagrangian frame of reference they define the position of the water parcels in which the oil (or hydrocarbon) floats. The second class of processes includes those that affect the oil and its distribution as it floats in the water. These processes clearly will depend on the physi- cal and chemical characteristics of the oil as well as the environmental conditions. Oil/wave/wind interactions, mousse formation, and aglomer- ation with sediment particles are all contained in this second class of processes. To develop an observation program and research effort that will offer tactical support during a spill situation and lead to a systematic improvement in our ability to forecast oil movement during future events we must consider all of these processes in some detail. In particular for coastal regions and expected oil types we must identify investiga- tive and descriptive techniques that have proved useful, specify to what accuracy data fields must be known, and finally identify major gaps in our understanding of the processes that will require additional re- search. When considering the first class of processes we may ignore the presence of oil and concentrate on the movement of the water and a passive tracer. The distribution of such a tracer will be described by the mass balance or distribution of variables equation (Sverdrup et al., 1942). This equation simply relates the local change in concentration to the divergence of the advective flux and diffusive spreading: ac Wcu) + (kVc) *Pacific Marine Environmental Laboratory, NOAA, Seattle, Wash.. 7 In-an attempt to interpret this equation in an oceanographic con- text an immediate problem occurs with respect to the resolution of the velocity field specified in the advection term. In particular, any time dependent or unsteady components of the flow that are not included in the description of the currents contribute to the diffusive spreading term. Following the original development of Reynolds, effective diffu- sion coefficients can be defined which are typically orders of magnitude larger than those associated with molecular processes. Conceptually, once we have determined how the water is moving we can treat the remainder of the trajectory problem by d 'escribing how the oil moves relative to the water. These relative motions will depend on the oil and its physical properties. These properties in turn will be governed by the complex chemical makeup,that is typical of hydrocarbons. We can expect that such bulk.properties as density and viscosity will certainly be significant. In addition there is considerable evidence suggesting that the oil's behavior is strongly influenced by processes that act across the oil/water and oil/atmosphere interfaces. Although these are poorly understood, afew examples can be noted. Evaporation and.fractionation during spreading will alter the composition of the upper surface of the oil, giving the exposed layer a set of characteristics different from those of the bulk of the oil. The result is the formation of a surface crust that can significantly alter the behavior of the oil slick as a whole. For centuries seafarers have used oil floated on the sea to sup- press wave action. The phrase.to "put oil on troubled waters" has become part of common speech.. Standard navigation texts have comments on the relative effectiveness of animal and vegetable oil vs. crude oil or gasoline (Bowditch, 1966). Despite this long observational history, the dynamics of the wave/oil slick interaction are poorly understood. It is just these details that are ofparticular significance to the oil transport and environmental impact problems. It is observed that short gravity waves and capillary waves are quickly damped out when entering an oil slick. The wave momentum must be transferred to the oil slick or a boundary layer just beneath it, or possibly both the slick and a boundary layer. The consequences of this process are at least twofold. First, the momentum exchange acts to propel the oil slick through the water, thus making it move faster than the surface drift in the direc- tion of the dominant waves (downwind). In addition, since the shorter gravity waves and capillary waves have some components coming from all directions there will be an additional momentum transfer acting as a compressional force on the oil slick. This effect acts to counter the natural spreading of an oil slick and tends to reinforce surface tension effects. It can be seen that two major components needed in trajectory predictions appear to be closely tied to this wave/oil momentum transfer process: 1) differential oil water movement and 2) final expected spreading, pancake formation, etc. 8 Hydrocarbons once released in the marine environment cannot be treated as conservative quantities. As times goes on they are both modified in form and removed from the surface by a number of processes including evaporation, emulsification, sediment interactions, and biol- ogical degradation. Some hydrocarbons will evaporate from a surface slick, resulting in significant losses of mass to the atmosphere. This process is not at all uniform and depends on a number of characteristics of the oil. Obviously.the lighter molecular fractions of the oil tend to evaporate more rapidly than the heavier ones. This process modifies the bulk properties of the slick in such a way that certain feedback mechanisms become important. The heavy residuals left at the surface of the slick can form a crust or skin that inhibits further evaporation until mechan- ical processes, such as wave action, break or perturb the surface. Another important secondary effect associated with evaporation is the fractionation of the oil, which leaves the heavier component behind. In some cases the heavier fractions may be dense enough to sink. There have been examples where patches have sunk in relatively large chunks, and recent,studies (Mattson, 1978) suggest that small flakes (which were presumably originally in suspension in the lighter oil fraction - USNS Potomac spill) can sink as a residual after evaporation. Observational data show very large variations in the loss of mass of oil due to evap- oration from spill to spill. Although the accuracy of the observations can certainly be.questioned, the range of losses appeared to be from practically nil in the Argo spill (#6 oil) to over 50% in,the Ecofisk spill (light crude oil). A second weather process is associated with emulsification. It" occurs in two ways, leading to quite different results. Oil-in-water emulsifications can form where'small oil droplets go into suspension in water. In such a case the oil no longer behaves as a surface slick, but moves with the water, mixing throughout the upper layer.somewhat like plankton. Sustained weather effects in this form are not known, but oil-in-water emulsions appear to get rid of the oil slick as a surface contaminant, so emulsification agents are often considered part'of a cleanup strategy. A second, common type of emulsification is one in which the mixture contains up to 80% water. Such a water-in-oil emulsi- fication, often called mousse, appears to resist certain types of con- tinued weather and takes on physical properties quite different from those of surface oil. The development of algorithms to,predict mousse formation is of major importance for predicting overall oil impact. A.third type of weathering process affecting oil slicks is related to oil interacting with suspended sediments in the water column. In at least some cases, oil droplets appear to adhere to sediment particles. This is not a universal effect, and probably depends o"a complex geochem- ical interactions as well as oil characteristics. For example, in the Santa Barbara blowout, sediment from the Ventura river sank large quan- titie.s of oil whereas large amounts-.of oil from the Argo spill did not 9 appear to end up in the sediments. In other cases (the Arrow, the West Falmouth, and the Metula spills) it appears that mechanical mixing was actually responsible for oil being driven into the sediments where the weathering processes and residence times were entirely different from those of oil in the water column. A fourth weather process is related to biological utilization of the hydrocarbons as an energy source. This tends to be a slower process than the ones mentioned above and consequently is of secondary impor- tance at least during the initial stages of a spill. For the long term fate of spilled hydrocarbons, biological breakdown is still likely to be significant, but this is typically beyond the period when trajectory tracking techniques can contribute to a meaningful estimate of the hydrocarbon mass balance. 2.2 Physical Processes Studies Beginning our specific discussion of physical processes affecting the movement and spreading of oil spilled from the Amoco Cadiz it is necessary to consider the basic oceanographic background. This means looking into the dominant physical mechanisms controlling the regional surface flow. Before doing this, however, we will consider the purely observational data that describe the form of the floating oil. During the Amoco Cadiz study the SOR Team took a large number of photographs of floating oil and it is useful to try and categorize them. 2.2.1 Dominant Forms of Floating Hydrocarbons The most common form of heavy oil concentration was a pool of floating mousse (Plate 2-1). This was generally brown to reddish-brown in color. Thicknesses were estimated to be typically about 1 mm al- though along shorelines thicknesses of as much as 25 cm were observed. A number of near-shore samples were collected and appeared to be very stable water-in-oil emulsions with 50 to 70 percent water contents. The time required for an oil to form a water-in-oil emulsion or mousse depends on the type of oil and the mixing energy available. For the Amoco Cadiz spill the formation appeared to take place very quickly. During overflights on March 21 and 22 the oil leaking from the ship appeared to change color from black to a brown characteristic of mousse in less than a ship length. A sample was collected on March 26. This sample was obtained at the point where the oil was upwelling to the surface mid-ship at the vessel. It proved to be a well developed mousse, indicating that the sea-water/oil combination in the ship's tank was forming an emulsion even before it left the ship. A second common form of the oil was a sheen. Plate 2-2 shows a mousse and sheen combination under high wind conditions. The sheen is quite thin showing rainbow colors to a light gray appearence. This suggests thickness of about 10 microns. Such sheens were often seen in 10 conjunction with mousse concentrations but also appeared by themselves. Under moderate and strong wind conditions sheens always appeared to form windrows as would be expected from Langmuir cells. Previous SOR team observation on the Hawaiian Patriot spill suggest that windrow distri- bution of both sheen and mousse is likely to occur under strong wind conditions at extended distances. More recent SOR team studies of the Potomac spill (Mattson, 1978) indicate that sheen formation actually represents a fractionation in the oil with lighter, lower surface- tension components going into the sheen. Lighter hydrocarbon fractions are also more rapidly weathered by evaporation and dissolution so, as the surface oil ages, sheens would be less likely and the remaining oil might be expected to have a different molecular composition. A third form of the Amoco's oil was a light brown foam (Plate 2-4). The chemical composition and origin of this form are unknown. It usually appeared in the highly energetic surf zone and was originally hypothesized to be a violently mixed mousse, a frappe, or perhaps mousse shake. It is also possible that this could be a surface product left as a residual after the use of dispersants. For whatever the reasons, the froth form apparently did not occur except in the surf zone and if it ever contributed to the development of more dense concentrations of hydrocarbons, that was not documented. During the cruise of Le Suroit in early April it was possible to observe mousse concentrations at sea that had weathered for several weeks. Plate 2-3 shows a close-up photograph of weathered mousse that had congealed into smaller globs. It appears that this form does not have the extensive sheen that was seen earlier in the spill. It should also be noted that nothing is now known about the chemical composition of mousse in this form, or about its appropriate physical or environ- mental descriptors, its toxicity, effective viscosity, etc. So far we have considered the empirically observed form of the oil in its most general catagories. We must now consider specific processes and dynamic forces affecting the spilled oil distribution. 2.2.2 Tidal Processes A first glance at the Brittany coast of France suggests tidal action as a dominant process. A spring tidal range of 7 m-certainly controls the near-shore currents. Within the estuaries and coastal zone the ebb and flow will contribute to beaching processes. On a slightly larger scale the tidal currents may or may not represent a significant process in the distribution of hydrocarbons. The answer to this ques- tion will depend on 1) the net flow over a tidal cycle; 2) the presence of convergences or divergences in the surface tidal currents; and 3) the possibility of correlations between the tidal currents and sources and sinks for the oil. To the extent that tidal currents are linear the net flow over a tidal cycle will be zero and, although any water parcel will go through a displacement of perhaps several kilometers, the longer term drift will not accumulate. We know however that the tides are not strictly linear and that frictional effects, field acceleration terms, and shallow water effects all contribute to net displacements. Analytical estimates of these effects are difficult to obtain, but numerical modeling techniques can be used to indicate typical values (Nihoul, 1975). In his book Nihoul discusses work by Ronday (1972) which *considered the residual flow patterns for the North Sea. Ronday estimated a transport through the English Channel in January to be 0.24 x 106 m3/sec. If approxi- mately correct this value would imply, for a cross-sectional area typical of the Brittany region, net average flows of a few centimeters per second. The tidal currents along the channel are known to be affected by rotation so the average value is certainly low for the French Coast, but even if it were doubled to account for this asymmetry it would still be about 5 cm/sec or less. This value of -1/10 knot does not appear to be significant in the context of the Amoco Cadiz spill. The next aspect of the tidal flow that will be of interest in the oil spill problem is the horizontal convergences or divergences. Proud- man (1953) described the tides in the English Channel as made up of co- oscillations with the Atlantic and North Sea. A more detailed and observationally base description is presented in Defant (1961). The relevant result of these independently driven co-oscillations is a series of convergence and divergence lines. Defant describes three different sets of these, with the westernmost one entering the Channel from the Atlantic and first appearing off the Brittany Coast. These convergence and divergence lines are also presented in the tidal current tables for the channel (S'ervice Hydrographique et Oceano- graphique De La Marine-Paris-No. 551). Figure 2-1 shows the progression of these through a tidal cycle. As they move across the region, the line of convergence will concentrate bands of floating pollutants and divergence lines will cause spreading.' For patches of floating mousse this process can certainly be expected to cause periodic changes in the percent of surface concentration of oil. If the convergence line is sharply defined and the initial concentrations heavy we may actually expect patches to run together with a subsequent change in the thickness distribution. If horizontal motion were the only consideration these moving fronts would periodically concentrate and rarefy the patches of floating oil with perhaps little net effect. The consequences of these tidal convergences can be expected to have a quite different effect on oil fractions whose relative buoyancy is reduced. This might include thin sheens, oil in accommodated droplets, or oil in water emulsions such as would result from the use of dispersants. For all of these forms the vertical velocity associated with the tidal convergence will carry the hydrocarbons away from the surface. This vertical transport process that continually sweeps along the channel may represent a domi- nant mechanism for mixing. During each tidal cycle the oil that is 12 @ a. b. Ply uth Ply outh Cherbourg Chi;r3ourg CD Brest Brest Figure 2.1 Hourly progression of tidal convergence line asso- ciated with (a) flood currents (eastward flowing off Brittany) and (b) ebb currents (westward flowing off Brittany). Succes- sive position of line moves from west to east. advected down can then mix horizontally and although the following tidal divergence will tend to replace some surface water from below it in no sense un-mixes the oil, and the overall net flux is downward. It may also be worth noting that these regular convergence patterns seem to be most prominent slightly offshore, which is where dispersants were regu- larly used during the Amoco Cadiz spill. This suggests that subsurface hydrocarbons may have been distributed through greater-than-expected depths. This would tend to enhance overall mixing, thus impacting larger portions of the marine environment, but with reduced concentra- tions. The third tide-related process that could potentially affect hydro- carbon distributions depends on correlations between the tidal currents and any other transport or source/sink processes. The wind data for the Brittany Coast are being analyzed, but are not expected to be corre- P I y ;mo u t @h'@ Ply @outh c:) @Br e s\t lated, with the tides over any significant number of tidal cycles. The question of correlation of sources and sinks with the tidal flow is likely to require a bit more thought. The Amoco Cadiz, grounded as it 13 was and subject to large changes in sea level, probably did not release oil at anything like a constant rate. The tides may easily be thought of as having a washing or pumping action. The details of this must be speculation at this point. Even without knowing the details, however, we can expect that such an 'action would introduce asymmetrics around the wreck with a length scale on the order of a single tidal excursion, i.e., a few kilometers, and beyond this the effects would be minimal. Along the coastline and offshore rocks the beaching process and subse- quent refloating of oil certainly depend upon the stage of the tidal cycle and are thus correlated with the tidal currents. These shoreline processes are discussed in more detail in sec. 2.2.5. 2.2.3 Quasi-Steady Currents Background currents off of the Brittany coast are caused by more then just tidal action, and it is necessary to try and estimate what these might have been during the Amoco Cadiz spill. The average longer period flow along the coast is usually in at least quasi-geostrophic balance, with both baroclinic and.barotropic modes being present. The appropriate time and length scales for the set-up and adjustment of these currents is associated with the coastal upwelling problem. A number of studies of this process have taken place for many coastal regions. Of primary interest are the surface currents which are caused by the sea surface gradient normal to the coast. These gradients are caused by the Ekman transport onshore which in turn is related to the alongshore component of the wind. To determine characteristics of this flow we may consider modeling studies recently carried out by Hamilton and Rattray (1978). They show that alongshore wind stress of 1 dyne/ CM2 res'ults in a current structure that builds up over a 5 to 10 day period with velocities in the first 10 to 20 kilometers offshore on the order of a knot and in the direction of the wind. The surface currents are seen to depend somewhat on the stratification, geometry, and mixing coefficients, but the qualitative results are not changed. During the first ten days of the Amoco Cadiz spill when the majority of the oil was discharged the dominant wind j7i-re-ction was from the west. This set up the necessary conditions for a coastal current to the east along the Brittany coast. Obviously the winds were not constant and the appropri- ate independent parameters are unknown but flows of about I knot are probably a reasonable estimate for this period. 2.2.4 Direct Wind Driven Oil Movement As we have suggested the regional winds averaged over a few days will set up an alongshore current that should be a major factor in the advection of the oil. The wind will also contribute more directly to the movement of the floating oil. The wind/wave/oil momentum exchange, which is usually simply parameterized as a wind factor, will require a more detailed look at the wind field. Figure 2-2 presents stick dia- grams representing the winds measured along the Brittany coast. These clearly show the dominance of winds from the west during the last part 14 T ZI --ZZZZ Cr. ZI 22 23 E4 ?_ 5 26 Z7 28 Z 9 30 1 MARCH RBERWRAC'H Z /A. 1. Cr. [email protected] -4- 4- --4 21 22 23 24 25 26 27 28 29 30 31 MARCH- BREHRT Figure 2.2 Stick diagram of wind observations for a number of locations along the Brittany coast. of March. One conspicuous exception to this trend occurred on March 27- 28 when strong winds developed with a northerly component. By combination of the barotropic coastal current and the wind drift factors, initial trajectory estimates can be obtained. We must cer- tainly expect that for most periods the hydrocarbons will move east and remain near the French coast. The wind event of March 27-28 would be an exception with oil moving offshore in a NNE direction. According to results of standard trajectory techniques the oil or mousse in the band along the coast could be expected to advance at speeds of about 1 knot with higher or lower velocities depending on the winds. These admittedly first-order trajectory estimates point to two things. First is the obvious and easily observed fact that the Amoco Cadiz oil could be expected to impact the coast from the scene of the wreck spreading rapidly east. The second is that standard trajectory or forecasting techniques are not going to be particularly useful or infor- mative for this spill. The most striking features of the Amoco spill were its massive size and its lee shore position. This means that very near shore transport and beaching processes will be significant and the opportunity to study them excellent. We now turn our attention to those near-shore processes. 15 2.2.5 Near Shore Processes As oil approaches the coast under the influence of winds and tidal currents it encounters a boundary which acts initially by stopping its forward progress. This simple kinematic constraint allows the rela- tively thin sheen and mousse concentrations to accumulate in deep pools at the coastline. An onshore component of the wind creates the waves and Stokes drift necessary to propel the patches and streamers of oil towards the coast. In addition as a thicker pool forms it effectively absorbs the incoming waves, with the momentum transfer and associated radiation stress acting to hold the oil in contact with the beach face. Plate 2-5 clearly shows the formation of such a coastal pool. Streamers of sheen are evident in the water offshore. The incoming waves are seen to damp out over a few wavelengths. Figure 2-3 shows a suggested cross section through such a pool. It is important to note that as the on- shore wave pressure and oil accumulation build up, the region of beach face actually "wetted" by the oil increases. This defines the area over which the hydrocarbons come into direct contact with the sediments and will be the area where we can expect the most deposition of pollutants. Oil Water .*--Region of Beach Face .*-Region Where Oil is`.. "Wetted" by Floated By Sea Water Oil Figure 2.3 Suggested cross section through an oil pool held against the beach face by wind and wave stress. The accumulation of mousse in pools along the shore is obviously a small-scale process and we can expect that the local geometry and beach face orientation will play an important role in determining where these occur. Plate 2-8 shows a small bay where an oil pool is being fed by offshore streamers. As the oil accumulates it simply fills up the available surface area of the bay and spills in a stream on down the coast. *Small coves appear to act as ponds in the alongshore stream of oil. They are obviously holding areas for the oil that is pushed against and along the coast. 16 To try and better understand the movement of oil or mousse along the beach we must consider the currents just off the beach face. Between the surf zone and the beach we expect the flow to be dominated by the longshore current (Shepard, 1963). Plate 2-7 shows a heavy mousse concentration moving along in this nearshore band. The pool is obviously being fed from offshore. The wind direction is clearly seen by the orientation of the windrows and wake pattern behind the moored boat. In addition the waves in the mid-distance are seen to strike the beach at an angle that would drive the alongshore currents towards the lower part of the picture. Moving in this direction the mousse will accumulate as it is fed from the left. The maximum concentration along- shore is seen at the lower edge of the [email protected] This picture was taken just after high tide and, as was characteristic of many observa- tions, heavy mousse concentration was left stranded in a belt along the high-water mark. The fact that floating oil naturally accumulates in the band domi- nated by alongshore drift leads to the conclusion that oil concentra- tions will tend to follow the same accumulation patterns that finer sediments do while undergoing beach drift (Kuenen, 1950). This analogy will prove useful along exposed beaches and we should expect tombolos to concentrate oil and rip currents to eject oil through the surf zone back. offshore. Trying to extend these ideas into a low energy situation however is certainly not going to be correct since floating oil will act differently from either surface water or sediments, no matter how fine. To get a clearer idea of what to expect in these cases we may look at Plate 2-6. This picture shows mousse and sheen moving through a narrow opening between offshore rocks. A number of small-scale physical proc- esses are seen. The wind direction is clearly indicated by the orienta- tion of the windrows with upwind being toward the data panel. Wave patterns refracting through the opening are also clearly evident. Of particular interest is the separation of the floating oil in the lee of. the rocks. The surface oil does not continue to "wet" the shorelinebut is blown offshore and does not move with the water. In addition it continues to float and will not settle out the way sediments would to form a sand spit or bar. From Plates 2-6, 2-7, and 2-8 we can see that the small-scale orientation of the coast relative to the wind and waves will determine the patchiness expected in the alongshore distribution of oil. Alongshore drift will determine the movement of the oil along exposed beach sections, but headland and rock outcrops will protect lee areas, provided that a pocket is not formed that can fill up before spilling out back into the alongshore stream. It would [email protected] consider- able interest to understand the separation process-taking Place in Plate 2-6. Such processes will ultimately determine how much sheltering can be expected. It is also possible that protected lee areas offer a separation of direct wind and wave interactions with the oil and would make useful areas for observational studies. In the previous discussion of transport mechanisms associated with tidal action, the occurrence of correlation between tidal currents and 17 coastal sources and sinks was listed as a potentially significant trans- port process. We can now consider this in more detail. Many examples of mousse being stranded by the receding tide were observed during the Amoco Cadiz study. In nearly all the cases the heaviest oil [email protected]_ations were deposited right along the high-water line. Plate 2-9 shows a striking example of this. Here we see a deep pool of mousse that was left by the tide and subsequently drained down the face of the beach. The mousse appears to be in a gravitational drainage pattern and obviously flowed more slowly then the actual tidal water receded. To the right and left of this pool stained sediments and oil accumulation in the rocks are also evidence of heavy exposure. Returning our attention to figure 2-3 it is possible to speculate on the factors contributing to the stranding of these heavy concentrations at the high water level. As the mousse forms a wedge along the shore because of onshore wave and wind stresses, the band where the beach face is actually in contact with theoil is moved up to the high-water mark. When the tide turns this oil tends to adhere to the sediments and be stranded, whereas below this point.the water under the oil tends to float it free and relatively little is deposited. Subsequent tides may refloat the oil, bury it or add to it, depending on the onshore stresses and the stage in the spring neap cycle. In terms of transport processes it is significant to note that oil appears never to be deposited on a rising tide, but only during the ebb. The movement of oil alongshore then has full exposure to the flood tide currents and a somewhat reduced statistical exposure to the ebb current direction. Along the Brittany coast this contributes one more component to the eastward transport. This form of tidal transport is not limited to the coast line proper but also applies to offshore rocks. Plate 2-10 shows a rock outcrop during a rising tide. It definitely appears as a source re-introducing oil into the flooding tide. The significance of this mode of transport relative to other components must depend on the onshore stresses, the intertidal area, the general morphology of the coast, and the lee shore nature of the spill. 2.3 Summary and Conclusions The Amoco Cadiz disaster presented a unique opportunity to study oil spills in the marine environment. The massive amounts of oil dis- charged, and its position close to a lee shore all made this a particu- larly interesting spill to study. A review of previous oil spill re- search and the conceptual state-of-the-art for oil spill trajectory modeling techniques indicates that in the past forecasting development has concentrated on open ocean spills. Contrasted to this, major envi- ronmental concern tends to be focused on the coast line. In addition improvements in trajectory analysis and impact assessment will require a better understanding of the processes controlling the thickness distri- bution of the oil. These conditions set the stage for planning specific studies to be carried out at the Amoco Cadiz spill. 18 The spilled oil appeared in a variety of forms. These could be described in terms of four classes: 1) mousse, 2) sheen, 3) light foam, and 4) weathered mousse as small globs. Estimates were made of what was thought to be the dominant oceano- graphic or meteorological processes affecting the movement and spreading of the oil. Winds were strong during much of the spill event and con- tributed to the oil movement both directly and indirectly. Direct wind forcing was through wind/wave/oil interactions, and indirect forcing was hypothesized to take place through a sea surface set-up along the coast and subsequent development of an alongshore current system. Both components of the wind forcing tended to move the oil eastward in a coastal band during the March period of study. Tidal forcing was in- vestigated and estimated to play an important role through convergences and divergences in the offshore area and through the beaching/tidal pumping sequence that took place along the coast. Nearshore transport and beaching processes that lead to the strand- ing of oil were investigated. The orientation of the coastline and alongshore current system were seen to affect the oil distribution. The stranding of heavy oil concentrations appeared to occur only during ebbing tides and seemed conditional on the intertidal beach face (Fig. 2-3) coming in direct contact with the oil. Photographic records from a number of transects were collected for an analysis of oil coverage, but these records have yet to be studied in detail. The data collected at the Amoco Cadiz spill have given new insights into oil movement in the marine environment. These will prove useful in the development of conceptual algorithms to describe fundamental-pro- cesses such as the stranding or beaching of oil, sheltering of areas in the lee of headlands, role of alongshore drift in oil transport, and the effects of tidal pumping. These new conceptual understandings can be expected to contribute to the next generation of oil spill forecasting models and hydrocarbon impact assessment studies. 2.4. References Bowditch, N. (1966): American Practical Navigator, An Epitome of Navigation. Hydrographic Office Pub. No. 9., U.S. Naval Oceano- graphic Office. Defant, A. (1961): Physical Oceanography, Vol. II, Macmillan, New York, N.Y. Hamilton, P., and M. Rattray (1978): Numerical model of the depth dependent wind-driven upwelling circulation on the Continental Shelf (in revision for publication in J. Phys. Oceanogr.). 19 Kuenen, Ph. H. (1963): Marine Geology, Wiley, New York, N.Y. Mattson, J. S. (1978): Personal communication. Nihoul, Jacques C.J., Ed. (1975): Modeling of Marine Systems, Elsevier, Amsterdam, Oxford, N.Y. Proudman, J. (1953): Dynamical oceanography, Methuen, Strand, England. Ronday, F. C. (1972): Modele mathematique pour Vetude de la circula- tion residuelle dans la mer du Nord. Marine Science Branch, Manu- script Report Series, 27, Ottawa, Canada. Shepard, F. P. (1963): Submarine Geology, second edition, Harper & Row, New York, N.Y. Stolzenbach, K. D., 0. S. Madsen, E. E. Adams, A. M. Polack, and C. K. Cooper (1977): A Review and Evaluation of Basic Techniques for Predicting the Behavior of Surface Oil Slicks. Ralph M. Parsons Laboratory, Report No. 222, MIT, Cambridge, Mass. Sverdrup, H. U., M. W. Johnson, and R. H. Fleming (1942): The Oceans, Their Physics, Chemistry and General Biology, Prentice-Hall, Engle- wood Cliffs, N.J. 20 3. CHEMICAL COMPOSITION OF SELECTED ENVIRONMENTAL AND PETROLEUM SAMPLES FROM THE AMOCO CADIZ OIL SPILL John A. Calder,' James Lake, 2 and John Laseter3 3.1 Introduction The analyses described in this document represent initial chemical investigations by the University of New Orleans' Center for Bio-Organic Studies (UNO-CBS), the U.S. Environmental Protection Agency, Environ- mental Research Laboratory, Narragansett (EPA-ERLN), and the National Oceanic and Atmospheric Administration's National Analytical Facility (NOAA-NAF), on the composition and fate of oil spilled along the Brit- tany coastline by the Amoco Cadiz. While many of the analyses are qualitative in nature, much quantitative information is presented. The information reported is useful in studying the nature and composition of the initial petroleum entering the environment and the transformations of this material as part of the weathering process. Selected samples were collected at different locations along the Brittany coastline during the days and weeks immediately following the oil spill. Station locations are shown on the map of the Amoco Cadiz oil spill study area, Fig. 3-1. Sample locations and descriptions are presented in Table 3-1. Many samples were collected in areas that were heavily contaminated and had visible oil. These samples included weath- ered oil samples floating on the water surface, samples of the mousse (water-in-oil emulsion) and oily froth, soils, sediments, water column samples, and biota samples such as sea grass, polychaetes, and peri- - winkles from the tidal zone. Also a neat, medium Arabian crude oil was analyzed as a standard. There are approximately 120 samples discussed in the report. These were used for over 200 individual gas chromato- graphic analyses and approximately 20 gas chromatographic-mass spectro- metric (GC-MS) analyses. Due to limited space only.representative portions of these analyses are reported. 1NOAA/ERL, OCSEAP, Boulder, CO 80302 2U.S. EPA/ERL, Narragansett, RI 02882 3University of New Orleans' Center for Bio-Organic Studies, New Orleans, LA 70122 21 STUDY AREA FRANCE [email protected] NOAA 12,13 45 47 AMC I A A C 13 cin MC 12 4) JW_7 A MC 11 PLOUGUERNEAU INGAA 5.6 0 1 x 36 "OAA 1, 2.16 A P P R 0 x -3 -a MOU M9 WREC k SITE UABER WRAVH AMC 4 40 VABER LESNEVEN NOAA &4 AMC 3 [email protected] 5 BENOIT LANNILIS ?AMC 2 AMC 1 32 PORTSAIL 3' as 87 UNO-1 Figure 3-1. The Amoco Cadiz oil spill study PERsPODER area on the nor hern coast of Brittany, showing the locations of sampling stations 0 listed in Table 3-1. Map prepared by Erich R. Gundlach, Miles 0. Hayes, R. Craig Shipp, and Nanette Muzzy. 22 NOAA A IS EPA-I ILE DE BATZ AMC AMC 6 AMC 7 RO OFF AMC 16 czz:) 23 22 21 AMC 10 booon 2926 [email protected] CARANrec,,. Figure 3-1 (continued). 23 ILE AUX MOINES PLOUMANAC so no oil ILE GRANDE PERROS GUIREE ps AMC-1 EPA-2 79 TRESEURDEN LANNION A .16 ILOCQUIRIEC AMC-115 ST. MICHIL-EN-GRIEVE 10" AMC -DETAILED STUDY AREA$ %- AREAS VISUALLY INSPECTED Clh C L CA04 'Olt- AC-CUMULATION "OU MANAk, n @o o ILE IGRANDE PERROS GUIRE E. no .I ,[email protected] I TRESEURDEN Figure 3-1 (continued). 24 SILON DE TALBERT C;m 62 AMC-17 ILE OE SREMAI 68 PC PLOUGRESCANT. REOUIER PAIMPOL 0 lokm Figure 3-1 (continued). 25 Table 3-1. Location, description, collection date, and method of sample preservation of Amoco Cadiz oil spill samples analyzed. Locations are shown in Figure 3-1 or other figures as indicated. Method of Collection sample Code Description and location date preservation Mousse & oils AMC-1 Portsall center, long profile across heavily oiled tidal flat, mousse on water surface 31 Mar 78 a AMC-14 Kerlouan Yacht Club, brown froth downslope from dark brown mousse 27 Mar 78 a AMC-16 Pointe de Lekar upper beach face, large gravel beach, mousse 5 cm thick 28 Mar 78 a AMC-17 Port la Chaine upper beach,'heavily oiled beach 29 Mar 78 a AMC-18 Ile Grande upper marsh, heavily oiled marsh 29 Mar 78 a F-82 (UNOI) Near Pointe de Landunvez from mid beach face, boulder beach, some tar on rocks 31 Mar 78 a Control Medium Arabian crude oil supplied by Aramco NOAA I & 2 Mousse collected near Amoco Cadiz by helicopter 23 Mar 78 NOAA 3 & 4 Mousse--north beach at Portsall 24 Mar 78 NOAA 5 & 6 Mousse--Les Dunes, middle beach 24 Mar 78 NOAA 7 & 8 Mousse--Dunes at Ste. Marguerite 24 Mar 78 - NOAA 9 Mousse--Dunes at Ste. Marguerite, stranded at mid-tide level 24 Mar 78 - NOAA 10 & 11 [email protected] de Lilia 24 Mar 78 - NOAA 12 & 13 Mousse--Meneham, thick mousse in tide pools 24 Mar 78 - NOAA 14 & 15 Mousse--Roscoff, very thick at sea wall 24 Mar 78 - NOAA 16 Mousse--near Amoco Cadiz by helicopter 27 Mar 78 - (AMC-30) Sediments and soils AMC-1 Portsall center, ground water across, long profile of a heavily oiled harbor-tidal flat 31 Mar 78 a AMC-3 Portsall north, ground water, low tide berm, heavily oiled, protected sand beach (sediment sample) 31 Mar 78 a AMC-3 Portsall north, mousse on surface, heavily oiled, protected sand beach (sediment sample) 31 Mar 78 a AMC-12 St. Cava, heavily oiled beach, many dead cockles 27 Mar 78 a UNO-2 Upper cliff--Aber Benoit bridge, close to Treglonou, above the tidal zone 31 Mar 78 a UNO-2 Bottom cliff--Aber Benoit bridge, close to Treglonou 31 Mar 78 a UNO-2 Oil cliff--Aber Benoit bridge close to Treglonou, soil at the tidal base of oiled cliff 31 Mar 78 a NOAA 17 Sediment from Aber Wrac'h tidal flat near the small town of Perros--same location as EPA-7 6Apr 78 EPA-1 Roscoff--surface sediment (sand) obtained on (beach) beach 70 meters from seawall 27 Mar 78 b EPA-1 Roscoff--surface sediment (sand) obtained on tidal (tidal flat) flat 270 meters from seawall. Water depth was ap- proximately 2 cm. 27 Mar 78 b EPA-2 Ile Grande--surface sediment (clay and silt) obtained after mousse and oil had been scraped from the surface 30 Mar 78 b 26 Table 3-1. (continued) Method of Collection sample Code Description.and location date preservation Sediments and soils (continued) EPA-3 (0-5 cm) (sand) Top five centimeters of a beach core 31 Mar 78 b EPA-3 (5-10 cm) (sand) 5-10 centimeters of a beach core 31 Mar 78 b EPA-4 Locquirec (sand) surface sediment taken approxi- mately 30 meters from surf zone 2 Apr 78 b EPA-7 L'Aber Wrac'h (silty sand), surface sediment from Aber Wrac'h tidal flat near small town of Perros 6 Apr 78 b Water AMC-17 Port la Chaine, ground waters below top of heavily oiled beach 29 Mar 78 a Stations 1-7 Subsurface water from l'Aber Wrac'h--total of 8 samples (see Fig. 3-24) 24 Mar 78 c Stations A, Subsurface water from I'Aber Wrac'h--total of B, C 7 samples (see Fig. 3-25) 25 Mar 78 c Stations A, Subsurface water from I'Aber Wrac'h--total of 8, C, D 16 samples (see Fig. 3-26) 27 Mar 78 c Stations 1, 3, Subsurface water from offshore, Le Suroit _e Ts- 6, 7, 9, 16, cruise, Leg I, total of 26 samp] s ee 30 Mar - c 29, 37, 39 Fig. 3-31) 4 Apr 78 Stations 1-7, Subsurface water from VAber Wrac'h (see bridge Fig. 3-27) 3 May 78 c EPA-3 Subsurface water sample obtained at 0.5 meter depth in water approximately 1 meter deep 31 Mar 78 b EPA-4 Locquirec interstitial water from beach (Interstitial approximately 30 meters from surf zone 27 Apr 78 d water) EPA-4 (surf) Locquirec sample taken at 1 meter depth 27 Apr 78 d EPA-4 Locquirec sample taken in pool surrounding rock .on beach 6 Apr 78 b EPA-5 Beach at St. Efflam, interstitial water from (interstitial beach 27 Apr 78 d water) EPA-5 (surf) In surf at St. Efflam, sample taken at approximately 1 meter depth 27 Apr 78 d Biota AMC-4 Periwinkles 29 Mar 78 a AMC-17 Limpets 29 Mar. 78 a AMC-18 Polychaetes 29 Mar 78 a Seagrass, Portsall 31 Mar 78 a *a'. Chloroform added to sample--transported at room temperature. b. Frozen as soon as possible following collection and maintained at -201C. c. Transferred immediately from Niskin bag sampler to hexane-washed green glass jug with Teflon-lined cap. Stored at ambient temperature until extracted. Aber Wrac'h samples extracted within 36 hours of collection. Offshore samples extracted on April 5, 1978. d. Dichloromethane added to sample--transported at ambient temperature. 27 Prior to GC analysis, the total lipid extracts were simplified by liquid/solid chromatography. The silica gel (Davison, grade 923, 100- 200 Mesh) was activated by overnight heating at 1500C. Aliphatic type compounds were eluted with three bed volumes of n-hexane. More polar compounds and aromatic type compounds were eluted with three bed volumes of 40%.benzene in n-hexane. All other components were displaced with three bed volumes of methanol. The eluates from each fraction were reduced in volume on a rotary evaporator to approximately 5 ml and stored in a freezer until analyzed by GC and GC-MS. All Burdick and Jackson solvent's were distilled in glass prior to use and their purity checked by GC. A splitless method of sample injection was employed for all gas chromatographic analyses, using Hewlett-Packard Model 5711 gas chromatographs equipped with FID detectors. These data were digitized into "area slice" data and transmitted to an HP 3354A central laboratory data system. UNO-CBS-developed software was used to integrate GC peak. areas. Plots of the gas chromatograms, for display purposes, were generated from the digital raw "area slice" data on a Tektronix 4662 digital plotter by software developed at the Center. Similar plotting routines were employed to generate the three-dimensional displays. The GC columns were 30 m by 0.3 mm ID and coated with either SE-52 or Carbowax 20M as the liquid phases. Extracts were injected, with the GC oven at 501C and with a helium flow rate of 38 cm/sec. The oven was temperature-programmed at 41C per minute to 2400C and held at 240*C un- til all peaks had eluted from the column. Back purging of the splitless injector system was activated 35 seconds after injection. Mass spectral data were collected on a Varian MAT 311A high-resolu- tion mass spectrometer. Separation conditions were the same as those described in.the preceding paragraphs for GC. Effluents from the column were introduced directly into the ion source of the mass spectrometer via a heated glass capillary line without going through an enrichment device. Mass spectra were scanned every 3.8 second at 70 eV and all data were stored on magnetic disc. The source temperature was 2500C. For routine sample runs, the resolution of the mass spectrometer was 1000 (m/M at 10% valley) and the'mass range scanned was from 35 to 600 AMU. All mass spectral data were acquired in digital form by a Varian Spectro- system 100 MS'data system. Mass chromatrograms of specific ions were generated to aid in locating certain classes of compounds in the complex sample types-analyzed in this program. Photo-oxidation experiments were carried out in a two-phase system in which a given oil or mousse'sample was dissolved in n-hexane on an aqueous saline solution (40 gm/L). Under co'nditiohs simulating environ- mental-conditions, this system was irradiated with a visible source (Sylvania EHC 500 watt tungsten lamp covered by a uranium glass filter) which has a spectral output that approximates that of the solar spectrum. When necessary, oxygen was introduced through a fritted glass inlet. The products were isolated and fractioned in a fashion similar to that described previously. 28 The exact age of the weathered oil samples and the extent of expo- sure of oil to marine sediments, benthic organisms, and flora is not known because of the nature of the insult. Oil leaked from the grounded tanker over a period of approximately two weeks, making an exact assess- ment of the length of environmental exposure or degree of weathering of the oil a difficult task. The analytical techniques used to examine these samples were pri- marily designed to establish quantitatively and qualitatively the extent of environmental contamination. Methods included high-resolution glass capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis of up to three fractions from each sample isolated by liquid-solid chromatography. The three fractions were the saturated aliphatic type compounds, the aromatic type compounds, and the more polar organic compounds. Additionally, ultraviolet fluorescence (UV-fluorescence or UVF)'was determined on aliquots of the hexane ex- tracts from subsurface water samples collected in a heavily impacted estuary (I'Aber Wrac'h) and offshore oceanic waters. A towed underwater fluorometer was deployed in the estuary to provide real-time information on subsurface oil-in-water concentrations. 3.2 Methods The following is a brief summary of the analytical methods employed by each participating laboratory. A survey of the data suggests that very similar results were obtained irrespective of the variations in extraction and analytical procedures employed. Compare gas chroma- tograms of the reference mousse (Figs. 3-4, 3-6, and 3-35) obtained by the participating laboratories. In all instances care was taken to insure that samples were not contaminated during collection, storage, or transport. Sample preservation methods are listed in Table 3-1. 3.2.1 UNO-CBS Procedures Immediately prior to analysis of mousse samples, the entire content of the glass container was thoroughly homogenized and a small aliquot removed for fractionation. This aliquot was dissolved in 15% CH2C12 in n-hexane and any water was separated using a separatory funnel. The organic extract was reduced in volume on a rotary evaporator prior to column chromatography. In the case of biota, the samples were homoge- nized and then freeze-dried prior to extraction by refluxing overnight with 15% CH2C12 in n-hexane. The organic solvent was separated from the aqueous material after centrifugation using a separatory funnel, and then reduced in volume on a rotary evaporator prior to saponification. The saponification of biota lipids was accomplished using 0.5N NaOH or KOH in methanol/water reflux for five hours. The nonsaponifiable com- pounds were extracted three times with 60 ml of n-hexane. The extract was then reduced in volume prior to fractionation. 29 3.2.2 EPA-ERLN Procedures .Water samples were frozen or poisoned with 100 ml of dichloro- methane after collection. -After thawing (if,necessary) samples were extracted three times with 100 ml of dichloromethane in a separatory funnel. Sample extracts were passed through a column of Na2SO4 and reduced in volume on a Kuderna-Danish evaporator fitted with a three- ball reflux: column. Following solvent exchange to hexane, the volume was reduced under a stream of.nitrogen. Extracts were analyzed intact or separated into aliphatic and aromatic fractions on a silica gel column. A dry weight for the sediment samples was determined by drying an aliquot at 105-115'C for two hours. After addition of internal stand- ards and additional water, the sediment was extracted under reflux: in a solvent mixture of 70% 0.5 N KOH in absolute methanol. The sediment- solvent mixture was filtered through a glass fiber filter and the fil- trate was extracted in a separatory funnel with petroleum ether. The combined extracts were evaporated to dryness on a rotary evaporator, redissolved in petroleum ether, and analyzed intact or separated into aliphatic and aromatic fractions on a silica gel column. Extracts were analyzed by gas chromatography on a 30 m by .27 mm I.D. glass capillary column of SE-52 in a Hewlett-Packard 5840A gas chromatograph. A temperature program from 350C to 2901C at a rate of 5*C/minute was used. The initial time was 4 minutes. The injection temperature was 290'; the flame ionization detector temperature was 280*. The splitless injection port was purged I minute after injection. The GC-MS analyses were performed on a similar SE-52 column in a Shima.dzu gas chromatograph connected to a Finnegan model 1015 mass spectrometer with a System Industries data system. A weighed amount of the reference mousse (NOAA-16) was dissolved in hexane and used as an intact mousse standard. The separation of ali- quots of.this standard on a silica gel column yielded aliphatic and aromatic.standards. Qua ntification of chromatograms was accomplished by planimetering the areas of chromatograms and comparing the areas with areas obtained from known amounts of a mousse sample. 3.2.3 NOAA-NAF Procedures Mousse.samples were dissolved in n-hexane and a 5 ml aliquot was concentrated to ^- 0.5 ml. An internal standard was added and the re- sulting mixture was then directly analyzed by GC. In selected cases the mousse samples were centrifuged to break the emulsions. Because centri- fugation at 2000 g for several hours was insufficient to break many of the mousses completely, high speed centrifugation was attempted. A 30 Beckman model L preparative ultracentrifuge (SW 50.1 rotor) was utilized for this test, employing polyalomar, 5 ml capacity tubes. The separa- tion was performed at about 40,000 rpm (ca. 150,000 g), with refrigera- tion maintaining the unit at 180C. The separation achieved was a considerable improvement over the low-speed centrifugation, although complete separation was still not achieved in some cases. A sample which contained ca. 40% unseparated mousse at 2000 g still retained 3% as an emulsion even at 150,000 g. However, the time required to achieve this separation with the high- speed centrifuge was only 30 minutes, compared.to several days for the low-speed procedure. The minimal amount of both handling and time minimizes losses of the more volatile compounds that are essential to the characterization of the oil from the mousse by gas chromatography (with respect to degree of weathering). Most of the samples were separated into three layers: an oil layer, a water layer, and residual material that could not be further separated. The NOAA team also prepared n-hexane solutions of aliquots of the mousse and separated oil and analyzed them by GC, using a standard temperature program for petroleum hydrocarbons. Silica gel column chromatography was performed on selected mousse samples and oil samples and the three fractions generated were analyzed by GC and GC-.MS. All GC analyses were conducted with a Hewlett-Packard 5840A chroma- tograph equipped with glass capillary columns and FID detectors. An SE-54 liquid phase was employed on a 30m x 0.25mm WCOT column. A helium carrier at 24,psi with a 3 pl splitless injection was employed; the split valve was opened after 18 sec. The chromatographic oven program was held isothermal at 50'C for 5 min and then programmed at 4*/min. to 280', then held at 280' for 30 min. UV-fluorescence was determined on aliquots of the hexane extracts of subsurface water. The measurements were performed on a Perkin-Elmer MPF-44A dual-scanning fluorescence spectrophotometer. Mousse sample NOAA-16 was utilized as the best representative of cargo oil; other samples were compared to it as the standard. Every day that samples were processed, a new calibration curve was developed from serial dilu- tions of the reference mousse (NOAA-16) at an emission wavelength of ca. 360 nm. Emission was scanned from 275-500 nm, offset 25 nm from the excitation wavelength, and the major peak occurred at ^- 360 nm for the reference mousse solutions (see Fig. 3-2). In each sample, the concen- tration of fluorescent material, a total oil estimate, was calculated from its respective fluorescence, using the linear relationship of fluorescence vs. concentration of the reference mousse "standard." A.correction factor was applied to account for the reference mousse containing only about 30% oil. 31 STANDARDS AT Y SETTING STANDARDS AT B SETTING A. 30-132 A. 9.8 ng/pk 98 [email protected] solution of 30-16 B. 0.98 ng/lit B. 30-133 9.8 ng/pP. solution of 30-16 C. 4.9 ng/wt C. 30-181 0. 3.3 ng/@@X 49 ng/vk solution of 30-16 E. o.49 ng/pt D. 30-182 (coarse 3; fine 7-2) 33 ng/pZ Solution of 30-16 E. 30-139 0.98 ng/pt solution of 30-16 STANDARDS AT a SETTING A. 0.98 ng/lit B. 0.49 ng/VZ C. 98 p9/WZ D. 0.33 ng/liZ (coarse - 10; fine 7.2) Figure 3-2. UV-fluorescence synchronous scans of serial dilutions of the reference mousse in hexane (figures showing y, 0, and a settings). Remaining figure shows hexane blank at most sensitive (0) setting. Major peak occurs at about 360 nm for the reference mousse. 32 3.3 Results 3.3.1 Mousse and Oil Figures 3-3 and 3-4 show high-resolution chromatographic separa- tions of the n-hexane and 40%-benzene-in-n-hexane fractions of the med:@um Arabian crude oil control sample (standard) and the NOAA-16 reference mousse, which represents a freshly formed mousse collected at the spill,site. The n-hexane fractions of both samples showed similar normal, isoprenoid, branched, and cyclic hydrocarbon patterns from approximately C10 to C30 range. The normal [email protected] in the highest concentration generally occurred in the C16 to C18 range. Figure 3-4 illustrates the mass spectrometric identifications of the normal alkanes in the reference mousse sample, whereas Fig. 3-5 illustrates the identi- fied aromatic components in the 40%-benzene-in-n-hexane fraction of a mousse sample collected at Ile Grande. The aromatic compounds numbered in Fig. 3-5 are identified in Table 3-2. This fraction was low in unsubstituted species, showing only a modest quantity of phenanthrene and dibenzothiophene. Notable was the inability to detect the four-ring and larger polycyclic aromatic hydrocarbons and their alkylated homologs. The GC profiles of the control and reference mousse samples collected adjacent to the Amoco Cadiz are very similar in the distribution of aromatics above lEh-ealkylated naphthalenes. There has apparently been a loss of the alkyl benzenes and related volatile aromatics in the mousse samples as compared to the control. It must be pointed out that the only completely satisfactory standard for a chemical comparison is the cargo oil prior to environmental exposure. Such a sample was not avail- able. . In one field exercise a series of mousse samples was collected during the same day from the surface of the water adjacent to the Amoco Cadiz and at beaches from Portsall to Roscoff. The oil content of these samples was generally in the 30-40% range (Table 3-3)._.The samples were subsequently analyzed by extraction and direct GC analyses with no pre- GC sample fractionation to minimize loss of volatiles during handling. The reference mousse treated in this fashion shows the dominant alkane as n-C11 (Fig. 3-6). The loss of volatiles is evident in samples collected as little as 2 Ian from the wreck site (Table 3-3) when the concentration of the lighter hydrocarbons is normalized to n-C24. Fig. 3-7 demonstrates the loss of volatiles from a mousse collected at Meneham (NOAA-13), about 25 km from the wreck. The weathering trend is discon- tinuous with distance from the wreck, representing the variable input of fresh oil. The light aromatics also show evidence of weathering as demonstra- ted in Figs. [email protected], 3-9, and 3-10 (see Table 3-4 for numbering of aromatic hydrocarbons in these figures). The concentration of internal standard (IS) is identical for all three samples. Mousse #13 shows considerable 33 AMOCO CADIZ OIL SPILL CONTROL HEXANE FRACTION z OUANT. INJ.=0.0067 E-4 V) w Ld 0 U AhA JL_j Uj j CONTROL 40% BENZENE FRACTION GUANT INJ.=1.8 E-4 w V) z 0 w 0 U w TIME (MINUTES) [email protected] [email protected] 50 60 20 so 90 130 170 210 240 240 TEMPERATURE (DEG. 0 Figure 3-3. Computer-reconstructed high-resolution gas chromatogram of the n-hexane and 40%-benzene-in-n-hexane fractions of the medium ilk Arabian crude oil sample (control). Peaks are identified in Figs. 3-4 and 3-5. (UNO-CBS) 34 7 AMOCO CADIZ OIL SPILL AMC 30 HEXANE FRACTION z =0.57 E-4 OUANT TNJ. Ul A Lj @j AMC 30 0 z 40% BENZENE FRACTION OUANT,INJ.=0.91 E-4 0 U @j TIME CMINUTES) Ii0 2i0 3i0 4!0 sio 610- so 90 130 170 210 240 240 TEMPERATURE (DEG, C) Figure 3-4. Computer-reconstructed high-resolution gas chromatograms of the n-hexane and 40%-benzene-in-n-hexane fractions of the reference mousse (NOAA-16). Numbers above peaks in the upper trace refer to n-alkanes of-corresponding chain length. (UNO-CBS) 35 AMOCO CADIZ OIL SPILL Lij AMC 18 15\ 16 37 \38 48 U) 40% BENZENE I / 51 z 77 25 4245 52 0 14 / 18 30 111 /53 0- 13 W FRACTION 6 11 1 28 3 [email protected] %1 3334 14 54 2 22 QUANT INJ I k 1 3 ji 19 2 :9 9 10 w! =7 5 E-4 5 1 3 39 0 U 27 TIME (MINUTES) Si 10 I'S 2? 25 310 35 so 70 go 110 130 ISO 170 190 TEMPERATURE (DEG. 0 wi V) 55 AMOCO CADIZ OIL SPILL z 160 0 2158 1 1AMC 18 1517'1161 63 5 40% BENZENE FRACTION' w 64 OUA NT IN =7 5 E w 62 0 56 59 fy U WO TIME (MINUTES) 35 40 45 50 55 6iO 65 i I I I-_ 56 1,90 210 230 240 240 240 240 TEMPERATURE (DEG. C) Figure 3-5. An expanded and numbered section of the high-resolution 31 57 1 56 -gas chromatogram from the 40%-benzene-in-hexane fraction of the mousse sample AMC-18. Refer to Table 3-.2 for the identity of the numbered peaks. (UNO-CBS) 36 is 12 13 14 15 16 17 18 19 20 21 4 22 23 24 26 27 ,!8 29 30 jjj,j29 30 Figure 3-6. High-resolution gas chromatogram of a hexane solution of the reference mousse (NOAA-16). Numbers refer to n-alkanes of corresponding chain length. (NOAA-NAF) is 16 17 15 18 19 20 21 22 00 14 3 24 25 26 13 27 28 29 30 12 Figure 3-7. High-resolution gas chromatogram of an n-hexane solution from the of mousse NOAA-13, collected about 25 km wreck site. @2 L ( Numbers refer to n-alkanes of corresponding chain length. (NOAA-NAF) 3 6 4 5 is 7 7 7 8 9 10 Figure 3-8. Gas chromatogram of the aromatic fraction of mousse sample #1, from the Amoco Cadiz oil spill. For peak identities see Table 3-4. (NOAA-NAF) is 6 7 5 7 3 7 4 8 9 10 Figure 3-9. Gas chromatogram of the aromatic fraction of mousse 9 wo 4 4 @@ @ @ @ sample #11, from the Amoco Cadiz oil spill. For peak identities see Table 3-4. (NOAA7--NAF) is 7 6 7 7 10 8 5 9 3 4 Figure 3-10. Gas chromatogram of the aromatic fraction of mousse sample #13, from the Amoco Cadiz oil spill. For peak identities see Table 3-4. (NOAA-NAF) Table 3-2. Identified and numbered components in the 40% benzene fraction of sample illustrated in Fig. 3-5 (UNO-CBS). Identi- fication was by high-resolution GC and GC-MS techniques. 1. C, naphthalene isomer 35. C2 fluorene isomer 2. C, naphthalene isomer 36. C2 fluorene isomer 3. C4 alkyl benzene 37. C, dibenzothiophene isomer 4. Biphenyl 38. C, dibenzothiophene isomer 5. C2 naphthalene isomer 39. C, phenanthrene isomer 6. C2 naphthalene isomer 40. C, dibenzothiophene isomer 7. C2 naphthalene isomer 41. C, phenanthrene isomer 8. C2 naphthalene isomer 42. C, phenanthrene isomer 9- C2 naphthalene isomer 43. C, phenanthrene isomer 10- C2 naphthalene isomer 44. C2 dibenzothiophene isomer 11. C3 naphthalene isomer 45. C2 dibenzothiophene isomer 12. C3 naphthalene isomer 46. C2 phenanthrene isomer 13. C3 naphthalene isomer 47. C2 dibenzothiophene isomer 14. C3 naphthalene isomer 48. C2 dibenzothiophene isomer 15. C3 naphthalene isomer 49. C2 dibenzothiophene isomer 16. C3 naphthalene isomer 50. C2 dibenzothiophene isomer 17. C3 naphthalene isomer .51. C2 phenanthrene isomer 18. C3 naphthalene isomer 52. C3 dibenzothiophene 19- C4 alkylbenzene + C phenanthrene 20. C4 naphthalene isomer 53. Cs dibenzothiophene isomer 21. C4 naphthalene isomer 54. C3 phenanthrene 22. C4 naphthalene isomer 55. C3 dibenzothiophene 23.' C4 naphthalene isomer 56. C3 dibenzothiophene 24. C4 naphthalene isomer 57. C3 dibenzothiophene 25. C4 naphthalene isomer 58. Cs dibenzothiophene 26. C4 naphthalene isomer 59. C3 dibenzothiophene 27. C, fluorene isomer + C3 phenanthrene C, fluorene isomer 60. C3 dibenzothiophene 29. C, fluorene isomer 61. C3 dibenzothiophene 30. dibenzothiphene 62. C3 phenanthrene 31. phenanthrene 63. C3 dibenzothiophene 32. C2 fluorene isomer + C3 phenanthrene 33. C2 fluorene isomer 64. C3 phenanthrene 34. C2 fluorene isomer 65. C3 phenanthrene 42 PURPUP49 LPUJOIUI 'SI S8u8LeqjqdPN-Z3 9uajq-4upua4dL,K4'4aW-T *TT au8Le4,4qdeULRq'48WLa-q'z 9uaJ44ueuO4d 'OT all9LL,4-4qdpULA4laW-T auejonLj -6 8u8Le44qdieuLA44aW-Z 'E 8uaLeqj4deuLA44aWLJJ-q'E'Z *0 8uaLe44qdieN 'Z sauaLe4-jqdeN-vO 'L auazuaqLA4'4aweJ48.L-t,'E'Z'T 'T OT-E Pup '6-C 'S-E *sBLJ UL suoqjeoo.ApA4 OL-4eWOUe pajaqwnu 10 UOL'4e3LjijUapj -t,-E OLqe.L -assnow SLqj UL LIO %OE Pa-4RDLPUL UOL438LLOO JO 8WL4 -ZIP s4uawainseaw PLaLj "41SURUI pup a6ejo-4s BuL.An p assnow [email protected] WOJJ pa,4eiedas aAeq XRW Ja4RA MOS JVN-VVON Aq SLsALPuV VT 8*T 8'0 O*Z Z*Z 9*T 9*0 0*0 TE ST-VVON Z'T 9'T 8*0 9*1 L'T O'T Z'O 0'0 oc CI-VVON Z*T T'Z 6'0 tP*Z 9*E L'Z Z*T S'O T*TZ 9Z TT-VVON O*T L'T 0'0 8*1 O*Z 9*1 CO Z'O oc 6-VVON VT 9'T O'T S*T lg*l G'O 1*0 0'0 Z*9T otr L-VVON t,*T 8*T 6'0 6*T T'Z 6*T UT C*O t1t, G-VVON Z*T 8'T 8*0 6*T Z*Z O'Z 9*T VO T'6 Z68 E-VVON VI FT O'T O*Z C*Z UZ UZ 6'T OE 91-VVON 4R4d 813 SLJd LTj 9TO VTD ZT3 OTO LIO UL LP % aLdweS LeL,A8'4eW OL-JeJ "o-U/UOqjpoojpRH JeLod % ,assnow jo 6ULJ8qjPat4 -C-E aLqei loss of aromatics from C4-benzenes to C3-naphthalenes compared to sample #1 (NOAA-1), collected at the wreck site. Sample #11, collected 10 km from the wrecki shows an intermediate loss of these molecules. Also demonstrated is the persistence of the phenanthenes and higher boiling components. Further evidence of weathering processes is indicated in the polar content of the mousse-oil. The sample from Portsall (NOAA-3) contained 9% polars while.the sample from les-Gre'ves de Lilia (NOAA-11) contained 21% polars. Volatile oxygenated compounds were tentatively identified in a headspace analysis of NOAA-7, performed by NOAA-NAF. This sample .had a definite H2S smell when opened, indicating microbial activity in the mousse'. Normal branched and aromatic ketones and aldehydes contain- ing from 5 to 8 carbon atoms were indicated by GC-MS of the headspace. Confirmation with authentic standards is in progress. These data, if confirmed, would constitute solid evidence for the active oxidation of mousse, probably by microbial processes. Additional evidence on the production of polar material is presented in a following section. Con- tinued and improved effort on the analytical chemistry of polar material is required to fully assess the environmentalimpact of spilled oil. Examples of more pronounced weathering can be seen in Figures 3-11 and 3-12. AMC-14 represents a brown froth collected *downslope from a mousse located on an open section of beach. As can be seen, the level of normal alkanes such as n-C17 and n-C18 have decreased almost to that of the level of the chromatographically adjacent isoprenoids. Also, there was a corresponding alteration in the chromatographic profile of the aromatics. By comparison, however, the most striking example of weathering was observed in sample F-82 which was collected from the surface of rocks along the mid-beach face near Pointe de Landunves. The native material appeared similar to tar, being dark and having a thick consistency. As can be seen in Fig. 3-11, phytane actually exceeds the concentration of a-CI8. Additionally, the presence of distinct aromatic components is difficult to observe. Fig. 3-13 is a three-dimensional plot comparing the relative con- centration (vertical axis) of selected aromatic hydrocarbons (axis into the page) in several-similar samples, the reference mousse and the control oil (horizontal axis). The concentration of components within a sample is displayed relative to the concentration of dibenzothiophene which was.given a value of 100. "A" and "B" (Table 3-5) are the medium Arabian crude oil and NOAA-16 reference mousse respectively. Careful examination of the three-dimensional plot shows remarkable similarity in the distribution of aromatic components in the Arabian crude and the NOAA-16 mousse samples. Additionally, these profiles are consistent in all mousse samples analyzed except sample "E" (AMC-14) and sample "J" (F-82). These data clearly display the greater degree of environmental modification in these two samples when compared to the others. 44 [email protected] CADIZ OIL SPILL AMC1,4 HEXANE FRACTION OUANT INJ.=3.5 E-4 Li 0 z 0 Uj 0 U w TIME (MINUTES) 10 20 3,0 4,0 so 6P 7,0 so 90 so 90 130 170 210 240 240 240 240 240 TEMPERATURE (DEG. C) AMULU CADIZ.OIL SPILL F-82 w U) HEXANE FRACTION z 0 OUANT. INJ.=4.3 E-4 a- W w w 0 U w TIME (MINUTES) 10 20 30 40 so 60 70 9,01 so 90 130 170 210 240 240 240 [email protected] 2'4 0 TEMPERATURE (DEG. 0 Figure 3-11. Computer-reconstructed high-resolution gas chromato- grams of the hexane fractions'of samples AMC-14 and F-82. (UNO-CBS) 45 AMOCO CADIZ OIL SPILL w F-82 V) z 40% BENZENE FRACTION 0 QUANT. INJ.=4.9 E-4 w Of iy w 0 1 w 111 (Y- TIME (MINUTES) I 2iO 3i0 4iO sio 6io so go- 130 170 210 240 240 TEMPERATURE (DEG. 0 AMOCO CADIZ OIL SPILL w w AMC.14 z 0, Q_' 40% BENZENE FRACTION w OUANT. INJ.=7.5 E-4 W, 0, Ul TIME (MINUTES) 1P 20 3P 4P 5!0 6P so 90 130 170 210 240 240 TEMPERATURE (DEG. 0 Figure 3-12. Computer-reconstructed high-resolution gas chromato- grams of the 40%-benzene-irr-hexane fractions of samples AMC-14 and F-82. (UNO-CBS) 46 L 17 X REL. CONC. w &k cn m -4 m w 0 w to w tD w m to i A- -b-- in- 0-0 GO to to 00CDCDOO w 0 CD to w 0 w 0 0 n M OQ0 rA rt W 0 n @oM co ct IV ct 0 0 ft m0 0 H.. 0 H. " ca ft 0wH. 0 m (D 190 n mr) o wrt 0 m m rr 0 :3 0 0) ft "" H. [email protected] N 90 ft 0 0t -n - m W. 0 t+ H. 0 "0 rr 0 rt H. rA0 W. V- o 0 (D N r+ 00 > 0 H. P-h r+ t-i 0 4 r.r rh H. 10 o0o @-A M m0 0 4)0 nr) w ts0 Mrt w t3 ta0 go Table 3-5. Identification of samples and selected aromatic hydrocarbons displayed in Fig. 3-13 (UNO-CBS) Samples Selected aromatic hydrocarbons A. Medium Arabian crude oil (Control) 1. C1 naphthalene isomers B. AMC-30 (cargo oil) 2. C2 naphthalene isomers C. AMC-1 (31 Mar 78) mousse or slick 3. C3 naphthalene isomers D. AMC-12 (27 Mar 78) beached oil, mousse 4. C4 naphthalene isomers E. AMC-14 (27 Mar 78) brown froth 5. C, fluorene isomers F. AMC-16 (28 Mar 78) mousse 6. C2 fluorene isomers G. AMC-17 (29 Mar 78) beached oil, mousse 7. dibenzothiophOne H. AMC-18 (29 Mar 78) mousse 8. C, dibenz.othiophene isomers I. AMC-3 (31 Mar 78) sediment 9- C2 dibenzothiophene isomers J. F-82 (31 Mar 78) tar on rock 10- C3 dibenzothiophene isomers 11. phenanthrene 12. C, phenanthrene isomers 13. C2 phenanthrene isomers 14. Ca phenanthrene isomers 3.3.2 Sediment The concentrations of hydrocarbons present in sediment samples obtained at EPA stations 1-7 (see map) following the wreck of the Amoco Cadiz are listed in Table 3-6. The concentrations ranged from 742 ppm (dry weight) to 4 ppm (dry weight) but no consistent pattern of decreas- ing oil content with distance from the tanker was observed. This re- sulted from the wind-driven distribution of large masses of mousse from the wreck. In some windbound coves and marshes, large amounts of oil collected, while other leeward areas remained relatively clean. This patchy distribution was also observed on a smaller scale. Samples EPA-1 (beach) and EPA-1 @tidal flat) demonstrate this irregular distribution. EPA-1 (beach) was obtained at Roscoff on March 27., 1978. This surface sediment sample was-taken approximately 70 meters seaward of the seawall.. Thirty meters landward of this sample location a large amount of mousse had been deposited.. The total hydro- carbon concentration of EPA-1 (beach) was 79 ppm (dry weight). Examin- atioa of gas chromatograms from aliphatic (F-1) and aromatic (F-2) por- tions of this sample (Fig. 3-14) and the n-C17/pristane and n-C,S/ phytane ratios (Table 3-6),indicate that the oil in this sediment sample was quite fresh. Similar but slightly more weathered oil was evident in chromatograms from EPA-1 (tidal flatj sediments. This sample was taken 200 meters seaward of EPA-1 (beach) on a tidal flat that was covered with [email protected] 2 cm of water. 'Its total hydrocarbon content was 10 ppm (dry weight). 48 Table 3-6. Sediments Concentration n-C17/ n-Clg/ Samples pg/g (dry weight) pristane phytane EPA-1 (beach) Roscoff 27 Mar 78 F-1 65 3.1 2.0 F-2 Total 79 EPA-1 (tidal Flat) Roscoff 27 Mar 78 F-1 6 1.5 F-2 4 Total UO EPA-2 Ile Grande 30 Mar 78 F-1 164 1.7 2.6 F-2 62 Total 226 EPA-3 (0-5 cm) 31 Mar 78 F-1 5 0.9 0.7 F-2 20 Total 25 EPA-3 (5-10 cm) 31 Mar 78 F-1 31 .7 F-2 17 Total T8- EPA-4 Locquirec 2 Apr 78 F-1 3 1.3 0.8 F-2 1 Total 4 EPA-7 I'Aber Wrac'h 6 Apt 78 F-1 539 0.5 0.4 F-2 203 Total 742 NOAA-16 Mousse sample (reference) 26 Mar 78 49 09 lip 6. 9 6.35 7.04 O-S 00 rA V m 0 14.87 @r W M 0 17.96 M 0 19* 14 o :C m t9.57 t9.98 0 22 23.57 0 23. al 23.49 rb 8 0) 23.21 ft 3 25.97 r) I-h 0 26.22 26.13 00 20.72 28.55 29 ,22 0 9.55 9 .74 0 0 30.66 39.9-3 @o m I-t 31.05 -4 0 0 32.40 V 32.99 33.93 ct H. @3.36 33.2 33.71 34.23 [email protected] rb rt 17 H. 36. LF' 0 37vI4 37.55 o-, 0 38.99 S M rt W as co rD 0 a. (A Q. rt 42.52 9 PI m 0) 44.19 45.79 rt 0) 47.35 49.15 51.24 6-31. @ 3t 2. E.4 29' @.. From these limited data it appeared that as the mousse was rafted over the tidal flat a relatively small amount of incorporation of oil into the sediments occurred. As the mousse moved shoreward, the combina- ,tion otdecreasing water depth and increasing wave-action caused more incorporation of oil into sediments at the lower beach face. Finally, the mousse was deposited on the top portion of the beach. A core sample obtained at EPA-3 on March 31, 1978, was cut into a 0-5 cm and a 5-10 cm section. The concentrations of total hydrocarbons were 25 ppm (dry weight) in the 0-5 cm section, and 48 ppm (dry weight) in the 5-10 cm section. While gas chromatograms from the aliphatic (F- 1) and aromatic (F-2) portions of both core sections were similar (0-5 cm F-1 and F-2 chromatograms shown in Fig. 3-15), the proportions of hydrocarbons present in the aliphatic and aromatic fractions were different (Table 3-6). The cause of these differences is unknown, but may have resulted from the incorporation of dispersed oil droplets from Ahe overlying water. The water sample obtained at the location was tinted brown and contained 42 ppm hydrocarbon material. The highest concentrations of oil were found in sediment samples from heavily polluted I'Aber Wrac'h (Plate 3-6) (EPA-7) and the oiled .marsh Ile Grande (EPA-2). At Ile Grande oil and mousse were scraped from the sediment surface before the sample was taken. The lowest concentration observed in sediment samples was obtained on the beach at Locquirec (EPA-4). Landward of this sample location large quantities of mousse had accumulated. Presumably this low-value reflected the small- scale patchy distribution of oil in sediments of this area. Table 3-6 lists the n-C17/pristane and n-C,8/phytane ratios calcu- lated from gas chromatograms of the sample extracts. These ratios may be utilized to determine the bacterial degradation of the n-alkanes present in petroleum, because bacteria degrade straight chain alkanes (i.e., n-heptadecane and n-octadecane) more rapidly than the branched chain isoprenoids pristane (2, 6, 10, 14-tetramethylpentadecane) or phytane (2, 6, 10, 14-Tetramethylhexadecane). No consistent pattern is observed relating the distance from the wreck to the amount of bacterial degradation of petroleum present in the sediment samples. There are several possible explanations for this inconsistency: (1) The oil leaked from the wreck for a period of about two weeks, which resulted in different lengths of environmental exposure for oil in the sediments sampled. (2) The spilled oil contaminated different sediments. Its path from the tanker may have varied. (3) Variations may have existed in the amount of oil present in sediments relative to the bacterial population able to degrade the oil. 51 Z9 IM 3.20 3.80 3. [email protected] OR OR 6. @O 6.37 7.05 10.49 ct (D 0. 0 H. 9m go m C+ U.) M r+ n r) o I.- 11) Pi 0 17.89 m C m0 19.11 m 0 H 20.02 '20.07 m al C+ C+n M 72 20.77 go Hol ?! k . 744 H. A) tl 22.04 00 2 , -.12 9 1 23.., 24.08 24.62 o 25.25 25.15 r+ 00 2 957 25.91 26.04 > Z6 H. 2 4 28-6 wl 0 00 21.61 29-67 30. LZ 0 30.72 [email protected] 04) V 3JZ?tl r+ 0) 63332.97 (A 32.94 33.22 33. 79 [email protected] m Fi. 35 54 35.02 n 36.22", 3fe% 37-06 37 @LO- - Ln 30.89 C(D 39.24-03 00 1 Ln 96". AN-ZJ- CA 42.44 44.10 n 4-5.70 47.25 '31.33 Similar variations in degradation were observed in soil and sedi- ments taken on a vertical transect up a cliff at l'Aber Ben oit. Recon- structed gas chromatograms obtained from the aliphatic and aromatic fractions of these samples are shown in Figs. 3-16 and 3-17. These figures show that relatively low levels of aliphatic and aromatic hydrocarbons were found in the soil sample taken above the high water mark on the face of the cliff. The chromatograms of this sample were not similar to those obtained for contaminated samples, indicating that the oil did not impact this soil. Chromatograms obtained from sediments taken 30 cm below the high water mark and at the base of the cliff showed the presence of petroleum hydrocarbons in the aliphatic and aromatic fractions. Comparisons of these chromatograms indicated that the oil in the sediments at the cliff base was more weathered than the oil from sediments on the face of the cliff. The increased weathering is shown in the chromatograms of sediments at the cliff base by a de- crease in the peak heights Of n-C17 and n-Cls relative to the isopre- noids, pristane and phytane, in the aliphatic fraction, and a decrease in resolved vs.. unresolved components in the aromatic fractions. Again, this sample series shows that variations in weathering of oil occur in samples taken only a few meters apart, but, due to the continuous leakage of oil from the wreck, the length of time that the oil was present in these samples may have been different. Fig. 3-18 shows a three-dimensional plot of the concentration of selected aromatics in these cliff samples. This figure also demonstrates that concentrations of these aromatics were below detection limits in the upper cliff soil sample, and shows the variation in distribution of these aromatics on the cliff face and in the sediments at the cliff base. 3.3.3 Photochemical Processes Figure 3-19 shows the high-resolution gas chromatograms of the methanol fractions from AMC-12, AMC-14, AMC-16, AMP-1 (photolyzed medium Arabian crude oil), and AMP-C (nonphotolyzed medium Arabian crude oil). The presence of a complex unresolved mixture (hump) in the photolyzed control sample and the two environmental samples, with absence of any significant hump in the unphotolyzed control sample, provides indirect evidence for photo-oxidation processes in the environmentally exposed mousse samples. Additional evidence was obtained by inspection of mass chromatograms of the ion fragments characteristic of the sulfoxides of dibenzothiophene and its n-C, and n-C2 alkyl homologs in the same metha- nol fractions. Ion fragments thought to be associated with the complete series of sulfoxides were observed. The presence of substantially higher quantities of the sulfoxides in the methanol fractions of the environmentally derived mousse samples and the photolyzed control oil sample was confirmed by comparison of the full mass spectra in each sample with authentic standards. 53 AMOCO CADIZ OIL SPILL UPPER CLIFF U) z 0 HEXANE FRACTION Lj U W! W OIL CLIFF V) HEXANE FRACTION 01 az 0 W cz U BOTTOM CLIFF 0,1 HEXANE FRACTION z 0 V) W W U W h [email protected] TIME (MINUTES) 1P 2P 3P 4P 52 6P 7P 8P 90 so 90 130 @170 210 240 240 240 240 240 TEMPERATURE (DEG. C) Figure 3-16. A computer-reconstructed high-resolution gas chromato- graphic separation of the n-hexane fraction of extracts from soil samples collected at I'Aber Benoit. The upper trace represents a sample taken above the high water mark on the cliff face. The middle trace is from about 30 cm below the high water mark and the lower trace at the base of the cliff. All samples were collected in a vertical line. (UNO-CBS) 54 AMOCO CADIZ OIL SPILL UPPER CLIFF zi 0 0- 40% BENZENE FRACTION w OIL CLIFF LIJ [email protected] 40% BENZENE FRACTION z 0 0 BOTTOM CLIFF w U) 40% BENZENE FRACTION z 0 I V) 0 U Li TIME (MINUTES) 10 20 30 40 5 @o [email protected] [email protected] 9,0 130 170 210 240 240 TEMPERATURE (DEG. C) Figure 3-17. Computer-reconstrtkcted high-resolution gas chromato- graphic separation of the 40%-benzene-in-n-hexane fraction of extracts from soil samples described in Fig. 3-16. (UNO-CBS) 55 1400 1220 1002 U Bee H _j W 600 420 14 1Z 200 0 A B C D E F G H I j SAMPLE Figure 3-18. Three-dimensional plot showing the relative concentra- tion (vertical axis) of selected aromatic hydrocarbons (axis into page) in selected samples (horizontal axis). All components are compared relative to the concentration of dibenzothiophene in each sample. Refer to Table 3-7 for identification of samples and aromatic hydrocarbons. (UNO-CBS) Preliminary data indicate that there is at least ten times more oxidized product in the environmental and lAboratory-irradiated samples than in the non-irradiated medium Arabian crude oil control. Further experiments have shown that aromatic hydrocarbons will stimulate photo- oxidation substantially. Known photo-oxidation products of naphthalenes and phenanthrenes were not detected in the methanol fractions of the two mousse samples investigated. 3.3.4 Biota Only four biota samples were extracted and analyzed in time for incorporation in this report. These included periwinkles, limpets, polychaetes, and a seagrass. All biota samples were collected alive and were not obviously coated with oil. Fig. 3-20 'illustrates the chromato- graphic separation of the n-hexane and 40%-benzene-in-n-hexane fractions 56 ARAB MEDIUM CRUDE OIL PHOTOLYSIS AMOCO CADIZ OIL SPILL AMC 16 Uj AMP1 H+N w METHANOL FRACTION @',ETHANCL FRACTION SE-52 COLUMN 0 @E-S2 [email protected]!N V); @@UANT. INJ 40.E-4 [email protected]@E (MINUTES) -ME (KNUTES) @C 2'@ 321 4,3 [email protected] 6,0 72 82 92 -1 a 20 3? 4a so 63 [email protected] so -_2 ! a 70 210 240 240 2 40 240 .3 [email protected] lea Ha 80 220 250 250 250 250 252 TEMPERATURE (DEG C) TEMPERATURE CDEG, C) AMOCO CADIZ OIL SPILL AMOCO CADIZ OIL SPILL CONTROL AMC 14 w METHANOL FRACTION V) Z11 METHANOL FRACTION .z SE-52 COLUtIN 01, SE-52 0 0. COLUMN V) W U Lo W 0 IL i TIME (MINUTES) TIME (MINUTES) 1,0 [email protected] @O [email protected] [email protected] [email protected] 7e 80 93- .0 21,6 3,0 4P [email protected] 6,0 70 80 9- so 90 133 170 210 240 240 2'4 0 2'4 0 240 so 90 130 170 210 240 240 240 240 240 TEMPERATURE (DEG. C) TEMPERATURE (DEG. C), AMOCO CADIZ OIL SPIL_ AMOCO CADIZ OIL SPILL w AMC 12 V" : [email protected] CCNT.ROL BLANK 0) z zi METHANOL FRACTION 01 Q I: @ETIIHANO_ FRACTION n- SE-52 COLUMN V) V) SE-7-2 COLUMN w U TIME (MINUTES) TIME (MINUTES) 1"0 2P 30 40 52 60 70 8p 9p [email protected] 3P [email protected] [email protected] IP [email protected] @O go so 92 132 172 212 240 240 240 240 240 so 90 130 170 210 240 240 240 240 2'4 0 TEMPERATURE (DEG C) TE MPERATURE (DEG. C) Figure 3-19. Computer-reconstructed high-resolution gas'chromato- grams of the methanol fractions from samples AMC-12, AMC-14, AMC-16, AMP-1, and AMP-C. Samples AMP-1 and AMP-C are the photo- lyzed and control samples, respectively, of the medium Arabian crude oil sample. (UNO-CBS) 57 AMOCO CADIZ OIL SPILL W AMC 4 TISSUE v): HEXANE FRACTION z1 01 QUANT. INJ.=2.3 E-4 W W 0 ff 0 U W TIME (MINUTES) 10 20 30 4P so 60 [email protected] 8P 910 so 90 130 170 210 240 240 240 240 240 TEMPERATURE (DEG. C) AMOCO CADIZ OIL SPILL [email protected] AMC 4 TISSUE W iI 40% BENZENE FRACTION Z11 01: 0_11 OUANT. INJ.=4.7 E-4 V): Wi: j WI! 0, 0 E, TIME (MINUTES) I io 2P 3!0 4P 5i0 6i0 50 90 130 170 210 240 240 TEMPERATURE (DEG. C) Figure 3-20. Computer-reconstructed high-resolution gas chromato- grams of the n-hexane and 40%-benzene-in-a-hexane fractions of the soft tissue from periwinkles collected at AMC-4. (UNO-CBS) 58 of the soft tissue from perwinkles collected at AMC-4. As can be seen, the normal alkanes range from n-C13 to n-C33 and the profile is remark- ,ably similar to a number of mousse samples analyzed that had undergone a modest weathering process. The aromatics were also present in the @periwinkle tissues. Only a trace of methyl naphthalene isomers was present. However, the chromatographic profiles of the full complement of n-C2 and n-C3 naphthalenes, dibenzo-naphthalenes and the other aromat- ics are ver obvious. Fig. 3-21 illustrates the chromatographic separa- tion of the aliphatic and aromatic fractions of the seagrass sample collected at Portsall on May 31, 1978. This sample was collected from a pool of water that had no visible evidence of petroleum either on the surface or in the water. As can be seen the profiles are similar to those in Fig. 3-20 in the periwinkles. It would appear that the mousse from the surrounding environment is either absorbed on the surface or ingested intact by these organisms. The other biota samples analyzed also demonstrated very similar chromatographic characteristics. Fig. 3-18 is a three-dimensional plot, similar to that illustrated in Fig. 3-13, showing the relative concentrations of selected aromatic hydro- carbons. Table 3-7 provides information on sample identification and the selected aromatic hydrocarbons displayed in Fig. 3-18. Samples G, h, I, and J represent the biota samples analyzed. 3.3.5 Analysis of Oil in Subsurface Water in I'Aber Wrac'h Estuary Towed Underwater Fluorometer The Environmental Devices Corporation (ENDECO) Petro Track towed underwater fluorometer system was deployed by ENDECO under contract to NOAA to determine the capability and usefulness of this syst .em under real spill conditions. The system was deployed in l'Aber Wrac'h during three cruises on board an 18 m fishing boat. Subsurface (1 to 3 m) tran- sects from the estuary mouth to its head, conducted on each of the three cruises, resulted in a consistent description of relative hydrocarbon concentrations (Fig. 3-22). Offshore concentrations were relatively low, but still higher than ENDECO personnel had previously experienced. At the shoal area, concentrations increased abruptly about fivefold, and then diminished to intermediate values as one progressed up the estuary. There were no substantial changes in concentration from inside the shoal area to the bridge near Paludenn. The violent wave action in the shoal area apparently forced more oil into the water column, some of which remained there. Several depth profiles were taken, all of which indi- cated that the estuary was well mixed vertically and that high oil-in- water concentrations were in contact with the benthos (Fig. 3-23). The availability of real-time relative concentrations made it clear that detailed analysis at one offshore, one shoal, and one upstream station would adequately describe the hydrocarbon burden of the water column in l'Aber Wrac'h. 59 AMOCO CADTZ OIL SKL_ w HEXANE FRACTION V) z OUANT.INJ.=3.9 E-2 0 a- V) 01 U. [email protected] 40% BENZENE FRACT T43N w QUANT. INJ.=6.2 E_L2 0 w w 0 U w METHANOL FRACTIO.,j w co SE-52 COLUMN z 0 W w 0 Of 0 U w TIME (MINUTES) 2 3 4P 5P 6 [email protected] 8 9P 90 130 170 210 240 240 240 240 240 TEMPERATURE (DEG. C) Figure 3-21. Computer-reconstructed gas chromatograms of seagrass collected near Portsall. (UNO-CBS) 60 Table 3-7. Three-dimensional plot of the concentration (vertical axis) of selected aromatic hydrocarbons (axis into page) for certain Amoco Cadiz samples (horizontal axis) as shown in Fig. 3-18 (UNO-CBS) Samples Selected aromatic hydrocarbons A. Oil Cliff 1. C, naphthalene isomers B. Upper Cliff 2. C2 naphthalene isomers C. Bottom Cliff 3. C3 naphthalene isomers D. AMC-1, ground water 4. C4 naphthalene isomers E. AMC-3, ground water 5. C, fluorene isomers F. AMC-17, ground water 6. C2 fluorene isomers G.. AMC-4, periwinkles 7. dibenzothiophene H. AMC-17, limpets 8. C, dibenzothiophene isomers L AMC-18, polychaetes 9- C2 dibenzothiophene isomers J. Seagrass 10. C3 dibenzothiophene isomers 11. phenanthrene 12. C, phenanthrene isomers 13. C2 phenanthrene isomers 14. C3 phenanthrene isomers Concentrations reported by the towed fluorometer varied from 2 to 21 times the concentrations derived from discrete water samples. The towed fluorometer reading appeared to have a compressed dynamic range. The towed fluorometer was cal-ibrated with a diluted oil-in-water emul- sion. The difficulty involved in preparing such a mixture in a quanti- tative way is undoubtedly partly responsible for the sometimes large discrepancies between the concentrations derived from the towed fluorom- eter and those from discrete water samplings. UV-Fluorescence Analysis of Water Samples Collected in l'Aber Wrac'h Simultaneously with the deployment of the towed fluorometer, dis- crete samples were collected with Niskin sterile bag samplers. The sampler was positioned just in front of the towed fluorometer intake to facilitate comparison of the results from the two methods.. Water sam- ples were removed from the bags immediately after retrieval and stored in hexane-rinsed glass jugs with Teflon-lined caps. Samples were ex- tracted in the laboratory within 36 hours. The first transect up the estuary (March 24, 1978; see Fig. 3-24) indicated that the concentration offshore at 3 m depth was 36-ppb (Table 3-8). At the shoals in the mouth of the estuary the concentration rose dramatically to 250 ppb, probably reflecting the physical entrainment and downward movement of surface oil by the violent wave action in the shoals. Inside the shoal area, the concentration was reduced to 140 ppb, with further reduction to 26 ppb at the bridge near Paludenn. 61 1600- Z 01AMPLET HIGH TIDE OF 3-24-79 0 Z 0 1200- >.Z 0 q Z W W Z (L Z 0 Boo 0 3AMPLET 400- HIGH TIOE OF 3- 5-78\ 0 A 0 20- 0 a) 40- 0 (L W 0 >@ 60- 0 Cr Q. Q_ < B 3000- 0 3-27-78 W 2500- SAMPLEa FLOOD TIDE Z 2000- 0 Z [email protected], W u 1500- Z EBB TIDE 0 U SAMPLET X W 1000- 0 C 6 DISTANCE FROM c-ND OF ESTUARY (kilometers) Figure 3-22. Towed underwater fluorometer transects in l"Aber Wrac'h. A: Concentration versus horizontal distance for cruises I and 2. B: Approximate water depth. C: Concentration versus horizontal distance for cruise 3. Concentrations determined by fluorescence do not necessarily represent the absolute concentra- tions of petroleum in water. (ENDECO) 62 0- 3-25-78 3-27-78 q? 2- 4- OUTGOING FLOW qj NEWLY INCOMING STATION A FLOW tj INCOMING FLOW STATION B 12- 14- STATION C 16- f A B 18 0 200 400 660 800 6 IdOO 2000 3000 CONCENTRATION OF OIL- IN-WATER (,pg/ 1) Figure 3-23. Vertical profiles of oil in water measured in I'Aber Wrac'h with the towed fluorometer. Concentrations determined by fluorescence do not necessarily represent the absolute concentra- tions of petroleum in water. (ENDECO) The second cruise (March 25, Fig. 3-25) resulted in depth profiles in the shoal area and upstream, based on data from the in-situ fluorom- eter with discrete water samples collected near surface and near bottom. Near-surface concentrations both upstream and in the shoal area were similar to those of the previous day (Table 3-8). Near-bottom concen- trations were higher than near the surface, particularly in the upstream sample. Turbulence is again suspected as the cause'for elevated concen- trations in the shoal area. During the third cruise (March 27, Fig. 3-26) depth profiles in the o shoal area over a tidal cycle and an offsh re and upstream sample were 63 Figure 3-24. Station locations for l'Aber Wrac'h, cruise 1, March 24, 1978. CQ, do ILA t PLOUGUERNEAU to' e j pj b w C, L NDED b Figure 3-25. Station loca- tions for l'Aber Wrac'h, cruise 2, March 25, 1978. I A PLOUGUERNEAU to e 1-0 p i w 0 LANDED C, X,bi4e 64 JZ? D I LA PLOUGUERNEAU to' e jo w LAN'DED xx b b i Figure 3-26. Station locations for l'Aber Wrac'h, cruise 3, March 27, 1978. I A PLOUGUERNEAU to' e b Ob LANDE b 6C Figure 3-27. Station locations for I'Aber Wrac'h, cruise 4, May 3, 1978. 65 Table 3-8. Concentrations of fluorescent compounds in subsurface water from I'Aber Wrac'h as determined by comparison with dilutions of the reference mousse (NOAA-16). These concentrations do not neces- sarily represent the absolute concentrations of petroleum in water.' Station2 Depth(m) Conc(ppb) Cruise 1 (24 Mar 78) 1--offshore 3 36 2--shoals 3 250 3 3 140 4 1 110 6 1 [email protected] 6 1 33 7--bridge 1 26 Cruise 2 (25 Mar 78) A 2 57 10 103 B 2 59 C 2 290 10 330 Cruise 3 (27 Mar 78) A upstream 1 50 B (ebb tide) 2 73 7 69 C (tide turning 1 175 to flood) 10 250 C (flood tide) 1 255 7 340 0 offshore 15 130 'Analysis by NOAA-NAF 2See Figs. 3-24, 3-25, and 3-26 for station locations 66 collected. The upstream concentrations of 50 ppb were similar to those of the previous cruises. Near the shoal area, concentrations were near 70 ppb on the ebb tide and 175 to 340 ppb on flood tide with, again, evi- dence of greater concentration at depth. L'Aber Wrac'h was still re- ceiving oil with incoming tides and this oil was not being completely flushed on ebb tide. The oil being retained in the estuary did not appear to be building up in the water column as upstream concentrations were stable near 50 to 100 ppb. The increases in concentration with depth may indicate a sinking of the oil, possibly due to flocculation/adsorp- tion on particles, and accumulation in sediments. Analyses of one sediment from I'Aber Wrac'h indicated very high concentrations of oil, in excess of 2 mg/g dry weight. In early May 1978 (see Fig. 3-27), NOAA personnel collected addi- tional water samples.from l'Aber Wrach for UV-fluorescence analysis. These data (Table 3-9) indicate that concentration of oil in the water column had decreased in the 48 days since the accident, but had not yet reached background levels typical of offshore water. Concentrations at the upper end of the estuary had decreased much less than those nearer the mouth. Table 3-9. Concentrations of fluorescent compounds in subsurface water collected May 3, 1978, from I'Aber Wrac'h as determined by comparison with dilutions of the reference mousse (NOAA-16). These concentrations do not necessarily represent the absolute concentrations of petroleum in water.1 Station2 Depth(m) Conc(ppb) 1 1 4.2 3 3.8 2 0.5 6.5 3 0.5 lost 4 0.5 9.2 5 0.5 15 6 0.5 9.7 7 0.5 19 2 22 Bridge (7 May 78) 1 75 'Analysis by R.C. Clark, Jr., NOAA-NWAFC 2See Fig. 3-27 for station locations 67 Gas chromatograms of hydrocarbons extracted from water taken near the shoal area were similar to chromatograms of the reference mousse (Figs. 3-5, 3-28, 3-29). Alkanes from n-Clo to n-C30, pristane, phy- tane, and many other less prominent branched/cyclic and aromatic hydro- carbons were detected in the water samples. As would be expected some weathering was apparent, particularly the loss of volatiles. In the unfractionated reference mousse sample, n-C11 was the most abundant normal alkane. In the water, n-C17 was usually the most abundant. Microbial degradation removes normal (straight-chain) alkanes in prefer- ence to branched alkanes, such as pristane and phytane. In the unfrac- tionated reference mousse, the n-C17/pristane and n-C18/phytane ratios were between 2 and 3, while in water samples the ratios were 1 or less, indicating the possibility of microbial degradation of middle-molecular- weight n-alkanes. The peaks in the region of the mono-,.di-, and tri- methyl naphthalenes were also enriched-compared to the normal alkanes in the water samples, consistent with their greater water solubility and greater resistance to degradation. Samples taken in the shoal area on all three cruises were similar, but displayed varying amounts of weath- ering because fresh oil was still being released from the wreck during the sampling period. Water samples taken upstream of the shoal area contained a much lower GC pattern of hydrocarbons, but were obviously more contaminated than any offshore station except that near the wreck site (Fig. 3-30). Analysis of Oil in Subsurface Water Off the North Coast of Brittany From March 30 to April 4, 1978, the French research vessel Le Suroit (Southwest Wind) occupied 46 stations (Plate 3-2, Fig. 3-31). French scientists conducted extensive sampling for measurements of subsurface oil in water, as, well as for standard chemical and biological parameters (Plates 3-3 and 3-4). At the invitation of Dr. Michel Mar- chand of the Centre Oceanologique de Bretagne, NOAA personnel partici- pated in the cruise. At nine of these stations, near-surface and near- bottom samples were collected with the Niskin sterile bag sampler (Plate 3-5). Samples were transferred immediately upon retrieval to hexane- washed glass jugs with Teflon-lined caps. Extraction of the water with hexane was performed upon return to the shore laboratory. The extracts were analyzed by both UV-fluorescence and glass capillary gas chromatog- raphy. This cruise was conducted two weeks after the wreck occurred and .several days after the bulk of the oil had leaked from the ship. Thus, the concentrations reported here may not represent the maximum values attained at the height of the spill. Background values are taken as 0 to 2 ppb as determined by UV-fluorescence on water from station 16 (Table 3-10). 68 is is is 17 16 5 14 2 19 20 21 22 13 23 24 2 25 26 28 27 1 30 LIO Figure 3-28. High-resolution gas chromatogram of n-hexane extract j @ @@ A @ b jvv., of water from I'Aber Wrac'h, station C, cruise 2. Numbers refer to n-alkanes of corresponding chain length. Internal standards marked IS. (NOAA-NAF) ot hd 0010 w 00 @.o 0 0 ct 0 Wgo PRISTANE rt (A 0) :[email protected] - -- rt0 PHYTANE H. P, 0 0 rt 0 000 In m0 I-h (D lw 0 [email protected] rb (D 00m rbx - 0Ct ,!I.m ct @.Xj000 LA) ctW IIDI I,"L. 000 0 0 (b rD ca 0 0P. 0 PRISTANE PHYTANE rt0 H. :7. 0 0 bd co 0 (D0 C/)m mgo p - (D m OQ Mx r+ 0) 0 S. 50, 4(Y 4*30' 20, lo, 4' 40* 3*30, Po' 1.6 3. 50' 40 2'30' 20' 49. 30' 35*- 10 34 16 UERNE EY 20, 36 33 *17 154 14 lol- -13 49* 32 10 40 8 25 J, "LESSEPT ILES 7 22 25 50, 12 .31 27 *?3 2 411 39#3 .1, U".. - 30 'j-,! 24 5 F - ------ OSCOP-/... -LANNI Rr ON 182 29 420 STPOL 40' DE LEON T LOUGUERNE AU MORLAIX 44 RTSALL PC - ST. E EUC' 148' 43 30' C-1 @L,@,D'6"UESSANT BREST 45 PTE 20' THIEU 5--- 6UEAI'E' ST \[email protected] [email protected] _iT IZI \E Figure 3-31. Map of stations occupied by the ship Le Suroit to collect water samples from March 30 to April 4. Table 3-10. Concentrations of fluorescent compounds in offshore waters as determi'ned by comparison with dilutions of the reference mousse (NOAA-16). These concentrations do not necessarily repre- sent the absolute concentrations of petroleum in water.1 Station2 Depth(m) Conc(ppb)3 1 2 90 3 2 21 100 26 6 2 40 40 48 7 2 1.5 20 12 9 2 3.4 70 16 16 2 0 60 2.1 29 2 9.1 60 140 37 2 1.5 90 0.1 39 2 0.8 90 1.7 'Analysis by NOAA-NAF 2See Fig. 3-31 for station locations 3Average of duplicate analysis--average deviation about the mean 20% 73 Surface mousse, slick, or globular oil, was present at stations 1, 3, 6, and 29. These stations also showed high concentrations of oil (9 to 90 ppb by UVF) at 2 m depth. Surface oil was absent at the other stations and the concentration at the 2 m depth was lower (0 to 3 ppb by UVF), essentially at background levels. Stations 1 and 3 were reoccu- pied as stations 37 and 39 near the end of the cruise (April 3). Con- centrations observed at this later time were near background levels. All oil had leaked from the ship by this time and the water column did not contain residual hydrocarbons. Except at station 1 (37), near-bottom samples contained greater hydrocarbon concentrations than at 2 m depth, even when floating oil was observed at the surface. The highest offshore concentration was 140 ppb at 65 m depth at station 29. The role of dispersants and sinking agents used to counteract the oil spill must be clarified with regard to the observed increase in hydrocarbon concentration with depth. Gas chromatographic data reflect the relative UV-fluorescence data. The chromatogram of station 1, 2 m (90 ppb) contains n-C12 to n-C32 n- alkanes, pristane, and phytane (Fig. 3-32). At station 9, the 2 m sample (3.4 ppb) contains nothing that can be attributed to the oil (Fig. 3-33) while the 70 m sample (16 ppb) has elevated concentrations of a few peaks which bear a resemblance to the station 1 sample. Analysis of Oil in Interstitial Water from Beaches Interstitial and ground water samples were obtained by digging a hole in the beach, placing a closed sampling container in the hole, allowing the hole to fill with water, and opening the sampling container. The cap of the container was then replaced before the container and sample were withdrawn. Fig. 3-18 shows a three-dimensional plot of the concentration of selected aromatics in samples of ground water obtained from AMC-1, AMC-3, and AMC-17. Almost no aromatics were found in these samples. Table 3-11 lists the concentrations found in interstitial water samples and in surf samples obtained at EPA-4 and EPA-5 on March 27, 1978. The chromatograms of the samples from the interstitial water and the surf were quite similar at EPA-4. The chromatograms from inter- stitial and surf water samples from EPA-5 showed some differences (Fig. 3-34), but the presence of oil was evident. The finding of petroleum hydrocarbons in interstitial water at the EPA sample sites contrasts with the absence of oil aromatics in ground water samples analyzed by UNO-CBS. This discrepancy may be explained by differences in sample locations, sample size, or detection limits of analytical instrumentation, but is believed to result from differences in the types of water sampled. The EPA samples were taken within 30 meters of the shoreward limit of the surf zone and represe 'nted inter- stitial water at that location. The UNO-CBS samples were obtained in areas higher on the beach and probably represented an input from ground water from natural aquifers. 74 0 a rD En w 0 0 (n 0 cn ft (D 0 (D F" 0) PRISTANE (D rD 0 PHYTANE tl rD 00 x 0 t4 rt 0 0 I Z cn (D 0) ;@PRISTAI is 15 Figure 3-33. Gas chromatogram of a hexane extract of seawater from Station 9, 2 m. See legend, Fig. 3-28. (NOAA-NAF) LL 6.33 8.95 9.55 0 0) OQ > (D v m 17.34 @o ?o 0 22. 152..s 3c 23.47 m 0 925.13 ct rt 26. @5 21- > " 0 -30 28.50 2..51 Z En 29"' %-., 0 W. 88 [email protected] 3..83 A9 3 31ql rt M rD 34.51 35.14 35.22 3-3 7 rt ft 37. 13 31. @7 39-2 64 ft 40.83 4B.88 rt (D *P. 79 > 42.79 4 19 3. 19 44.2Z .26 4s' .5..2 .39 4 bA.W A 47-39 7..3 4e A 8,32 4i. 67 49.27 49 co rD ;:92H 26 5 17,34 6:3 74 9 @5- @3 2-3. @7 2 '[email protected] 3 3 3v '2 4 lp 2 [email protected] 43 _19 .26 k4 4 @bA '39' 4e4 Be "e 8,32 48 *67 .9 ,g Analysis of Oil in Water Taken from Beach Surf One subsurface water sample was collected from a calm surf west of the mouth of l'Aber Benoit (EPA-3, see Fig. 3-1). This sample contained an exceptionally high concentration of oil, 42 mg/l (42 ppm). The water itself had a brown coloration believed to be the result of oil droplets dispersed in the water. The calmness of the surf and the absence of visible surface mousse indicated that entrainment of mousse into the water column was not occurring at the time of sample collection. One could speculate that the extensive use of dispersants in offshore areas resulted in this finely dispersed oil. Table 3-11. Oil in surf water and beach ground water' Date n-C17/ n-C,8/ Station Description collected Conc(ppm) pristane phytane NOAA-16 Reference mousse 26 Mar 78 - 3.3 2.3 EPA-3 Subsurface water 31 Mar 78 42.0 0.4 0.3 from surf zone EPA-4 Locquirec, inter- 27 Apr 78 0.3 3.0 > 1.8 stitial water EPA-4 Locquirec, surf 27 Apr 78 0.9 2.4 1.7 water EPA-4 Locquirec, tide 6 Apr 78 0.2 3.3 - EPA-5 St. Efflam, in- 27 Apr 78 3.0 1.7 1.13 terstitial water EPA-5 St. Efflam, surf 17 Mar 78 0.6 1.8 0.9 'Analysis by EPA-ERLN A comparison of the chromatogram from this water sample with one obtained from the reference mousse sample collected on March 26, 1978, is shown in Fig. 3-35. The mousse sample shows a series of normal alkanes (n-alkanes) from n-Cs to n-Cso. In addition to the n-alkanes, peaks of 78 6L 4. 97 6.23 ?.as 7. 7 S.53 -C, 9 18.96 0 I..Ge @2.2. v 12-132 C+ I 1?R 94 L4. 39 15.34 16.23 18.-.3 16.4. 10-33 @8.9a 00 91) W .64 [email protected],, 22.31 r) 21.6 rr M 0 23.47 [email protected] 23. @2 0 m 24. 08 (fly r+ 25.77 0 26.83 @6_6_ 00 cIv 2Q.44 29. 29. 64 3Q. 34 30.93 30.74 31.97 [email protected] 32.9? 33.oo "62C'T co 33.94 pAyf..t 3%@41 34.99 g 35-71-", 0 i6.29 ;c rt [email protected],?4 m 0 [email protected] r+ 0 39.51 46.68 0 4) 41.41 h-C,1L 43.62 43, @4 h- CIL3 (b gal 44.87 m 0) .4.-- - (a " r+ (D 45.67 0 m 4-1 pv [email protected] > 4e. 05 !4 0 (D - Ca 53.31 11,46 -C., F9 [email protected] 7 29t [email protected]'97i1 A 3 12 5..53 h - the isoprenoids 2, 6, 10, 14-Tetramethylpentadecane (pristane) and 2, 61 10, 14-Tetramethylhexadecane (phytane) and other peaks representative of cycloalkanes are present. The chromatogram of the water sample taken at EPA-3 shows n-alkane peaks from n-C9 to n-C30, but smaller amounts of the lower molecular weight compounds are present. This probably occurs because the compounds of lower molecular weight evaporate and/or dis- solve more rapidly. Table 3-11 lists the n-C17/pristane and n-C18/phytane ratios from the reference mousse and water samples. These ratios give an indication of bacterial degradation of an oil sample, because bacteria degrade n- alkanes more rapidly than branched chain alkanes. As seen by comparing the ratios, the oil in the water sample has undergone more bacterial degradation than the oil in the mousse sample, indicating that the oil had not recently been added to the water column from mousse. The water sample also shows a large unresolved complex mixture which is the large area on the chromatogram underneath the resolved peaks. This unresolved portion of the oil is believed to consist of cycloalkane, naphtheno- aromatic, and aromatic hydrocarbons which are also more resistant to bacterial degradation than n-alkanes. Separation into aliphatic and aromatic components by liquid chromatography and subsequent analysis by gas chromatography indicated that the petroleum in the water sample was largely aliphatic material with only small amounts of aromatics present. Further analyses were done on the mousse and water sample extracts by GC-MS. Extracted ion current chromatograms at m/e 57, 71, 85 (typi- cal of alkanes) on both the mousse and the water extract were almost an exact trace of the total ion current chromatogram, showing as a pre- liminary finding that compounds other than hydrocarbons (surfactants, etc.) were not present as major resolved components. It is possible, however, that surfactant type molecules had already degraded, were present in the unresolved complex, or (depending upon the type of com- pound) were not extracted by the CH2Cl2. 3.4 Conclusions Examination of the data from these chemical analyses leads to several initial conclusions: (1) The importance of obtaining a non-environmentally exposed sample of the cargo oil cannot be overstated. In lieu of obtaining this material, a medium Arabian crude oil was used as a control. Evidence indicates that this.Arabian crude-is-very similar to the reference mousse collected at the site of the spill, adding credence to the use of this mousse as a reference standard. Analytical data indicate that the composition and distribution of components in the majority of mousse samples are remarkably similar. 80 (2) While minor differences in methodology existed among the three analytical laboratories analyzing samples, the close similarities of gas chromatograms obtained from samples of the intact reference mousse and from aliphatic and aromatic fractions of that mousse (separated by each laboratory) indicated a high degree of uniformity among the laborator- ies. (3) Continuous oil leakage from the grounded tanker resulted in different areas of coastline having varied lengths of exposure to oil. This fact, in combination with the diversity of environments contami- nated by the oil, has resulted in observations of uneven oil weathering in samples of sediments and water obtained along the Brittany coast. These variations in weathering have been observed on both the large (km) and small (m) scale. Differential weathering caused difficultiei in determining the length of exposure of oil.in the environment, but weath- ering processes were observed in extracts from environmental samples. Most notable were losses of lower molecular weight components, decreases in peak heights of n-alkanes relative to isoprenoids, reductions in resolved vs. unresolved material in aliphatic and aromatic fractions, and increases in oxygenated material. (4) Gas chromatograms of oil in water in I'Aber Wrac'h were simi- lar to the chromatogram of the reference mousse, indicating that the oil in water was in an emulsified state. This is most likely the result of the turbulence at the mouth of the estuary which forced surface mousse into the water column. Some of this emulsified mousse remained in the water and was detectable further up the estuary. The distribution of oil in water in the estuary was uniform vertically, indicating that the benthos were exposed to oil. Six weeks after the grounding, this estu- ary still contained elevated concentrations of oil in water, particu- larly at the upper end. Offshor e, high concentrations of oil in water were observed under patches of mousse or slick, but, interestingly, near-bottom water usual- ly contained even greater quantities of oil. This phenomenon may be related to the extensive use of dispersants and sinking.agents in off- shore waters. (5) The towed underwater fluorometer proved valuable in determin- ing relative oil-in-water concentrations and aided in selection of sites for more intensive sampling for laboratory analysis. Accurate field calibration of the towed fluorometer appears to remain an unsolved problem. (6) Biota samples were collected alive and while not obviously coated with oil, contained substantial contamination from the spilled oil. Chromatographic profiles of these samples closely resembled those of mousse samples. 81 (7) A careful analysis of mass spectrometric data indicates the presence of photo-oxidation products of dibenzothiophene and its alkyl homologs. There was no mass spectral evidence for photo-oxidation products of the naphthalenes and phenanthrenes. Further, it should be pointed out that evidence for the photo-oxidation of mousse is found in the complex unresolved chromatographic mixture (hump) in the methanol fractions in laboratory-photolyzed and environmental mousse samples. Volatile oxygenated molecules were tentatively identified in the head- space over a mousse sample, presumably produced by microbial metabolism within the mousse. (8) It is obvious that further studies of weathering, including bio- and photo-oxidation, of spilled oil are needed. These studies will require special sampling and analytical techniques since many of the primary oxidation products of petroleum aromatic compounds are labile. (9) Selected field sites should be resampled for hydrocarbon pre- sent in the water column, at the air-sea interface, in the biota, and in sediments at regular intervals for a period of time sufficient to trace the loss of oil from the environment and the subsequent accumulation of oil-related products. 3.5 Acknowledgments Many individuals and organizations contributed substantially to the contents of this chapter. The field chemistry program was supported by the Outer Continental Shelf Environmental Assessment Program (OCSEAP) of NOAA with funds derived from the Department of Interior Bureau of Land Management (BLM). Laboratory analyses were supported by an additional funding from BLM to NOAA. Ship time was provided by CNEXO-COB. The laboratories providing sample analysis are to be commended for their rapid response and the high quality of their work. In particular, the authors acknowledge the following: UNO-CBS. Dr. Edward B. Overton and Dr. Jayanti R. Patel, project managers; Doug Carlisle, Chris Raschke, MaryAnn Maberry, Robert Bowles, Dianne Adamkiewicz, Chuck Steele, Jo Ann McFall, Wayne Mascarella, for help in analyzing the samples; and Diane Trembley and Michelle Aguiluz for preparing the manuscript. EPA-ERLN. Mr. Curt Norwood of ERL-N, Mr. Randy Dimock, Mr. Robert Bowen, and Dr. Eva Hoffman of University of Rhode Island Graduate School of Oceanography, for their valued assistance in preparing and analyzing samples. 82 NOAA-NAF. Dr. William D. MacLeod (Manager), Donald W. Brown (Assistant Manager), Scott Ramos, Russell Dills, Don Dungan, Andrew Friedman, and Terry Scherman. NOAA-NWAFC. Robert C. Clark, Jr. ENDECO. William Williams, Dr. Ed Brainard, and Dr. William Kerfoot. Special thanks to Lt. John J. Kineman (NOAA Corps--OCSEAP) for providing field logistics and managing the towed fluorometer program, and to Dr. Michel Marchand of COB for providing laboratory space, equipment, and supplies and most importantly his understanding and friendship. 83 finally, sheltered rocky coasts (no. 8), sheltered tidal flats (no. 9), and estuarine marsh systems (no. 10) once again proved to be the most vulnerable of all coastal environments to oil spill damage. These observations provide encouragement and incentive to continue to apply ,the vulnerability index to areas in the U.S. threatened by potential oil spills. The Brittany coastline is particularly analogous to the coast- line of Maine and parts of southern Alaska. During the first week after the grounding, oil on tidal flat and beach surfaces lifted off the bottom with each incoming tide. However, one month later, a large patch of oil mixed with sediment was found on the tidal flat surface at Portsall, and many beaches retained oil during the flooding tide. In these cases, oil became sediment-bound and re- mained on the bottom. The physical mixing of oil with sediment to form a denser-than-water mixture provides a possible mechanism for causing oil from the Amoco Cadiz to sink to the bottom. Although the surfaces of the beaches and tidal flats at many places were free of oil, the interstitial ground water was contaminated. This may have been the cause of the extensive biological kills at certain areas. Unfortunately, the use of large pits and trenches as collection sites for the oil may increase the amount of ground water contamination. The use of bulldozers to plow heavily oiled gravel into the surf zone for cleansing by wave action is a sound practice, from a geological point of view because no sediment is removed from the beach. Removal of sediment from certain areas increased the rate of beach erosion. The unrestricted use of heavy machinery on the beach and low-tide terrace generally turned oil deeper into the sediments. Where possible, traffic should be limited to specified access routes. 84 4. INVESTIGATIONS OF BEACH PROCESSES Erich R. Gundlach* and Miles 0. Hayes* 4.1 Synopsis According to our best estimate, 64,000 tons of the Amoco Cadiz oil came ashore along 72 km of the shoreline of Brittany during the first few weeks of the spill. A prevailing westerly wind pushed the oil against west-facing headlands and into shoreline embayments as it moved east. A wind reversal in early April moved the oil in the opposite direction, contaminating previously untouched areas and transporting the oil as far southwest as Pointe du Raz (southwest of Brest). At the end of April, the total volume of oil onshore was reduced to 10,000 tons, but, by that time, 320 km of shoreline had been contaminated. Coastal processes and geomorphology played a major role in the dispersal and accumulation of the oil once it came onshore. For exam- ple, oil accumulated at the heads of crenulate bays [email protected] on tombolos (sand spits formed in the lee of offshore islands). Local sinks, such as scour pits around boulders, bar troughs (runnels), marsh pools, and joints and crevasses in rocks, tended to trap oil. The grounded mousse was either eroded away, or buried (up to 70 cm) under new sediment deposits, in response to the vagaries of the beach cycle. The details of oil erosion and burial were determined by resurveying 19 permanent beach profiles which were established during the first few days of the spill. Classification of the coastal environments of the Amoco Cadiz oil spill site according to our oil spill vulnerability index (scale of 1-10 on basis of potential oil spill damage) revealed a good correlation with earlier findings at the Metula and Urquiola oil spill sites. Exposed rocky coasts and wave-cut platforms (index nos. 1 and 2) were cleaned of extremely heavy doses of oil within a few days. Fine-grained sand beaches (no. 3) proved to be easily cleaned, whereas coarse-grained sand beaches (no. 4) showed considerable oil burial in areas where berms were developed. Exposed tidal flats @no. 5) underwent extensive biological damage and experienced potential long-term pollution of the interstitial ground water. (No. 6 was not represented.) Gravel beaches (no. 7) were deeply penetrated by the oil, creating special cleaning problems. And *Coastal Research Division, Dept. of Geology, U. of South Carolina, Columbia, SC 29208. 85 4.2 Introduction The objectives of the work discussed in this chapter are to de- scribe the influence of beach processes and sedimentation on the disper- sal, grounding, burial, and long-term fate of the Amoco Cadiz oil. These observations should provide valuable [email protected] -for coastal zone managers in the United States concerned with contingency planning for oil spills. This is true especially with regard'to understanding the vulnerability of different coastal environments to oil spill impacts, as well as to planning for the availability of equipment and manpower needed for shore protection and clean-up in the event of a major spill. In order to achieve these objectives, a program of field studies was begun on Sunday, March 19, 1978, three days after the initial wreck of the tanker. In total, 15 days were spent in the field during the first visit. The first field crew consisted of Miles 0. Hayes, Erich R. Gundlach, and R. Craig Shipp of the U. of South Carolina (under contract to the Research Planning Institute, Inc. (RPI) of Columbia, South Carolina, U.S.A.). Also, Laurent D'Ozouville of the Centre Oceano- logique de Bretagne (COB) participated in several days of field activ- ities. The site was revisited between April 20 and April 28, 1978, by Gundlach and Kenneth Finkelstein of RPI. Dr. D'Ozouville again partici- pated in each day of the field work. In the field, our work consisted of overflights and intensive ground inspection and surveys of the entire affected area. For purposes of description, the study area is divided into 11 sections. Descrip- tions of 19 permanent beach survey stations and 147 beach observation stations (Fig. 4-1) are given under the discussion of each of the 11 sections (below). Extensive photography was carried out, with approxi- mately 3,000 photographs being taken on the first trip and approximately 1,200 on the second. Thirty-five representative color photographs that illustrate the beach processes are given in Plates 4-1 through 4-33 (Appendix B). 86 Study Area A MC-8 AMC. ROSCOFF 9 13914 AMCO FRANCE -10 '21 . ... .. V 3 136-7 57 [email protected] 7 so 4 .8 12 30 29 86 AMC-13 119 AMC-14 V 114 113 118 113 123 124 @41 5 116 ,, 44 141 111 ]AS j [email protected] 3-5 0 AMC-12 117 WRECK SITE AM - 1 3 IVPLOUGUERNEAU ?38 39 r Vrac'h + .. ........ AMC-4 AMC 5 40 L Abe i4 LESNEVEN AMC_Y . AMC-2 LANNILIS 4- 2 %1 P *AMC-1 k 2 ORTSALL 31 85 + 83 L Aber Benoit 10 00 '08 PORSPODER 4 + 107 106 105 4 104 OIL COVERAGE 0 10km 103 19 MARCH 2 APRIL (HEAVY) 102 101 100 LE CONQUET 99 +++' + 20-28 APRIL 98 LIGHT HEAVY 97 Figure 4-1A. Locations of observation stations within western portion of the spill-affected area. Oil distribution for study periods one (March 19 to April 2) and two (April 20 to 28) are indicated. Study Area A SILLON DE TALBERT 6 + AMC-17 J* FRANCE + 4 jr 6 59 CP 67 63 62 4- + 68 126 a 131 57 + @69 j 129 71 70 127 7 ILE GRANDE.'.`. 60 13058 AMC-18 T 0 . 2 73 64,,, 4. 1* PERR S- 4-:-: 78 75 74 TREQUIER X 132-135 GUIREC 79 -80 [email protected] AMC-7 + ++ + LANNION 00 AMC-6 94 + + *AmC-16 00 ROSCOFF 14489 145 @4- AMC-15 147- 95 93 92 42) 41 0 ST.-MICHEL-EN-GREVE 1211 96 914' 9 AMC-19 13 5 It OIL COVERAGE 515 54 14 19 MARCH 2 APRIL (HEAVY) 9 0 10km 6 146 +++ + 20-28 APRIL LIGHT HEAVY Figure 4-1B. Observation stations within eastern portion of the spill- affected area., Oil distribution is indicated. 4.3 Acknowledgments The primary purpose of our work on the Amoco Cadiz spill was to provide assistance to the NOAA Spilled Oil Research team (SOR) in the areas of coastal processes and oil-sediment interaction. All of our work was performed under Contract No. 03-78-BOl-50 with the Environmental Research Laboratories (ERL) of NOAA. We wish to acknowledge the help and support of a number of SOR team personnel, including Wilmot Hess, Jerry Galt, David Kennedy, Bud Cross, and Peter Grose. We also gained from helpful discussions with Roy Hann of Texas A & M University. Living facilities, a stimulating scientific environment, and miscel- laneous logistical support were provided by CNEXO, Centre Oceanologique de Bretagne. Our field work was greatly facilitated at all times by the helpful and enthusiastic cooperation and support we received from Laurent D'Ozouville of COB. We anticipate that we will continue to work together and that'several joint publications related to the scientific aspects of the spill will result. 4.4 Geological Setting The entire area affected by the Amoco Cadiz oil spill lies within a geological province of France called the Massif Armoricain. This province is composed of a succession of zones of anticlinoria an 'd syn- clinoria that trend WNW and ESE. The surficial rocks of the synclinoria are usually Paleozoic metamorphic and sedimentary rocks, whereas the surface rocks of anticlinoria contain the oldest rocks in the area, Precambrian granites and metamorphic rocks (Debelmas, 1974). Localized massifs of granite intruded during the Hercynian orogeny (approximately 300 million years before present (B.P.) occur throughout the area. Two major zones of strike-slip faulting separate the central area (Domain Centre Armo,ricain) as a resu-1t.of relative westerly motion of the north shore region and easterly motion of the south shore region during the Hercynian (Fig. 4-2). In short, the geology of the Brittany peninsula is dominated by a suite of ancient igneous and metamorphic rocks that have been subject to a complex deformational history. The principal rock types along the oil spill site are granites, migmatitesi , and metamorphic rocks. Inasmuch as the last major tectonism took place 200 million years B.P., the area is tectonically stable at the present time. Howev er, the resistant nature of the rocks to erosion and adjustments of land-sea levels over the past few thousand-years has created a rugged coastline composed of numerous inshore islands and erosional cliffs separated by minor pocket beaches and ria2 systems. Everywhere, the primary shoreline trends are A composite rock, composed of igneous and metamorphic materials mixed together as a result of intensive igneous and metamorphic action. 2 Drowned river valley. 89 .......... ........ .... Dowme Dom ... W Dom- ............ am. rZ, 6 7 our$ Figure 4-2. Tectonic development of the Massif Armoricain (from Debel- mas, 1974); (1) zone of early activation, (2) major shear zones, (3) region of minor activation of Hercynian basement by pre-Cambrian granites, (4) Paleozoic cover sheets and regions of large synclines, (5) post-Stephanian fractures, (6) primary displacement, and (7) secondary displacement. 90 controlled by bedrock geology, with local trends being controlled by weathering and erosion along structural elements, such as faults, joints, and dikes. An example of this type of control along the coast near St. Malo is illustrated in Figure 4-3. 4.5 Coastal Processes Information on physical processes of the spill site is discussed by Galt and Grose in Chapter 2. This section is a brief discussion of those physical processes related directly to the beach dynamics and oil grounding. Cap FrOhel SMaio Dinan + ++++++" + + +++++++++ + + ++ + + ++++++ +++ + +++++++ ++++++++++ -9 1 .0 km Medez. -Aelaw. Figure 4-3. Orientation of vein field and jointing pattern of north- central Brittany (from Debelmas, 1974). Note control of structural elements on shoreline configuration. 91 Our field observations indicate that the spill site-is one of in- tense dynamic coastal processes. These conditions of high wave and tidal energy are generally conducive to rapid natural dispersion of the oil in exposed environments. However, the intricate topography of the shoreline allows for the sheltering of some environments from the waves and currents. 4.5.1 Winds and Waves Wind patterns played a major role in the dispersal of the Amoco Cadiz oil along the shoreline. Data collected by the French Meteorolog- ical Agency (presented in Fig. 4-4) show that the wind blew consistently from the west between March 18 and April 2, the time during.which all the oil was lost from the tanker. Winds commonly blew over 20 km/hr throughout this period. This consistent strong, westerly wind accounts for the uniform west-to-east dispersal of oil during late March. The wind changed on April 2 and blew consistently from the northeast until April 10, the date on which our records (from the French Meteorological Agency) end. Presumably, it was these and later northeast winds, aided by tidal currents, that dispersed the oil to the west and south during early April. Wind measurements that we made in the field between April 22 and 26 showed variable results, but easterly winds predominated. 00 I Apr 270Q---900 17 M 1800 20 Mar 25 Mar 5 Apr km/hr 0-11 6hr duration 11-22 12hr duration 22-33 33-43 44-58 10 Apr Figure 4-4. Wind pattern for March 17 to April 10, 1978,'from the French meteorological station 1 km north of l'Aber Wrac'h. The wind shift on April 2 caused the oiling of previously clean coastal areas south of the wreck site. 92 Large waves were observed at high tide throughout the first field study period (March 19 to April 3). Estimates of significant wave heights were consistently on the order of 1 to 1.5 m, with heights of 2 m being common during the first few days of the spill. On the other hand, waves observed during the second field visit.in late April were quite small, rarely exceeding 15 cm (at low tide). Unfortunately, no precise wave measurements (i.e., wave gauge recordings) were made during the spill to our knowledge. 4.5.2 -Tides and Tidal Currents The mean tidal range at Morlaix, which is centrally located in the spill site, is on the order of 6 to 7 m (Fig. 4-5). These large tides generated strong tidal currents throughout the spill site. The tida 'I current variability for the area is illustrated by the graphs in Figure 4-6. Our team measured (with floats) tidal currents of 1.4 m/sec in the channel north of Roscoff. From the air, streaming lineations of mousse and other floating debris around stationary objects (e.g., rocks and buoys) gave evidence,of the strong tidal currents. An exceptional spring tide of 8.1 m, which was caused by a combination of spring tides and wind set-up associated with an intense low pressure system, occurred on the weekend of March 25-26 (Fig. 4-7). This high tide greatly enhanced the pollution potential of the spill, in that areas not normal- ly reached by the sea were exposed to the oil. 4.6 Coastal Morphology The portion of the Brittany coast impacted by Amoco Cadiz oil is an irregular, low-lying ria3 coastline, which is composed mainly of small drownedriver valleys and protruding rocky headlands. The Brittany coast is one of the most widely recognized ria coasts in the world, as a result of the writings of de Martonne (1903; 1906) and Guilcher (1948; 1958). Guilcher's (1958) text on coastal morphology is liberally endow- ed with references to and illustrations of the Brittany coast. A more recent publication by Chass6 (1972) describes the morphology and sedi- ments of selected segments of the spill site in great detail. "Rias may be defined as river systems partly or wholly flooded by the sea. The degree of drowning depends on the magnitude of the movement of base-level and on the altitude of the source of the rivers. The subaerial origin of rias is demonstrated by the occasional existence of incised meander as on the Aulne at Landevennec in the Rade de Brest." (Guilcher, 1958, p. 153) 93 30' 80 30' 70 30' 60 30' 5a 30' 4o 30' 30 30' 20 30' 10 30' 0' 30' 10 30' 20 30' 30 Waterford Cardigan lspwich,:L 520 __V -520 Cork `[email protected] Milf Maldon ord Swansea New port LONDRES Y", Cardiff Bristol @30' 30 OD 0 h rn 5 M E Minehead Douvres stende 51 Soutl 51o ampton Ot [email protected]' -z" Dunkerque Carnbeik Bridport [email protected] whaven Calais 2m I I 11 .1 Bou ogne Padstow PlYrr outh' 7 h 4 30' Scite [email protected]_ 50o 10 Dieppe Fdcarnp 11-4 Havre her ur b- Rouen 30' ko % bl\ 11 Honfleur Port en Bessin cl 0 istreham 490 49'@ 0 ARIS 16 Granville Paimpol Avranches 30 Brest Morlaix o S -Maio 30' St-Brieuc 48"@ Dcuarnenez--- CO-TIDAL AND Concarneau Lorient o Vannes RANGE LINES CO-TIDAL LINES 30' 30 M TIDAL RANGE LINES St-Plazaire io 30' 8* 30' 70 30' 6' 30' 5o 30' 4 30, Y Longitude 2' Ouest lo 30' OG 30' jo Longitude 20 Est Figure 4.5. Tidal range lines for the English Channel (from French St P Hydrographic Service Pub. 551). Tidal range increases, going from 6 m at Brest to over 9 m at Paimpol. 04-02 2/48 '* 5a, of 00 07-04 22-10 @)qj herbour herbDu r iul 30 --23-12 21- 2 33-1 Z2412 -3' 32 24j2_ -- Paimpoll Pairn I PO S -Malo S -Maio res Morlaix so Brest Morlaix 0 euc SI-Brieuc t-Bri 'Inu. Dcuarnenez 'Dcuarnenez Concarneau L;oncarneau Lorient Lorient V" ,1.061 @1-33 -0-10 \% ".'4 '. n u 6 %1W h h 10 rbour Ao fill 14-11 15-06 Z. \? 17- 15 07 -11 14- to-- I -L75. .14-'12 10 09-01 07-03 nu 1-05 PaWnpo 11 o6 Paimpoill [email protected] S - at S -Maio Brest [email protected] Bres Morlaox so Morlaix nut I-Brieuc St-Brieuc 49- D uarnenez Dc lAarnenez C D oncarneau Concarneau 9, Lorient ALM '1__1 9. Lorient Figure 4-6. Currents (m/sec) for the English Channel north of Brittany (from French Hydrographic Service Pub. 551). (A) 6 hours before high tide at Cherbourg; (B) 4 hours before; (C) 2 hours before; and (D) during high tide at Cherbourg. 8- 4 2- is 20 22 24 6 28 30 MARCH 1978 Figure 4-7. Tide curve for Morlaix from March 17 to May 2 E (from French Hydrographic Ser- > vice Pub. 785). Spring tides W 4- during March 25 to 28, coupled with an intense low-pressure storm, spread oil very high 2 4 6 8 10 1 1"2 1161 APRIL along the shoreline. ,(B I keS D, Ail* 2 is 22 24 26 28 30 2 APRIL MAY 95 Depositional beaches are rare on the Brittany coast. Where present, they consist of sheltered pocket beaches, crenulate bays4 (Plate 4-20), and tomboloss (Plate 4-21). In some embayments, broad tidal flats (mostly fine-sand) are exposed at low tide. Salt marshes are small compared with those of most coastlines with tidal ranges of this magni- tude. Occasional dune areas are located near the mouths of the small streams. The dominant aspect of the area is one of shoreline erosion, with bedrock composition and structure controlling shoreline orientations. Rock scarps flank the seaward portions of all the islands and headlands. Beach sediments are generally thin and overlie eroded marsh clays and other eroded material. From Portsall east, all morphological indicators (spit orientation, crenulate bays, etc.) show a dominant.longshore sedi- ment transport direction from west to east, which agrees with the direc- tion of transport of the oil during the first two weeks after the spill. The shoreline in the region of Brest and the Baie de Douarnenez, however, is more complex, showing no general trend of sediment transport direc- tion. Takin g the impacted area as a whole, some regional morphological trends are apparent: (1) The shoreline in the large embayments of the Rade de Brest and Baie de Douarnenez are flanked by high cliffs with narrow intertidal zones. Coastline orientations are controlled by major structural elements, such as regional faults (e.g., the south shoreline of Baie de Douarnenez). (2) Granite plutons which form massive headlands predominate along the northwest and northern shores. Minor structural elements such as .minor faults and joints control local shoreline orientations. The western sides of those headlands, which usually have wide intertid- al wave-cut platforms, have suffered more erosion than the eastern sides, which have steeper intertidal areas. (3) Intertidal areas increase in width from west to east, as a result of the increasing tidal range (Fig. 4-5). The wider tidal flats to the east appear to contain a greater abundance of sediments than those to the west. 4 A crenulate bay is an asymmetrical semicircular bay carved by re- .fracting waves that has a shape resembling a fish hook. Sediment is normally transported up the shank of the hook away from the barb. A tombolo is a sand or gravel spit which connects an offshore island to the mainland or to another island. "In the [email protected] archipelago in [email protected], certain islets are connected twice a day (at low tide) to the larger islands and are called Breton 'ledenez' ('extension of the island')" (Guilcher, 1958, p. 90). 96 The closest analog to this coastline in the United States is the northern half of the coast of Maine, which bears many similarities. The most notable comparisons are the bedrock and coastal topography (massive granite plutonic headlands separated by drowned river valleys), as well as similar wave and tidal conditions. 4.7 Coastal Sediments Beach and intertidal sediments of the spill site show a wide range of size, sorting, and composition. House-sized granite boulders occur at retreating headlands and along some arcuate beaches (see examples in Plates 4-16 and 4-22). Intermediate-sized, well-rounded cobbles (20 to 40 cm in diameter) make up some beaches exposed to high wave action (Plate 4-27). In more sheltered areas, gravel beach ridges similar to those of New England and Alaska have accumulated (Plate 4-14 and 4-15). In places, moderately sorted gravel accumulations occur as a high tide rim around intertidal sand flats (Plate 4-13). Thin gravel veneers overlie clay and peat substrates on some of the erosional beaches (Plate 4-33). Sand also occurs under a variety of conditions. Steep, cuspate coarse-sand beaches occur in some of the more exposed pocket beach areas (e.g., Plate 4-12). Sheltered pocket beaches usually contain flat, fine- grairfed sand beaches (Plate 4-26). The finest sands are found in the coastal dunes that occur at several localities between Portsall and Roscoff (Plate 4-23). A 'wide variety of sediment types may occur within a small geo- graphic area because of the complexity of the nearshore and coastal morphology. For example, note the variation in grain size of the sedi- ments in the vicinity of the tombolo illustrated in Plate 4-21. After the spill, dead organisms became a part of the transported sediment. At St. Cava, dead cockles were transported along with quartz pebbles and accumulated in rows at the toe of the beachface (Plate 4-25). Swash lines of dead razor clams and heart urchins were accumulated along the beach at St. [email protected] on April 2 (Plate 4-7). Muddy sediments are rare in the spill site, presumably because of the high wave and current energy conditions that prevail. Some of the rias (in Brittany, the ria is often called an aber, Guilcher, 1958, p. 154) contain muddy flats in their upper reaches, and the salt marshes usually contain muddy sediments. Chass4 (1972, p. 3) made the following comment about the sediment variability of the spill site (translated by Jacqueline Michel): "Brittany's shoreline offers a great diversity of headlands, bays, and rias., Present-day sediments are a complex mixture of sand of Tertiary age and aeolian silts, fluvia pebbles, and more 97 or less relict sand of Quaternar3, age (both Tyrrhenian and Flan- drien). But all along this submerging coast of rias and incised marine gulfs (Morbihan, Bay of Douarnenez, Rade de Brest, Aber Wrac'h, Bay of Morlaix, etc.), only one sediment type is poorly represented, the aeolian quartz dune sands between 200 and 400 microns, which corresponds to the most mobile grain size." Chass6 presented detailed maps of the sediment distribution in several of the areas where oil accumulation was heaviest. These maps will provide a useful base for follow-up studies. 4.8 Methods of Study The study of a major oil spill requires techniques, amenable to rapid implementation, that provide for maximum information gained with the least amount of field time expended. Large geographic areas have to be classified and sampled rapidly. In order to achieve this goal, we applied a modified version of the zonal method to the Amoco Cadiz oil spill site. 4.8.1 The Zonal Method The zonal method was developed by Hayes and associates (first described by Hayes et al., 1973) in order to determine the geomorphic variation of large sections of coast. It has been applied in several areas of the world, including the southeast coast of Alaska (Hayes et al., 1976b) and during studies of the Metula, Urguiola, and Jakob Maersk oil 'spills (Gundlach and Hayes, 978). A modified form of the zonal method has been used to determine the vulnerability of coastal environments to oil spills in several parts of Alaska under the sponsor- ship of NOAA's OCSEAP program. In a study of Lower Cook Inlet (for the State of Alaska), a total of 1216 km of coast was classified within 21 days by a team of three persons (Hayes et al., 1976a). A similar ap- proach was taken during our study of the Amoco Cadiz oil spill. 4.8.2 Flights Extensive aerial photography and tape descriptions were carried out during the following flights over the Amoco Cadiz spill site: (1) March 21--Wreck site to Roscoff. (2) March 30--Mont St. Michel to Roscoff. (3) April 3--Portsall to St. [email protected] (4) April 20--Pointe du Raz.to Portsall. (5) April 28--Pointe du Raz to Roscoff. These flights were taken for purposes of visual inspection of oil distribution along the shoreline, observation of oil transport and dispersal processes, and for inter'reting shoreline morphology and p sedimentation patterns. 98 4.8.3 Beach Stations A total of 166 beach stations was visited (locations in Fig. 4-1). Stations of two types were established, F-stations (plain numbers) and AMC-stations (numbers preceded by AMC). A brief description of each station is presented under each section heading. At the 147 F-stations, the site was visually inspected, photographs were taken, and observa- tions were recorded on tape. Work at the 19 AMC-stations included the following: (a) A topographic profile of the beach (at low tide) was measured. The profile is measured by the horizon-leveling technique of Emery (1961). As the profile is measured, notations are made concerning all relevant changes of the beach, including the nature and occurrence of the oil. Permanent stakes were established to mark the location of the profile. Six of the profiles were resurveyed twice during the first visit and one was resurveyed three times. All of these stations will be re- visited to repeat the surveys. (b) Three equally spaced sediment samples were collected. These were taken for the purpose of characterizing the beach with respect to its oil penetration and burial. These samples have been analyzed for textural characteristics (mean grain size, sorting, etc.) in the laboratory and they are discussed below; 53 sediment samples were collected on.the first trip. (c) Trenches were dug to determine the distribution of buried oil. Each trench was sketched and photographed in detail. (d) A sketch was drawn to show the general coastal geomorphology and the-surficial oil distribution. Several examples are given in discussions of the different shoreline sections. (e) A number of photographs were taken of all aspects of the beach. 4.8.4 Oil Distribution Distribution Maps The occurrence of oil along the shoreline was mapped both from the air and from the ground during both visits to the site. The oil distri- bution for the two time intervals is shown on Figures 1A and 1B. Calculation of Tonnage During study o f each AMC-station, the thickness of mousse was measured at a maximum interval of 5 m along the profile line. The per- cent oil coverage of the surface was also noted. The assumed volume of 99 mousse present is the measured thickness multiplied by the overall length of the beach as measured on 1:25,000 scale topographic maps.- Where oil did not cover the entire area, appropriate reductions were made. Buried oil was noted and photographed. An estimate of the amount buried was made by calculating the volume of oiled sediment and assuming that 10% of this volume was mousse. The 10% value was derived from analyses by Anne Blount (of our group) on over 50 oiled sediment samples from the Metula site. All mousse was assumed to be 60% water. The specific gravity of the oil, used to calculate total metric tonnage, was assumed to be 0.85 gm/cc. In order to derive the total amount of oil on the beaches in the spill area, an average oil content per km of shoreline was calculated from our 19 AMC-stations. The amount of similarly oiled.coastline was then measured on 1:25,000 scale topographic maps and multiplied by this value. This was done for both study periods (March 19 to April 2 and [email protected] to 28) to determine the net change. 4.8.5 Observations of Biological ITpact Because of the emergency situation surrounding the spill as well as the opportunity to contribute to a basic understanding of oil spill impacts, a special effort was made by our group to observe the bio- logical effects of the spill, although this was not our primary objec- tive. Notes were taken on tape, and numerous photographs were taken wherever biological damage was observed. Some of our general observa- tions are presented in our descriptions of the individual coastal sec- tions for the record. For a complete discussion of the investigations of biological processes, refer to Chapter 5. 4.8.6 Chemical Samples Samples of mousse and oiled ground water were collected at selected localities for chemical analyses (during both trips). These samples were passed on to the SOR team or to John L. Laseter of the University of New Orleans' Center for Bio-Orgaaic studies for processing. 4.8.7 Observations of Cleanup Activities Wherever cleanup was observed in progress, photographs were taken (see Plates 4-4, 4-5, 4-8, 4-9, 4-11, and 4-19) and conclusions were recorded on tape in order to note in detail the success or failure of each method. Cleanup was studied in depth by Roy Hann and his asso- ciates from Texas A & M University (see Chapter 6). Reference is made to the cleanup effort in this chapter where either (a) the cleanup technique affected the normal beach processes, or (b) an understanding of beach processes would aid in the cleanup exercise. 100 4.9 Field Observations of Oil Impact For purposes of description, the impacted coastline is divided into 11 separate sections (located on'Figures 4-8 and 4-9). The individual sections will be discussed in sequence from west to east. Observations made during both of the field visits are included. 4.9.1 Section I--Pte. du Raz to Penfoul Section I is located to the south-southeast of the Amoco Cadiz wreck site (Fig. 4-10). The coastline generally consists of [email protected] rocky headlands with small pocket beaches. Cliffs over 40 m in height are common toward the south. Although the tidal range is 5.5-6.0 m, little more of the coast is actually exposed during low tide than at high tide because of the steeply-dropping offshore bathymetry. This is in distinct contrast to the many wide tidal flat systems that lie to the north and northeast. Oil impact, March 17-April 2 During the first two weeks after the grounding, little or no oil was transported to this area. Winds were blowing strongly from the west and southwest. A survey of station F-82 and stations further north on March 31 revealed only a few small tar blotches (of unknown origin) on the rocks. A sample was taken for chemical analysis. Oil impact, April 20-28 A distinct change in oil distribution was observed during our second study period. During the aerial survey on April 20, heavy oil accumulations were observed as far south as Pointe du Raz, 126 km (77 miles) from the wreck site. Very heavy oil accumulations were observed at station F-104 (Fig. 4-10) and northward. A photograph of station F- 82 that was taken on the following day is presented in Figure 4-11. Stations F-97 to F-103 were lightly to,moderately oiled. Table 4-1 sum- marizes oil impact for this area. A photograph of a newly oiled area near Argpnton (F-109) is presented in Figure 4-12. As observed during the aerial survey on April 20, moderate to heavy oil accumulations were found at (a) beaches near Camaret, (b) in small pocket coves along the cliffs from Douarnenez to Pointe du Raz, and (c) at the beach at Pointe du Raz. Lighter accumulations were observed at Ile de Sein, located offshore of Pointe du Raz. The last two areas mark the most southerly extension of major contamination from the Amoco Cadiz. The heavy oiling of this section during April was a result of the offshore winds of March 28-31 followed by strong south/southwest winds during April 2-10. The wind at this time blew ashore much of the oil that was still at sea, therby causing the oiling of an additional 91 m of shoreline. 101 ILE DE BATZ [email protected]@A. '8 _A11-9 9. 01SCOFF A MC-10 m AMC 13 AMC-14 e4 S AMC-12 WRECK SITE M *PLOUGUERNEAU L'Aber Vrac'h AMC.4 kMC-3 AMC_2 AMC-5 LANNILIS LESNEVEN MC-1 LL P TSA L Abe, senoa PORSPODER POINTE DE CORSEN 1 0 10km U: CONQUET SECTIONS 1-Y1 Figure 4-8. Locations of Sections I to VI of the spill study area. X1 SILLON DE TALBERT AMC-17 x ILE G E AM PERROS- GUIREC TREQUIER TREBEURDEN AMC-7 VIL - LANNION 'AMC-6 LOCOU OSCOFF IREC Am'C.16 15 r' ST.-MICHEL-EN-GREVE AIC 19 0 10km ' " LIORIPODER SECTIONS U-XI .T Figure 4-9. Locations of Sections VII to XI of the spill study area. 102 ILE D'OLIESSA NT + "Irt 82 SECTION I + 109 ++. F 108 16'7 PORSPODER 106 105 =j) 104 103 BREST + 102 101 100 99 LE CONQUET C N.E X,O 98 97 ta + CAMARET MOUSSE SWASHES OBSERVEb 20 APRIL CLEAN ON 28 APRIL 777. 77. DOIJARNENEZ 0 10 k m -+ POINT DU RAZ Figure 4-10. Locations of observation stations in Section I, Pointe du Raz to Penfoul. No oil was in this area during the first two weeks of the spill. The pattern between heavy lines indicates oil distribution as 'observed during second study period (April 20 to 28). Pluses indicate moderate to heavy oiling of upper intertidal rocks and/or beachface; circles indicate moderate oiling of lowtide terrace; dot pattern indicates light oiling on rocks or beachface. Mousse swashes and heavy oiling were observed south of F-97 during aerial survey of April 20. By second flight on April 28 the oil was no longer present. 103 Figure 4-11. Heavily oiled rocks at station F-82 on April 21. Three weeks before, the area was observed in detail and found to be clean except for some small tar blotches. Re-oiling occurred as a result of a wind shift during the early part of April. @= Pit Figure 4-12. Heavily oiled pocket cover near Argenton (F-109) on April 28. Mousse also covers the surface of the water. 104 Table 4-1. Field observations of oil distribution at stations of Section 1, Pointe de St. Mathieu to Penfoul. Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact F-97 21 Apr Pointe de St. Mathieu . A few oil blotches along the swash A rocky platform with a small line - mostly small; a few 5 cm tar cobble beach. or mousse balls; rocks spotted with small amount of mousse. Area seemed biologically productive - much algae and limpets. F-98 21 Apr Gr%eve de Porsliogan Light oil at all swash lines. Algae A small cove/pocket, medium productive. Many worm burrows. grained sandy beach surround- Some oil burial of 5 cm - very mi .nor. ed by a rocky area. F-99 21 Apr Le Conquet - Beach Very light oil swash lines with more A small sandy pocket beach oil along the upper swash line and on surrounded by a rocky area. some of the rocky areas. F-100 21 Apr Pointe de Kermorvan Small amounts of mousse in water. A boulder beach. Heavy oiling of boulder beach on the north side of the lighthouse. F-101 21 Apr Le Conquet-Harbor (East side) Free of oil - boom at harbor entrance. Large sand flat exposed at low tide. F-102 21 Apr Plage de Blancs-Sablons Oil streaks over the entire intertidal Wide sandy (fine to medium- portion of the beach. Heavy mousse on grained) beach. Rocks at rocks in NE corner. Oil pools of m6usse both ends of beach. located on beach - some mousse in water. F-103 21 Apr Port Illian Oil streaked swash lines. Small mousse Small pocket beach protected patches left on the beach surface. by a jutting rocky headland. Fine-sand on beachface; some gravel on the lower portions. F-104 21 Apr Rubian Heavily oiled rocks; moderately oiled Coarse-sand beach with many coarse-sand beach. Oil pools 5 cm cobbles especially on lower thick in some areas and a coating on beach. the boulders at the base of the sand. Oil buried due to clean-up activity. F-105 21 Apr I'Aber Ildut - Estuary Oiled seaweed along the edge of the Narrow entrance with 2 booms channel. Oil sheen on both sides of present. the booms. F-106 21 Apr Melon - South side Entire intertidal zone heavily oiled. Small rocky beach with little Very heavily oiled rocks and mousse wave activity. in water. F-107 21 Apr Melon - North (harbor) Very heavily oiled beach. Rocks in A u-shaped harbor with an is- northern pocket very heavily oiled. land offshore to protect it. Active clean-up effort. Fine-sand beach. F-108 21 Apr Porspoder Rocks heavily oiled; 10-15 cm thick Fine-grained pocket beach oil on the beach: Mousse in water. with rocky headlands on both Clean-up operation in effect. sides. F-109 21 Apr Argenton Thin oil layer covers most of the Small cove, very well pro- beach. Heavy oil along edge of the tected fine-grained beach. pocket cove. Small amount of mousse in water. F-110 21 Apr Penfoul Heavy oiling on both sides of the Small fine-grained estuary. estuary; slicks seen over entire area. Clean-up operation in effect. F-82 31 Mar- Pointe de Landunvez -minor tar blotches (3-5 cm) on rocks, 21. Apr- High energy boulder beach on -heavily oiled rocks and boulders with wave-cut granite platform. some mousse in the water. 105 Table 4-2. Field observations of oil distribution at stations of Section II, St. Sampson to Les Dunes-East. Station Number Date(s) Visited Loc.ation and Type of Environment Description of Oil Impact F-81 31 Mar St. Sampson No oil. Boulder beach on wave-cut rock platform; high energy (I m waves present). F-1 19 Mar- Tre"Mazan -light mousse in water and along shore. 20 Mar- Boulder beach on wave-cut -very heavy oiling, oncoming waves 2 rock platform (close to m in height. wreck site). 31 Mar- -only very small scattered blotches of oil remain. 21 Apr- -heavily reoiled. AMC-1 (F-2) 20 Mar (F)- Portsall -very heavily oiled beach and tidal 22 Mar- Sheltered embayment, with flat; extensive skimming operation. 31 Mar- seawalls, small coarse- -still heavily oiled beach; minor grained beaches and fine- oiling on tidal flat. sand tidal flat. 21 Apr- -still heavily oiled beach; some sta- tionary oil on tidal flat; heavy oil- ing of rocks and seaweed along eastern shore; little oil on surface of water; extensive shoreline clean-up activity. AMC-2 22 Mar Portsall Heavily oiled beach; clean tidal flat. 31 Mar Angular, gravel beach; fine- 21 Apr sand tidal flat. AMC-3 (F-3) 20 Mar (F)- Portsall-North -heavily oiled beach, upper low-tide 22 Mar- Cobbles against a seawall a- terrace and rocks. 31 Mar- long the upper beachface; 21 Apr- coarse-sand on rest of beach- -moderate coverage of beachface with face; fine-sand low-tide thick (10 cm) mousse swashes; still terrace with some algae cov- ered rocks. heavily oiled rocks. F-84 31 Mar- Prat Leac'h-Kerras -very heavily oiled beachface; exten- 0.5 km sand pocket beach with sive clean-up operation. 21 Apr- eroding sedimentary backshore. -clean beach but new erosion scarp formed along the backshore. AMC-4 (F-4) 23 Mar- Les Dunes-West -very heavily oiled beachface and Three pocket, sand beaches upper tidal flat along eastern shore. within a large sheltered cove. Very large amphipod kill. Center A fine -sand tidal flat is ex- beach has moderate oiling; western posed at low tide; each beach beach clean. 31 Mar- has a clay base with eroding -heavily oiled upper beachface. 21 Apr- clay scarp along the backshore. -heavy oil swashes; front-end loaders removing oil and sand from beachface. AMC-5 (F-5) 20 Mar M- Les Dunes-East -moderate oil streaks on eastern side; Large deposition area with a fewer on western side. 23 Mar- grass stabilized dune field. -very heavy oil covering the entire A flat profile fine-sand beach on east side and on upper beach beach/low-tide terrace abuts of west side. 26 Mar- an eroding dune scarp. -very heavy oil on east side of stream; large amount of oil buried on west side. 31 Mar- -clean east side; very heavy oil on west side. 22 Apr- -very light oil swashes; some oil burial on both sides of stream. 106 During our last aerial survey on April 28, no oil was observed at Camaret and Pointe du Raz. Nor was oil seen on the surface of the water. However, north of station F-97, the oil appeared the same as before. A large cleanup operation also remained active in the area. Although we did not observe any oil on the beaches south of-Pointe de St. Mathieu (F-97) from the air, it should be noted that in all likelihood a ground survey would find light swashes of small mousse balls on these beaches. These features were very common throughout the study area, and were even found on the beach next to the CNEXO lab at Brest. Summary Section I proved to be a surprise to us.: (1) It had become very heavily oiled more than three,weeks after the spill, illustrating the ability of massive quantities of oil still to be transported several weeks after initial spillage. (2) Thick mousse concentrations were observed on the water's surface along the cliffs between Douarnenez and Pointe du Raz, a full month after the beginning of the spill. (3) Heavy oil accumulations extended southward to Pointe du Raz, a total of 126 km (77 miles) from the wreck site. 4.9.2 Section II--St. Sampson to Les Dunes-East This section, shown on the maps of Figures 4-13 and 4-14, is located in the vicinity of the wreck site; it was the first area to be oiled (Table 4-2). South of station F-1 (Fig. 4-13), the shoreline consists of an eroding wave-cut platform in granite that has a shoreward scarp 3 to 15 m in height. The intertidal platform is covered with large boulders. Portsall Harbor Week of March 20. Stations AMC-1 and AMC-2 (Fig. 4-13) are both located in Portsall Harbor, a sheltered, relatively low-energy environ- ment. Figure 4-15 is a detailed map of the Portsall area which shows the oil distribution at first impact and at one*month later. During the first week after the wreck, a large oil mass was located in the harbor. The profile at station AMC-1, which crosses the embayment (Fig. 4-15), was measured at that time (see field sketch in Fig. 4-16). As the profile was surveyed, measurements of oil thickness and estimates of percentage of oil cover were made as often as warranted. A plot of these measurements along the surveyed topographic profile-is presented in Figure 4-17. Sediment grain size data for the A, B, and C samples are presented in Table 4-3. All the sediments are poorly sorted, with 107 SECTION II WRECK SITE Lj,/ 0 _a' A a Am 4 AMC-5 LES DUNES 84 AMC-3 AMC-2 FIRST STUDY PERIOD PORTSALL AMC- i Area Exposed at Low Tide KERSAINT 0 2km Figure 4-13. Locations of observation stations in Section II, the Port- sall, area, during the first study period (March 19 to April 2). Heavy oil accumulations are indicated by the dark-stippled pattern. SECTION II WRECK SITE 0- 3" Am 4 AMC-5 LES DUNES 84 + 4- r -1 AMC -3 4- SECOND STUDY PERIOD AmC-2 PORTSALL N AMC-] Area Exposed of Low Tide + + + KERSAINT 0 2km + Figure 4-14. Oil distribution for Section II for second study session, April 20 to 28. Heavy and light oil coverage are indicated by the plus and light-dot patterns, respectively. 108 Table 4-3. Grain size data for AMC stations of Section II. All statistics are calculated according to Folk (1968). Sample Graphic Mean Size Classl Skewness Standard Deviation2 AMC-1A 0.691 CS 0.101 1.594 (PS) AMC-1B 0.952 CS 0.197 1.413 (PS) AMC-1C 1.954 MS -0.134 1.350 (PS) AMC-2A -4.0 P ( PS) AMC-2B 1.492 MS [email protected] 1.119 (PS) AMC-2C no sample AMC-3A -7.0 C (PS) AMC-3B 2.415 FS -0.571 1.243 (PS) AMC-3C 0.123 CS -0.042 1.316 (PS) AMC-4A 0.503 CS -0.263 1.024 (PS) AMC-4B 0.847 CS -0.003 0.561 (MWS) AMC-4C 2.082 FS -0.383 0.978 (MS) AMC-5A 1.047 MS -0.001 0.759 (MS) AMC-5B 2.415 FS -0.207 0.593 (MWS) AMC-5C 2.026 FS -0.134 0.757 (MS) ISize Class 2Sorting C = cobbles MWS = moderately well sorted P = pebbles MS = moderately sorted CS = coarse sand PS = poorly sorted MS = medium sand FS = fine sand 109 Ilk AMC-3 PORTSALL Figure 4-15. Detailed location map for the Portsall area. Oil dis- AMC-2 tribution,, as observed during our o7 "C-1 two study sessions, is indicated. 2LL cross I WEEK AFTER SPILL ER 0 250 M the coarsest sediment occurring near shore. Our calculations indicate that 50.2 metric tons of oil were present in the AMC-1 area during the first survey (after subtracting 60% for water content of the mousse)6. This relatively low value is attributed to the lack of very thick accumulations on the tidal flat surface. Clean-up activities initially consisted of the deployment of several tank trucks with skimmers, Their ability to remove the floating oil was restricted to periods of high tide, since the harbor is dry at low tide (see Plate 4-9, 4-19, and 6-4). During the survey of AMC-1, we counted several dozen polychaetes on the surface of the flat in a generally moribund condition. However, several live polychaetes and small shrimp were found in the sediment, even though the interstital water was seriously contaminated with oil. By walking around on the flat, we found five different species of dead fish (Plate 5-20). Each had oil-blackened gill structures. 6 Inasmuch as the oil was usually distributed in distinct masses, these oil volume calculations are an attempt to include the whole mass in a given area. This particular calculation includes all the oil in the eastern and southeastern portion of Portsall Harbor (Fig. 4-15), as determined from ground surveys and aerial photography. 110 PORTSALL tank trucks 00 44 V1 % Figure 4-16. Sketch of station AMC-1 (Portsall) on March 22. Sediment sampling sites A, B, and C are indicated. 60 80 20 40 95 75 0 % OiL COVERAGE 0 4 4 THICKNESS: MM 10 ROCKS C ED Cc CD OIL CONTAMINATED INTERSTITIAL WATER LLJ m LLJ 0'.00 410. 00 8,0.00 1'20. 00 1160.00 2bo. 00 24o.00 2'80. 00 '320. 00 DISTRNCE (M) Figure 4-17. Topographic beach profile and oil coverage for station AMC-1 on March 22. The thickness of the shaded line is roughly pro- portional to the oil thickness. Letters A, B, and C indicate sediment sampling sites. Table 4-4. Change in estimated oil tonnage at AMC stations in Section IL Oil increased at station AMC-2 because of oiling of the upper beach face and seawalls during spring tides. Station Number Date Oil Present Date Oil Present % Change (metric tons) (metric tons) AMC-1 22 Mar 50.2 22 Apr 7.3 -85.46 AMC-2 22 Mar 1.8 22 Apr 2.4 +33.00 AMC-3 22 Mar 44.6 22 Apr 5.5 -87.70 AMC-4 23 Mar 284.1 31 Mar 36.9 -87.01 22 Apr 2.5 -93.22 AMC-5 23 Mar 1146.9 22 Apr 2.5 -99.80 AMC- 2 22 MAR 78 ramp 60 - 90% Coverage TIDAL FLAT (SAND) oi I/seawe swas es [email protected] 190160 1901 70 10-10 % OIL COVERAGE I MM AVERAGE OIL THICKNESS Q Z:C LE @1- LU C3 _J C) 0.00 20.00 40.00 6b. oo Bb. oo DISTRNCE (M) Figure 4-18. Sketch and topographic beach profile for station AMC-2 on March 22. A thin coating of oil was present on the beach at this time. After the spring tide conditions of March 25-28, the coating of oil extended 1.5 m up the seawall. 112 Station AMC-2 is located a short distance west of AMC-1 (Fig. 4-15). It was surveyed because it represented a coarse gravel environ- ment with little wave activity. A sketch and profile of the area on March 22 is presented in Figure 4-18. Grain size data for the beachface area are,presented in Table 4-3. During the March 22 survey, a thin coating of oil covered the lower beachface. The total volume present at that time was 1.8 tons. Week of March 29. The beachface at AMC-1 was 100% covered by a thin layer of oil on March 29. Oil coverage of the intertidal flat area was reduced to 10%-15%. At station AMC-2, the beachface and lower portion of the seawall had become completely covered with oil. From observations, it became obvious that the majority of the oil was lifted off the tidal flat and transported shoreward to the beaches and seawalls as the tide rose. By March 29, the clean-up operation had changed from a skimming operation to cleaning the oiled walls with high-pressure hoses (Plate 6-14). Week of April 20. Over a month after the grounding of the Amoco Cadiz, we resurveyed our stations at Portsall. The beachface5 of both stations (AMC-1 and AMC-2) were still covered with a 2 mm layer of oil. At AMC-2, an apparently new layer of mousse, brown in appearance, had been deposited at the last high tide swash line. The surface of the tidal flat had a few light oil sheens and a few large patches (approxi- mately 30 m in diameter) of sediment-bound oil. The algal-covered rocks on the western side of the harbor were 80%-90% covered by brown mousse. Our calculations showed 7.3 metric tons present at AMC-1 (85% decrease) and 2.4 metric tons at AMC-2 (33% increase; see Table 4-4). It appears that while most of the incoming oil was lifted off the tidal flat with each incoming tide (observed on March 22), a small . percentage of it eventually became sediment-bound and stabilized on the bottom of the flat. These patches are not subject to resuspension and would be expected to degrade slowly by physical action. A diagram of this process is presented in Figure 4-19. The interstitial water of the tidal flat remained oil-contaminated. Cleanup activity still continued on April 22. At least 30 men were raking up oil'and seaweed, which was placed in buckets and carted away. Summary. Because of the initially large quantity of oil within the Portsall area, much of the surface of the tidal flat was covered. As time progressed and the tidal range increased, much of this oil was lifted and transported shoreward. However, some oil did become sedi- ment-bound and remained on the bottom. By April 22, the nearshore areas, especially the rocks with algae on.the west side of the harbor, were still covered with oil. In addition, some oiled sediment patches remained in the center of the tidal flat. All interstitial water was still oil-contaminated. 113 FIRST WEEK AFTER SPILL LOW TIDE HIGGH TIDE (NEAP) gmunded mms lifted -w ONE MONTH AFTER SPILL LOW TIDE HIGH TIDE (NEAP) ittle sp-9 il n -W h' t' ba-d ine MD Figure 4-19. Observation of oil response at Portsall. During the first week after the spill, most of the oil lifted off the surface of the sand flat with every incoming tide. During our second survey mousse mixed with the sediment remained on the sand flat and beachface even as the tide flooded. Only a light oil sheen was visible on the surface of the water. Station AMC-3 AMC-3 is located in a semi-sheltered area north of Portsall, some- what closer to the wreck than stations AMC-1 and AMC-2 (Fig. 4-13). The station consists of a small beach composed of mixed sand and cobbles, which has a low-tide terrace with some algal-covered rocks. Grain size data are presented in Table 4-3. A sketch of the site during maximum coverage by oil (on March 31) is shown in Figure 4-20. There were approximately 44.6 metric tons of oil on this beach at that time. The leaching of ground water from the beach removed 10%-15% of the total surface cover. Also, in the area where the stream crossed the beach at low tide (Fig. 4-20), all oil was removed. This observation suggests that a similar technique (i.e., using flowing water to wash oil into collecting basins or troughs) could be used to clean similar beaches with a great deal of efficiency. The major difference between our site surveys on March 22 and 31 at AMC-3 was the progressively higher oiling of the beach and seawall as a result of the spring tides of March 25 through 28. The amount of oil present did not significantly vary between the two visits. On March 31, there was an extensive cleanup operation taking place in which mousse and seaweed debris were raked, placed in buckets, and then dumped into a large metal container. A screen separated the newly added seaweed from a pool of oil below. Soldiers forced the oil through the screen by stomping. 114 AMC-3 31 MAR 78 LOW 'TIDE wall TERRACE X" i% I re am 100 85 90 0 60 % OIL COVER C) 1 3 10 stream 10 THICKNESS: mm M CD A cc @'> 0 8 LLJ - C 1-3, WL LLJ I 0'.00 210. 00 4b. 00 60.00 80.00 100.00 DISTANCE (M) Figure 4-20. Topographic profile and oil coverage at station AMC-3 on March 31. High spring tides of March 25-28 were responsible for spreading oil up the wall behind the beach. Sediment sampling sites. A, B, and C are indicated. By April 21, most of the oil was gone from the area. An apparently new mousse swash line formed along the upper beachface. There were also some light oil streaks across the beach. The cobble area was still as heavily oiled as before. We calculated that 5.5 metric tons of oil were present on April 21, a reduction of 88% (Table 4-4). In terms of biological damage, the most impressive observation was C the presence of thousands of dead amphipods along the uppermost portion of the beach (by the steps). In contrast, new grass was found growing 115 in the same area. On the low-tide terrace, new worm burrows were common. Oiled but empty cockle shells were also found, indicating the possible death by oiling-of these organisms. No burial of oil was observed on this particular beach, partly because of the occurrence of a hard peat-like layer from a relict marsh a short distance below the surface of most of the upper and middle @beachface. Station F-84 F-84 (Prat Leac'h-Kerros; Fig. 4-13) was an area that was also ,exposed to an extremely large quantity of oil.. The entire intertidal zone was heavily oiled. An extensive cleanup program utilizing many trucks and tractors was,carried out during the first few weeks after the spill. By April 21, the beach was 95% clean. However, some erosion of ,the scarp behind the beach had occurred, possibly as a result of removal of beach sediments during the cleanup operation. Station AMC-4 This station lies within a northwesterly'-facing cove which contains three arcuate beaches (Fig. 4-21A). Because of the strong prevailing westerly winds during the first weeks of the spill (a) the west side of the cove escaped oiling completely; (b) the central beach was oiled only ,on the eastern side; and (c) the remaining beach (AMC-4) was heavily ,inundated. The station at AMC-4 consists of a coarse-s'and beachface grading into a fine-sand low-tide terrace. Dune sands overlying a clay base occur behind the beach. A sketch of the area on March 31 is pre- sented in Figure 4-21B. The survey of March 23 is illustrated in Figure '4-22. Between March 23 and 31, the quantity of oil on the beach had @decreased from 284 to 37 metric tons (see Table 4-4). During that same time interval, a total of 14.5 m3 of sand was eroded from each meter of beach width (see Fig. 4-23). The cause of this extensive erosion was either the storm waves during the week of March 22 or the cleanup method applied, or possibly, a combination of the two. A small amount of recovery had already occurred when the profile was measured on March 31, in that some oil burial had taken place at the mid-beachface area and a small neap berm had formed. The high spring tides of late March permitted the waves to wash oil high up onto the dune scarp (see sketch of March 31 in Fig. 4-21). Thousands of dead amphipods, identified by Jeff Hyland as Talitrus saltator (an upper intertidal species), littered the dune scarp (see Plate 4-24). By April 21, deposition of 475 M3 of sediment had occurred along the central port *ion of the beach (Fig. 4-23B). Oil was buried 20 to 25 cm by new sand. The beach appeared quite clean with only a light mousse swash along the last high tide swash line. Oil volume further 116 ILE CARN LOW TIDE LINE N WRECK SITE AEAVILY OILED. WIND ROCKS AMC-4 NO OIL OIL Figure 4-21A. Detailed location map vAk>/ and oil coverage for station AMC-4 during initial oiling. PORSGUEN METERS C) 3 iled rocks BS FS 1000's of killed arnphipo berm seaweed -water line N 5 cm mous e s P clay 0 t ro P CD M c:j 100 % OIL COVERAGE C) :z [email protected] 50 2 3 30 THICKNESS: MM Cr_ U-jo _j cz LLJ - 12 cm burial;;@'_ WL c3 m 0.00 20.00 '4b. 00 6'0.00 8b. oo 1100.00 1 @0. 00 [)ISTRNCE (M) Figu. re 4-21B. Topographic profile and oil coverage at station AMC-4 on WR \K S, 1E CID March 31. During the previous week, the shoreline had eroded signifi- cantly back, removing most of the oil from the lower beachface and exposing a relict red clay surface. Thousands of dead amphipods (Talitrus saltator) littered the dune scarp (Plate 4-27). 117 95 100, 95 %OIL COVERAGE 15, 80 100 W CD1 2 CD 1_1 01 [email protected]_ 20 THICKNESS: JAM A no burial a: UJCD _J9 RMC4 UJ LO 1150 1 23 3 78 C) 0 00 4b. oo t3b. oo I @0. 00 1'60. 00 2bo. oo DISTRNCE W Figure 4-22. Beach profile and oil coverage at station AMC-4 on March 23. Oil coverage was more extensive on this date than during our second survey on March 31 (compare with Figure 4-21). decreased to only 2.5 tons. There remained an ongoing cleanup operation in which oil on the beach was shoveled into buckets and then carted away by trucks and front-end loaders. Unfortunately, the use of heavy machi- nery on the beach may have succeeded in working oil deeper into the sediments. Station AMC-5 The beach at AMC-5 (Fig. 4-13) consists of a wide fine- to medium- sand (Table 4-3) beach and low-tide terrace backed by an eroding dune scarp. The dunes, which are stabilized by short grasses, extend back from the beach over 1 km. Figure 4-24 shows a field sketch of the site on March 26. We surveyed this station five times in order to monitor the short- term variability of the deposited oil. In addition, the beach was observed from mid-flood to mid-ebb tides on March 23, during which time all oil was lifted off the beach and transported further shoreward (because of the increasing water level). More importantly, most of the oil was transported into the channel behind the foredunes. As the tide receded, oil was again deposited on the beach. Oil was not transported alongshore because of the refraction of the incoming waves around the offshore mass of rocks. This system is diagramatically illustrated in Figure 4-25. We call this a tombolo effect. The role of the tombolo 80 R,% A no bu effect in causing locali,zed oil deposition was observed in several other localities. 118 Co A 0 AMC-A EROSION 23 MAR 78 31 MAR 78 DEPOSITION Cr [email protected] Ui 0 0.00 2b. 00 40.00 6b. oo 8b. oo lbO.00 1'20. 00 DISTRNCE (M) CD B [email protected]_ EROSION C! Z=r DEPOSITION APR 78 CrO _j LU 0-.131 MAR 78 0.00 20.00 40.00 60.00 80.00 100.00 120.00 DISTRNCE (M) Figure 4-23. Comparison of beach profiles for site AMC-4 on (A) March 23 and March 31, and (B) March 31 and April 22. The erosion along the upper beachface was caused by storm waves, the applied cleanup operation, or a combination of both. The deposition of new sand on the beach by April 22 caused deep (25 cm) oil burial. By March 31, a great quantity of oil was still present, but it had shifted across to the eastern side of the stream. All that remained on the western side were some very light oil swashes. In contrast, the eastern side contained oil layers 3 to 5 cm thick. A cleanup operation utilizing a front-end loader and dumptruck was underway (Plates 4-8 and 6-31). Oil and sand were being actively removed. During the spring tides of a few days earlier, the grassy areas along the stream channel behind the foredunes became heavily oiled. This area was being cleaned by bucket and shovel. 119 bow of FS dunes @,,Amoco Cadiz BS stream t C LOW-TIDE oil TERRACE swa rocks oil no FINE-SAN'D 100 % OIL COVERAGE 100 100 clean 10 dunes 5 C3 C3 20- THICKNESS: MM MC3 C3 a: 4cm A B U-J, C 12 cm burial C3 CD '[email protected] 0 @O 2 @OO 0 @Lwj 0 0 @0, 0, . @,OrO 8 @,O, r, n n @n .00 100.00 120.00 140.00 DISTRNCE (II-) Figure 4-24. Topographic profile and oil coverage at station AMC-5 on March 26. Oil was trapped in this area because of the tombolo effect (see Fig. 4-25). By April 22, the entire area appeared quite clean. Only light (probably recent) oil swashes remained. There was oil burial on both sides of the stream, but even this was relatively minor. We estimate that 2.5 tons of oil remained across the entire area. It appears that the use of the front-end loader was effective since the oil was thickly pooled in a single area. The removal of sand from this area will pro- bably not prove to be a serious problem because the wide dune area 4 @,- A B behind the beach should provide adequate sand to replenish the beach. 120 LOW TIDE .N T! c7 rocks water line HIGH TIDE ater line --------- - clunes -00V.0 .3 3 WAVE FRONTS Figure 4-25. Illustration of local geomorphic control of oil deposition' at station AMC-5. Oil became trapped because of the refraction of waves around the offshore rocks (a tombolo effect). During flood tide, all oil was lifted off the surface of the fine-sand beach and transported back into the marsh channel causing serious oiling. As the tide receded, oil was redeposited on the beachface. This cycle continued until the oil was removed by front-end loader (Plates 4-8 and 6-31). 121 SECTION III SECTION III no -4 4 :4 4 + '113 + T13 2 112 7 41 CIV 41 ....... [email protected] CAYA ST C` .,c .C I, N hill 4 34? 34 IT RES PRE U ILE STE. it 1IT1111 7, MARGUERITE no 37 36 oil 373 9 36 38 39 39 First Study Period SECOND STUDY PERIOD 40 40 --------------- 6 6 5 . P.qu SPABU mod. oil L A& I 'Abe, Benoit L 0 3k. 3k. 31 85 31 .Figure 4-26. Detailed location map Figure 4-27. Oil distribution along of Section III for stations be- Section III during our second stu- tween Les Dunes (East) and the dy period, April 20-28. Heavy and Plouguerneau peninsula (F-6 to F- light oil coverage are indicated 142). Initial oil concentrations by the plus and light-dot patterns, are indicated by the dark-.stippled respectively. Oiled marshes are pattern. indicated by a circled M. Summary The stations surveyed in Section II illustrated a wide variety of morphological controls of oil deposition and oil-sediment interaction, including the following: (1) The rocky environment south of Tr6mazan illustrated how rapidly oil can be removed under heavy wave action. Also, the re-oiling of these beaches three weeks later demonstrated the persistence of oil in the offshore waters during a massive oil spill. 122 (2) In the low-energy environment of the Portsall region, the upper levels of the beaches showed an increase of oiling through time. The behavior of oil on the tidal flats also changed through time, with the oil being lifted off the flats at high tide during the first few days, but later being partly sediment-bound to the bottom. (3) Station AMC-4, which is located in a large, sheltered cove, illus- trated how winds and coastal morphology can interact to cause heavy oiling on one side of the embayment, while opposite beaches remain clean. (4) AMC-4 also illustrated a definite beach erosion phase during the early stages of oil inundation. The erosion period was followed by sand deposition, which caused deep burial of some of the oil. (5) An illustration of the tombolo effect was provided by station AMC- 5, where an oil mass became compartmentalized behind offshore rocks, thus escaping alongshore transport. With respect to biological impacts, stations AMC-3 and AMC-4 had total kills of the indigenous amphipod populations. All stations con- tained heavily oiled algae. Dead fish and polychaetes were found on the tidal flat at Portsall. 4.9.3 Section III--Les Dunes East to Plouguerneau Peninsula Section III includes two north-south trending bedrock headlands as well as two major rias, l'Aber Benoit and l'Aber Wrac'h (Figs. 4-26 and 4-27). Each ria was an important aquaculture area before the oil spill. The headlands have 1 to 2 km wide intertidal flats on the northwesterly- facing exposures. These flats were probably formed as a result of erosion by major storm waves approaching from the northwest. Oil impact was extremely heavy along most of the westerly-facing areas because of their position relative to the wreck site (for description of individual stations, see Table 4-5). 123 Table 4-5. Field observations of oil distribution at stations of Section III, Les Dunes-East to the Plouguerneau peninsula. Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact F-6 20 Mar Ker-Vigorn Oil boom deployed - no oil at this Mouth of estuary. time - to become heavily oiled start- ing 21 March. F-31 26 Mar Grand Moulin Very light sheen. Western arm of I'Aber Benoit; tidal flat (mud) with rocks along shore. F-32 26 Mar Le Carpont Heavily oiled. Ann of I'Aber Benoit; tidal flat. F-85 31 Mar Treglonou Heavily oiled along shoreline. Large fine-grained tidal flats. F-40 26 Mar I'Aber Benoit Boom in place. Entrance to estuary. F-39 26 Mar Prat Allan Heavily oiled with a large oil pool Arcuate cobble beach. offshore. F-38 26 Mar- Presqu'ile Ste. Margarite -heavily oiled. 22 Apr- Coarse-sand pocket beach. -oil burial 70 cm and 35 cm with light swashes on surfaces. F-37 26 Mar Presqu'ile Ste. Margarite Heavily oiled. Coarse-sand pocket beach. AMC-11 26 Mar- les Dunes de Ste. Margarite -heavily oiled; extensive clean-up op- Medium-sand pocket beach backed eration with manpower, front-end load- by eroding dune scarp. ers, and backhoes. 1 Apr- -heavily oiled upper berm; front-end loader removing oiled sand. 22 Apr- -95% cleaned; some minor burial. F-33 26 Mar South of Penn Enez Heavily oiled. Sand pocket beach. F-34 26 Mar Penn Enez 60 m - heavily oiled. Boulders in front of small scarp beach. F-35 26 Mar Penn Enez (East side) Moderate oiling. Small pocket beach. F-36 26 Mar Poullac Harbor No oil. Wide exposed sand flat. 124 Table 4-5 (continued) Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact AMC-12 27 Mar- St. Cava -very heavy oiling of beach and upper Coarse-sand beach with a me- tidal flat; large kill of cockles. 1 Apr- dium-sand, very broad, low- -still heavily oiled beach; manual tide terrace lying between two rocky headlands. clean-up operation. 23 Apr- -beachface is oil-stained, but without s',jnificant accumulations; oil mixed 17 cm into the low-tide terrace by the heavy trucks; interstitial water still contaminated. F-41 20 Mar- Kervenny Brag -very light swashes. 27 Mar- Sand tidal flat abutting a -very heavily oiled; extensive clean-up seawall and rocks located in operation underway. a large pocket cove. 23 Apr- -95% clean, but the tidal flat has been churned up by heavy equipment. F-7 20 Mar- Lilia Rocks with algae along a chan- -oil streaks on the water; very light nel at tow tide. oil on shore. 1 Apr- -light oil sheen on water; very light oil on shore. 23 Apr- -definite mousse zone on algae and rocks. F-111 23 Apr Kerjegu Marsh in upper portion of embayment - Small embayment off of a large lightly oiled; otherwise clean. sand flat. F-112 23 Apr Kelerdut Clean tidal flat, but badly oiled shore- Large tidal flat embayment pro- line; oiled gravel is piled up to be tected by island and rocks removed. offshore. F-113 23 Apr Porz Guen All of the rocks heavily oiled, espe- Rocky headland with small cially the northern corner of the harbor/embayment. harbor; beachface is lightly oiled; clean-up operation previously removed much of the oiled algae. F-42 27 Mar Porz Guen Lightly oiled. Angular boulder beach. F-114 23 Apr Porz Guen No oil. Sandy pocket beach pro- tected by rocky headlands on the north and west. 125 Oil Impact, l'Aber Benoit and l'Aber Wrac'h No oil was visible in l'Aber Benoit during our first visit on March 20. A number of booms had been laid in preparation for the oil. However, during our flight on the next day, oil could definitely be seen entering the estuary through the booms (Plate 4-30). Later, oil cover- age became very heavy along the edge of the estuary and on some surfaces of the fine-grained tidal flats. L'Aber Benoit has been selected for special study by CNEXO-COB. Dr. Laurent D'Ozouville had prepared a preliminary report on their work, and has given us permission to include his results in this report. His report follows (translated by Jacqueline Michel): Impact of Pollution by the Amoco Cadiz in I'Aber Benoit L'Aber Benoit can be divided into three geomorphological units: Part A: from the entrance of l'Aber Benoit to Loc Majan (Fig. 4-28A), a zone characterized by well-developed sand or pebble beaches. Part B: from Loc Majan to Treglonou (Fig. 4-28B), a narrower zone with midflats flanking a rocky shore. Part C: from the port of Treglonou to the head of l'Aber Benoit (Fig. 4-28C); this zone is dominated by marsh grasses which become more prevalent toward the head of the bay. Oil Distribution in l'Aber Benoit (1.1) Geographical distribution Several aerial surveys (fixed wing and helicopter) allowed us to map the oiled zones in l'Aber Benoit. It appears that: -past the port of Treglonou toward the head of l'Aber, little pollution occurs. -between the entrance of l'Aber Benoit and the port of Treglonou, the orientation of the shoreline with regard to the winds and currents explains the geographical distribution of the oil and helps us understand why certain areas are less polluted. 126 ............................................................................... HHT ................................ . .................................. HT MUD ......................... LT A. SCHEMATIC CROSS SECTION AT LOC MAJAN ........... . ....................... iHHT OILED ZONE ........................................ . : HT ............................ LT MUD B. SCHEMATIC CROSS SECTION BETWEEN LOC MAJAN AND TREGLONOU ....................................................................................... HHT HT VEGETATION IT C. SCHEMATIC CROSS SECTION AT TREGLONOU Figure 4-28. Oil distribution within l'Aber Benoit: (A) at Loc Majan, (B) Loc Majan to Treglonou, and (C) Treglonou to the head of the Aber (from preliminary report by D'Ozouville). (1.2) Distribution with depth: variable depending on the nature of the substrate. -sand: penetration occurs but it is hard to say just how deep. -mud: surficial, yet animal burrows permit some oil to penetrate. -marsh grass: oil sits on the surface of the @CN ... ........ ...... MUD ,S [email protected]]T.ON BETWEEN . ........ . .............. ... .. . ............ - __ - - - . . ................. ....... VE E AN G 1A ON SAND grasses which are covered only during high tides. 127 A. LOW TIDE :HHT . ............................................................................... [email protected] .41 VEGETATION MUD Ll B. HIGH TIDE ........................................................................................ JHHT OIL :HT VEGETATION MUD LT A Figure 4-29. Oil reaction within I'Aber Benoit estuary during low and high tides. Much of the oil was resuspended off the flat as the tide flooded'. (From a preliminary report by D'Ozouville.) (1.3) Study of the pollution along transverse cross- sections (Fig. 4-29). Oil which has accumulated in depressions in the rocks and grasses flows downhill on the surface of the mud during ebb tide. During flood tides., some oil is resuspended and slowly removed. It should be noted that a simple disturbance in the water causes the resuspension of bottom-held oil. It appears that the oil held in these depressi ons will have a long residence time in l'Aber Benoit. 128 Recommendation for Cleanup Generally, it is necessary to prevent mechanical equipment on the polluted areas, and even more so on the marsh grasses. (2.1) *Upriver of the port of Treglonou--this area is covered by marsh grass and was not affected much by the oil. It is best not to attempt to clean this area except locally where the oil has accumulated in gaps in the marsh grass. (2.2) Between Loc Majan and the port of Treglonou--this zone is primarily rocky, and is best cleaned by water spray and recovery of the oiled water. (2.3) From Loc Majan to the mouth of l'Aber Benoit-- cleanup consists of manual methods for the beaches and water spray for the rocks. (2.4) Aerial observations showed that there were places of preferential oil accumulation (indicated on Figure 4-26). At these sites, with well-placed booms, oil could be accumulated rapidly and removed by pumps much more easily. After these reflections, it seems to us indispensabe to continue the study of I'Aber Benoit. Through further study, we will gain a better understanding of the mechanisms of estuarine oil pollution and recovery. Also, the economics of the oyster fisheries make it essential to follow the de-con- tamination of the estuary in space and time. Oil Impact on the Coast between.F-36 and F-39 The area under disc 'ussion is the headland that separates l'Aber Benoit from l'Aber Wrac'h. Initially, oil accumulation was very heavy on the western side of the headland, while the eastern side (F-36) escaped oiling entirely (Fig. 4-26). As a result of the strong westerly winds, large oil pools formed at each indenture in the coastline. Station F-38 was particularly interesting in that it contained several thick layers of buried oi 1 (Fig. 4-30), the deepest of which was 70 cm. This was the deepest burial observed during our study. A detailed study was conducted at station AMC-11, a medium- to fine- sand pocket beach. A sketch of the area is provided in Figure 4-31. Sed- iment.data are presented in Table 4-6. This area was selected because of its location with respect to the wreck site, the.large amounts of oil present in the area, and because it had an ongoing cleanup operation. 129 % V1119 4V P"!, Figure 4-30. At station F-38 on April 22, we found buried oil, the deepest of which was 70 cm (not pictured). This was the deepest burial we observed at any site during the entire study. The sediment is composed of well sorted coarse-sand. On March 26, oil covered the entire beachface and much of the fine- sand low-tide terrace (Fig. 4-31). We estimate that 175 tons of oil were present at that time (Table 4-6). In an attempt to remove the oil, a long trench was dug with a backhoe to collect the oil on the incoming and receding tides. The trench system was necessary to operate the suction hoses from tank trucks and honeywagons. 'Sand was taken from the base of the dune scarp to form a barrier to direct oil runoff into the trough. Upon our return on April 1, some erosion had occurred at the upper beach face, possibly in response to the previous sand removal. As is shown in Figure 4-32, approximately 3 m of beach was lost. The upper 25 m of beach remained heavily oiled, up to 1.5 cm thick in some areas. A newly formed neap berm buried oil 5 cm below the surface. The lower part of the beach was clean, more likely due to wave and tidal current action than to mechanical cleanup. The trench that had been dug earlier was filled in. Unfortunately, the sand filling the trench was heavily mixed with oil. This oil could be the source of the noticeable ground water contamination in the area, and, hence, could have a long-term impact on the biological productivity of the area. 130 fs h vily oiled rocks ea @i7 ,n B LOW-TIDE TERRACE "i" T_ M newly dug trench medium waterline f ine sand 100, M; 100 80 % OIL COVERAGE '0 _2 THICKNESS: mm 1 2 1 [email protected] @, ;@4 [email protected] Z 30 B 5 cm burial,' Cr 1 co 1 60.00 80.00 100.00 015TRNCE (M) Figure 4-31. Topographic profile and oil coverage at station AMC-11 on March 26. Heaviest oil accumulations occurred on the lower portion of the beach. When we returned to the site on April 22, we observed very little oil on the beachface. By our calculation, only one ton of oil remained on the whole beach (Table 4-6). Therefore, over 174 tons of oil was removed during the month following the spill. The upper beachface was extensively populated by amphipods, even in areas previously heavily oiled, indicating a rapid recovery by that organism. Cleanup activities had shifted from the beach to the still heavily oiled rocky areas on either side. Cleanup consisted of blasting the oiled cobbles Iwith water under high pressure. The process was successful, though it mixed oil into the cleaner sediments on the beach, but was very time consuming. On the southern side, volunteers were scooping oil from between the boulders by hand. 131 AMC-11 Figure 4-32. About 3 m of beach 26 MAR 78 erosion occurred at ANC-11 during the week after mechanical removal DEPOSITION of sand from the base of the dune 'EROSION Cc scarp. Deposition on the lower I APRIL 78 W, beachface caused oil to be buried _J9 5 cm below the surface. [email protected] 0.00 20.00 LAO. 00 60.00 80.00 DISTRNCE (M) Table 4-6A. Grain size data for stations AMC-11 and AMC-12 in Section III. Sample Graphic Mean Size Classl Skewness Standard Deviation2 AMC-11A 1.947 MS -0.116 0.536 (MWS) AMC-11B 2.124 FS -0.059 0.639 (MWS) AMC-11C 1.798 MS -0.117 0.690 (MWS) AMC-12A 0.533 CS 0.168 0.531 (MWS) AMC-12B 0.106 CS 0.201 1.993 (PS) AMC-12C 1.306 MS -0.125 0.689 (MWS) 1Size Class 2Sorting CS = coarse sand MWS = moderately well sorted MS = medium sand PS = poorly sorted FS = fine sand Table 4-6B. Change in oil quantity at stations AMC-11 and AMC-12. Station Number Date Oil Present Date Oil Present % Change (metric tons) (metric-tons) AMC-11 26 Mar 175.2 22 Apr 1.0 -09.40 AMC-12 27 Mar 357.7 23 Apr 6.3 -98.30 132 Oil Impact on the Coast between AMC-12 and F-42 This west-facing shoreline (Fig. 4-26) was exposed to predominant wave and wind approach during the early days of the spill. The area between stations AMC-12 and F-7 was impacted by major concentrations of oil, whereas the more northerly stations received lesss. Station AMC-12, which was studied in some detail, is a c oarse-to medium-sand beach abutting an eroding, low-lying dune field (see Table 4-5 for sediment data). Rocky headlands flank both sides of the beach. A sketch and topographic profile are presented in Figure 4-33. ries clean LOW- TIDE 17 TERRACE /ro ------------ ........... 35 100 1.00 30 % OIL COVERAGE W IQ .27 %A 10 THICKNESS: MM 0. 30 45 30 50 15cm Cr burial W _JM LLJ .I 10.00 20.00 410. 00 6b. 00 8b. 00 IbO. 00 1'20. 00 140-00 DISTANCE M Figure 4-33. Topographic profile and oil coverage at station AMC-12 on March 27. The thickness of the oil coverage line is proportional to actual oil thickness. Heaviest accumulations occurred on the low-tide terrace in a low-relief runnel beh ind a ridge. 133 On the date of our first survey (March 27), the beachface at AMC-12 was entirely coated with oil, as was much of the low-tide terrace. Oil was ponded 4 cm thick in a runnel landward of a low-relief ridge on the low-tide terrace. Our estimates indicate that 358 metric tons of oil were present on the beach on March 27 (see Table 4-6)7. A large number of dead cockles (Cerastoderma) had accumulated along the step of the high-tide beachface (avg. of 6/mz; see Plate 4-25). During our return visit on April 23, the beachface and low-tide terrace were cleared of massive quantities of oil; however, 70*/,, of the beach sediments still appeared oil stained. Some slight burial (6 cm) was observed. The hard gravel and clay base that underlies the beach inhibited much oil penetration. On the low-tide terrace,.oil was mixed 17 cm deep into the sand by the trucks used in the cleanup operation. Interstitial waters were contaminated to as far as 50 m seaward on the low-tide terrace. We estimate that 6.3 tons of oil remained on the beach on April 23. When we first viewed station F-41 (Kervenny Brag) on March 20, it contained only light oil swashes. By March 27, it was extremely heavily oiled. An extensive cleanup operation which began before March 27 continued past our visit of April 1. By April 23, the sand flat was 95% cleared of oil. Only the seawalls retained oil. Unfortunately, the tidal flat was badly churned up by the cleanup machinery. Some of the areas north of F-41 were moderately oiled (F-112 and F- 113 in particular), but most areas only received light oil. These areas appear to have escaped major oil damage because of the sheltering effect of offshore islands. Summary Section III provided a number of interesting observations with regard to oil deposition: (1) Oil booms across the mouth of l'Aber Benoit and l'Aber Wrac'h were ineffective in preventing pollution in those rias, which were badly damaged in places. (2) The maximum depth of oil burial observed in the study (70 cm) occurred at the coarse-sand beach at F-38. (3) There was noticeable erosion of the dune scarps at beaches where sand was removed by the cleanup operation. 7 This is a revised value from our preliminary field report, in which we reported 538 tons on this beach. 134 (4) The trenching technique observed at AMC-11, while effective for cleanup, probably increases the pollution of the interstitial water of the beach. (5) Oil deposition is closely controlled by local beach morphology, as was illustrated by oil accumulation in the runnel at AMC-12 (see Fig. 4-33). (6) In general, most of the stations in this section located on the exposed headlands were remarkably clean one month after the spill, especially considering the large volumes of oil that came ashore during the first few days of the spill. The rapid natural cleaning of these areas is probably a function of the high degree of ex- posure of the headlands to northwest winds and waves. The general erosional nature of the area is evidenced by (a) the overall re- treat of the shoreline (leaving behind a wide, wave-cut intertidal platform), and (b) the thin, non-depositional character of many of the beaches. 4.9.4 Section IV--Trouloc'h to Brignogan-Plage The coastline of Section IV is oriented northeast-southwest (Fig. 4-34). Much of the coastline consists of depositional dune areas with granitic bedrock outcrops. An exception to this general shoreline orientation is the Neiz Vran peninsula (AMC-13), which is oriented roughly north-south. Table 4-7 gives brief descriptions of the study sites, and Table 4-8 presents sediment and oiling data. Oil Impact Little of the oil spilled by the Amoco Cadiz impacted this coast- line. Oil impact during the first two eeks of the spill was generally restricted to those areas that are aligned in a north-south direction (e.g., stations F-44, AMC-13, F-48, and F-50; see Fig. 4-34). One month after the spill, all major oil accumulations were dis- persed. Only light oil swashes were visible at all stations. Sheltered rocky areas commonly were more heavily oiled than neighboring sand beaches. Station AMC-13 (Fig. 4-34) was studied in detail. It consists of a small medium- to fine-sand crenulate beach-oriented north-northeast/ south-southwest. Rocky headlands are located on both sides of the beach. Because of its orientation with respect to the wreck site, a large quantity of oil estimated at 248 metric tons (Table 4-8B) accu- mulated during the first two weeks after the spill. During our first site visit on March 26 , most of the beachface and upper low-tide ter- race was 100% oil covered. The topographic profile and oil coverage diagram are presented in Figure 4-35. Thick (30 cm) mixtures of mousse and algae accumulated at the upper portions of the beach and along the 135 Table 4-7. Field observations of oil distribution at stations of Section IV (Trouloc'h to Brignogan-Plage). Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact F-115 23 Apr Penn ar Stre"jou The beach contains some light oil Small sandy pocket beach fac- swashes; rocky areas are moderately ing north; sandy dunes backing oiled; some of the algae is coated the beach; tidal flat in front by a thick covering of mousse. of beach. F 116 23 Apr Corejou No oil on north side of jetty; lightly Neck of a peninsula,connects oiled cobbles on south side. an island offshore; embayments north and south. F-43 27 Mar- Mogueran -clean; no oil. 23 Apr- An embayment with a large tidal -some new oi.I has come onshore; very flat ([email protected] km) in front; rocky light, a mousse froth that:is on the on both sides with much rock debris on beach. upper portions of the beach and is mixed in with the algae, F-117 23 Apr la Secherie Lightly oiled along the swash lines as Large sandy beach with sand well as on some of the rocks, dunes backing it. F-44 27 Mar- Le Curnic -rocks on the jetty are lightly to Contains a jetty separating moderately oiled. 23 Apr- two sandy beaches; much rock -light oiling of rocks on both sides debris on the'beaches. of jetty; beaches clean except for light oil swash lines. F-118 23 Apr Lerret Marsh in the upper intertidal zone is Near the head of a large es- moderately oiled; light oil swashes tuary/tidal flat. on sand leading down from oiled seawall. F-119 23 Apr Tre'sse"ny Lightly oiled rocks and seaweed swash Middle of a large estuary/ line. tidal flat. AMC-13 27 Mar- Roc'h Quelennec -very heavily oiled beachface; oil Medium- to fine-sand beach 30 cm thick, mixed with algae along and tidal flat with rocky upper swash zone. 23 Apr- headlands on both sides; -surface 99% clean, but deep 38 cm large boulders on beachface. burial along upper beachface; also has oil contaminated interstitial water. F-45 27 Mar- Neiz Vran -no oil. 23 Apr- Mixed-sand and rock debris -upper intertidal algae and seaweed beach with large tidal flat lightly oiled. in front. F-46 27 Mar Boutrouille Very light oil swashes. Well-sorted granule beach F-120 23 Apr (near) Louc'h an Dreff Clean except for a few minor oiled Coarse-grained beach with a swash lines. fine-sand low-tide terrace. F-47 27 Mar (near) Keriouarn Lightly oiled rocks. Steep, mixed-sand and gran- ule beach. 136 Table 4-7 (continued) Station Number, Date(s) Visited Location and Type of Environment Description of Oil Impact AMC-14 27 Mar- Kerlouarn -5 m wide heavily oiled grasses. 23 Apr- Sheltered, grassed, embay- -a dirt road constructed over oiled ment used as a small harbor. swash. F-48 27 Mar- Carrec zu -light oil swashes. 23 Apr- Sandy beach with large dune -clean sand with light oil swashes. system; relict marsh outcrop- ping on beach - therefore, an erosional beach. F-49 27 Mar (near) Chapelle Pol Heavily oiled rocks. Sandy beach with large dune system; some rocks and rock debris scattered along beach. F-50 28 Mar- Lighthouse at Pointe de Beg Pol -heavy oiling on both rocks and beaches. 23 Apr- Rocky point sticking out --sand tinted brown, but now only light- with sandy beaches on both ly oiled; rocks also oiled lightly. sides. F-121 23 Apr Kervernen Sand is clean, but rocks are lightly Rocky beach with some sand to moderately covered with oil; some underneath. algae is clinging to rocks and sur- viving the oil coverage. F-122a 23 Apr Brignogan Plage Light oil swashes; light oil on algae; Large harbor tidal flat. some of the rocks are dark from light oil staining. SECTION TV 0 122 46 BRIGNOGAN -17 AMC-14 PLAGE 47 AMC 1 46 120 AI 19 ]is 100, KERLOUAN 44 117 LA SECHERIE GUISSENY 0 2 4Km "t43 Figure 4-34. Locations of stations in Section IV, from Trouloc'h to Brignogan-Plage. Initial oil depositon was generally limited to those areas trending perpendicular (north/south) to overall oil transport. Initial oil depositon is indicated by the dark-stippled pattern. Oil coverage during our second study period (April 20-28) was light in all areas (indicated by the light-dot pattern). 137 Table 4-8A. Grain size data for AMC stations 13 and 14 located in Section IV of the survey area. Sample Graphic Mean Size Classl Skewness Standard Deviation2 AMC-13A 1.824 MS 0.116 0.640 (MWS) AMC-13B 2.400 FS -0.409 0.948 (MS) AMC-13C 2.348 FS -0.367 1.016 (PS) AMC-14 1.468 MS -0.245 1.210 (PS) ISize Class 2Sorting MS = medium sand MWS = moderately well sorted FS = fine sand MS = moderately sorted PS = poorly sorted Table 4-8B. Estimated quantity of oil present during first and second surveys. Unfortunately, station AMC-14 was destroyed by road building and had to be discontinued. Station Number Date Oil Present Date -Oil Present % Change (metric tons) (metric tons) AMC-13 27 Mar 248.3 23 Apr 0.6 99.97 138 100 100 85 6 50 %OIL COVERAGE 85 0 0 1 1 2 4 2 THICKNESS: MM 4U C3 300 A C 13 1550 26 3 78 [email protected] Z: C3 ED=;_ ;:: I B CE no burial WL Llic, -Jm 0 C3 [email protected] 120.00 140.00 160.00 180.00 DISTANCE (M) Figure 4-35. Topographic profile and oil coverage at station AMC-13 on March 26. Thick oil and algae were found along the upper beach face. joint pattern of the rocks (see Plate 4-17). Around some of the large boulders on the beach, thick oil accumulations collected in the scour pits (see Plate 4-16). On our return visit on April 23, the beach had recovered remark- ably. The sand was clean with only recent, very light oil swashes. The rocks, previously dripping with oilo appeared only slightly blackened. According to a person living in the area, there was a cleanup operation during the first week in April. However, part of the visible recovery was due to the burial (38 cm maximum) of some of the oil by new sand. The comparison of our profiles (in Fig. 4-36) shows this deposition. The interstitial water of the low-tide terrace remained noticeably oil contaminated; however, castings of the worm Arenicola sp. were found in abundance. We have estimated that the oil remaining on the beach on April 23 was less than one metric ton. Altogether, an amazingly rapid recovery of the area is indicated, due to a combination of natural and man-engineered cleaning processes. Station AMC-14 is located in a small embayment populated by marsh grasses. On March 27, a 5-m-wide, 3-cm-deep band of mousse froth had been deposited on the grass. However, by April 23, a dirt road had been constructed over the oil, thereby destroying its value as a study area. .a @br 139 AMC-13 Figure 4-36. Comparison of topo- 23 APR 78 graphic profiles on March 26 and April 23. Oil was buried to a maximum depth of 38 cm by the Cr Oil buried max 26 MAR 78 deposition of clean sand. There- of38cm fore, the beach appeared unoiled. UJ'@. [email protected] 00 210. 00 4,0.00 6b. aa 810.00 015TANCE W Summary Section IV illustrates the following points: (1) There was a lack of significant oil deposition along those stretch- es of coast oriented NE-SWI which were at an angle of 45' to the primary oil transport direction. All areas trending roughly north-south (perpendicular to oil transport) were heavily impacted (particularly station AMC-14). (2) The burial of an oil layer by up to 38 cm of new sand at AMC-14 gave the beach a deceptively clean appearance on 23 April. (3) Oil was observed to accumulate in pools in scour pits around boulders at station AMC-14. 4.9.5 Section [email protected] de Goulven to Plougoulm Section V can be divided roughly into two sections, a depositional section to the west,.and an eroding granitic bedrock massif to the east (Fig. 4-37). The depositional system is composed of an extensive dune area and very wide fine-sand tidal flat ([email protected] de Goulven). Beaches within the bedrock area are usually small and bounded by rocks. Most of -the oil passed by this coast. However, there were significant accumula- tions during the first two weeks in those areas jutting north into the channel, and those that had coves or crenulate features facing west. A brief description of the individual study sites is presented in Table 4-9. 23 APR 78 "i.d m @6, 140 Table 4-9. Field observations of oil distribution at stations of Section V, Grieve de Goulven to Plouscat. Station Number Date(s) Visited Location and lype of Environment uescription of Oil Impact F-122b 23 Apr Gourven Very lightly oiled marsh grass. Large tidal flat/estuary with a fringing marsh. F-123 23 Apr Plage de Ker Emma Some light oil and small tar balls Wide sandy beach with dune aong the last high tide swash line. system; large rocks offshore Fresh mousse (moderate-heavy concen- as well as on the lower por- tration) coating on algae and rocks. tions of the beachface. F-124 23 Apr Anse de Kernic Some darkened marsh grass from light Large tidal flat with a har-- oiling; a few mousse balls along the bor on one side; fringing high tide swash line. marsh on shoreline. F-86 I Apr- Plouescai -heavily oiled marsh 23 Apr- Marsh at head of estuary. -oiled marsh grass all ripped out; little marsh grass remains; still some patchy oil, F-30 25 Mar- End Of SPit at Porz Meur -very light oil. 23 Apr- Beach with rocky area to the -rocky area moderately oiled; a lit- southwest. tle mousse foam in the water; light oil swashes on the last high tide line. F-29 25 Mar- Por au-Streat -beach heavily oiled; lots of clean- Breakwater harbor with sea- up activity. 23 Apr- wall protecting it from I direct wave attack. -just a little oil on beach with some burial along the upper swash line. The rocks are all lightly oiled. F-28 25 Mar Frouden Oil pools; clean-up operation in Rocky cobble beach with effect. some sandy areas. F-27 25 Mar (near) Au Gered Heavily oiled gravel beach and rocks. Pocket beach. F-26 25 Mar Point at St. Eden Heavily oiled rip-rap seawall. Pocket sand beach with rocky headland on both sides. F-25 25 Mar- Pornejen -heavily oiled rocks; 200 m slick of High energy boulder beach. mousse. 23 Apr- -light oil coverage on rocks; much of the oil on rocks removed by high pres- sure hoses. F-24 25 Mar Poulfuen Heavily oiled. Pocket beach with rocks on sides. F-23 25 Mar- Kerfissien -moderately oiled especially in the Small POCKet beach with eastern zone. 23 Apr- rocks on sides. -beachface was clean with half-buried, discontinuous mottled oil zone along the swash zone and a few buried tar balls at 50-60 cm. F-22 25 Mar- Anameid -beach is heavily oiled; heavy mousse High-energy beach with erod- swash. 23 'Apr- ing dune scarp and rocky -area entirely clean. headlands on both sides of a small embayment. F-21 25 Mar Tavenn Kerbrat Very light mousse in water. Sandy beach with heavy rock, debris. 141 Table 4-9 (continued) Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact F-57 28 Mar- Plage de Trestrignel -light sheen in water. 26 Apr- Sandy shoreline with some -light oil swash lines along the upper rocks sticking thru a muddy part of the shore; oil burial 6-8 cm sand flat at the center of on the upper portion of the beachface; the tidal channel. live amphipods found along the high tide swash. F-87 I Apr Kerbrat Lightly oiled. Side of estuary. F-136 26 Apr Kerbrat Very light oil swash along the high Fine- to medium-sand tidal tide swash line; no oil burial; live flat amphipods on the beach. F-137 26 Apr Cantel Marsh heavily oiled with 1 cm thick Marsh area at the mouth of coverage of oil over marsh; no clean- an estuary. up operation. F-138 26 Apr Traon Feunteun Very lightly oiled; boom ineffectively Upper portion of marsh where positioned. channel flows into the marsh. SECTION R C::@ 22 21 -2 23 25 136 [email protected] -26 [email protected] 137 57 27 26 -29 CLEDER [email protected] PLOUESCAT PLOUGOULMI [email protected]' 0 .0 initi.tj, @@7 -86 k,61e 1 23 1A24 0 A Km 122B Figure.4-37. Station locations and oil distribution for Section V ([email protected] de Goulven to Plougoulm). Oil distribution for the first (March 19 to April 2) and second (April 20-28 ) study periods is indicated. 142 Oil Impact The nature of oil deposition was distinctly different in the two morphological areas. Because the entire depositional system was shel- tered by the Brignogan-Plage peninsula of Section IV, no oil reached the beaches during March. On our return visit during mid-April, light oil swashes were present on all beaches but no oil burial was found. Beaches of the granitic massif were more exposed to the wind- transported oil; however, most of the oil simply passed by this area because of the general northeast/southwest orientation of the coast and the lack of large catchment areas. Significant amounts of oil accumu- lated only in those areas with crenulate shapes (crenulate beaches) or on those areas oriented more directly into the westerly winds (see Fig. 4-37). Commonly, the northern end of the beach would be heavily oiled, whereas the southern end would be clean. During our site survey of late April, only a very light oil swash was visible at most locations. Cleanup occurred rapidly because of the exposure of most of the oiled areas to high wave energy. The exceptions were the sheltered marsh environments, such as the one at Cantel (F-170). Summary Importantly, Section V illustrates the change in form that the oil spill took after a period of one month. Originally, large oil masses were trapped at specific locations, depending on local shoreline con- figuration with respect to the wind. As the oil became worked into the water column, and the winds shifted, oil was spread over almost every inch of the shoreline in the form of light oil swash lines, which were usually composed of very small mousse balls. 143 SECTIONM ILE DE BATZ boom 17 AMC-8 MC-6 _7th AMC-7 ROSCOFF + 139,, +. 140 AMC_9'@ @LPALUD Area Exposed at Low Tide 19 DOSSEN N 0 2km 4 20 AMC-10 FigureA4-38. Station locations and oil distribution for Section VI (Foret Dom. de Santec to Roscoff). Oil distribution for period one (March 19-to April 2) is indicated by the dark-stippled pattern. Heavy and light oil coverage during period two (April 20-28) are indicated by the plus and light-dot: patterns, respectively., 4.9.6 Section [email protected] Dom. de Santec to Roscoff Geomorphologically, this section can be divided into two distinct areas: (1) a large relict dune field with broad, flat fine-sand beaches (between stations AMC-10 and F-17; see Fig. 4-38); and (2) the highly embayed area around Roscoff. All the fine-sand beaches of the first area were heavily contaminated because of their north-south orientation and generally crenulate shape. Roscoff was one of the hardest hit areas in the whole spill site during the first week after the spill and, therefore, was studied more intensely than some of the other areas. Summaries of field observations in section VI are listed in Table 4-10. 144 Table 4-10. Field observations of oil distribution at stations of Section VI (Fore^t Dom.de Santec to Roscoff). Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact AMC-10 24 Mar (F) ForA Dom. de Santec -contains a 20 m band of oil along 25 Mar. (AMC)- Eroding dune scarp with wide the upper beachface; 12 cm buri-al. 1 Apr- fine-sand beach grading into -light oil swashes an beach surface; a broad low-tide terrace. a discontinuous layer buried 8 cm. 26 Apr- -very light oil swashes on beach sur- face; discontinuous layer buried a maximum of 23 cm. F-20 24 Mar Dossen -tombolo effect; heavy oiling of [email protected] 25 Mar- Wide fine-sand beach/low-tide tire area behind island. lApr- terrace behind an island. -surface of low-tide terrace clean; oiled rocks along shoreline; signs of a clean-up operation. 26 Apr- -rocks still moderately to heavily oiled; some burial 10-12 cm along upper beachface. F-19 24 Mar- Port au Vil -very heavily oiled. 26 Apr- Small pocket sand beach -clean beach surface and rip-rap, but 12 cm burial of 4 cm thick oil layer by spring berm deposition; signs of clean-up operation. F-18 24 Mar- Tevenn -very heavily oiled. 26 Apr- Large sand beach oriented in- -oil well mixed into the beachface by to direct wave attack; has a heavy machinery and trenches used in marsh deposit outcropping on clean-up operation; men working to the beachface. spray clean rocks to south. AMC-9 24 Mar (F) Cough ar Zac'h -very heavily oiled beachface and up- per low-tide terrace; 8 cm burial 25 Mar Broad medium- to fine-sand along upper beachface. beach backed by eroding dune I Apr- scarp; some rip-rap. -heavy oiling restricted to 12 m along upper beachface; 8 cm burial. 26 Apr- -only light swashes along beachface; burial to 25 cm; clean-up by raking. F-17 24 Mar- Centre Helio-Marin -very heavy oiling of the entire Wide fine-sand beach backed beachface. 26 Apr- by eroding dunes. -no oil on beach surface or buried, but has oiled interstitial water; evi- dence of mechanical clean-up effort. F-139 26 Apr Ruguel Light oil swashes and lightly oiled Large sand flat with seawall. rocks. F-140 26 Apr Lagadenou Very heavily oiled durin March; now Small beach with seawall has buried oil (3 [email protected] along beach- face; tidal flat still oiled and has fronting a large sand flat. oil contaminated ground water. AMC-8 24 Mar (F)- Roscoff - West heavy oil coverage of beach, tidal' Small mixed-sand and gravel flat and seawall; oil thrown over sea- beach leading onto a very wall and inio-park; oil boom in place across sand 'fiat. broad sand flat with some 25 Mar- algae coated rocks; seawall -decreased amountof.oil on the tidal and park back the beach. flat; the re�t'- [email protected]@tfiesame. I Apr- -very light oiling;[email protected] beach; oil buried under 20 ,qRo'f'cobbles; park- heavily oiled, bAlwalkway clean. 26 Apr- -oil stained cobbles ana wall, but beach appears clean; park is replafiXed. 145 Table 4-10 (continued) Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact AMC-7 24 Mar- Roscoff - central harbor -pooled oil 6 cm deep by seawall; rest of-beach 70-90% oil covered. Small medium-sand beach be- 25 Mar- tween rocks on both sides; -an approximate 70% reduction in oil backed by a seawall. coverage. 1 Apr- -some oil-bound sediment on low-tide terrace; oily sheen present; beachface. clean; cleaning wall with detergents. 26 Apr- -clean beachface; very minor amount of oil buried at 22 cm. AMC-6 24 Mar- Roscoff - East -the entire beachface and low-tide Small coarse-sand and gravel terrace had 35-100% oil coverage. 25 Mar (F)- beach grading onto a fine- -total oil coverage decreased to approx- sand tidal flat, rocks are imately 20%. 1 Apr- found on both sides; seawall -beachface very lightly oiled; seawall abuts the shore. and rocks on tidal flat still oil blackened; oil contaminated intersti- tial water. 26 Apr- -still lightly oiled rocks and seawall; cobbles of beachface are oil stained; interstitial water still contaminated. Oil Impact in Western and Central Areas Station AMC-10. This station, which is located at [email protected] Dom.de. Santec, is a very broad fine-sand beach backed by an eroding dune scarp. The total length of beach is 1250 m. A sketch of the area on March 25 is presented in Figure 4-39. Sediment data are listed in Table 4-11. During our site visits on March 24 and 25, oil was deposited along the uppermost 20 m.of beachface. Because of the compact nature of the fine- grained sediments, heaviest accumulations occurred along the upper swash zone. The quantity of oil present determined the total amount of sur- face area coverage. Some burial of oil was observed (see Fig. 4-39), illustrating that minor deposition had occurred since oil first came onshore. The quantity of oil present along this beach was estimated at 446 metric tons (Table 4-12). 146 AMC-10 25 MAR 78 water line I 109pole CLEAN SANDFLA [email protected] B'f C HEAVY OIL 100 10 %OIL COVERAGE 0 T _T H: F1 CK N E S S: M M 5 C3 C) C3 A B __C CE ___;'12crn b.,ia-i_- LU.I; 0.00 20.00 40.00 60.00 DISTRNCE (M) Figure 4-39. Sketch and topographic profile for station AMC-10 on March 25. All oil deposition was along the upper beach face. The total width of oil deposition on similar fine-sand beaches depends on the total quantity of oil within the area. Greater quantities will cover more of the beach face. Two distinct oil layers were buried, illustrating deposition of new sand since initial oil impact. On our follow-up survey of April 26, only lightly oiled seaweed debris, and a series of light oil swashes remained on the beach surface. A 5-cm-thick oil/sediment layer was buried 10 to 15 cm below the surface by a newly formed berm. This recent deposition of clean sand gave the beach the appearance of being completely unoiled. We estimated that 6 tons of oil remained in the area, a net decrease of 87%. Approximately half of this oil was buried. 147 Table 4-11. Sediment data for AMC stations in Section VI. All values are calculated according to Folk (1968). Sample Graphic Mean Size Classl Skewness Standard Deviation2 AMC-6A 0.306 CS -0.129 1.601 (PS) AMC-6B 1.007 MS -0.813 2.670 (VPS) AMC-6C 2.597 FS -0.678 1.275 (PS) AMC-7A 1.887 MS -0.291 0.733 (MS) AMC-7B 1.538 MS -0.393 1.339 (PS) AMC-7C 2.495 FS -0.161 0.901 (MS) AMC-8A no sample AMC-8B 2.536 FS -0.545 1-.103 (PS) AMC-8C 2.158 FS -0.235 0.728 (MS) AMC-9A 1.959 MS 0.010 0.434 (WS) AMC-9B 2.112 FS -0.049 0.459 (WS) AMC-9C 2.197 FS -0.011 0.486 (WS) AMC-10A 2.955 FS -0-095 0.358 (WS) AMC-10B 3.005 VFS -0.093 0.389 (WS) AMC-10C 3.017 VFS -0.123 0.419 (WS) 1Size Class 2Sorting CS = coarse sand WS = well sorted MS = medium sand MS = moderately sorted FS = fine sand PS = poorly sorted VFS = very fine sand VPS = very poorly sorted 148 Table 4-12. Estimates of the quantity of oil present at AMC stations in .Section.VI during first and second field surveys. Station Number Date Oil Present Date Oil Present % Change (metric tons (metric tons AMIC-6 24 Mar 51.8 26 Apr 1.0 -98.10 AMC-7 24 Mar 102.5 26 Apr 1.7 -98.30 AMC-8 25 Mar 9.6 26 Apr 0.4 -96.50 AMC-9 25 Mar 1039.4 26 Apr 10.6 -99.00 AMC-10 25 Mar 46.3 26 Apr 6.0 -87.00 Coast between Stations F-20 and F-18. Station F-20 provided another example of the tombolo effect. Waves coming around both sides of the offshore island caused a large amount of oil to accumulate at Dossen. Follow-up surveys showed that the surface of the area was cleaned, but some oil still remained on the rocks as well as buried along the upper beach face. There Were signs of cleanup at each station (F-18, 19 and 20); however, we saw none in operation. Stations F-19 and F-18 proved to be very similar. Each initially had very large oil accumulations. During the mid-April survey, the surface of each area was generally clean, but some oil was buried. Station F-18 remained slightly more oiled than the other. Station AMC-9. This station.is a 2.0 km long, very broad medium- to-fine-sand beach. Sediment data are presented in Table 4-11. As at Station AMC-10, the beach area is backed by an extensive dune field. The waves are eroding the dunes at high tide forming a steep scarp. A sketch and topographic profile of the area are presented in Figure 4-40. At the time of our survey on March 25, much of the beach face and low-tide terrace were covered with oil. Thickness of the oil varied from 6 m along the mid-beachface to 3 mm along the low-tide terrace. There was some oil burial along the upper beach face. An estimated total of 1039 metric tons of oil was on the beach on March 25. By April 1, heavy oiling was restricted to the uppermost 12 m of beach. Oil thickness varied from 2 cm to 3 mm. Oil was found buried in a discontinuous layer 10 to 15 cm below the surface (Plate 4-26). Natural processes were responsible for the cleansing of the lower beach- face, since there had been no signs of beach cleanup effort. 149 AMC-9 25 MAR 78 N, aw kel W, 'n M"..' RK, A dunes N 51 t-.T -Tw Waterlinew FIN AND '.4 BEACH SANDFLAT 195 [email protected]_ 95 85 %OIL COVERAGE 3 THICKNESS: MM [email protected] 10 60 CC @> A Lu 8 Cm bu ial [email protected] 8 Uj C 6._00 2b. oo 4b. oo sb. oo ab. oo ibo.oo i2o. oo i4o. oo ilo. oo i bo. oo DISTRNCE W Figure 4-40. Topographic profile and oil coverage of Station AMC-9 on March 25. Oil covered most of the beach face and upper low-tide terrace. The profile is compressed, compared with the computer plot. On April 25, only light oil swashes remained on the beachface. However, a good deal of oil was buried in two layers up to 25 cm deep. Comparison of beach profiles show that the formation of a neap berm caused the burial of the oil (Fig., 4-41). The rip-rap wall to the south continued to be heavily oiled. An estimated 11 metric tons of oil remained in the area. This comparatively large amount of oil is essen- tially due to the exceptional length of the beach over which the calcu- lation was made. 150 [email protected]_ AMC-9 [email protected] Figure 4-41. Although the beach at A,'NEAP BERM AMC-9 appeared clean on April 1, Cr (depositional) oil had been buried in two layers 1 APRIL 78 _J0 burial up to 25 cm beneath the surface by formation of the neap berm. 0'.00 2b. 00 4'0. 00 6'0. 00 8,0.00 DISTANCE W The coast from F-17 to F-140. Station F-17 was very similar to the others of this coastline (e.g., AMC-10, F-18 and AMC-9). Backed by a small dune field, it contains a broad fine-sand beach and low-tide terrace. This area was initially very heavily oiled. Plate 4-10 shows this area on March 21. On April 26, little evidence could be found to indicate how extremely contaminated this area had been. Station F-139 is located in a sheltered sand-flat embayment. Because of the prevailing westerlies during the first two weeks of the spill, no oil came into this area. During our second site inspection on April 26, minor oil swashes were found along the upper portions of the sandflat, and the rocks were lightly oiled. Across the bay at site F-140, it was a different situation. This area was very heavily oiled during the first days of the spill. Skim- mers and tank trucks worked to remove some of the floating oil. During site inspection on April 26, we found several layers of oil buried in the beach, and a surface film of oil on the sand flat. The interstitial water of the flat was noticeably contaminated. Oil Impact in the Roscoff Area Station AMC-8. This station is located on the west side of Roscoff. It consists of a steeply dipping mixed coarse-sand-and-gravel beach leading onto a sandy tidal flat. Grain size data are presented in Table 4-11. Behind the beach is a large seawall with a small park located at street level. We observed that the beach and most of the sand flat were oil covered during the flight of March 21 (see Plate 4-32). Our station is located along the seawall at the upper right of this photograph. b 151 By March 25,.much.of the oil on the tidal flat was gone. However, the lower beach face remained oiled. An estimated 10 tons of oil remained (Table 4-12). Figure 4-42 and Plate 4-33 show the extent of the surface oiling. A hard, sandy gravel substrate prevented deep penetration of the oil. The walkway and park above the beach had re- ceived heavy oiling due to overwash by large, mousse-laden waves on March 24. Over 3 cm of oil was on the walkway at that time (Fig. 4-43). By the first of April, little oil remained on the beach face. A minor amount was found buried by pebbles along the upper beach face. The walkway was cleared of oil, but the park was still blackened. By April 25, the park had been restored. Only thelightly stained cobbles and blackened sea wall (which was being cleaned with pressurized steam) remained.as evidence of the spill. We estimated that less than 0.4 ton of oil remained in this particular area on April 25(Table 4-1.2). Station AMC-7. This station is located within the jetties at Roscoff harbor (Fig. 4-44). The site is pictured in the background of' Plate 5-17A. It is a small medium-sand beach bounded on both sides by large rocks. A fine-sand tidal flat is located seaward of the beach, while.in back is a high seawall. Sediment data are presented in Table 4-11. Our observations indicate that the heaviest accumulations of mousse arrived in Roscoff on March 20. On March 24, there was heavy oil coverage over most of the intertidal area at low tide (see our survey of that day, Fig. 4-45). Only where the ground water rills cropped out on the beachface did oil coverage reduce (to 70%). Some oil was also found buried. Returning the next day (two tidal cycles later), 60%-70% of the oil in the area.had been removed. Comparing the two beach profiles presented iniFigure 4-46, it can be seen that a lar Ie amount of material had been eroded from the beachface. In total, 23 m of sediment per 1 m width of beach had been removed during the night. High wave activity brought abourby a low pressure storm and near spring tides combined to create the new beach profile. 15100 100 % OIL COVERAGE 3 5j -j MM AMC-8 0 9 25 MARCH 78 Z 0- 0 > Figure 4-42. Topographic profile LU -A U.0 15 cm burial and oil coverage for'station AMC-8 on March 25. The beach is composed @15cm @buial v! I r- of mixed sand andgravel leading 0.00 20.00 40.00 DISTANCE (M) onto a large sand flat. 152 Figure 4-43. More than 3 cm of oil was thrown up onto the walkway at station AMC-8 in Roscoff on March 24. The small part to the right was also heavily oiled. Most of the oil was cleaned up before April 1. The park was restored a short time after. IL Figure 4-44. Aerial photograph of the harbor at Roscoff on March 21. Station AMC-7 is the beach to the center-left of the photograph. Station AMC-6 is located at the far left. 153 100 100 70 go 1%1011 COVERAGE 20 1 2 4 3 THICKNESS: MM 60 8 THICKNESS Fo Figure 4-45. Topographic profile and oil coverage for station AMC-7 (Z- in Roscoff on March 24. A sig- RMC7 nificant portion of the oil was 1500 removed by.erosion of the beach ol 24 3 78 during the following two tidal @L I . cycles (see Fig. 4-46). 0.00 b. on 4b. 00 5b 0080.00 100.00 D15TRNCE (M] On our return on April 1, we found that the entire beachface was clean. Howevery there was some burial of oil on the lower beachface (to depths of 3 cm). By comparing profiles (Fig. 4-46), it can be shown that new sand had been deposited between March 23 and April 3, thereby burying some of the oil. In total, nearly 30% of the original volume of sediment previously lost had been returned. By April 26, only very light oil swashes were found on the beach. In addition, slightly oiled sediment was found 22 cm below the beach surface in one locality. The walls had been cleaned in some spots. The remaining oiled rocks and walls were being cleaned with high pressure water and detergents. This is the only place where we saw detergents applied to any oiled area. The total amount of oil present on April 26 was estimated at 1.7 tons (Table 4-12). Another cleanup instrument, a vortex skimmer, was moored at this locality, but was seen being towed only once, and then it did not have the hoses connected for actual operation- Station AMC-6. This station is located on the eastern side of Roscoff next to the lobster pens shown in Plate 5-17A. It consists of a small, 150 m gravelly sand beach that grades into a fine-sand low-tide terrace. Rocks are located on both sides of the beach. A seawall abuts the upper beach (see Fig. 4-47). The oil pollution history of this area is very similar to that of AMC-7. During our overflight on March 21, the entire intertidal zone was covered with oil (Plate 5-17A). At the time of our survey on March 24, a considerable amount of oil remained*on the beach face and low-tide terrace. Figure 4-47 shows oil coverage superimposed on the beach profile. We estimate that 52 metric tons of oil were present, excluding oil within the rocky areas. After a storm on the night of March 24, approximately 80% of the surface oil was removed. Once the oil drifted into the main channel) swift currentsy aided by strong winds, carried it further to the east) towards Ile Grande. 154 AMC-7 AMC-7 OIL [email protected]_ -EROSION EROSION AK 24 3 78 -DEPOSITIO N 25 3 78 25 3 78 4 78 cl: a: W. _J _J. '[email protected] 3cm oil burial '6. 00 2b. 00 4b. 00 6b. 00 8b. o 21". 40.0-0 10... 11.0 DISTANCE M DISTANCE M Figure 4-46. Extensive erosion occurred at station AMC-7 during the night of March 24. During this time, 60%-70% of the oil in the area was removed. The partial recovery of the beach on April 1, by the deposition of new sand on the beachface, caused a 3 cm burial of old oil. A follow-up survey on April I showed a further diminution of the oil. On April 26, the beach still remained lightly oiled and the rocks and sea wall were still oil-blackened. The interstitial water was also contaminated. Approximately 1 metric ton of oil was still in this particular area on April 26. Limpets on the rocks seemed to be healthy, illustrated by their being able to hold firmly to the rocks when prodded. Summary (1) Exposed fine-sand beaches were cleaned rather rapidly (2-3 weeks) by natural processes. Only where oil was artificially worked deep into the beach sediments by cleanup machinery, did major contamina- tion remain. (2) Another example of the tombolo effect on oil accumulation was observed at station F-20 (Dossen). (3) Tremendous quantities of oil were removed from the beaches of Roscoff overnight during a period of high wave intensity (March 24 and 25). Even though the large majority of oil was removed natural- ly, total recovery of the environment at Roscoff still seems some- what distant. Oil that was naturally removed probably drifted eastward and contaminated other environments to the east. (4) The use -of sprayed detergents to clean the rocks at AMC-7 was the only use of chemicals we saw during our field studies. @ "ON POSI -D E TI( 2 155 ROSCOFF Hotel Bellevue ty 'z rbkcks eWA 5311gae-, L -TIDE TERRACE OW g, A gL z ........ ..... Rik, _p _p p _p _p _p _p .......... r zzi W [email protected] [email protected] ..... . . . . . . . GRAVELLY SAND ioo 60 35 50 75 40 %OIL COVERAGE 2 4 3 4 THICKNESS: MM M M A C no burial Cr Ui [email protected] _j c3 W '@ - 0.00 2b. oo qb. 00 60.00 80.00 ibo.oo i @o. oo i 4o. oo i @o. oo DISTRNCE (M) Figure 4-47. Sketch, topographic profile, and oil coverage for station AMC-6 in Roscoff on March 24. On the evening of March 24 approxi- mately 80% of the accumulated oil was removed from the area by natural processes. 156 4.9.7 Section VII--Roscoff to Pte. de Plestin A location map for Section VII is given in Figures 4-48 and 4-49. The coastline is oriented roughly east-west. Geomorphologically, the coastline is quite similar to Section IV, with a depositional, estuarine (ria) area to the west and a granite massif to the east. In this case, there are two large fine-grained tidal flat systems in the west sepa- rated by a bedrock headland, Locquirec peninsula. Another.difference is that this bedrock area (between Locquirec and Primel-Tr6gastel) forms steep cliffs often over 20 m in height. The individual stations in the section are described in Table 4-13. Oil Impact The coast from F-147 to F-96. This enti re section of coastline was sheltered from initial oiling by the Roscoff peninsula. No oil was found in this area during our first survey, which ended on April 2. There was a very long floating oil boom located across the eastern side of the estuary at this time (indicated in Fig. 4-48). The effectiveness of the boom could not be determined. Since much of the large oil pools had shifted location with the changing wind direction of early April, we remonitored the area on April 27 in greater detail than before. During this survey, light oil Iswash lines were found at stations F-147, F-13, F-11,,and F-96 (see Fig. 4-49). The rest of the area continued to be unoiled. The coast from F-96 to F-89. This area was more exposed to the oil drifting over from Roscoff in the early days of the spill. Many areas became heavily oiled. Stations F-94 and F-95 were.among the hardest hit. The latter consists of a large heavily oiled cobble beach. Be- cause oil sank deep into the sediments, tractors and high pressure hoses were being used to clean the area. A tractor cut across the upper beachface creating a trough in front of the heavily oiled section (see Fig. 4-50). Water under high pressure was then applied to the oiled cobbles. The oily runoff drained into the trough and was later collect- ed. Station F-94 at Primel-Tr6gastel is a sheltered rocky environment which acted as a perfect sink for the oil. Even after an extensive cleanup of the area, it was still heavily oiled on April 27. Along the cliffed rocky coast between F-92 and F-91, mousse string- ers were still seen floating on the water surface on April 27, more than 5 weeks after the beginning of the spill. Wave reflection kept most of the oil a short distance offshore (Plate 4-28). However, some small cobble coves became heavily oiled. Oil is not expected to remain in this area because of the highwave energy,conditions. 157 SECTION VU 45 94 92 A P EL 93 95 Rl 89 TREG STEL 91 144 no oJ 90 14 147 no oil Q LOCQUIREC 142 52 II no oil 51 ARAN EC 14 no oil% 9, FIRST STUDY PERIOD 146 8 0 2 4 6 KM LMORLAIX Figure 4-48. Location of stations in Section VII, Roscoff to Pointe de Plestin (F-142). Oil distribution during the first study session, March 19 to April 2, is indicated by the dark-stippled pattern. SECTION ZI 4 +1 4- 94 45 x + + 92 + 93 A89 95 PRIMEL 1-1 TREGASTEL 91 4 144 147 90 143 96 LOCQUIREC 142 52 51 CARANTEC @14 no W N SECOND STUDY PERIOD 9 146 0 2 4 6KM MORLAIX Figure 4-49. Oil distribution along the coastline of Section VII during the second study session, April 20-28. Heavy and light oil coverage C are indicated by the plus and light-dot patterns, respectively. 158 Table 4-13. Field observations of oil distribution at stations of Section VII, Roscoff to Pte. de Plestin. Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact F-147 27 Apr Port de Pem Poul Light oil swashes. A seawalled harbor; coarse- sand tidal flat. F-14 24 Mar- Pont de la Corde -no oil. 27 Apr- Tidal flat/estuary with -no oil. small channel; station at bridge over river. F-13 24 llar- Carantec - West -no oil. 27 Apr- A harbor with a sandy beach -light oil swashes. and large tidal flat. F-12 24 Mar Carantec - North No oil. Near the mouth of a large estuary and tidal flat. F-11 24 Mar- Carantec - East -no oil. 27 Apr- Granule beach. -very light oil on rocks; sand was re- moved to protect it from being oiled - it will be pushed back later; some light discontinuous burial. F-10 24 Mar- (near) Ty Nod -no oil. 27 Apr- Gravel beach. -no oil. F-9 24 Mar- East toward Dourduff -no oil. 27 Apr- Tidal flat/estuary. -no oil; possible light sheen in the water. F-8 24 Mar (near) Horlaix (2 km downriver) No oil Small tidal flat with channel. F-146 27 Apr Dourduff en Mer Clean except for an occasional mousse Wide tidal flat area. glob on the upper portion of the tidal flat (3 mousse globs/m2); algae very productive. F-96 2 Apr- Terrenez -no oil; boom deployed offshore. 27 Apr- Small harbor with cobble -light oiling of cobble beaches. beaches on both sides. F-95 2 Apr- le Diben -heavily oiled. 27 Apr- Cobble beach gently sloping -beach and rocks on low-tide terrace onto a very rocky low-tide heavily oiled; extensive clean-up terrace. operation - tractors pushing oiled cobbles into lower swash zone to be cleaned by the waves; high pressure water also being used. F-94 2 Apr- Primel Tre/gastel - West -very heavily oiled; extensive clean-up. 27 Apr- Sheltered harbor; cobble -moderately to heavily oiled; rocks and boulder beach. are extensively coated with oil. F-145 27 Apr Primel Tregastel - East Upper beach is moderately to heavily Gravel beach with a large oiled. sand tidal flat fronting it; backed by a seawall; upper beach portion consists of cobbles and boulders. 159 @Table 4-13 (continued) Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact F-93 2 Apr- St. Jean de Doigt -light oil on rocks. 27 Apr- Cobble and gravel beach. -rocks and gravel all heavily oiled; oil has sunk into the gravel beach; signs of previous clean-up effort. F-92 2 Apr- West of St. Jean de Doigt -no oil on shore; mousse streaks Small rocky indentation of offshore. 27 Apr- the coast. -some mousse still in the water and now the rocks have a light coating of oil. F-91 2 Apr- Poul Rodou -no oil. 27 Apr- Pocket beach surrounded by -moderate to heavy oil on the rocks rocky headlands. along the shoreline; light oil swashes on the beachface. F-90 2 Apr- le Moulin de la Rive -moderately oiled rocks; clean low- Cobble and gravel beach. tide terrace. 27 Apr- -rocky area heavily oiled; low-tide terrace moderately oiled; active clean- up operation - a tractor is pushing oi 1 ed cobbl es onto the 1 ower beachface; also use of a high pressure hose. F-144 27 Apr les Sables Blancs Headlands moderately oiled; light oil Small sandy beach backed by swashes on beach; location of an oil dunes; algal covered rocks storage pit. on low-tide terrace; rocky headlands on both sides. F-89 2 Apr- Locquirec -moderately oiled rocky area. 27 Apr- Rocky and sandy beach with -rocks are moderately to heavily oiled; a similar low-tide terrace. even the rocks on the low-tide terrace are oiled; a very small clean-up attempt is in effect - mainly steam cleaning. F-143 27 Apr Locquirec Port Both sides of jetty clean and no oil Small jetty protecting a in the water; boom in place at front little harbor. of the port; this area is very bio- logically productive. F-51 28 Mar- Toul an H6ry -no oil. 27 Apr- Upper part of tidal flat in -light coating of mousse globs along harbor. the shoreline; some very light oiling of the seaweed. F-52 28 Mar- (near) Kerdrehoret - West -no oil. 27 Apr- Beach and tidal flat in harbor. -very light oiling here - one small oil glob for each 2 square meters; other- wise, completely clean. F-142 27 Apr (near) Kerdrehoret - North Some oil droplets on the surface of the Small fine-sand pocket beach. rocks; beach is entirely clean; no burial. 160 Figure 4-50. Oil clean-up at the cobble beach at station F-95 on April 27. A tractor created the runoff trench at the foot of the beach. High pressure water helped remove the deeply penetrated oil from the cobbles. The method is sound from a coastal geomorphic standpoint since beach sediment is not removed. Reworking by waves will re-establish the normal beach profile. Closer to Locquirec, most of the rocks were still moderately oiled on April 27. At F-90, a tractor was pushing oiled gravel into the swash zone, and a small steam cleanup operation was in effect at F-89. The coast between F-143 and F-142. This large embayment reacted similarly to those at the western side of Section VII. No oil was initially deposited along the shoreline, since the Locquirec peninsula acted as a barrier. However, during the survey on April 27, light swash lines of small mousse balls (less than 1.0 cm in diameter) were found throughout the area. These mousse balls apparently drifted in as a result of shift in wind direction. Summary Two points of interest are illustrated in Section VII: (1) It is possible to use tractors and high pressure water to clean heavily oiled coarse gravel beaches without removing the gravel. (2) Thick mousse stringers remained in the nearshore water more than 5 weeks after the beginning of the oil spill. Therefore, previously unoiled areas were still subject to potential pollution, depending upon the vagaries of the winds and currents. 161 SECTION -79 4TREBEURDEN ---------- -80 [email protected] BEGIEGUER 56 Figure 4-51. Location of + AMC-16 survey stations in Sec- + tion VIII (St. Efflam to + Kerhellen). This sec- ++ tion included the large + sand flat at St. Michel- + [email protected] Oil distri- + J$ TREDREZ but-ion for study period + one is indicated by the dark-stippled pattern. AMC-15 Heavy and light oil cov- ------ + 4 St. MICHEL-EN-GREVE erage during the second 141 4+ AMC-19 (ss) study period are indi- 4 0 1 2 Km cated by the plus and ... .... .... -dot patterns, light `t54 respectively. 53 St. EFFLAM 4.9.8 Section VIII--St. Efflam to Kerhellen This section includes the broad sandflat called the [email protected] de St. Michel, as well as a cliffed, north-south trending bedrock shoreline (Fig. 4-51). The sandflat of St.-Michel, which extends for over 2 km from the high tide line to the low tide line, was the scene of a massive oil-caused kill of most of the shelled infaunal organisms. For this reason, this area will be discussed in detail. The extent of oiling along the bedrock system was generally heavy, increasing toward the north. The summary of our field observations for this section is presented in Table 4-14. 162 Table 4-14. Field observations of oil distribution at stations of Section VIII, St. Efflam to Kerhellen. Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact F-141 27 Apr Pointe de Plestin No oil except for very light oil Exposed pocket beach consist- splattering along the high tide ing of medium- to coarse- swash lines. grained shell material. F-53 28 Mar- les Carrieres -no oil 27 Apr- Large tidal flat embayment. -some heavily oiled rocks; no oil at the lower portion of the tidal flat. F-54 28 Mar- St. Michel-en-Gr'eve (South) -oiled swash lines and some small Large tidal flat embayment. mousse pools. 2 Apr- -millions of dead organisms. 27 Apr- -light sheen on upper tidal flat; no oil on the lower portion. AMC-19 28 Mar (F)- St. [email protected] -heavily oiled along upper portion (F-55) Very large sand flat/embay- of beach; large clean-up operation ment. with much manpower and many tractors; oil contaminated interstitial water. 2 Apr (F)- -millions of dead organisms. 25 Apr (AMC)- -light swashes on beach; oil buried (30 cm) in infilled collection troughs; interstitial water still oil contami- nated. AMC-15 28 Mar- St. [email protected] (NE corner) -80 to 100% oil coverage of the beach- Mixed sand and gravel beach face and near edge of tidal flat, 25 Apr- on edge of very fine-sand -still heavily oiled beachface and tidal flat. rocky edge of tidal flat; signs of an extensive clean-up operation; inter- stitial water oil saturated. AMC-16 28 Mar- Pointe de Sehar -very heavily oiled; 30 cm penetra- Large pebble beach between tion of oil into the gravel along two bedrock areas. the upper beachface. 24 Apr- -still oil soaked; at least 15 cm penetration over entire beachface; presence of a bulldozer pushing oiled gravel into furrows to be re- washed by incoming tide and waves. F-56 28 Mar Plage de Notigou Heavily oiled beach and rocks. Sandy pocket beach with out- cropping rocks. F-80 31 Mar- Plage de Tresmeur -heavily oiled. 25 Apr- Cobble beach leading onto a -cobble moderately oiled; low-tide sandy low-tide terrace. terrace very clean; tractor pushing cobbles seaward so as to allow nat- ural cleansing; high pressure hoses also in use to clean the rocks. F-79 31 Mar- Plage de Porz Termen -heavily oiled. 25 Apr- Medium- to coarse-grained -beachface is clean but the rip-rap beach within a harbor, walls behind the beach are heavily oiled. F-78 31 Mar- Kerhellen -heavily oiled. 25 Apr- Coarse sandy beach with -rocks on both sides moderately oiled; rocks on both sides. light oil along the last high tide swash line; also much burial along the upper beachface. 163 Oil Impact St. [email protected] Observations at St. [email protected] present one of the most massive kills of infauna by oil ever recorded. The initial site visit on March 28 showed extensive oil coverage within the southeast pocket of this tidal flat/fine-sand beach. A large cleanup operation was underway (see Plates 4-4, 4-5, 6-8, 6-9, 6-24), but no biological damage was evident. By the time of our return visit on April 2, the entire 2 km of sand flat was littered with millions of shells, including empty shells of heart urchins, tissue-laden shells of razor clams, and many small bi- valves (see Plates 4-6, 4-7, 5-10P 5-11, 5-12, 5-13). Approximately 1 km from the beach, samples were taken for infaunal analysis. Living annelids and polychaetes, were found. Shelled infauna were not present. The ground water was contaminated with oil. Three estimates of numbers of dead organisms were made: (1) A swash line of dead heart urchins (Echinocardium sp.) 300 m long and 25 m wide was counted, based on the number of dead organisms occurring within a one-meter wide swath measured perpendicular to the swash line. The total arrived at was 120,000 dead urchins within that one swash line. (2) A swash line (250 m long and 6 m wide), made up predominantly of dead razor clams) was also measured using the same method as in 1. According to our estimate, there were 45,000 dead razor clams within that single swash line. (3) At evening low tide (7:00 p.m.) on April 2, the entire intertidal area was littered with shells of dead organisms (Plate 4-4). As the tide fell, a cover of approximately 3 to 5 dead organisms/m2 was left behind. Heart urchins were by far the dominant species. At that time, the intertidal zone was measured to be 570 m wide. Assuming that each square meter contained four dead urchins (based on several counts), a 500 m long section of the beach would have contained 1,140,000 dead urchins. Therefore, several million dead urchins were present on the surface of the intertidal zone at that time, in addition to hundreds of thousands of dead clams and worms. Claude J. M. Chass6 of the University of Brest completed an exten- sive Ph.D. study of this flat (and other areas) in 1972 (Chass6, 1972). Apparently, follow-up studies will be carried out under his direction. We revisited the St. [email protected] sandflat on April 25. All dead organisms had been collected and removed from the surface of the flat. Approximately 1 km from shore, oiled rubble (mostly coarse gravel) 164 had been placed on the flat apparently to be cleaned by wave action (similar to that illustrated in Plate 6-30). Interstitial water in the area was still contaminated with oil. Because we wanted to monitor the effects of the cleanup operation, particularly the digging of numerous trenches in the intertidal zone, we established a new profile site (AMC-19) at St. [email protected] The topographic profile of the beach is shown in Figure 4-52. Sediment data are presented in Table 4-15A. At the time of our survey, light oil swash lines were found on the surface of the flat. However, the oiled remains of three cleanup trenches were located (Fig. 4-52, see also Plate 6-23). A.maximum of 35 cm depth of 'oiled sediment was measured. This profile site will be reoccupied to determine the persistence of the remaining oil. As at other sites, this could prove to be a long-term source of interstitial water contamination. Station AMC-15 is a mixed sand and gravel beach located at the northeast edge of the St. Michel sandflat. In some parts of the beach, a thin veneer of fine sediment was deposited over compact coarser mate- rial. The beach profile and oil coverage for the station on March 28 are presented in Figure 4-53. During the site survey on March 28, the beach at AMC-15 was heavily contaminated (see Plate 4-13). We estimate that 83 metric tons of oil were in the area (Table 4-15B). Oil extended approximately 50 m onto the sandflat. During our second survey, April 25, the beachface was still blackened in appearance, although the thick accumulations of oil were gone. The remaining quantity of oil was estimated 'at 4 metric tons. There were signs of a cleanup operation, so natural processes were not completely responsible for the oil removal. No oil burial was in evidence; however, the interstitial water was noticeably contami- nated. St. [email protected] to Pte. de Sehar. The coastline directly north of the St. [email protected] sand flat consists of steeply dipping, 70 m cliffs, half of which border the sandflat. Because of its north-south orientation, it became.heavily oiled during the first two weeks of the spill. It was still oiled on April 28. Station AMC-6, which is located at the northmost end of the bedrock cliffs, consists of a long, steeply dipping pebble beach (mean grain size = -4.690; Table 4-15). The topographic profile and areas of oil coverage for this site are presented in Figure 4-54. On March 28, the area was heavily oiled (see Plate 4-14). Digging into the beach, we found that taffy-like mousse had penetrated over 20 cm into the sediment (Plate 4-15). The estimated quantity of oil in the area was placed at 81 metric tons, much of which was incorporated into the beach sediment. Returning to the site on April 24, we found the area to be little different from before. Oil was still on the beach surface and had 165 _ - 100 '@ 95 so 80 % OIL COVERAGE '00 5 3 2 3 THICKNESS: MM A C 19 =3-- -80 I ,"' , 80 OILCOVI 1830 1 1141CINS' 25 4 78 50 ded trenches Zo @%ed CC W=; no 6urial cz=;- _j rn [email protected] RC15 _j OIL CONTAMINATED INTERSTITIAL WATER 1540 W 6b.co 28 3 73 01 .00 20.00 40.00 60.00 80.00 100.00 120.00 0.00 20.00 qb.oo 80.00 100.00 112 0 015TRNCE (M) 015TANCE (M) Figure 4-52. Topographic beach pro- Figure 4-53. Topographic profile file of station AMC-19 on April 25. and oil coverage of the beach at Oiled trenches remaining from the site AMC-15 on March 28. Oil was clean-up operation are indicated. restricted to the beach face and uppermost portion of the sand flat. penetrated 15 to 20 cm into the sediment over the entire beachface. Our calculated tonnage of oil present was 66 metric tons, indicating little change from,the previous visit. During our earlier studies of the Metula spill site in Patagonia, we had seen similarly oiled gravel completely cemented as the mousse dried and turned to asphalt. In an apparent effort to avoid a [email protected] situation at AMC-16, the cleanup crews used a bulldozer to push the oiled gravel seaward into furrows where the waves (at high tide) could rework the sediment,thus removing some of the oil (Fig. 4-55A). This is a valid method since sediment is not removed from the beach and it provides an artificial mechanism of mixing the oiled gravel before it becomes cemented by asphalt. In the future, wave action will probably restore the normal beach profile without marked erosion. The rapidity of beach cleaning will depend upon the amount of wave action. The coast from Pte. de Sehar to Kerhellen. This section of coast consists of small beaches, steep cliffs, and a large ria. Some of the oil that passed by Roscoff was deposited in this area. Most of this coast was observed to be heavily oiled at the end of March. During the site surveys and aerial reconnaissance of late April, most of the area was still moderately oiled. The tidal flat leading toward Beg-Leguer was heavily oiled. Cleanup activity similar to that at AMC-16 was in progress at F-80. Oil-soaked cobbles along the seawall were being pushed onto the low-tide terrace to be cleaned by natural wave action (Fig. 4-55B). 166 Table 4-15A. Sediment data for AMC stations in Section VIII. Sample Graphic Mean Size Classi Skewness Standard Deviation2 AMC-15A 3.136 VFS -0.057 0.461 (WS) AMC-15B 0.926 CS -0.633 2.819 (VPS) AMC-15C 3.277 VFS -0.052 0.363 (WS) AMC-16A -4.693 P 0.149 0.330 (VWS) AMC-19A 3.220 VFS -0.217 0.393 (WS) AMC-19B 3.319 VFS -0.124 0.353 (WS) AMC-19C 3.310 VFS -0.141 0.336 (VWS) ISize Class 2Sorting VFS = very fine-sand VWS = very well sorted CS = coarse-sand WS = well sorted P = pebbles VPS = very poorly sorted Table 4-15B. Estimates of oil tonnage for AMC stations in Section VIII. Station Number Date Oil Present Date Oil Present % Change (metric tons) (metric tons) AMC-15 28 Mar 83.3 25 Apr 3.9 95.30 AMC-16 28 Mar 81.2 24 Apr 66.3 184.00 AMC-19 NO DATA 167 100 2090 30 10 %OIL COVERAGE 1 5 M 30 R C 16 1745 C3 28 3 78 3 c Cr p n tration Uj" Figure 4-54. Topographic beach pro- _J9 Uj'_ file and oil coverage for station WL AMC-16 on March 28. Our return site survey on April 24 indicated that oil had penetrated 15 to [email protected] 00 2b. oo 4b. oo 6b. 00 a10.00 20 cm across the entire beach face. DISTRNCE W Summary The most striking observation in this area was the tremendous biological damage at the sand flat at St. [email protected], even though it was located 87 km from the wreck. Also, the technique used to clean the heavily oiled gravel beaches may have applicability in New England and Alaska where similar beaches are prevalent, should oil spills occur in those areas. 4.9.9 Section IX--Ile Grande area This section is one of the more important ones, because it includes a heavily impacted marsh area (Figs. 4-56 and 4-57). The general orientation of this shoreline is northeast-southwest. A large sandflat with scattered bedrock outcrops makes up most of the area. Except for the outer beaches of Ile Grande, the area is exposed to very little wave action. On a large scale map, it can be seen that this entire area protrudes out from the general shoreline trend (Fig. 4-1) making it a perfect interception point for.the oil that bypassed Roscoff. Descrip- tions of the study sites are given in Table 4-16. Oil Impact All areas, except station F-76, were observed to be heavily oiled during site visits at the end of March and April. Station F-76 is an exposed, high-energy beach composed of large granitic boulders that was only lightly oiled. Sheltered areas at F-88, F-77, and F-75 had been cleaned or were in the process of being cleaned, but still appeared heavily oiled on April 25. Heavy machinery often mixed the oil deep into the beach or tidal flat sediments, which made it impossible to R ' ' 6 17 45 28 3 78 C remove all the oil. 168 Z' [email protected] ; Vz3 Figure 4-55. (A) Heavily oiled cobbles of station AMC-16 were pushed into furrows to aid cleaning by wave action. (B) At station F-80, a similar method of clean-.up was in operation. 169 SECTION IX ----------- + LANDRELLEC + + @++ M 75 76 ILE GRANDE + 132 88 133 ++ M 134 A M C 18 0 A M 135 @M- 77 0 Km Figure 4-56. Locations of observation stations in Section IX. Oil coverage for the second study period is indicated as follows: heavy oiling--pluses, light oiling--dot pattern, and oiled marshes--circled M's. ILE GRANDE AC-1 13b N El UNOILED TIDAL FLAT Figure 4-57. The Ile Grande marsh 0 OILED TIDAL FLAT area observation stations and 2 OILED POCKS 0 500 m oil distribution on the tidal ROILED MARSH flat and marsh. LAND 170 Table 4-16. Field observations of oil distribution at stations of Section IX, the Ile Grande area. Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact F-77 31 Mar- Runigou -heavily oiled. 25 Apr- A sand flat with a rip-rap -sand flat all clean; rip-rap wall wall along the sides of the still heavily oiled; marsh remains flat. A small marsh is also in the area. moderately oiled. F-135 25 Apr- A116e Couverte -very heavily oiled, cleanup oper- South side of Ile Grande ation in progress; 5 cm of oil on Marsh; vegetation mainly much of the marsh; soldiers using Juncus marsh grass. squeegees to push the oil into the channels where it is being pumped out. AMC-18 29 Mar- Ile Grande Marsh, and -very heavily oiled; oil pools to west side of D21 bridge to 27 cm deep; average coverage about Ile Grande 3 cm; thousands of polychaetes Large marsh with a wide, worms crawling over the surface of muddy sand channel. the oil to escape. 2 Apr- -oil in same condition; polychaetes all dead and often found in small water pools on the surface of the oil. 24 Apr- -visit at hightide; only a light sheen visible on water surface. 25 Apr- -area has been manually cleaned; large oil pools drained; marsh still very black but some new green grass shoots appearing. F-134 25 Apr- West Road to Rulosquet -area oiled; extensive clean-up Part of Ile Grande Marsh operation underway: light sprinkler area. system rinsing the marsh as well as high-pressure hosing. F-133 25 Apr- East Road to Rulosquet -still completely oiled; many trenches Part of Ile Grande Marsh dug to drain oil; blackened; large area. clean-up underway. F-132 25 Apr- Dourlin -section 20 m wide remains thinly Western side of Ile Grande oiled after clean-up; numerous tire Marsh--a narrow fringing tracks, ditches, trenches on the marsh beside a sand flat. sand flat as a result of clean-up. F-88 2 Apr- Ile Grande Beach (East Facing) -heavily oiled. 25 Apr- Sheltered sandy pocket -heavily oiled shoreline and tidal beach; wave energy usually flat. low due to an island directly offshore. F-76 29 Mar- Northwest Ile Grande -lightly oiled boulder beach. Boulder beach. 25 Apr- -light oil coverage on boulders. F-75 29 Mar- (Near) Kerenoc -small marsh and rocks heavily Small marsh in northeast oiled. 25 Apr- corner of large sand flat, -very heavily oiled marsh grasses; with some rocks. some rocks with algae are completely oil covered; a large trench, dug to collect oil, causes serious oiling of the surface of the tidal flat. 171 The marsh at Ile Grande presents the most striking effects of oil impact in the entire spill site, especially considering that the oil was transported at least 86 km (53 miles) before it came ashore. During our first survey on March 29, we found oil on the marsh grasses as well as on the tidal flat surface. Plate 4-1 shows the oil coverage at that time. Both the marsh and tidal flat were heavily oiled (Fig. 4-57). Several ground-level photographs are presented in Plates 4-2, 4-3, 5-7, 5-8 and 5-9. This area provides an excellent opportunity for U.S. scientists to study the effects of oil on a large marsh, tidal flat ecosystem, inas- much as the types of marsh grasses and infaunal assemblages are similar to those in the eastern U.S. The marsh grasses are distinctly segre- gated by topography. Figure 4-58 (station AMC-15) gives a sketch of the area, as well as the marsh plant zonation. Briefly, from the high tide line seaward, the grasses consist of Juncus sp., Spartina patens and a succulent common to northern Europe [email protected]_lled Sesuvium sp. At the time of our first site visit on March 29, 3 to 5 cm of oil covered the entire marsh area. Oil thickness and surface area coverage as measured along our profile line are shown in Figure 4-59. On the tidal flat surface, oil was approximately 1 cm thick. Within many tidal pools (approx. 3 m x I m) on the surface of the flat, oil reached 15 cm in thickness. In our calculations of the approximate quantity of oil within the marsh system, we assumed an average value of 3 cm of oil over most of the oiled marsh and an average of I cm on the flat surface. An average thickness of 5 cm was measured for the marsh at F-135. By measuring the area of each marsh as marked in Figure 4-57, we estimate that 7400 metric tons of oil were present on March 29 (Table 4-17). At the time of our first site inspection on March 29, thousands of moribund polychaetes were found on the surface of the marsh. Many were observed wriggling on the surface of the oil pools. By the time of our return visit on April 2, the marsh was dead. Thousands of dead poly- chaetes littered the surface of the marsh, and collected in small salt- water pools within large (2 m x 1 m) oil pools. Crabs were found dead. Grasses were completely blackened. Four oil-covered, dead cormorants were also found. Our third site visit, on April 25, proved to be most interesting. The French military had begun an enormous cleanup operation within the area and about 80% of the marsh on the north side had been cleaned in some manner. In addition, 90% of the tidal flat was free of oil. Cleanup activities as observed at sites F-133, F-134 and F-135 (AMC-18 and F-132 had been cleaned already), consisted of high-pressure hosing (Figure 4-60A), low-pressure sprinkling, trenching of the thick oil pools, placement of oil into buckets, and use of tank trucks to remove oil from trenches or newly created pits. Over 200 men were working when we were there. The operation was successful in ridding the marsh and tidal flat of an enormous quantity of oil. Measuring along our profile 172 SS road 7 --- not oiled B very heavily oiled AMC-18 29 MARCH 1978 1850h 1.00 - TOPOGRAPHIC PROFILE 0.00- OIL SWASH LINE -1.00 .2.00 Juncu sp. -3.00 Sp-=tinD paten Sesuv4urn sp. Figure 4-58. Topographic profile and oil coverage for station AMC-18 (Ile Grande marsh) on March 29. Oil distribution along the profile is indicated in Figure 4-59. 100 100 % 0 8 0 10 '710 30 40. 30 CD CC Figure 4-59. Oil coverage along profile AMC-18 (Ile Grande marsh) on March 29. The thickness of _j C:) LLJ AMC-18 29MAR the depicted oil coverage line is '*'@O I L roughly proportional to actual 0.00 20.00 40.00 thicknesses. DISTRNCE 173 Table 4-17A. Grain size data for station AMC-18 in Section IX (Ile Grande marsh). Sample Graphic Mean Size Classi Skewness Standard Deviation2 AMC-18A 4.613 CS -0.295 1.863 (VPS) AMC-18B 2.100 FS -0.134 0.934 (MS) ISize Class 2Sorting CS = coarse silt VPS = very poorly sorted FS = fine sand MS = moderately sorted Table 4-17B. Calculations of oil quantity at AMC-18 during first (March 19-April 2) and second (April 20-28) study periods. Station Number Date Oil Present Date Oil Present % Change (metric tons) (metric tons) AMC-18 29 Mar 7400 25 Apr 2761.8 63.00 (station AMC-18), we found an average oil layer of 4 mm mostly coating the bottom sediments and grasses. We calculated the oil tonnage at this time on the following basis: (1) 20% of the original oiling (3 cm) remained on the north side, with 80% being lightly oiled (4 mm); (2) 5 cm oiling at F-135; and (3) 10% of the original 1 cm oiling on the tidal flat. On the basis of these assumptions, we estimate that 2762 metric tons of oil remained in the Ile Grande marsh area on April 25. This is a 63% reduction from our estimate for March 29 (before cleanup). Cleanup techniques could have been improved had personnel and machinery been directed to maintain a single road or work path. The unrestricted movement of men and machinery on the surface of the marsh and tidal [email protected] caused extra destruction of vegetation and churned oil deep into the underlying sediment (Figure 4-60B). 174 ;Z 4*_- =4 4 OAr, ',I,A Figure 4-60. (A) High-pressured hosing of the Ile Grande marsh on April 25 (station F-134). (B) The use of heavy machinery on the tidal flat at Ile Grande tended to churn up much of the area and mix oil deep into the sediment (station F-133, April 25). 175 One of the best opportunities for study in this area would be a time-series investigation of biological recovery. For example, although almost all of the marsh grasses were still blackened by oil on April 25, newly sprouted green marsh grass was already visible. Live fish and crabs were also seen in tidal pools within the main channel. Summary The Ile Grande marsh area has illustrated the enormous impact a massive oil spill can have on a thriving marsh/tidal flat ecosystem. This marsh in particular offers an excellent opportunity to monitor marsh recovery after a major spill. It would also be of interest to compare the recovery of this marsh with that of the marsh at Punta Espora, Chile, which was impacted by a heavy dose of Metula oil in August 1973. That marsh, which was not cleaned, has been very slow to recover (Hayes and Gundlach, 1975). 4.9.10 Section X--Landrellec to Trestel Section X is the northernmost extension of the granitic plateau of which Ile Grande is a part (Fig. 4-61). Much of the area near the coast is less than 20 m above sea level except by Ploumanac'h, where cliffs over 40 m are present. Major depositional embayments with-large sand flats are located at Ploumanac'h and Perros-Guirec, where the mean tidal range has increased to 8 m. This is one of the more popular tourist areas of this section of Brittany. Individual study site descriptions are given in Table 4-18. SECTION X ILE TOME k 0 oil 59 60 130 131 + PLOUMANACH + 57 73 129 + TREGASTEL PERROS-GUIREC 12 ;. i, - -75 +11 no oil TRELEVERN 74 0 2 Km LOUANNEC Figure 4-61. Locations of observation stations in Section X, Landrellec to Trestel. Oil distribution for the first study session is indicated by the dark-stippled pattern. For the second study period, heavy and light oil coverage are indicated by the plus and light-dot patterns, respectively. 176 Table 4-18. Field observations of oil distribution at stations of Section X, Landrellec to Trestel. Station Number Date(s) Visited Location and Type of Environment Description of Oil Imp act F-131 25 Apr- la Gr6ve Blanche -the beach is very clean with a clean tidal flat; the rocks are somewhat Sandy beach with a large tidal oiled, and are presently being cleaned flat and outcropping rocks. by a power hose from a water tank-truck. F-60 28 Mar- Coz Porz -lightly oiled; sand removed from beach as protection measure. Coarse-sand beach with large 25 Apr- rocks offshore. -a few isolated mousse balls on the beach; a light oiling on the offshore rocks. F-130 25 Apr- Ploumanac'h - South -clean except for a few oil globs; the rocks have been artificially Harbor with a sandy beach. cleaned. F-59 28 Mar- . Ploumanac'h - North -moderately oiled. 25 Apr- Protected small pocket beach; -a clean beach; no buried oil layers, coarse-sand and gravel. but the groundwater is oil saturated. F-58 28 Mar- East of Ploumanac'h -rocks clean; an oil sheen is on the water. Rocky coast with some small 25 Apr- gravel and cobble pocket -the pocket beaches are heavily oiled; beaches. exposed headlands are very lightly oiled; clean-up in progress. F-129 25 Apr- Plage de Trestraou -some light oil swashes on the beach; Large fine-sand pocket beach also some oiled cobbles being buried located between two rocky by the fine sand; a tractor is digging headlands which project almost up thecobbles and pushing them seaward due north. so that the waves can clean them. F-57 28 Mar- Plage de Trestraou -very clean except for a light sheen Sandy pocket beach. in the water. F-128 25 Apr- Perros-Guirec -jetty lightly oiled on the ocean Jetty and harbor. side; no oil in the interior of the harbor; boom across harbor. F44 29 Mar- Nanthouar' -rocky area [email protected] oiled. 24 Apr- Large gravel beach. -lightly-oiled swash line on the beach; rocks to the west are moder- ately to heavily oiled. F-73 24 Mar- Plage de Trestel -beach is clean; a new seawall is Medium-sand tidal flat and covered with plastic so as to prer- beach. vent its oiling. 24 Apr- -seawall still covered with plastic, so far unoiled; a few light oil swash lines on the beach. 177 Oil Impact Initial oil impact for most of the area was very light to moderate (Table 4-18). Only Stations F-74 and F-73 received major accumulations. Most of the oil still in the water drifted by without hitting the coast. Station F-60, which would have been expected to be oiled, was apparently protected by offshore rocks (see Figure 4-61). All areas on the east side of the Ploumanac'h peninsula were on the sheltered side during the westerly wind and were not initially oiled. However, during our second study session, April 23, the coast was much more heavily oiled. Apparently, the wind shift caused the oiling of the previously clean areas on the lee-side of the headlands. Rocky areas were particularly hard hit, especially at stations.F-57 and F-58. The area from F-74 to F-73 also was more heavily oiled than during the first study session. As was common at the other sections, the oil spill changed from having large oil pools at particular areas to being spread in varying quantities over the entire coastline. In many localities, the beach had become cleaner, but the rocks alongside the beach were more heavily oiled. A definite shift of oil from the beaches to within sheltered rocky areas had taken place. Summar Section X illustrates a standard pattern of oil dispersal for the oil spill area. Sites previously sheltered from oil deposition (e.g. F- 57 and F-58) during the first two weeks of the spill, became heavily oiled after the wind shift. Beaches were cleaned much more rapidly than sheltered rocky areas. In fact, the rocks probably act as a sink for some of the oil washing off the beaches. 4.9.11 Section XI--Port Blanc to Sillon de Talbert Section XI represents the farthest easterly extent of oil coverage that we observed (Fig. 4-62). The base of Sillon de Talbert is 130 km from the wreck site (by the most direct ocean route). On March 30, we flew the section of coast from Mont St. Michel Abbey to Sillon de Talbert and found no oil along the coast. Only a few small mousse patches were seen in these waters. Table 4-19 contains descriptions of the individual study sites. The coastline in Section XI consists of two large granitic head- lands separated by a large tidal flat/estuarine system. The tidal range reaches between 8.5 and 9.0 m. Many beaches of the area are naturally crenulate in shape (F-66, F-68 and AMC-17). The role of crenulate beaches as a localized control of oil deposition will be discussed in the following section. 178 Table 4-19. Field observations of oil distribution at stations of Section XI, Port Blanc to Sillon de Talbert. Station Number Date(s) Visited Location and Type of Environment Description of Oil Impact F-72 29 Mar- Les Dunes near Port Blanc -heavily oiled gravel and rip-rap Sand and gravel beach with near dune area. 24 Apr- a large tidal flat and dunes. -minor oiling along the high tide swash line; the tidal flat is very clean. F-71 29 Mar- Crech Arel -clean beach but some oiled rocks. Sandy beach with low-tide terrace. F-70 29 Mar- (Near) Pellinic -oiled marsh covered by an average Marsh. 3 cm of oil. 24 Apr- -still very heavily oiled; no clean-up. F-69 29 Mar- Bugelos - Coz Castel -oiled rocks surrounding large tidal Tidal flat surrounded by flat. 24 Apr- large rocks. -rocks still appear heavily oiled; no oil on tidal flat itself; marsh grasses appear oiled; clean-up operation has left area completely dug-up. F-127 24 Apr Anse de Gourmel Sand flat is very bioproductive; Large sandy tidal flat. thousands of worm burrows and many cockles; beach and tidal flat are clean except for a minor oiled sea- weed swash line along the last high tide swash; rocky areas on both sides of this sand area are heavily oiled. F-68 29 Mar- (near) Kergonet -tidal flat-and rocks both oiled. 24 Apr- Sandy beach with large tidal -very heavily oiled along the upper flat. portions of.the tidal flat as well as the beachface; tidal flat itself is all soaked with oil; trenches dug to trap and pump out the oil remain heavily oiled. F-67 29 Mar- Porz Scaff -oiled gravel and rocks. 24 Apr- Small pocket beach with a -all the cobble on the beach are seawall behing it. heavily oiled as is most of the lower beachface. F-66 29 Mar- Castel Meur -heavily oiled gravel beach; large Gravel and cobble beach with clean-up operation underway. 24 Apr- a large tidal flat; many -very heavily oiled here; mousse is cobbles outcrop on the tidal 1-2 cm thick on much of the beach; flat. some of the limpets have survived but many dead cockles and crabs are seen floating in oil pools; straw used to absorb some of the oil is still on the beach and tidal flat. F-65 29 Mar- Porz Bugale -no oil. 24 Apr- Small, mixed sand and cobble -light oiled swash line along the last beach. high tide line. F-64 29 Mar Troe'guier No oil. Estuarine tidal flat with a major channel flowing,north. 179 Table 4-19 (continued) 5tation Number ..Date(s) Visited Location and Type of Environment Description-of Oil Impact F-126 24 Apr Luzuret Beach area clean; rocks very lightly Broad rocky tidal flat. oiled. F-63 29 Mar- Plage de Beni -no oil. 24 Apr- Sand and cobble beach. -lightly oiled swash lines. F-62 29 Mar Kermagen A little oil on the boulders. Boulder and cobble beach. AMC-17 29 Mar- Port la Chaine -very thick oil accumMulations on beach; oil conta;iinated interstitial water. 24 Apr- Coarse-sand crenulate-shaped -light oil staining of beach sediments; beach between rocky headlands. some oil buried on beachface (15 cm) and on low-tide terrace; interstitial water still contaminated. F-125 24 Apr le Quebo Some minor oil blotches on the rocks; Mixed sand and gravel beach. otherwise completely clean. F-61 29 Mar- Sillon de Talbert -lightly oiled rocks; clean beach. 24 Apr- A flying gravel spit. -rocks lightly oiled; this is the furthest eastern extent of the oiling. SECTION XI 4.1+ + + DE TALBERT + 66A 65 61 AMC-17 62 ..... 67 63 -68 + PLEUSIAN 126 A 69 PLOUGRESCANT 7 A 7 70 127 0 2 Km [email protected]!Effliii"M _T: PENVENAN no oil 64 TREGUIER Figure 4-62. Locations of observation stations in Section XI, Port Blanc to Sillon de Talbert. Oil at the base of Sillon de Talbert represents the eastern-most extent of oil coverage observed. ft is 130 km (77 miles) from the wreck site. Oil distribution for the first study session is indicated by the dark-stippled pattern. For the second study period, heavy and light oil coverage are indicated by plus and light-dot patterns, respectively. 180 Oil Impact The coast from F-72 to F-66. Oil impact increased toward the north in the areas not shielded by the peninsula at Ploumanac'h (Section X). Initially, moderate to heavy oil accumulations occurred on most of these beaches. Particularly,hard hit was the headland at Castel Meur (F-66) which is located at the end of the peninsula. The cobble beach and adjacent sand flat were very heavily oiled. A large cleanup operation was active during our site visit on March 29. Oil was being pushed into newly dug trenches on the low-tide terrace so it could be suctioned-up by honeywagons. Two large oil storage pits were dug nearby as collect- ing ponds. Upon our second visit on April 24, the area was still heavily oiled, although most of the thick oil accumulations were gone. The cobbles and boulders of the beach were still oil-blackened. The tidal flat was severely dug up. The trenches had infilled but remained severely oiled. An oil sheen was common throughout the area. Live limpets were observed on the rocks, but many cockles and crabs were found dead. Speaking to a woman who lives by this beach, we learned that she depended on two things for her livelihood: summer tourists who come to the beach, and the collection of algae from along the swashline. Both sources of income were at least temporarily destroyed by the spill. The coast from F-65 to Sillon de Talbert. This segment includes a large estuarine sandflat system plus the rocky coast up to the Sillon de Talbert gravel spit. To our knowledge, no oil entered the estuary during the first two weeks of the spill. During our second survey, April 24, a light oil swash was present on all these beaches. Station AMC-17 bad the heaviest deposition o,f oil within this sec- tion and represents the major accumulation farthest from the wreck site. It has a poorly sorted, mixed sand and gravel beachface leading onto a very coarse-sand low-tide terrace. Sedimentary characteristics are presented in Table 4-20A. The overall shape of the beach is crenulate in nature, which served as a trap for the wind-transported oil. Oil was thickly deposited (up to 12 cm) at the northern end of the beach on March 29, whereas the beach to the south was free of oil. Plate 4-31 shows the beach at this time. Oil coverage as measured along the topo- graphic profile is presented in Figure 4-63. Penetration of oil into the beach was greatly inhibited by the compact substrate. The inter- stitial water of the low-tide terrace was noticeably contaminated. We estimate that 126 metric tons of oil were present at this time (Table 4- 20B). The military began to clean up the beach as we finished our survey. The hard substrate made it relatively easy to shovel up the oil into buckets to be carted away by tractors. On our second survey, on April 24, the major oil accumulation was gone, but the beach sediment and rocks appeared heavily oil-stained. In 181 Table 4-20A.. Grain size data for station AMC-17 in Section XI. Sample Graphic Mean Size Classi Skewness Standard Deviation 2 AMC-17A -0.174 VCS -0.238 2.236 (VPS) AMC-17B 1.461 CS -0.266 0.713 (MS) AMC-17C -0.577 VCS -0.498 2.000 (VPS) ISize Class 2Sorting VCS = very coarse sand VPS = very poorly sorted CS = coarse sand MS = moderately sorted Table 4-20B. Calculations of oil quantity at AMC-17 during first (March 19-April 2) and second (April 20-28) study periods. Station Number Date Oil Present Date Oil Present % Change (metric tons) (metric tons) 0 AMC-17 29 Mar 136.4 24 Apr 1.6 98.80 100 40 1-00 65 5 % OIL COVERAGE 10 I THICKNESS MM 20 2 5 120 AMC-17 1235 A a 29 3 78 Cr no burial C -1 UJI _J9 Figure 4-63. Topographic profile and oil coverage for AMC-17 on 20-00 10-00 60-00 80-00 Harch 29. DISTRNCE W 182 addition, some oil was buried 15 cm by new sediment along the upper beachface. A large (100 m2) mass of mousse also remained mixed into the low-tide terrace. The interstitial water was still contaminated, but healthy algae, snails, and limpets were found in abundance. We estimate that 1.6 metric tons of oil remained in the area (Table 4-20B). It was interesting that a large cobble beach directly to the south was signifi- cantly oiled on the second visit, whereas it had not been during the first. Apparently, some of the oil from AMC-17, or from other beaches, was redeposited in this area during the weeks between our first and second surveys. Summary Section XI encompasses the westernmost extent of oil pollution from the Amoco Cadiz (a distance of 130 km from the wreck). Station AMC-17 illustrates the importance of the trapping of oil along the northeast side of a crenulate bay during the first oiling and the eventual oiling of the southwest side as a result of a change in the wind direction. (According to C. J. M. Chass4, personal communication, the same thing happened on this coast during the pollution by the Torrey Canyon oil in 1967). 4.10 Preliminary Conclusions When our second site visit ended on April 28, significant quanti- ties of oil remained in the water and on the shoreline of the Amoco Cadiz oil spill site. it may take several years, or at least several months, for the remaining oil to be fully degraded. Therefore, any con- clusions drawn at this early date will have to be considered prelimi- nary. However, the complexity of the coastal system, plus the unusually large quantity of oil, provided a hitherto unequaled opportunity to learn about the behavior of spilled oil in the coastal zone. 4.10.1 Influence of Coastal Processes and Coastal Morphology Oil Dispersal Processes The spill of the Amoco Cadiz provided a classic field -experiment for the demonstration if-the effects of dynamic coastal processes and coastal morphology on oil deposition along the coast. Strong, almost unidirectional winds from the west rapidly forced the oil eastward during the first few days of the spill. The rugged and indented top- ography of the coast then played a major role in determining where the oil would be deposited. The shorelines facing west were hardest hit, whereas those facing east, particularly those within the larger embay- ments, were mostly unaffected. This process is depicted diagramatically in Fig. 4-64A. During early April, the dispersal pattern of the oil changed. Major oil accumulations were broken up and dispersed. Because of the wind shift at the beginning of April, the oil was spread far into 183 FIRST TWO WEEKS OIL TRANSPORT W I N D heavily oiled headlands no oil 'Figure 4-64. (Top) Oil pushed by AFTER ONE MONTH strong westerly winds during the first two weeks was mainly depos- WIND ited along westerly-facing head- land areas. Interior embayments less oil generally remained free of oil. less oil (Bottom) A wind shift during the beginning of April spread a light layer'of oil deep into the embay- lightly oiled ments. Previously deposited oil along the exposed headlands was greatly reduced in quantity. many of the large embayments, thereby oiling previously clean areas. However, instead of single large oil masses, only thin bands of small mousse balls or oiled algae were deposited along the swash lines. Oil dispersal during this time period is illustrated in Fig. 4-64B. Effects of Wave Action During our earlier studies of the Metula and Urguiola oil spills, we observed that the degree to which an area is exposed to wave action greatly influences the longevity, or persistence, of oil within that area. Similar observations were made at the Amoco Cadiz site. Rocks heavily oiled south of Portsall were clean a short time later because of high wave energy at that locale. Many of the exposed environments along each northward jutting peninsula were generally free of oil within 1 month. Conversely, as wave energy decreases, oil persistence increases. Very little change in oil coverage was noted inside the harbor at Portsall, at Castel Meur (F-66), or at Primel-Tr6gastel,(F-94). The marsh environment at Ile Grande illustrates an area with very low expo- sure to waves and, consequently, one with potential duration of oil effects. Beaches vs. Sheltered Rocky Areas W ND -ss [email protected] '.'g htly 0iled" In general, the sand beaches responded to natural cleansing much faster than sheltered rocky areas. Beaches undergo natural erosion and 184 depositional cycles in which large amounts of sediment are continuously reworked by waves. This action removes much of the oil within a rela- tively short period of time. In contrast, sheltered rocky areas and coarse-cobble beaches undergo change only during great storms. Also, oil seeping between rocks or into crevasses will be removed.from direct wave attack. Thus, under similar conditions of wave exposure, a sand beach is much more likely to be cleaned by natural processes than is a rocky area. Localized Geomorphic Controls of Oil Deposition Within the areas receiving the oil, specific morphological features influenced the oil distribution pattern. Included among these features are (1) crenulate bays, (2) tombolos, (3) low-tide terrace, ridge, and runnel systems, (4) scour pits around boulders, and (5) regional bedding and joint patterns in the bedrock. The catchment of oil by crenulate bays is illustrated in Fig. 4-65. Where crenulate bays occur on west-facing shorelines, as at Stations F-39, -62,-68 and AMC-9 and -17, they tend to trap oil at the head of the bay (northeast end), where the shoreline has its maximum curvature. The tail or southwest portion was usually free of oil during the first days of the spill (when winds were westerly). Another morphological feature, the tombolo (Plate 4-21), also had a marked influence on the initial deposition of oil. As illustrated at stations AMC-5 and F-20, oil became trapped behind rocks or a small island because of the convergence of wave fronts around the offshore rocks. This process is illustrated in Fig. 4-66. Other small-scale features that tended to cause localized oil deposition included scour pits around boulders, and jointing and bedding patterns in bedrock, both of which were observed at station AMC-13 (see Plates 4-16 and 4-17). An oil pond 5 cm deep was observed in a runnel on the low-tide terrace at station AMC-12. Oil Response to Beach Cycles Beaches undergo a cycle of erosion and depositi on in response to changing wave conditions. By making repeated measur6ments-of our per- manent beach profiles, we were able to observe the effect of the beach cycle on erosion and retention of the oil. The recovery of the beaches (by berm formation) after the initial period of high wave activity (during the early days of the spill) commonly caused deep burial of oil layers in the beachface. The removal of 80% of the oil from the Roscoff area during two tidal cycles can be attributed partly to the erosional phase of the beach cycle. Therefore, a basic understanding of the beach cycle provides a good foundation for interpreting the behavior of oil on the beaches. 185 WIND %NAVES MOUSSE -ROCKY HEADLAND TOMBOLO LONGSHORE L LONGSHORE TRANSPORT TRANSPORT CRENULATE BAYS beach* Figure 4-65. Entrapment of oil by Figure 4-66. Illustration of the crenulate bays. Generally, the tombolo effect causing localized southerly section.of each bay re- oil deposition behind offshore mained free of oil. rocks. 4.10.2 The Vulnerability Index On the basis of studies of the Metula and the Urquiola oil spills, we have developed the vulnerability index, a system of classifying coastal environments with respect to oil spill impacts (Hayes, Brown, and Michel, 1976; Gundlach and Hayes, 1978). The index is based mostly on predicted longevity of oil within each environment, but it has some biological criteria. Data derived from the study of this spill support some of our earlier conclusions and allow for further refinement of others. Following is a summary of the oil spill vulnerability index with particular reference to the Amoco Cadiz oil spill. The order listed (1- 10) is toward increasing vulnerability to oil spill damage; the higher the index value, the greater the long-term damage. A summary is pre- sented in Table 4-218. 8 it should be noted that the vulnerability index was developed in areas that could be-readily classified as erosional or depositional. The Brittany coast presents a variety of sand beaches which show deposi tional cycles, but which, for the most part, are undergoing long-term erosion. Scarps of either bedrock or dune material occur back of most of the beaches, partly inhibiting formation of a truly depositional beach profile (which normally has a well-developed berm, berm-runnel, and back-beach area). This affects the classification system by some what limiting our original estimates of oil penetration and burial, and generally reducing the overall persistence of oil in these areas. Still, in terms of general oil persistence, the basic order of the index holds true. 186 Table 4-21. The Oil Spill Vulnerability Index with particular reference to the Amoco Cadiz oil spill. Higher index values indicate greater long-term damage Sy the spill. For further information, consult Hayes, Brown, and Michel (1976) or Gundlach and Hayes(1978). Vulnerability Shoreline Type; Example Comments Index I Exposed rocky headlands; Wave reflection kept most of the oil Douarnenez to Pte. du Raz and offshore; no clean-up was needed. Primel-Tre"gastel to L6cquirec 2 Eroding wave-cut platforms; Exposed to high wave energy; initial south of Portsall and F-1 to oiling was removed within 10 days. F-82 3 Fine-grained sand beaches; All only lightly oil-covered after stations south of Roscoff one month, mainly by new oil swashes. (AMC-9 & 10) and east of Portsall,(AMC-5) 4 Coarse-grained sand beaches; Oil coverage and burial after one AMC-stations 4 (near Portsall) month remains at moderate levels. & 12 (St. Cava) and F-38 5 Exposed, compacted tidal No oil remained on the sand flat but flats; La [email protected] de St. Michel did cause the enormous mortality of urchins and bivalves. 6 Mixed sand and gravel beaches; The index value is due to rapid oil no really good example of this burial and penetration; all areas beach type had compacted subsurface which in- hibited both actions. 7 Gravel beaches-, stations F-80, Oil penetrated deeply (30 cm) into 95 and 129, also AMC.-i6 the sediment; clean-up by use of tractors to push gravel into surf zone seemed effective and not dam- aging to the beach. 8 Sheltered rocky coasts; Thick pools of oil accumulated in common throughout the study these areas of reduced wave action; area. clean-up by hand and high pressure hoses removed some of the oil (this process is valid in non-biologically active areas. 9 Sheltered tidal flats; Tidal flats were heavily oiled; clean- behind Ile Grande and at up activities removed major oil accu- Castel Meur mulations but left remaining oil deeply churned into the sediment; biological recovery has yet to be determined. 10 Salt marshes Extremely heavily oiled with up to 15 Ile Grande marsh cm of pooled oil on the marsh surface; clean-up activities removed the thick oil accumulations but also trampled much of the area; biological recovery has yet to be determined. 187 (1) Exposed steeply dipping or cliffed rocky headlands Two areas in particular fit into this category: (1) the cliff between Douarnenez and Pointe du Raz (Section I), and (2) the cliff between Primel-Tr4gastel and Locquirec (Section VII). In both areas, most of the oil was held approximately 10 m offshore by waves reflecting off the steep scarps. Some oiling did occur where reflected waves were dampened, as in small coves or pocket beaches. However, this is only a short-term condition since high-wave condi- tions will rapidly remove the oil. (2) Eroding wave-cut platforms A good example of this coastal type is located along the ex- posed coast between Tr6mazan (F-1) and Pointe de Landunvez (F-82) in Section II. Heavy oil accumulations that were originally found at Tr4mazan rapidly dissipated under repeated wave attack. (3) Flat fine-grained sandy beaches Fine-sand beaches are located to the southwest of Roscoff (stations AMC-9, AMC-10, F-17,-18 and-20) and to the east of Portsall (AMC-5). Each has a very broad beach/low-tide terrace. The beach profile is essentially flat. Within I month after being heavily oiled, each was categorized as having a light oil coverage, ,usually with only a minor oiled swash line. Cleanup activities at AMC-5 appeared to have caused little damage. (4) Steeper, medium- to coarse-sand beaches Beaches at stations ANC-4 and AMC-12 provide goodexamples of heavily oiled coarse-sand beaches. 'One month after heavy oiling, each still contained moderate to heavy oiling. Overall recovery was somewhat slower than at areas with index values of 1 to 3. Much of the beachface still contained oil or was oil-stained. Burial was also more common, but somewhat inhibited by underlying, relict marsh or compact sandy gravel material. Again, this illus- trates the complexity of the Brittany coast with regard to its erosional history.. The coarse-sand beach at F-38, with no under- lying base material, had 70 cm of oil burial. (5) Exposed, compactSd tidal flats The large sand flat at St. [email protected] falls under this classification. Most of the oil was pushed across the tidal flat onto the beach at its edge. The flat itself was not significantly oiled; however-, the enormous biological destruction caused by the. oil [email protected] its central position on this list. Perhaps, in terms of a truly biologically oriented oil spill index, this type of en- vironment should be placed higher. 188 (6) Mixed sand and gravel beaches There were no truly depositional-mixed sand and gravel beaches in the spill area. Our original designation of this beach type as (6) was based on expected deep oil penetration. Each mixed sand and gravel beach in the spill area (AMC stations 1, 2, 6, 8 and 17) had an underlying material of compacted sediments that totally prevented oil penetration. Of these beaches, three were heavily oiled after 1 month, but two had only light coverage. The dif- ference in remaining oil content is more attributable to variations in wave energy than to sediment type. (7) Gravel beaches All gravel beaches of the area remained heavily oiled 1 month after the spill. Typical examples are provided at F-stations 80, 95, and 129 and at AMC-16. In each case, oil penetrated deep into the beach sediment. Had cleanup not been started, it could be expected that the sediments would have become cemented together as the mousse turned to asphalt. This process was observed at the Metula site where no cleanup took place (Hayes and Gundlach, 1975). (8) Sheltered rocky coasts .After I month, many sheltered rocky areas remained heavily oiled. Cleanup by hand and bucket and with water under high pressure reduces the amount of oiling but it is a slow and very tedious process. (9) Sheltered estuarine tidal flats Examples of this environment type are best illustrated by the sheltered environments behind Ile Grande and at Castel Meur (F-66). Oil coverage at both localities was exceedingly heavy. Clean-up activities succeeded in removing 80%-90% of the oil on the surface, but also extensively'dug up the tidal flat. A large quantity of oil remains mixed into the sediment, and the interstitial water remains severely contaminated. The biological recovery of each area should be monitored. (10) Sheltered estuarine salt marshes The marsh at Ile Grande provides a classic example of the worst effects of an oil spill. A very extensive cleanup removed most of the 5 to 15 cm of pooled oil from the marsh, but overall biological recovery cannot'yet be guaranteed. 189 Summary Although the coastline of Brittany is exceedingly complex, the vulnerability index of coastal environments to oil spill damage, which was developed through studies at other spill sites, would have predicted the short-term behavior of Amoco Cadiz oil in each environment reason- ably well. Environments rated high on the scale generally remain more highly oiled today (and generally represent more severe environmental damage) than those areas with low values. Thus the utility and applica- tion of this scale as part of a contingency plan for threatened areas (e.g., the coast of Alaska) seems to be clearly justified. 4.10.3 Oil Response to Tide-Level Changes One of the questions raised by our previous oil spill studies (mainly those of the Metula and Urquiola spills) is whether the oil lifts off the bottom with every flood tide or instead becomes sediment- logged and'remains on the bottom. At Portsall (AMC-1) and Les Dunes- East (AMC-5), we monitored oil reaction during a flooding tide. At AMC- 5, we also watched oil reaction during the ebb cycle. During the initial oiling, the first week after the grounding, oil definitely lifted off with the incoming tide, and was redeposited on the ebb. However, during the second study period of late April, a large patch of sediment-bound oil was found on the tidal flat at Portsall. Some oil had mixed with the sediment and had sunk. Therefore, as has been hypothesized by others, a possibly significant percentage of the oil spilled by the Amoco Cadiz may have actually surik to the bottom. 4.10.4 Oil Contamination of Interstitial Ground Water After visiting a number of oiled areas, it became obvious to us that the problem of oil contamination of the ground water within the beach may be a cause of death to organisms living within the sediment. In many sites, even though the surface of the beach or tidal flat ap- peared completely clean, the interstitial ground water was severely oiled. Localities such as Portsall (AMC-1), Roscoff (AMC-6), and St. [email protected] (F-55) provide typical examples. The ground water within a beach rises and falls with each tidal cycle. On the receding tide, large quantities of the ground water flow out of the beach, creating a series of ground water rills. However, a significant portion remains tied up within the sediment by capillary forces. Oil may enter the ground water directly from the ocean water itself or through solution along the upper part of the beach. Contaminated ground water has an obvious oil sheen and often has visible droplets of mousse. If the concentration of oil in the ground water reaches lethal proportions, then death of infauna (cockles, heart urchins, razor clams and worms) may result, even though the surface of the area is not vis- ibly oiled. 190 A question that remains to be answered concerns the longevity of this type of oil contamination: Is the ground water periodically flushed clean, or will it remain contaminated for months or even years? Unfortunately, some of the methods now being employed to clean up the beach undoubtedly intensify the pollution of the ground water by the oil. The digging of large pits and trenches into the beach surface to use as catchment basins, such as those we witnessed At St. Michel-en- [email protected], can only increase the contamination. Follow-up studies of beach processes and water chemistry are needed for a better understanding of this problem. 4.10.5 Cleanup Activities Our perspective of the cleanup operation is from a geomorphological standpoint and not from the technical side. (See Chapter 6 for details on engineering techniques.) We are fortunate that our co-participant, Dr. Laurent D'Ozouville, has maintained contact with the Department of Equipment concerning the types of cleanup operations in force. Our combined suggestions follow: (1) Restrict vehicular traffic on the beac h, especially on the low-tide terrace. Oil often became deeply churned into the sediment as a result of heavy tractor usage. If tractors and trucks must be used, a single lane of traffic should be utilized. (2) The removal of oil by manually scraping the surface layer with wood squeegees into trenches, to be suction6d off, is a valid method. However, natural infilling after abandonment of the pit often caused the deep burial of large amounts of oil. This oiled sedi- ment should be dug up and placed in the surf zone so it can be cleaned by wave action. Long-term contamination of the inter- stitial water may otherwise result. (3) The use of front-end loaders to scoop up thick layers of oiled sediment is valid in low-populated dune areas. This practice in areas that lack a readily replenishable sand supply may cause serious beach erosion problems. In general, any removal of sedi- ment from the beach should be avoided. (4) The use of bulldozers to plow oiled gravel into the surf zone is an excellent method for oil removal, because the sediment balance on the beach is maintained and the normal beach profile can be re- established by natural wave action. (5) In general, the clean-up effort at Ile Grande marsh was laudable. The removal of oil from the marsh was necessary to establish any sort of biological recovery. The use of trenches to drain oil pools, as well as squeegees, buckets, and pressurized water, all seem valid from an environmental point of view. However, a problem 191 did arise by not limiting vehicles and personnel to certain access roads. The extensive walking and driving over the marsh may have further inhibited its recovery. 4.10.6 Where did-the oil go? Two of.the primary questions usually raised during an oil spill are "Where did the oil go?" and "How did it change?". In a very basic attempt to answer these questions, we have made extrapolations from our areas of detailed study to the entire oil-affected coastline. This method has two weaknesses: (1) Our study areas were generally limited to beaches. Thus, extrapo- lations to rocky areas may not be valid. (2) We may be counting the same oil twice. For example, most of the oil within our Roscoff stations was removed by erosion on the night of March 24. This could be the same oil that we encountered in the Ile Grande area on March 29. Calculations of oil coverage were made for the morphological -sections (I-XI) of the coast during each of the two study periods. The results of this calculation are presented in Table 4-22. Using 17 of the 19 AMC stations as a basis (AMC stations 14 and 19 were eliminated), we calculated the average oil quantity per km of coast. Table 4-22. Extent of oil'coverage during study periods one and two. Oil is descri 'bed as heavy only during study one (March 19- April 2). During study two (April 20-28), it is described as light or moderate-to-heavy. Section Study Period I Study Period 2 of Coast- (km oiled) km lightly km heavily total km oiled oiled of coastline 1 0 52 39 280 11 5 8 24 16 15 8 43 IV 4 30 0 38 V 4 43 0 43 Vi 8 10 4 27 VII 4 24 9 76 VIII 9 10 20 35 Ix 5 4 4 16 X 2 12 6 35 XI 9 8 9 36 Total 72 213 180 653 192 The results of these calculations are presented in Table 4-23. In order to determine the total amount of oil on the coast, the amount of oiled coastline (Table 4-22) was multiplied by the quantity of oil per km of coastline (as determined from the individual study sites; Table 4-23). The values used were 886.5 tons/km for all oiled areas during the first study, and 55.4 tons/km for moderately to heavily oiled areas, and 5.2 tons/km for lightly oiled areas during the second study. The results are presented in Table 4-24. Table 4-23. Oil quantity per length of beach for 17 AMC stations during study period one (March 19-April 2) and study period two (April 20-28). OIL CONTENT (metric tons) LENGTH AMC-STATION OF BEACH SESSION ONE SESSION TWO Light Coverage Heavy Coverage 1 500 50.2 7.3 2 250 1.8 2.4 3 250 44.6 5.5 4 200 284.1 2.5 5 1250 1146.9 2.5 6 200 51.8 1.0 7 200 102.5 1.7 8 200 9.6 0.4 9 2000 1039.4 10.6 10 1250 .46.3 6.0 11 450 175.2 1.0 12 400 357.7 6.3 13 550 248.3 0.6 15 300 83.3 3.9 16 400 81.2 66.3 17 300 136.4 1.6 18 4000 7400.0 500.0 SUB TbTAL 12.7 km 11259.1 24.4/4.7 km 595;2/10.75 km TOTAL (metric tons)/km 886.5 5.2 55.4 After clean-up 193 Table 4-24.. Summary of data concerning shoreline coverage by oil and estimated total quantities for study sessions one and two. Session one (19 Mar - 2 Apr) Session two (20 - 28 Apr) km shoreline heavily 72 180 oiled km shoreline lightly - 213 oiled total shoreline 72 393 oiled km total quantity 0'f 63,828 m tons 11080 m tons oil along shoreline Total reduction between sessions 83% During the first 2 weeks of the oil spill, a total of 72 km of coast was heavily oiled. Using our estimated quantity of oil per km of shoreline (886.5 tons) yields a total of 63,828 metric tons of oil (rounded to 64,000) that we are able to account To-r.TiF1-Si`sapprox- imately one-third of the total amount of oil lost from the tanker. The remaining two-thirds must be accounted for by evaporation loss, oil masses remaining on the water's surface, sinking to the bottom, and mixing into the water column. During the second study session, 213,km of coastline were lightly oiled and 107 km were heavily oiled. Using our oil estimates for ses- sion two (Table 4-22), we can account for 10,310 metric tons of oil (a loss of 84% of the oil on shore during the first visit). This continued loss of oil from the shore can be attributed to a combination of natural cleaning processes and a very active cleanup program. In conclusion, approximately one-third of the oil spilled from the Amoco Cadiz (estimated at 64,000 metric tons) went aground on 72 km of shoreline during the first 2 weeks of the spill. During the following 3 weeks, the quantity of oil along the shoreline was reduced by 84% (to approximately 10,310 metric tons). This reduction was due to natural dispersion and to cleanup activities by man. On the other hand, the amount of shoreline visibly contaminated by the oil increased to 320 km by late April. This increase was due to the break-down and'dispersion of the large oil masses by waves and currents and to a major shift in wind direction (from westerlies to easterlies). 194 4.11 References Chass6, Claude J. M. (1972): Economie sedimentaire et biologique (production) des estrans meubles des cotes de Bretagne: [email protected], L'Universit4 de Paris VI, 293 pp. Debelmas, Jacques (1974): Geologie de La France: Vol. 1 Vieux Massifs et Grands Bassins Sedimentaires: DOIN Editeurs, 8, Place de l'Odeon, 75006 - Paris, 293 pp. de Martonne, Emm. (1903): Le d6veloppement des c6tes bretonnes et leur 4tude morphologique: Bull. Soc. Sc. Medic. Ouest (Rennes), 12:244- 260. de Martonne, Emm. (1906): La peneplaine et les co^tes bretonnes: Ann. Geog., 15:299-328. Emery, K. 0. (1961): A simple method of measuring beach profiles: Limn. and Ocean., 6:90-93. Folk, R. L. (1968): Petrology of sedimentary rocks: Hemphill's, Austin, Texas, 170 pp. Guilcher, Andr6 (1948): Le relief de la Bretagne meridionale de la Baie de Douarnenez @ LaVilaine: [email protected], L'Universit6 de Paris. Guilcher, Andre (1958): Coastal and submarine morphology: translated by B. W. Sparks and Rev. R. H. W. Kneese, Methuen & Co., Ltd., London, 274 pp. Gundlach, E. R., and M. 0. Hayes (1978): Vulnerability of coastal environments to oil spill impacts: accepted for publication by Marine Tech. Soc. Jour. Hayes, M. 0., E. H. Owens, D. K. Hubbard, and R. W. Abele (1973): Investigations of form and processes in the coastal zone: in Coastal Geomorphology (D. R. Coates, ed.), Proc. Third Ann. Geomorph. Symp., Binghampton, New York, 11-41. Hayes, M. 0., and E. R. Gundlach (1975): Coastal geomorphology and sedimentation of the Metula oil spill site in the Straits of Magellan: Final report to NSF-RANN, Coastal Research Division, Dept. of Geology, University of South Carolina, Columbia, South Carolina, 103 pp. Hayes, M. 0., P. J. Brown, and J. Michel (1976a): Coastal morphology and sedimentation, Lower Cook Inlet, Alaska: with emphasis on potential oil spill impacts: Tech. Rept. No. 12-CRD, Coastal Research Division, Dept. of Geology, University of South Carolina, 107 pp. 195 Hayes, M. 0., C. H. Ruby, M. F. Stephen, and S. J. Wilson (1976b): Geomorphology of the southern coast of Alaska: 15th Conf. on Coastal Eng., Proc., 2:1992-2008. 196 5. BIOLOGICAL, OBSERVATIONS F. A. Cross,' W. P. Davis, 2 D. E. Hoss, 1 and D. A. Wolfe3 This report is a compilation of our own observations and data, combined with those of other NOAA/EPA specialists, and also includes information obtained from investigators at the Centre Oceanologique de Bretagne (COB), the Universit6 de Bretagne Occidental (UBO), the Station Biologique Roscoff, and others as noted. Observations by U.S. biolo- gists began March 26 following briefings from the NOAA Spilled Oil Research Team which had been conducting overflights and beach surveys since March 19--two days after the Amoco Cadiz went aground. . The information presented in this chapter does not reflect the results of a pre-planned biological study. Instead, predominantly qualitative observations were made by NOAA/EPA biologists from late March until late May while observing the development of French programs designed to assess the biological impact of the spill. During this time, selected sites were chosen to develop fam iliarity with the diverse ecological habitats involved and togather as much early event information as possible in an effort to obtain a general understanding of the effects of the oil spill on marine organisms in- cluding commercial species. These activities included (1) observing and photographing biological effects along the coast and, in some instances, making repeated observations at the same site over a period of about six weeks, (2) visiting two bird hospitals and a marine bird sanctuary, and (3) conduct-Ing interviews with representatives of various segments of the fishing industry. The geographical range of observations extended from le Conquet to Perros-Guirec--a distance of approximately 200 kilom- eters by coastline. In addition, a quantitative study on benthic organ- isms from three typical intertidal habitats was conducted by Jeff Hyland of the EPA, and his report is appended to this chapter. We hope that the following information will serve as a reference to assist in planning for ecological impact assessment research on oil spills and will prove useful until more in-depth collaborative studies by French, Canadian, and U.S. scientists are completed. INOAA/NMFS, Southeast Fisheries Center, Beaufort Laboratory, Beaufort, NC 28516. 2U.S. EPA/ERL, Bears Bluff Field Station, Johns Island, SC 29455. 3NOAA/ERL, OCSEAP, Boulder, CO 80302. 197 5.1 General Field Observations 5.1.1. Impact on Intertidal Communities The portion of the Brittany coast impacted by the oil spill con- sists of diverse ecological habitats and biological communities, includ- ing exposed sandy beaches, rocky headlands, protected bays, estuaries, and marshes. Biological communities in all these habitats were sub- jected to stress by the oil. As discussed in the previous chapter, shorelines facing westward were the first to be oiled and received the largest amounts. Although wave action effectively "cleaned" or removed much of the oil from ex- posed rocks on the open coast, a considerable amount of oil was trapped in tidal pools, or remained on macroalgae such as Ascophyllum, Pelve- tiopsis, and Fucus which are attached to rocks. On exposed sandy beaches, oil often was covered by a layer of sand that gave the beach the appearance of being clean (see Plate 4-26). In reality the buried oil contaminated interstitial water throughout the entire area of impact, and a visible sheen could still be observed in the interstitial water in late May. Impact of the oil on intertidal communities in general was quite severe (also see the Appendix, this chapter). As discussed above, macro- algae on exposed rocks tended to retain the oil long after it had been removed from bare rocks by wave action (Plates 5-1 and 6-10). In addi- tion to potential adverse effects of the oil on the macroalgae, reten- tion of oil by this material undoubtedly increased contact time between the oil and organisms living beneath the algae. Although many of the macroalgae had, at least, a thin coating of oil, they did not appear to be dead except in a few areas that were extensively and repeatedly oiled, such as the upper intertidal beaches directly inshore from the wreck. More chronic effects may be occurring, however, as several preliminary bioassays by R. Steele on these plants indicate that the fertilization process failed to occur in exposed algae (EPA Progress Report on Amoco Cadiz Oil Spill, May 2, 1978). In previous work Steele (1977) found that exposure to crude oil prevented germination in Fucus edentatus. In addition, preliminary studies by scientists at COB in- dicate that growth of some macroalgae (Laminaria) has been affected by exposure to oil, and erosion of the edges of the blades of these plants has been observed. Adverse effects from exposure to oil were noted on limpets (Patella vulgata and P. aspera) over most-of the impacted coastline. We observed limpets with @hells covered with oil (Plate 5-3) as well as limpets in a recently dead or moribund condition. As seen in Plate 5-5, mousse was trapped under the shell and retained there even after the surrounding rock had been cleansed by wave action or clean-up operations. The oil trapped under the shell caused these animals to lose contact with the rock, fall onto the sand and die, after which many of them were eaten by 198 seagulls (Plate 5-4). This sequence of observations was not uncommon, and the sensitivity of limpets to oil has also been noted by other investigators (Baker et al., 1977). Nearly complete mortality of limpets and periwinkles occurred in the rocky intertidal zone immediately inshore of the wreck, just north of Portsall. At most other locations, however, live limpets, many heavily oiled on the shell, could still be found 5 to 8 weeks after the spill. Many of the oiled limpets had moved to tidepools where the rock surfaces had not been oiled. At Roscoff there was clear evidence by May 20 that the limpets were grazing over lightly oiled rocks and con- tributing to the cleanup process. As the oil penetrated into the sand, molluscs and'polychaetes emerged to the surface where they were more susceptible to wave action and predators (Plates 5-2 and 5-6). Live cockles (Cerastoderma-Cardium edule), in particular, were observed on the surface in sandy environ- ments all alongthe affected coast. The valves of many of these ani- mals could be pulled apart easily, which indicated their weakened condi- tion prior to death. The mortality of intertidal organisms (e.g., cockles, limpets and snails, Littorina), in general, did not occur as soon as mousse entered their environment but was observed over a period of two months following the wreck. Heaviest mortalities probably occurred in the first 2 to 3 weeks. Six to 8 weeks after the spill most of the heavily impacted, sandy beaches had undergone extensive cleaning both from the concen- trated efforts of cleaning crews and from tidal and wave action. Large numbers of dead and moribund organisms were not seen at this time and many of the sandy intertidal areas appeared superficially "normal". Large numbers of Arenicola marina could be found actively extruding fecal matter from their burrows on most beaches. At two sites, however, we attempted to locate other living infaunal organisms with little success. On the beach at Dunes de Ste. Marguerite (AMC-11)* on May 7, 5 to 6 square meters were raked by hand for cockles and clams. None were found, although the dead shells on the beach suggested that they had previously been present in large numbers. Identical sampling of a similar but unaffected area on the south coast of Brittany produced 3 to 20 cockles per square meter along with associated clams (mainly Venerupis aurea). Exceptions to these observations did occur. The beach at St. Efflam is one notable example which is discussed later in this chapter. The intertidal sand beach at Corn ar Gazel, which was sampled for species composition of infauna, is another (see Appendix, this chapter). On March 31 the water of this embayment had a strong odor of oil and was *AMC designations represent geological stations; see Fig. 3-1. 199 milky-colored. A variety of freshly killed or moribund organisms was' found (see Fig. 5A-1, Appendix), the most notable of which was Arenicola marina. Several individuals of this species were observed extending part-way out of the sand, yet Arenicola has been generally shown to be resistant to at least low concentrations of oil (Gordon et al. 1978, Baker et al. 1977). The acute situation at Corn ar Gazel may have been related to the recent use of dispersants since the milky color of the water could have been due to droplets of emulsified oil. This milky water was very localized; a small embayment less than one-half kilometer to the west had normal-looking seawater, and relatively few dead organisms were observed. Although it is possible that the milky water came from offshore where ships of the French Navy were actively discharging dis- persants, these chemicals were also used by clean-up crews along the shore. In late April, a clean-up crew was observed using dispersants and the nearby water turned a milky color that could still be seen several hours later. Clean-up crews also had been working on the beach at Corn ar Gazel just prior to our arrival and may have been using dispersants as well. We observed dispersants being used to clean seawalls at Roscoff on April I and rocks near Santec on April 8 and between Ploumanac'h and Perros-Guirec on April 30. The operation at Roscoff consisted of men spraying the solution from canisters strapped to their backs prior to washing with water under high pressure. From discussions with the clean-up crew we learned that a much stronger dispersant had been used earlier but it irritated their eyes and skin and they had switched to a milder one. With this milder dispersant it was often necessary to use two treatments to remove the oil. On the beach directly below this cleaning operation, dead and dying cockles, nereid polychaetes, and periwinkles were observed. To what extent the use of dispersants con- tributed to these mortalities is not known, but the toxicity of dispers- ants and dispersant-oil.mixtures has been previously documented (Wilson, 1974; Nelson-Smith, 1968; Smith, 1968). Near Santec and Ploumanac'h, firetrucks containing mixtures of water and dispersants were being used. An empty drum at Santec was labeled Treatolite demulsifer, Petrolite Corporation, London. In some locations, part of the observed mortality could probably be related to cleanup activities. For example, intertidal.rocks on the beach at Meis-Vran had been cleaned prior to May 7 with water under high pressure or more probably with steam. These rocks retained none of the typical molluscan fauna. Shell of limpets (Patella), periwinkles (Littorina), and trochid snails (Gibbula-and Monodonta) were washed into drift rows streaming down from the rocks into the adjacent sand. In the .lower part of the intertidal zone, however, limpets were still living beneath seaweed attached to rocks. 200 Other mortalities were related to specific events. Large kills of amphipods (Talitrus saltator) were observed by the geological team at several locations. These kills can be related to the spring tides in late March which deposited oil high on the beach or at the base of dunes, thus impacting the habitat of this species on a single occasion (see Plate 4-24). The extent of petroleum impact on more protected environments such as estuaries, bays, and marshes was determined primarily by the config- uration of the coastline. Estuaries or bays facing west were much more heavily impacted by oil than those facing east (see Chapter 4). The Aber Benoit and Aber Wrac'h estuaries near.the wreck site and Rulosquet marsh at Ile Grande (AMC-18), about 90 kilometers by air from the wreck, acted as catchment basins, and relatively large volumes of oil were funneled into these habitats (see Chapter 3 for results of chemical analyses). Rulosquet marsh at Ile Grande, the beach at St. Efflam, and the Aber Benoit estuary, were the most impacted environments observed. A description of the extent of oiling in the marsh and associated biologi- cal communities is given in Chapter 4 and the Appendix to this chapter (also see Plates 4-1 and 6-16). Observations made on March 30 indicated that the entire community of the macrofauna was in the process of dying since the entire marsh was covered with a thick layer of oil. Crabs (Carcinus maenus), polychaetes (Nereis diversicolor), and cockles were the most abundant animals affected (Plate 5-7). Still live but heavily oiled crabs sought refuge on seagrasses and debris and were sluggish upon being touched. Polychaetes were emerging from the sediments and attempting to remain in small patches of unoiled seawater (Plate 5-8) but often.were observed struggling in the oil. Three days later (April 2) the NOAA geological team revisited the marsh and it appeared that virtually complete mortality of macrofauna had occurred. Thousands of dead polychaetes were observed in small saltwater pools contained within larger pools of oil (Plate 5-9), and many dead crabs were on the marsh surface. Live 'struggling animals were not observed as on March 30. (For additional description of t 'hese observations, see Chapter 4.) Initially we considered this location as an area for potential study of long-term effects of oiling on marsh ecosystems. Studies will not be possible at Ile Grande, however, since cleaning crews have removed the top 20 to 25 cm of marsh over most of the affected area. This removal started on April 30 and was done with heavy equipment which generally excavated the marsh plants including the entire root system, leaving a bare sand-clay surface. On May 19 the marsh was revisited, and at this time, heavily oiled high marsh grass (Juncus?) was observed around the perimeter of the excavated area. Many of these plants had 4 to 6 cm of new bright green growth beneath the blackened and dead oiled portion of the stem. The most dramatic biological effects of the oil spill that were observed occurred along a sandy beach near the village of St. Efflam on 201 April 2. This beach is located on the western side of an embayment (Lieue de [email protected]) approximately 84 km by air from the wreck site. The geological station (AMC-15) is on the eastern side of this same embay- ment near St. [email protected] On April 2, approximately [email protected] km of beach at low tide were covered by seven swash lines of dead organisms, predom- inantly urchins and molluscs, which extended for several hundred meters from the high tide line seaward (Plates 5-10 and 5-11; see also Plates 4-6 and 4-7). These organisms consisted primarily of tests of heart urchins (Echino.cardium cordatum), razor clams (Ensis siliqua and Pharus legumen), cockles, and small surf clams (Mactra cinerea). In addition, many polychaete tubes (similar to Diopatra along the east coast of the United States) were found along the lower swash lines. Several attempts were,made to quantify the extent of mortality. One approach was to mark off one-square-meter sections in several swash lines and count all dead organisms within each square (e.g., Plate 5- 12). Because the animals were not evenly distributed along the swash lines, we Attempted to select areas that appeared to represent average concentrations of dead organisms within a swash line. One square meter that was counted contained 93 urchins, 52 razor clams, 75 cockles, and 39 surf clams. Another square meter yielded 14 razor clams, 33 surf clams, 56 cockles, and numerous worm tubes that we did not count. Other organisms also present along the beach but in lesser numbers included mussels (Mytilus edulis), small clams (Venerupis decussata, Venerupis pullastra, Tellina tenuis and Lutraria lutraria) and several unidenti- fied tunicates. One dead cormorant was observed as well (Plate 5-13). Three estimates of the number of dead organisms were made along this beach on April 2 by the NOAA team studying the effect of coastal processes on oil-sediment interaction. The following estimates appeared in the preliminary NOAA report on the Amoco Cadiz oil spill, Appendix B. (1) "A swash line of dead heart urchins (Echinocardium sp.) 300 m long and 25 m wide was counted, based on the number of dead organisms occurring within a one-meter wide swath meas- ured perpendicular to the swash line. The total arrived at was 120,000 dead urchins within that one swash line." (2) "A swash line made up predominantly of dead razor clams 250 m long and 6 m wide was also measured using the same method as in (1). According to our estimate, there were 45,000 dead razor clams within that single swash line." (3) "At evening low tide (7:00 p.m.) on April 2, the entire intertidal area was littered with shells of dead organisms. As the tide fell, a cover of approximately 3 to 5 dead organisms/m 2 was left behind. Heart urchins were by far the dominant species. At that time, the intertidal zone was measured to be 570 m wide. Assuming that each square meter contained 4 dead urchins (based on several counts), a 500 m 202 long section of the beach would have contained 1,140,000 dead urchins.. Therefore, several million dead urchins were present on the surface of the intertidal zone at that time, in addi- tion to hundreds of thousands of dead clams and worms." In contrast to these massive mortalities, deposit-feeding poly- chaetes (probably Arenicola) appeared to have tolerated the elevated levels of hydrocarbons. Relatively high populations of these worms were actively pumping fecal material onto the surface of the sand in the region between the last swash line and the low water mark. An estimate placed their abundance at 15/m 2. This observation was not unique to this beach; we also observed active deposit-feeding polychaetes on beaches where cockles and clams, in the process of dying, were emerging from the sand. Although this kill was observed 16 days after the wreck, there is evidence that suggests that the die-off was recent and catastrophic in nature. This same beach had been visited at low tide by NOAA and EPA scientists on March 28 and on March 30, and this massive mortality was not then observed. We were told of the kill on April 1 while in Roscoff, so several million dead organisms were washed up on the beach over a 2 to 3 day period. Many of the dead molluscs had soft body tissues still attached to the shells (Plate 5-13); others appeared normal except that the valves could be pulled easily apart. On a follow-up trip made to the same beach on April 14, freshly dead clams were found, indicating that mortality was continuing among the clam populations. In addition, some mussels were observed to be dead or dying in the area at this time. Thousands of tests of dead heart urchins and the shells of razor clams were still present, but it was obvious that they had been dead for some time and no freshly killed specimens were observed. The polychaete population, on the other hand, appeared not to be acutely affected, as indicated by the large number of mounds of fresh fecal material in the lower tidal areas. By April 30, clean-up crews and wave and tidal action had removed nearly all traces of this earlier mortality from the beach. Only oc- casional urchin tests and razor clam shells could be found, half buried in the sand. Shells of the clam, Tellina tenuis, with the ligaments still intact, were abundant. Several shovelfuls of sand were shifted by hand and only one live Tellina was found. The onset of mortalities in the St. Efflam area could have been triggered at least two ways. First, this region received massive amounts of oil that were trapped by the coastline extending from St. [email protected] to Perros-Guirec. Retention of oil in these waters, particularly the Bay of Lannion, was probably high and a latent period was required for the dissolved concentrations of hydrocarbons to reach toxic levels, mix to the bottom (which may have been to depths of 40 to 60 m), and penetrate into the sediment. The other possibility is that 203 the use of dispersants in coastal waters accelerated the dissolution and vertical movement of the oil. Whatever the cause, oil was effectively mixed to the bottom in the Bay of Lannion; large numbers of dead urchins were photographed at 20 m depth during cruises of the CNEXO/COB ship R/V Thalia, and grab samples of sediment from this same area had extremely high concentrations of total hydrocarbons (Dr. L. Laubier, personal communication). The presence of polychaete tubes on the beach may have been caused by physical processes rather than by toxicity. The tubes appeared to have been broken or torn with the top portion being transported to the beach. Such an occurrence can be more easily explained as resulting from the heavy wave action that pounded the coast following the wreck than from toxic effects of'the oil. We would not expect the latter process to result in the breaking of the parchment-like tubes. This area of the coast is the site of proposed long-term studies by scientists at UBO and COB. Dr. C. Chass6 (UBO) had previously conducted an intensive ecological study of benthic fauna at Lieue de [email protected] as part of a doctoral dissertation (Chassg, 1972) that will provide baseline information for future studies. In addition, scientists at COB have begun to obtain quantitative data on benthic fauna in the Bay of Lannion, as well as to photograph benthic epifauna and measure hydrocarbon levels in the water and sediments at regular intervals. 5.1.2 Impact on Marine Bird Populations The oil spill occurred at a time of year when many species of marine birds were in the process of migrating to summer nesting grounds. Some species that winter in this area were in the process of leaving (e.g., loons, ducks); other species that winter to the south or at sea (e.g., gannets and auks) were arriving to begin the nesting season. Two organizations were responsible for tabulating kills by species (Plate 5- 15) as well as operating bird hospitals to treat live oiled birds. The Societ4 pour 1'@tude et la Protection de la Nature en Bretagne (S.E.P.N.B.), associated with UBO, was responsible for coastline west of Locquirec, and the Ligue Francaise pour la Protection des Oiseaux (L.P.O.), a private organization, was responsible for coastline east of Locquirec. The tabulated kill by April 14 was about 3,200 birds consisting of about 33 species. Four species, however, accounted for about 90% of the kill reported by S.E.P.N.B. and 80% of the kill reported by L.P.O. (Table 5-1) (S.E.P.N.B. and L.P.O., personal communication). These four species consisted of the razorbill (Alca torda), the guillemot (Uria salge), the puffin (Fratercula arctica) and the shag or cormorant (Phalacrocorax aristotelis). 204 Table 5-1. Predominant species of birds impacted by oil as of April 14-16, 1978. Species Reporting Organization L.P.O. S.E.P.N.B. No. of % of Tabulated No. of % of Tabulated Dead Kill for Dead Kill for Birds All Species Birds All Species Guillemot 302 28 513 24 Shag 162 15 415 20 Razorbill 183 17 379 18 Puffin 205 19 679 32 Estimating the total kill of birds along the section of coast impacted by the oil, on the basis of the above figures, would be dif- ficult for the following reasons: (1) Variations in wind and current patterns following the wreck affected the numbers of birds brought ashore or carried to sea. (2) Some parts of the coast are not readily accessible. (3) An unknown number of birds reportedly were picked up in the clean-up operations and not tabulated. (4) Species-specific behavioral patterns (e.g., those birds that spend most of their time swimming and diving rather than flying were most affected). A potential chronic impact on-marine bird populations may result from feeding on contaminated prey. Sea gulls were observed feeding on freshly-killed intertidal organisms at a number of locations along the coast. This was particularly true on sandy beaches or intertidal flats that were not heavily covered with oil. Shorebirds and seagulls were conspicuously absent, however, in areas heavily covered with oil, such as,the Aber Benoit estuary and the marsh at Ile Grande, although many recently killed invertebrates were present on the sediment surface. The single most important nesting area for marine birds within the area of impact is Les Sept Isles Bird Sanctuary. This sanctuary, com- posed of seven islands and many rocky outcroppings, is located about 3 miles off the coast of Brittany near the town of Perros-Guirec (Figs. 1-3 and 5-1). These islands, which are about 100 km by air from the wreck site, are a natural reserve under government control and are managed by L.P.O. They are restricted from human activity except for Ile Aux Moines, which can be visited only with special permission from L.P.O. 205 SEIZH [email protected]& Z FS SEP V .. ZIC CoSrAN C R Art Bot4lo 'ILI AUX RAU I AUX.114WIS CF OQUS CW3 Figure 5-1. Islands constituting Les Sept Iles (From Milon, 1972). Although many species of marine birds nest or feed on and around the islands, this sanctuary provides protection for three species of marine birds now considered rare or threatened in France. These are the .puffin, the razorbill, and the guillemot, which represent three of the four most impacted species relative to total numbers of birds killed along the coast. Two of the islands, Rouzic and Melban, support the southern-most nesting colony of the puffin in Europe (Plate 5-23). These islands are normally visited only once per year when two scientists conduct a census of nesting birds. Prior to the wreck of the Torrey Canyon, which occurred at the 'same time of year as the Amoco @[email protected], over 2000 nesting pairs of puffins inhabited these two isla;i-ds. Some of the oil from the Torrey Canyo reached this section of the Brittany coast and the number of nesting pairs on these islands dropped dramatically the next year. It had stabilized at about 800 during the past several years. Other marine birds that inhabit this sanctuary are the razorbill (less than 100 pairs), guillemots (about 300 pairs), kittiwakes (20-100 pairs), storm petrels, herring gulls, greater and lesser blackbacked gulls, and fulmars (100 pairs). After the Torrey Canyon incident the number of nesting razorbills and guillemots in this sanctuary also decreased sharply, from 250 to 90 and 400 to 150 breeding pairs respec- tively (Milon, 1972). This sanctuary received a considerable amount of oil since it was directly in the path of the main flow coming from the Amoco Cadiz. The occurrence of the spill at this time of year was unfortunate because 206 many of the birds, particularly puffins, were just arriving at the sanctuary from their wintering grounds. Upon arrival the puffins ini- tially spend their time swimming and diving around the islands before moving onto them to nest. This behavior pattern made the species par- ticularly susceptible to oiling. We visited the sanctuary by boat on April 2 accompanied by two ornithologists from L.P.O. This was the first visit to the islands by L.P.O. since the wreck. High seas and a fear of scaring birds from the islands into the oil-covered water had prohibited earlier visits. According to our colleagues from L.P.O., 200 to 300 puffins would nor- mally be present in the water or on rocks around Rouzic and Melban at this time of year. Only one puffin, however, was observed as we circled both islands, although several hundred dead puffins had been found along the mainland. It is not yet possible to know the impact of the oil on this nesting colony since the dead puffins found along the beach in- cluded members of other colonies that were in the process of migrating to more northern nesting grounds. As of April 14 more than 850 dead puffins had been reported (Table 5-1). What percentage these birds represent of the total puffin kill or of those that would have remained at Les Sept Iles is not known. A gannet colony of about 4,000 breeding pairs also inhabits the island of Rouzic (Plate 5-14). These birds did not appear to be acutely affected by the oil spill. Only 2% of bird mortalities reported by S.E.P.N.B. were gannets. Potential chronic effects may exist for this population, however, since oil-contaminated debris and seaweed may have been used to build nests. Another likely mechanism for impact of the oil upon marine birds is the surface contamination of incubating eggs, either from fouled materi- als used for nesting or from contamination of the brood patch of the parent. Microliter quantities of fuel oil supplied to the surface of mallard and eider eggs caused significant mortality of embryos (Albers, 1977; Szaro and Albers, 1977), and similar results have been obtained with Alaskan crude oil or gull eggs (Patten and Patten, 1977). Further- more the gulls tended the oiled eggs for an extended period and then abandoned their nests, failing to produce a second viable clutch. Evidence of such reduced hatching success should be watched for at Les Sept Iles. Marine mammals also were affected by the oil in the vicinity of the sanctuary. In addition, a small population of grey seals inhabits the islands, and efforts are underway to determine if they are an independ- ent reproducing colony. If so, it will be the second such colony along the coast of France. As of April 2 three dead seals were found along the northwest Brittany coast. 207 5.1.3 Potential Impact On Coastal Fisheries The region of the Brittany coast impacted by the oil spill is one of both traditional and developing fisheries. Like most coastal fish- eries, they are very diverse and the effect of the oil on them will be species-specific. The full impact may never be known. The nature of the effects will be complex and will vary from short-term impacts on popula- tion size and availability to fishermen to potential chronic effects on year-class. In addition, the future marketability of coastal fishery products with elevated levels of hydrocarbons is not known. In this section we will provide a brief overview of some of the more important fisheries along this part of the Brittany coast that may be impacted by the spill. Coastal waters from Le Conquet to St. Malo support a diverse com- mercial fishery for seaweed, crabs, clams, oysters, scallops, and several species of finfish. Mariculture is important in the commercial production of some of these species. Fishermen operate out of several small ports along the coast (e.g., Le Conquet, Portsall, Brignogan, Roscoff, and Perros-Guirec). The Amoco Cadiz went aground in an area where marine algae have been harvested for many years. This fishery is concentrated in coastal waters from Le Conquet to Brignogan (near AMC-14) and produces about 75% of the total seaweed harvest in France. The algae are harvested from the high tide mark to depths of 25 meters and consist primarily of Laminaria digitata, Laminaria flexicaulis, Fucus vesiculosus, Fucus serratus, and Ascophyllum nodosum. After tE7e--harvest the material is air-dried on meadows along the coast and shipped to factories for processing. Approximately 200 fishermen and 150 boats are involved in this fishery. One factory that we visited in Landerneau processed 6,000 dry metric tons per year and produced alginates, flours, powders and liquids for baths and shampoos, and a jelly used by the cosmetic indus- try. The subtidal or Laminaria fishery harvests from 4,000 to 6,060 dry metric tons per year in a season from April 15 to September 30. The principal product is alginates which are used as thickening and stabil- izing agents in foods and industrial products. During the first week of May, we observed Laminaria being unloaded from boats at l'Aber Wrac'h and at Roscoff. It is not known if this crop had been affected by accumulated oil from the Amoco Cadiz. Laminaria also has been tradi- tionally gathered from the beaches at Santec (about 6 kilometers west of Roscoff) As it washes ashore in late spring and summer. On May 18, the beaches in this area had visible sheens of oil in the interstitial water, and small quantities of mousse were still coming ashore. Thus the harvest of this beached material-also may be affected. The attached algae in the intertidal zone (Fucus and Ascophyllum) are hand-picked at low tide or gathered on the beaches. The harvest is 208 estimated at 6,000 to 7,000 dry metric tons per year, and is used pri- marily to produce a flour used as a supplement for cattle feed. Because of the location of the wreck, a significant portion of both the subtidal and intertidal algae important to the seaweed industry was exposed to large amounts of oil and its dissolved fractions. This exposure occurred just prior to the opening of the harvesting season, and the effects on the industry are now being determined in terms of growth, reproduction of plants, and accumulation of hydrocarbons. Large amounts of potentially harvestable seaweed were removed from the beaches during cleanup operations because of heavy oiling, particularly near Portsall. In the harbor of Portsall, oiled Fucus and Ascophyllum were systematically hand-picked in late May Tr-om intertidal rocks and jetties by military cleanup crews. Adverse effects on the mollusc fishery will probably be most significant for oysters and clams. Rearing of oysters (Crassostrea Rja,@s and Ostrea edulis) on racks is an important aspect of Brittany's shellfish industry, and several commercial operations were impacted by the spill. Most notable were those located in and just off the mouths of the Aber Benoit and Aber Wrac'h estuaries. As discussed earlier in this chapter, these estuaries received large amounts of oil because they were directly downwind from the wreck. Although some oysters were removed from gardens or holding pens prior to the arrival of oil, most of the crop was either killed or heavily contaminated both in the estuaries (Plate 5-16) and in adjacent waters (Plate 5-21). One dealer interviewed in St. Pabu on theAber Benoit estuary stated that he had released 119 of 125 employees as of April 4. In the Aber Wrach estuary, oysters contained visible oil around the fringes of the mantle in mid to late May, and the oyster industry was still shut down. A dealer inter- viewed at that time indicated that he may be required to dispose of his remaining stock of contaminated oysters. Another important culturing area is located in the Bay of Morlaix. Because it is farther from the wreck, dealers had time to remove and transport some of the oysters to beds in southern Brittany, although we understand that some mortalities and/or contamination of oysters did occur. We have no information at the present time relative to the total impact of the spill on the commercial oyster industry, nor the time that will be required for the re-establishment of an acceptable water quality. In addition to the oyster culture operations, a small clam fishery is located at Perros-Guirec. We observed dead and dying clams of com- mercial importance (Venus verrucosa, Venerupis pullastra and Venerupis descu'ssata) on beaches near Perros-Guirec, but do not know what the impact will be on this fishery. The impact of the spill on the scallop (Argopecten) fishery may be minimal. This industry is centered in and near the Bay of St. Brieuc, which yields about 10,000 metric tons/year. This region was not heavily 209 contaminated by the spill. A small scallop fishery (about 100 metric tons per year) is located in the Bay of Morlaix and could be affected. Divers from the Roscoff Biological Station have observed mousse on the bottom of the Bay of Morlaix. This could affect either the scallops themselves, or could interfere with fishing for them. Two species of crab are fished in the impacted area, Cancer pagurus and Maia squinado (spider crab). As with the other fisheries, it is too early to assess effects. Spider crabs were in the process of migrating into shallower coastal waters when the spill occurred. In the nearshore areas between Roscoff and the Bay of Morlaix, many fishermen were observed running their traplines during May, and spider crabs were being landed at Roscoff and at Le Diben (2 km SSW of Pointe de Primel). The Societ6 Langouste at Roscoff is a specialized commercial operation that deals primarily with lobsters (Plates 5-17 and 5-17a). It imports lobsters (both Homarus and Palinurus) from around the world (e g., Canada, United States, South Africa, Brazil, Argentina), holds th;m in pens exposed to natural seawater, and sells several hundred tons per year to dealers in France. In addition, oysters and clams caught locally are held and sold depending on price fluctuations. The oil arrived at this facility at 2:00 a,m. on March 21 just 2 hours after all the lobsters were removed to tanks with a closed cycle recirculating system. An oil control boom was placed in front of the pens (Plate 5- 17A) but high winds and tides drove the oil across the booms and into the pens (Plate 5-18). The oiling of this facility was so extensive that it is expected to be out of operation for at least a year. All wood will be replaced and oil will be burned off the concrete, which will then be recemented. Some spiny lobsters and oysters were being held in the closed recirculating system on the day of our visit (April 1) and the seawater was being transported from Brest by truck. Although some fish, such as rock fish, gobies, and one species of gadidae (Plate 5-20), were killed within a 10 km radius of the ship- wreck, there is very little known as yet about the effects of the oil spill on the commercial fishery of the area. Few dead commercially- important fish, such as mullet, mackerel, pollock, bass or flatfish species, were collected. Flatfish such as plaice (Pleuronectes platessa) may suffer from adverse effects on year-class strength since [email protected]_ae and juveniles wereconcentrated in estuaries and bays that were heavily oiled. What effect the oil suspended in the water column will have on the survival of the larvae of these species is unknown, but contamina- tion at this critical phase could-have'serious consequences (Michael, 1977). Mackerel (Scomber scombrus), on the.other hand, spawn elsewhere and migrate into these waters to feed during the spring and summer. Adverse effects on this species may be minimal except for possible food web contamination. In any case, there are few data on fishing effort in the impacted area, and this will make it difficult to determine impacts on coastal fisheries in future years. If significant quantities of oil 210 are present on the sediment in traditional fishing area, both gear and catch may be fouled and economic losses will be incurred. A fisherman at l'Aber Wrac'h indicated that gear fouling was a problem in offshore areas that he had fished in late April and early May. 5.1.4 Potential Impacts on Terrestrial Communities Although we have focused upon marine communities, terrestrial communities must be considered as well. Volatile fractions of the petroleum, strongly evident to the human observer, caused dizziness, headaches, and nausea. The lobster dealer at Roscoff noted that song birds left that area 2 to 3 days before arrival of the oil. These birds may have been responding to the presence of air-borne hydrocarbons. They reportedly began to return 1 to 2 weeks later. Transport of airborne fractions of petroleum to farm crops may have been substantial. In a few instances crops directly adjacent to the coast were oiled and had to be destroyed (Plate 5-19). The process of assimilation of volatile fractions of petroleum by crops and transport of measurable fractions of these compounds to humans either directly by consumption of the crops or indirectly by consumption of livestock may be unique to this oil spill. 5.1.5 False Color Photo Infrared Pictures Infrared pictures were taken by the SOR team on an experimental basis as a possible aid in identifying beached oil and documenting changes in the flora. Kodak Ektachrome infrared film was used with a wratten #12 filter as recommended by Kodak for biological work. As seen in Plate 5-24a, Amoco-Cadiz oil on the rocks and on the beach (not shown) appears greenish. Also apparently healthy Fucus can be seen in the background appearing red. In normal light, fucus and oil are hard to distinguish, especially from the air. Also, live and dead seaweed appear the same in normal light, whereas the "healthy" red color in infrared is lost when the plant dies. Most plants will show changes in infrared when under stress, before any change is detectable in normal light. Fig. 5-24b shows the greenish color of oil mixed with the red of the grass in the area that has been covered with oil. 5.2 Summary Adverse biological effects of oil spilled from the Amoco Cadiz were observed along the northwest coast of Brittany ranging from Portsall to Perros-Guirec--a distance of about 150 km of coastline with numerous rocky outcroppings and islands. Habitats impacted by the spill con- sisted of exposed sandy beaches, rocky headlands, bays, estuaries, marshes, subtidal areas, and neretic waters. Biological communities in these habitats were subjected to varying degrees of stress depending. upon type of habitat, distance from the spill, and location relative to the configuration of the coastline. 211 Intertidal communities on coastlines facing west, as well as the Aber-Benoit estuary and Rulosquet marsh near Ile Grande, were severely impacted by the petroleum. The effects were maximized by spring tides which occurred just after thd wreck. Massive mortalities of intertidal, communities occurred near St. Efflam and at Rulosquet marsh over a relatively short time (a few days) whereas mortalities of other pop- ulations were observed to occur more gradually (over several weeks). Populations of intertidal crabs,-nereid worms, bivalve molluscs and limpets were much more acutely affected by the spill than was the deposit-feeding polychaete Arenicola. For epifauna, mortality appeared to be related to physical coating by the oil. The dissolved fraction of oil that penetrated into the interstitial water was probably the primary factor contributing to mortalities of infauna. Acute effects generally were not observed on attached macroalgae although some evidence obtained in an independent study indicated that the fertilization process of exposed plants may be impaired. Extremely large concentrations of dead and dying organisms were observed at two locations 16 days after the wreck. On April 2, several million dead molluscs and urchins were present along [email protected] km of beach near the village of St. Efflam. These organisms consisted primarily of heart urchins (Echinocardium cordatum), razor clams (Ensis siliqua and Pharus loguma), cockles (Cerastroderma edule) and surf clams (Mactra cinerea). At Rulosquet marsh near Ile Grande on the same day, thousands of dead polychaetes (Nereis diversicolor) and large numbers of dead crabs (Carcinus maenus) covered the marsh surface. Although some-'fish kills were reported in the general vicinity of the wreck prior to the time our observations began (March 29), we rarely observed dead fish. Larval fish populations of certain species present in the area at the time may have been affected but the specific effects will be difficult to determine. Some fish species may become contamin- ated by the transfer of hydrocarbons through the food chain. Dispersants, which were used both in coastal waters and in shoreline cleanup operations, may have contributed to the fish mortalities observed at Corn ar Gazel and St. Efflam. The use of dispersants in cleanup operations varied along the coast but they were used extensively near Roscoff in early April. To what extent these chemicals contributed to mortalities in intertidal areas is not known. The oil spill occurred at a time when many species of marine birds were migrating from wintering to nesting grounds. Over 3,200 deaths were recorded which consisted of more than 30 species. About 85% of these deaths, however, consisted of four species (shag-cormorant, guillemot, razorbill, and puffin), the last three of which are consid- ered rare or threatened in France. More chronic effects on marine birds may occur from feeding on contaminated prey. For example, seagulls were observed feeding on freshly killed intertidal organisms all along.the impacted coastline. 212 The Sept Iles Bird Sanctuary near Perros-Guirec provides important nesting grounds for several species of marine birds along the northwest coast of Brittany, particularly for puffins, razorbills, and guillemots. Two islands in the sanctuary support the southernmost nesting colony of puffins in Europe. This colony was severely reduced as a result of the Torrey Canyon oil spill and may be further reduced by the Amoco Cadiz incident. Coastal waters along the northern coast of Brittany support a di- verse commercial fishery for seaweed, crabs, clams, oysters, scallops, and several species of finfish. The Amoco Cadiz went aground along the section of the coast that produces [email protected];u-t75% of the seaweed harvested in France. Both subtidal (Laminaria) and intertidal (Fucus and Ascophyllum) species were exposed to extremely high [email protected]_of oil just prior to the opening of the harvesting season. The effects on the industry are now being determined in terms of growth and reproduction of plants, and accumulation of hydrocarbons. Mariculture operations for oysters were severely affected in the Aber Benoit and Aber Wrac'h estuaries and the Bay of Morlaix. Large numbers of oysters were either killed or contaminated by the spill. The holding pens of the commercial lobster operation at Roscoff was heavily oiled and probably will be out of operation for a year. The main scallop fishery in Brittany is located east of the impacted area and adverse effects may be minimal. At the present time, we have no information on the impact of the spill on the crab industry. Little is known as yet about the effect the oil spill on the com- mercial finfish industry although few dead commercially-important fish were reported. Obviously those species whose young inhabit bays and estuaries (e.g., plaice) will probably be affected more severely than species that spawn in offshore waters and migrate into coastal waters to feed (e.g., mackerel). The transport of oil or its volatile fractions to terrestrial com- munities may have been substantial. In late March gale-force winds and spring tides combined to deposit oil above the high tide mark. More importantly, some of the airborne fractions of the petroleum can adhere to plants and be transported to humans through farm crops or livestock. A coordinated program to assess the biological consequences of the Amoco Cadiz oil spill is currently being developed by French scientists from Roscoff, UBO, and COB. For example, proposals have been made to study the repopulation of intertidal communities in areas where pre-spill baseline information exists; the occurrence of neoplasms in shellfish (some oysters and cockles were collected shortly after the spill for this purpose); the effects of the oil spill on the'year-class strength of plaice; the effects of growth and reproduction of attached micro- algae; and the accumulation of hydrocarbons by a variety of species including birds. In addition research programs between French scientists and scientists from other countries, such as the United States and Canada, have also been planned. 213 5.3 References Ablers, P. H. (1977): The effects of external applications of fuel oil on hatchability of mallard eggs. In: (D. A. Wolfe, ed.). Fate and effects of petroleum hydrocarbons in marine organisms and eco- systems, Pergamon Press, New York, 158-163. Baker, J., J. Addy, B. Dicks, S. Hainsworth, D. Levell, G. Crapp, and S. Ottway (1977): Ecological effects of marine oil pollution. Rapp. P.-V. Reun., Cons. Int. Explor. Mer, 171:196-201. Chass4, C. J. M. (1972): Economie, sedimentaire et biologique (produc- tion) de Bretagne. Ph.D. Thesis, Station Biologique de Roscoff, Faculty of Sciences, UBO. 293 p. Gordon, D. C., Jr., J. Dale, and P. D. Keizer (1978): Importance of sediment working by the deposit-feeding polychaete Arenicola marina on the weathering rate of sediment-bound oil. J. Fish. Res. Board Can., 35:591-603. Michael, A. D. (1977): The effects of petroleum hydrocarbons on marine populations and communities. In: (D. A. Wolfe, ed.), Fate and effects of petroleum hydrocarbons in marine organisms and ecosys- tems, Pergamon, New York, 129-137. Milon, P. (1972): La mort sur Vile, Crepin-Leblond et Cie, Paris, France, 107 p. Nelson-Smith, A. (1968): The effects of oil pollution and emulsifier cleaning on shore life in southwest Britain. J. Appl. Ecol., 5:97-107. Patten, S. M., Jr., and L. R. Patten (1977): Effects of petroleum expo- sure on hatching success and incubation behavior of the Gulf of Alaska herring gull group (Larus argentatus X Larus glaucenscens). NOAA Environmental Research Laboratories, OCSEAP Principal Investi- gator Reports, Boulder, Colo., 22 p. Smith, J. E. (ed.) (1968): "Torrey Canyon" pollution and marine life, Cambridge Univ. Press, 196 p. Steele, R. L. (1977): Effects of certain petroleum products on repro- duction and growth of zygotes and juvenile stages of the alga Fucus edentatus de la Pyl ([email protected]: Fucales). In: (D. A. Wolfe, ed.). Fate and effects of petroleum hydrocarbons in marine organ- isms and ecosystems, Pergamon Press, New York, 138-142. Szaro, R. C. and. P. H. Albers (1977): Effects of external application of No. 2 fuel oil on common eider eggs. In: (D. A. Wolfe, ed.). Fate and effects of Petroleum hydrocarbons in marine organisms and ecosystems. Pergamon Press, New York, 164-167. 214 Wilson, K. (1974): Toxicity testing for ranking oils and oil dispers- ants. In: (L. R. Beynon and E. B. Cornell, eds.). Ecological aspects of toxicity testing of oils and dispersants. Applied Science Publishers Ltd., Essex, England, 11-22. 215 APPENDIX, CH. 5 ONSHORE SURVEY OF MACROBENTHOS Jeffrey L. Hyland* Introduction An onshore preliminary survey was conducted March 27 to March 31, 1978 along the northern Brittany coast from Argenton east to Ile Grande for the purpose of evaluating the extent of the oiling and the magnitude of [email protected] impact. General ecological observations and photographs generated along route have been incorporated into various other sections of this report. The following section summarizes results relevant to two 'specific objectives: (1) to observe and photograph obviously oiled, dead, or moribund organisms found on contaminated beaches, and (2) to develop a general understanding of the spatial and numerical distribution of benthic macrofaunal species considered at risk. Results reflecting these two objectives are discussed for each of several habitats investigated. Sampling Techniques and Treatment of Data The types of habitat of research stations included an intertidal sandy cove with algal-coated rocky zones (Roscoff--EPA station 1); a salt marsh (Ile Grande-EPA station 2); and a high energy, ocean-exposed sandy beach,backed by steep dunes (Corn ar Gazel--EPA station 3). Each station was photographed, and samples of dead, moribund, and oil-coated organisms were returned to the laboratory for gross observation and species identification. Routine techniques of field sampling and data reduction were employed for describing the distribution of species at risk. Sampling was conducted during low tide, 3 to 5 days after the arrival of spring tides. In'the rocky intertidal zone at Roscoff, density estimates of macroepifauna were made at five substations using 0.25 m2 quadrats. The *U.S. EPA/ERL, Narragansett, RI 02882. 216 macr6infauna was sampled at Roscoff from three additional sandy substa- tions (high water mark on beach at Mariner's Home--substation 1-1; mid- dle of cove between Roscoff and tip of Perharidic peninsula--substation 1-2; and low water mark at mouth of cove, near edge of channel between Roscoff and Ile de Batz--substation 1-3). The macroinfauna alone was sampled from one substation at Ile Grande (on a mud flat along southern edge of main channel intersecting highway D21) and from three sandy substations at Corn ar Gazel (10 m above low water-mark--substation 3-1; low water mark--substation 3-2; and 5 m below low water mark--substation 3-3). Each infaunal substation was represented by 10 pooled, replicate samples collected with a 0.01 M2 polyvinyl chloride corer to a depth of 20 cm. and rough sieved through a 2.0 mm screen. Contents on the screen were preserved in a 10% formalin solution in the field and returned to the laboratory for identification and enumeration of all macroinverte- brates. Most organisms were identified to the species level with the aid of the following literature: Polychaeta: Fauvel (1923, 1927), Clark (1960), Day (1967) Mollusca: Cornet and Marche-Marchad (1951), Allen (1962), Tebble (1966) Crustacea: Sars (1890), Truchot and Toulmond (1964), Bourdon (1965), Allen (1967), Barnard (1969), Bouvier (1940), Chevereux and Fage.(1925) Other general works that were useful included Barrett and Yonge (1958), Eales (1967), Day (1969), and.Gosner (1971). Data analysis included the generation of preliminary species lists with numerical abundances and the calculation of species diversity (H', in bits per individual) with its components, species richness (Gleason diversity, D G) and evenness 01). Additional samples of sediment and organisms were collected from each station for routine hydrocarbon analysis, the results of which are discussed elsewhere in this report. Field work was facilitated through the services of Jim Lake (EPA, Narragansett, Rhode Island) and Bud Cross (NOAA, Beaufort, North Caro- lina). Taxonomic assistance was provided by Sheldon Pratt (U. of Rhode Island, Oceanography Dept.), Robert Bullock (U. of Rhode Island, Zoology Dept.) and John Scott (EPA, Narragansett, Rhode Island). Rocky Intertidal Zone at Roscoff Table 5A-1 lists macroepifaunal species identified and enumerated within the five rocky intertidal substations. The species are con- sidered members of the mesolittoral zone and were found attached or crawling on bare rock or on dense patches of algae (mostly Ascophyllum nodosum and Fucus at approximately 0.5 to 1.5 m above the base of 217 the substrate. The list includes only the obvious species that were large enough to recognize and enumerate in the field, and is therefore exclusive of the smaller organisms, particularly amphipods and small gastropods, associated with microhabitats. Limpets (Patella vulgata) and periwinkles (Littorina obtusata and L. littorea) were the most numerous. Other species included the gastropod, Gibbula umbilicalis; the chiton Lepidochitona cinereus; the tube dwelling polychaete, Spirorbis borealis; and the barnacle, Elminius modestus. Table 5A-1. Species list for rocky intertidal quadrats at Roscoff. Species Quadrats (no.'s per 0.25 m2) 1 2 3 4 5 Gastropoda Patella vulgata 2 - 4 16 16 Littorina obtusata 1 1 6 - Littorina littorea - I - - Gibbula umbilicalis - 1 - Polychaeta Spirorbis borealis occasional 2 occasional - calcareous calcareous tubes tubes Amphineura Lepidochitona cinereus 1 Cirripedia Elminius modestus - dense population Algae Mostly Ascophyllum 80 to 100% cover nodosum & Fucus spp. All species within these quadrats were exposed to the oil, because thick layers of oil were still heavily concentrated on the rocks and algae. Consequently, most organisms were considered at risk and some were in the process of being eliminated at the time the survey was .conducted on March 29. Limpets and periwinkles, for example, were 218 particularly affected, and dead and moribund individuals were observed at the base of the rocks. Some limpets were beginning to lose purchase on the rocks and were easily removed with the flick of a finger. Lim- pets are unable to hold their shells firmly against the substrate for long periods of time, since the adductor muscles must relax occasionally allowing the shells to lift slightly. When this occurs in heavily oiled areas the oil may penetrate beneath the shell margin, thus contaminating the gills-and other delicate tissues. Close examination of the limpets revealed contamination of the soft body parts and deterioration of the flesh. Shore birds were observed pecking the upturned shell contents. Other epifaunal species not necessarily occurring within the five quadrats were found dead or moribund in the immediate vicinity. These included the topshells (Gibbula cineraria, G. umbilicalis, and Calli- ostoma zizyphinum) and the green crab (Carcinus maenus) (Fig. 5A-1). Close examination of dissected crabs revealed that the oil had formed a thick coating around the gills. Figure 5A-1. Dead and moribund organisms at EPA Station 1, Roscoff. Left to right: Top-row--Venerupis descussata, Cardium edule, Patella vulgata, and Littorina littorea (with attached Elminius [email protected]_s_tus).__ffi;_d_dle row-- Littorina obtusata (one black and one yellow specimen), Gibbula umbilicalis, Gibbula cineraria, and Calliostoma zizyphinum. Bottom row--Nereis diversicolor and Carcinus maenus. 219 These same rocky intertidal species were similarly affected along Cornish coasts in 1967 after exposure to a mixture of detergents and crude oil spilled from the Torrey Canyon (Smith, 1968; Nelson-Smith, 1968a). However, in contrast to Smith's account that oil alone had caused little harm to shore life, effects on rocky intertidal organisms were observed in an area where detergents were allegedly not used prior to sampling. Mussels, Mytilus edulis, were not observed on the rocks at Roscoff. However, dense populations were found subsequently at Locquirec (EPA station 4). The mussels were oiled, yet they appeared unharmed at that time. Intertidal Sand Cove at Ro8coff The sandy cove between Roscoff and the Perharidic peninsula is almost entirely exposed at low tide. Consequently, oil not only concen- trated in thick layers. high up on the beaches, but with receding spring tides was also dispersed throughout the cove. This spreading was ob- served as visible droplets of mousse at depth in the sediment and as occasional surface stains even in the middle of the cove. That the underlying sediment and ground water contamination had reached toxic levels was evident since some dead and moribund infaunal specimens were collected throughout the cove, particularly toward shore where the oiling was most concentrated. These species included the edible cockle, Cardium edule, the carpet shell, Venerupis decussata, and the polychaete, Nereis diversicolor (Fig. 5A-1). The epifaunal green crab, Carcinus maenus, was also found dead in large numbers. Quantitative sampling of the three sand substations revealed a relatively diverse infaunal assemblage consisting of a rather large number of species (i.e., in comparison with the other stations, and in view of the rather small sample size and large sieve size used) (Table 5A-2). Structural variation between substations was observed, with the number of species and other structural indices (diversity, species richness, and evenness) increasing from substation I to substation 3. There are several possible explanations for this variation: (1) the greater availability of microhabitats toward substation 3 as a result of the increase in grain size, (2) an increase in environmental stability toward substation 3 (e.g., increase in depth of water at high tide and decrease in environmental fluctuations), and (3) the elimination of some species from substation 1 as a result of the greater concentration of oil on the beachface. The substation 3 sample consisted of 15 species and 73 individuals per 0.1 m2 , and was characterized by relatively high values for H'(3.34), DG (7.51), and J'(0.85). The dominant organism was the polychaete, Nereis diversicolor, which was found at substation 1 at a density of 52 per 0.1 ml. AbunTant on the sediment surface were the shingled tubes of the polychaete, Lanice conchilega, (90/m 2) and the casts of the lugworm, Arenicola-marina, (36/mil); however these species were not well represented in the infaunal samples. 220 Table 5A-2. Species list and associated structural indices for the various research stations. Species Research Stations Roscoff Ile Grande Corn ar Gazel 1-1 1-2 1-3 2 3-1 3-2 3-3 Polychaeta Nereis diversicolor 52 1 - 14 - - - Scoloplos armiger 17 12 15 - 2 Polycirrus aurantiacus 1 1 1 - Notomastus latericeus 2 5 20 Arenicola marina - 1 - 1 - 1 Nephtys hombergii - 1 1 - 3 - Spio filicornis - 1 5 - 1 - 1 Nicomache sp. - 5 - - - - - Aonides oxycephala - - I - - - - Nephtys sp. - - 1 - - - - Perinereis cultrifera - - 3 - - - - Lanice conchilega - - 3 - - - - Syllis sp. - - 1 - - - - Phyllodoce sp. A. - - 1 - - - - Phyllodoce sp. B, - - - - - - 1 Clymene sp. - - 13 - - - - Harmothoe lunulata - - - - 1 - - Glycera convoluta - - - - - - 2 Audouinia tentaculata - - - - - - 4 Amphipoda HaustoriUs arenariLIS 2 - - - - - - Phoxocephalopsis 1 1 - - - deceptionis Decapoda Carcinus maenus - 1 1 - - Cancer pagurus - - - - - Bivalvia Tellina tenuis - 1 - - - Loripes lucinalis - 4 1 - - Loripes sp. - - 6 - 1 - Gastropoda Littorina obtusata - - - - 1 1 - S (no. species/O.IM2 6 12 15 2 5 2 7 N (no. individuals/O.lM2) 75 34 73 15 7 .2 12 H1 1.30 2.90 3.34 0.35 2.13 1.00 2.58 DG 2.66 7.18 7.51 0.85 4.71 3.33 5.56 if 0.50 0.81 0.85 0.35 9.91 1.00 0.91 221 Since such large numbers of organisms were found still living within the sediments at the time of sampling on March 29, it appeared that up to this time many of the infaunal species had escaped initial impact. Perhaps the surrounding sediment provided a blanket of protec- tion against immediate impact, whereas rocky intertidal organisms suc- cumbed to the effects of direct physical contact with heavy oil slicks. These infaunal species are nonetheless considered at risk in view of several observations including the visible levels of sediment and ground water contamination throughout the study area, and the observed death of member organisms (e.g., cockles, clams, and polychaetes) in the immedi- .ate vicinity. Subsequent surveys of neighboring localities (e.g., at St. [email protected] four days later) revealed massive kills of infauna, particularly heart urchins (Echinocardium cordatum) and razor clams (Pharus legumen and Ensis siliqua). Dead urchins and razor clams were similarly reported along the Cornish coast after the Torrey Canyon spill (Smith, 1968). Also, impact of oil spills on soft-bottom intertidal communities has been reported elsewhere by Hampson and Sanders (1969), Thomas (1973), and Bender et al. (1974). A striking observation was that of reproductively active poly- chaetes throughout the infaunal samples. Perinereis cultrifera was found in its heteronereid stage, and other polychaetes including Phyllo- doce sp., Glycera convoluta, and Nephtys hombergii were carrying numer- ous ripe-ova. It is possible that adult mortality at such a sexually productive period could have an effect on the recruitment of young, thus significantly altering the numerical distribution of species for some time to come. Larval forms are also known to be extremely sensitive to petroleum pollutants. Salt Marsh at Ile Grande Oil coverage of the marsh at Ile Grande was extensive, contamin- ating vegetation (Juncus Spartina patens, and Salicornia @p.) and leaving most mud surfaces coated with several centimeters of mousse. Dead and moribund invertebrates were commonly found in large numbers on the oil-soaked mud flats, and included polychaetes (Nereis diversicolor and Arenicola marina), cockles (Cardium edule), and green crabs (Carci- nus maenus) (Fig. 5A-2). Quantitative sampling of the infauna was conducted on March 30 along a mud flat immediately adjacent to the main channel. Sampling was nearly impossible because of the nature of the soft sediments coupled with the extent of oiling. 'Therefore only one substation was sampled, and this became feasible only after large areas of surface oil were scraped away. Table 5A-2 reveals the extremely low diversity at this site, with only two species present, Nereis diversicolor and Arenicola marina. Although Nereis was the most @_b_unda_nt, neither was found alive in large numbers. 222 [email protected] 0 1 2- CM Figure 5A-2. Dead and moribund organisms at EPA Station 2, Ile Grande. Left to right: Top row--Nereis diversicolor and Cardium edule. Bottom row--Carcinus maenus and Arenicola marina. It is not uncommon to find low species diversity in salt marshes. However, many characteristic marsh species large enough to be sampled in a 2.0 mm sieve (e.g., larger gammarid amphipods, capitellid and spionid, polychaetes, and lamellibranch molluscs) were absent from the collec- tion i It is believed that the observed absence of species is not only a result of the natural tendency for marshes to exhibit low numbers of species, but also a result of the demise of organisms as a result of-the spill. Prior to this survey, Eric Gundlach at the sam&-site reported thousands of moribund polychaetes attempting to escape their oily envi- ronment, only to end up on the surface of oil pools. Ecological damage to salt marsh communities has been reported previously as a result of the Chryssi P. Goulandris spill in Milford Haven, England (Nelson-Smith, 1968b); the Arrow spill in Chedabucto Bay, Canada (Thomas, 1973)- and the West FalmoutK spill in Massachusetts, U.S.A. (Michael et al., 197.5). 223 Intertidal Sand Beach at Corn ar Gazel Station 3 was situated on a high energy, ocean-exposed sandy beach, located approximately 500 m N.W. of the small town of Corn ar Gazel and 6 km S.E. of the wreck site. The beach was apparently once well coated with oil, since at the time of sampling on March 31 occasional stains and droplets were still visible both on the surface and at depth in the sediment. Also, grass growing on the sides of the steep dunes still showed traces of oil. For the most part, though, the waves and tides effectively removed the bulk of surface oil from the beachface. On the other hand, seaward the oil was still heavily concentrated and appeared as an oil-in-water emulsion throughout the water column. Nearby boul- ders located just offshore were still heavily oiled. Toxicity was apparent. The jetsam line was littered with a large number of dead and moribund organisms, many of which revealed visible quantities of oil. Species included the edible crab, Cancer pa&urus; an unidentified fish; the lugworm, Arenicola marina; an unidentified,Holo- thuroidean (sea cucumber); the gastropods, Patella @2., Calliostoma. zizyphinum, Gibbula cineraria, and G. umbilicalis; and the bivalves Dosinia exoleta, Venerupis pullastra, and Venus verrucosa (Fig. 5A-3). Some of these washed up from the neighboring rocks (e.g., Patella and Gibbula); others arrived from the soft-bottom intertidal and subtidal areas. Oil was also lethal to organisms living higher up on the shore. For example, Eric Gundlach observed on a similar beach 5 km west thou- sands of dead sand hoppers, Talitrus saltator, which normally live among the deposited jetsam. Many of these species were similarly affected after the Torrey Canyon spill (Smith, 1968). Table 5A-2 reveals the results of the quantitative sampling of infauna. There were no apparent patterns in the distribution of species between substations and variation was most likely attributable to normal spatial patchiness. In general, values for the number of species, species diversity, and richness were between those observed at the two remaining stations. Values for J' for all three substations were par- ticularly high, revealing an even distribution of the relatively few individuals among the species present. The presence of fewer species (particularly at substation 2), in comparison with the situation at Roscoff, was most likely a result of natural factors, such as a less stable physical environment (e.g., shifting sands and exposure to wave action). However, one should not rule out the possibility that some infaunal species were eliminated as a result of the oil, since visible oil levels were observed both in the water column and in the sediments. Also, many dead and moribund organisms were observed on the sediment surface in the immediate vicinity. Here, as elsewhere, several species of polychaetes that were still alive were found in sexually productive states. Glycera convoluta, Nephtys hombergii, Audouinia tentaculata, and Arenicola marina were all carrying ova. One dead Arenicola that was examined also contained a large number of ova. 224 y" _71 or Figure 5A-3. Dead and moribund organisms at or near EPA Station 3, Corn ar Gazel. Left to right: top row--unidentified Holothuroidean, unidentified fish, and Arenicola marina. Middle row--Cancer pagurus, Venus verrucosa, Venerupis pullastra, and Dosinia exoleta. Bottom row--Gibbula cineraria, Gibbula umbilicalis, Talitrus saltator (above), Calliostoma zizyphinum (below) and Patella sp. Summary To assess the impact of the spill on onshore macrobenthos a recon- naissance survey was conducted with two objectives in mind: to observe and photograph obviously oiled, dead, or moribund organisms found on contaminated beaches; and to informally examine the spatial and numeri- cal distribution of macrofaunal species considered at risk. Research stations included an intertidal sand cove with algalcoated rocky zones (Roscoff); a salt marsh (Ile Grande); and a high energy, ocean-exposed sand beach (Corn ar Gazel). All stations were heavily oiled. However, the marsh at Ile Grande was the most polluted. Removal of oil from the substrate surfaces as a result of the waves and currents was most effec- tive at the higher energy stations, particularly at Corn ar Gazel. 225 Dead and moribund organisms were observed at all stations and included limpets (Patella vulgata), periwinkles (Littorina obtusata and L. littorea), topshells (Gibbula cineraria, G. umbilicalis, and Calli- ostoma zizyphinum), cockles (Cardium edule), clams (Venerupis decus- sata), polychaetes (Nereis diversicolor) and green crabs (Carcinus maenus) at Roscoff; polychaetes (Nereis diversicolor and Arenicola marina), cockles (Cardium edule) and green crabs (Carcinus maenus) at Ile Grande; and edible crabs (Cancer pagurus), fish (unidentified), sea cucumbers (unidentified), limpets (Patella sp.), top shells (Gibbula cineraria, G. umbilicalis, and Calliostoma zizyphinum) at Corn ar Gazel. Numerous dead amphipods (Talitrus saltator), sea urchins (Echinocardium cordatum), and razor clams (Ensis siliqua and Pharus legumen) were collected from neighboring sites. Informal sampling of macroinfauna (>2.0 mm) revealed a relatively high diversity of species for the intertidal sand cove at Roscoff, an intermediate level for the sand beach at Corn ar Gazel, and an extremely low diversity for the marsh at Ile Grande. At Roscoff, 15 species and 73 individuals per 0.1 m2 were collected from one substation, in compar- ison with only 2 species and 15 individuals per 0.1 m2 at Ile Grande. These infaunal [email protected] considered threatened because of the visible levels of sediment and ground water contamination and the ob- served kill of organisms in the immediate surroundings. Investigators should therefore make subsequent observations in these areas if possible to delineate future changes in the numerical and spatial distribution of species. 'It is anticipated that the preliminary species lists and observations presented here will be useful as "quasibaseline" informa- tion or guidelines for later comparison. However, if a long-term in- faunal sampling program is initiated, a more sophisticated approach is recommended and should incorporate larger sample sizes and a smaller screen size for sieving (e.g., a 1 mm sieve in addition to the 2 mm sieve). Several species of polychaetes were examined microscopically and were observed in sexually active states. The heteronereid stage of Perinereis cultrifera was found in one sample, and other polychaetes (Phyllodoc6 sp., Glycera convoluta, Nephtys hombergii, Andouinia tentaculata, and Arenicola marina) were carrying numerous ripe ova. Excessive adult mortality during such a sexually productive period could affect the future recruitment of species and thus accentuates the eco- logical significance of the initial impact. References Allen, J. A. (1962): Fauna of the Clyde Sea area. Mollusca. Scottish Marine Biol. [email protected],88-p.- Allen, J* A. (1967): Fauna of the Clyde Sea area. Crustacea: Eupha - -j- siacea and Decapoda. Scottish Marine Bi 1. Assoc., 116 p. 226 Barnard, J. L. (1969): The families and genera of marine Gammaridean amphipods. Smithsonian Inst. Bull. 271, 535 p. Barrett, J. and C. M. Yonge (1958): Collins pocket guide to the sea shore. Collins, London, 272 p. Bender, M. E., J. L. Hyland, and T. K. Duncan (1974): Effects of an oil spill on benthic animals in the lower York River, Va. In Proceed- ings of Marine Pollution Monitoring (Petroleum) Symposium, Gaith- ersburg, Md., May 13-17, 1974. IOC-UNESCO, WMO, USDC-NBS, 257-260. Bourdon, R. (1965): Inventaire de la faune marine de Roscoff. Decapodes- Stomatopodes. Editions de la.Station Biologique de Roscoff, 45 p. Bouvier, E. (1940): Faune de France, Vol. 37. Decapodes Marcheurs. Librarie de la Facult4 des Sciences, Paris (Kraus Reprint, Nendeln- Liechtenstein, 1970), 404 p. Chevereux, E. and L. Fage (1925): Faune de France, Vol. 9. Amphipodes. Libraire de la Facult6 des Sciences, Paris (Kraus Reprint, Nendeln- Liechtenstein, 1970), 488 p. Clark, R. B. (1960): Fauna of the Clyde Sea area: Polychaeta, with keys to the Briti genera. Scottish Marine.Biol. Assoc., 71 p. Cornet, R. and I. Marche-Marchad (1951): Inventaire de la faune marine de Roscoff. MollusqHes. 5. Aux Travaux de la Station Biologique de Roscoff, 80 p. Day, J. H. (1967): Polychaeta of Southern Africa. Part 1, Errantia; Part 2, Sedentaria. Brit. Mus. (Nat. Hist), [email protected]__P- Day, J. H. (1969): A [email protected]@ to marine life on South African shores. A. Balkema Co., Cape Town, 300 p. Eales, N. B. (1967): The littoral fauna of the British Isles; A handbook for collectors. Cambridge Univ. Press, 306 p. Fauvel, P. (1923): Faune de France, Vol. 5. Polychetes Errantes. Libraire de la Faculte-des Sciences, Paris (Kraus Reprint, Nendeln- Liechenstein, 1969), 488 p. Fauvel, P. (1927): Faune de France, Vol. 16. Polychetes Sedentaires. P. Lechevalier, Paris, 494 p. Gosner, K. 1. (1971): Guide to identification of marine and estuarine invertebrates. Wiley-Interscience, N.Y., 693 p. Hampson, G. R. and H. L. Sanders (1969): Local oil spill. Oceanus, 25:8-10. 227 Michael, A. D., C. R. Van Raalte, and L. S. Brown, (1975): Long-term effects of an oil spill at West Falmouth, Mass. In Proceedings of Conference on Prevention and Control of Oil Pollution', San Fr'an- Cisco, Calif. March 25-27, 1975, API, EPA, USCG, pp. 573-582. Nelson-Smith, A. (1968a): Biological consequences of oil pollution and shore cleansing. In J. D. Carthy and D. R. Arthur (eds.) The biological effects of oil pollution on littoral communities, Fld. studies 2 (suppl.), 73_-80- Nelson-Smith,'A. (1968b): The effects of oil pollution and emulsifier cleansing on marine life in south-west Britain. J. Appl. Ecol., 5:97-107. Sars, G. 0. (1890): An account of the crustacea of Norway, Vol. 1, Amphipoda (Text and Plates). Universitetsforlaget, Bergen and [email protected] 711 p. Smithl J. E. (ed (1968): Torrey Canyon pollution and marine life. Cambridge Univ. Press, 1T6 p. Tebble, N. (1966): British bivalve seashells. Brit. Mus. (Nat., Hist.), 213 p. Thomas, M. L. H. (1973): Effects of Bunker C oil on intertidal and lagoonal biota in Chedabucto Bay, Nova Scotia. J. Fish. Res. Board, Can., 30:83-90. Truchot, J., and A. Toulmond (1964): Inventaire de la fauaa marine de Roscoff. Amphipodes-Cumaces. Supplement Aux Travaux de la Station Biologique de Roscoff, 42 p. 228 6. OIL SPILL CLEANUP ACTIVITIES Roy W. Hann*, Jr., Les Rice*, Marie-Claire Trujillo*, and Harry N. Young, Jr.* 6.1 Introduction The oil spill from the supertanker Amoco,Cadiz off the Brittany Coast of France overshadows by far any other oil spill into the marine environment. In terms of oil reaching the shore, it was on the order of four times the amount of the Torrey Canyon spill in the same general geographical area or the Metula spill in the Straits of Magellan. As a result, the spill and the subsequent activities to clean up the oil and mitigate damage provided a fascinating laboratory for those interested in institutional structure, planning, resource requirements, technology, and training to deal with disasters of this magnitude. Those who wish either to evaluate the cleanup operations from the Amoco Cadiz or to prepare to deal with a similar problem elsewhere need to have a good grasp of the size of the problem. The oil, the resulting oil-water emulsion (mousse), and sand, seaweed, and detritus that became incorporated into or contaminated by the oil, were enormous in volume and weight. Fig. 6-1 shows the 220,000 metric tons of oil spilled, WEIGHT AND VOLUME OF OIL WEIGHT AND VOLUME OF MOUSSE GENERATED (based on 40% evaporation and loss to to water column 220,000 Metric Tons 488,371 Cubic Meters of Mousse 232,558 Cubic Meters of Oil 488,371 Metric Tons of Mousse (.86 S.G.) (SGZ1.0) 1,613,000 Barrels 18,940,000 Cubic Feet of Mousse (7.33 Barrels/Ton) 537,208 U.S. Tons (2,000 1b) ' 67,760,000 U.S. Gallons 141,621,@000 U.S. Gallons of Mousse 232,558,000 Liters Figure 6.1. Relative weight and volumes of oil and mousse expressed in different units. *Texas A&M University, College Station, TX 77840, participating under the support of the NOAA-USCG Spilled OilResearch Team 229 expressed in different weight and volume units. The volume of oil that will come ashore or could come ashore in a spill is a function of many parameters. A schematic diagram of these processes is shown as Fig. 6-2. As will be discussed in the next section, the Amoco Cadiz oil on the water surface quickly became emulsified with approximately 2.5 parts of water by-volume mixing with 1 part of oil. On the basis of this ratio, and assuming that 40 percent of the oil was lost to the atmos- phere by evaporation or into the water column by natural dispersion or by going into solution, the volume of mousse that had to be dealt with ashore was calculated to be over 488,000 metric tons. The total is also expressed in Fig. 6-1 in difj[jerent weight and volume units. This amount of mousse is capable of coating 359 miles of coastline with a layer of mousse 1 inch thick and 120 feet wide. The specific gravity of the oil- water mixture would range from 0.98 before the light ends evaporate to almost 1.028, the specific gravity of sea water after the light ends evaporate. To provide a further measure of the volume of oil or mousse with which one must deal, it is worthwhile to relate it to the load capacity of the shore based equipment that must move the material. 'Fig. 6-3 shows the numbers of farm honeywagons, commercial vacuum trucks, dump trucks, tank trucks, and railroad tank cars necessary to move this amount of mousse. These numbers do not include the volume of seaweed, sand, and other detritus that are collected with the mousse and that in the later stages of the cleanup predominate in weight and volume, often DISPERSAL By WINDS, EVAPORATION WAVES,AND DISSOLUTION CURRENTS INIV -WATER LIGHT EMULSIFICAT-ION] SUPRATIDAL FRACTIONS ZONE HEAVY FR CTION ENTRAPMENT IN INTERTI AL AND ON BEACH ZONE MATERI L HII H TIDE fAJBTIDAL INTERACTION ONE WITH SUSPENDED LOW SEDIMENTS ENTRAINMENT TIDE IN SE MENTS Figure 6-2., Mass balance components. 230 being equal to 20 times the amount of oil collected. The figures should help the reader to recognize the magnitude of the problem facing the French administrative system when the spill took place at an unforeseen time and place. In this chapter, the authors discuss in detail the physical proper- ties, behavior, and movement of the oil and its ultimate deposition on the beaches. The organizational structure established to deal with the spill and the strategy of control that appears to have been followed are presented and evaluated with regard to their utility in other spills. In addition the processes and unit operations used on the beaches are discussed. Estimates of the manpower and equipment used at different times throughout the spill are based on extensive reviews of newspaper VOLUME OF LOADS TO LOAD- MOVE MOUSSE 750 gallons 188,830 1,800 yallons 78,678 252 cu.ft. 75,170 1.,884 gallons 4,000 gallons 35,405 8,000 gallons 17,702 Figure 6-3. Equivalent truck and tank car loads necessary to remove potential volume of mousse from shore. 231 reports and daily pollution reports issued by the Department of Equip- ment. The final section discusses what has been learned from this experience. 6.2 Physical Properties, Behavior, and Movement of the Oil That Affected Control Operations The general dimensions of the Amoco Cadiz and locations of the breaks in the hull are shown in Fig. 6-4. The oil lost from the Amoco Cadiz was a mixed cargo of Light Arabian Crude and Light Iranian Crude and the remaining Bunker C fuel of the ship. Shortly after grounding at or near midnight on March 16, 1978, the ship broke in two near the bulkhead between the third and fourth (and last) row of tanks. In addition many of the other tanks were punctured or the bulkheads broached. Thus the early release of oil was a major one. The hull broke a second time approximately a week later near the foreward port of the number 2 row of tanks, resulting in another heavy release. n n 85.93 FT. 1,095.91 FT. @2-' BREAK BREAK 167.53 FT. REG45TRY: MONROVIA LIBERIA OWNER;AMOCO TRANSPORT CO. CALL/OFF N9.: A8AN/4773 POWER: 2SA 8CYL. DIESEL ; 980mm x 2DOOmm 22,6781(@/30,400 BHP. (SINGLE SCREW) TANK LAYOUT AND VESSEL SPEED: 15.25 KTS. DRAWINGS NOT AVAILABLE. MAX. DRAFT: 65 FTJ 19.81 M. CAPACITY: 233,690 DWT. 109,700 GRT. 91,000 NET/TONS ABOVE DATA PER LLOYDS REGISTER. Figure 6-4. General layout and dimensions of Amoco Cadiz showing locations of breaks. 232 In the second week, t he newly escaped oil recontaminated cleaned areas causing additional work, and negatively affected the morale of the cleanup workers ashore. To overcome this problem, the ship was bombed to release the remaining cargo. Fig. 6-5 is an estimate of the cumula- tive releases of oil from the ship compiled from newspaper reports and other sources. During the first 11 days of the spill, during which it is estimated that 90 percent of the cargo was lost, the winds ranged from the west to the northwest at speeds of about 20 to 30 knots. The wind-driven trans- port vector was superimposed on an oscillating tidal component from the southwest to the northwest with an excursion of -8 kilometers with neap tide to 15 kilometers with spring tides. This tended to spread the oil into a broad band to be carried toward shore. The wind vector coupled with the deflection of the coastline caused the oil to spread along the coastline in substantial volume from approximately 10 kilometers south of the site of the grounding to approximately 200 kilometers to the east. The heaviest oiled areas were 250 - TOTAL CARGO 220,000 TONS 200- REPORTED LEFT 81 THE zi 01 150 - .. I 1 (A BREAK IN I TANX 2 00 IL I Q W 100- ID I z z i_X I 41z W _j0 W I.- U) 50 - BREAK BETWEEN TANKS 364 CHRONICLE DAV 6 7 8 9 10 11 12 13 14 15 166 17 IS 19 20 16 17 8 19 20 21 22 @3 @4 i5 [email protected] i7 i8 @9 iO @ 'I j @ .4 5' 6' MARCH APRIL Figure 6-5. Estimated cumulative oil release from Amoco Cadiz spill. 233 the beaches, coves, and estuaries with openings to the west. Those that faced east and northeast were generally spared from substantial initial deposits of oil. Northeast winds during the third and fourth weeks after the spill moved the oil southeast along some of the beaches and extended the impacted zone south from the spill site an additional 10 kilometers along the western Brittany coastline to Pointe de Saint Mathieu. Major zones of the coastline that were affected are shown in Fig. 6-6, which also gives the numbering system used to identify the individ- ual beach areas. On this map the coastal areas to the south and west of Pointe Scoune, north of Portsall, are given "W" designations, and those east and north of Pointe Stoune are given "E" designations. Not shown on the map are labeling systems for individual estuaries, such as AB-1 through AB-6 for l'Aber Benoit. This numbering system was used exten- sively during the trip of April 20 to May I for photo reference and for beach survey and beach cleanup report purposes. Table 6-1 is a detailed listing of the individual zones referenced to geological maps and geo- graphical names. All of the oil that came ashore was in the form of some type of oil-water emulsion or mousse. The incorporation of water into the oil substantially increased the volume and weight of material that had to be pumped or hauled from the beach as part of cleanup operations. The lack of an adequate method to evaluate the mousse components had hindered past oil spill studies and led to the funding of a Sea Grant Project at Texas A&M University, This project developed accurate methods to make and break oil-water emulsions; the methods were used to analyze the oil- water emulsions from the Amoco Cadiz. Reports of water content from past oil spills have ranged from 20 to 85 percent for naturally formed emulsions. During two visits to the Amoco Cadiz spill site and coastal areas, samples were collected from 23 sampling stations covering the period of March 29 to April 24, 1978. Twenty-four samples from 16 of these sampling sites were analyzed using a technique that results in better than a 99 percent separation of the oil, water, sand, and clay in water-in-oil emulsions. The separation technique uses an emulsion-breaking compound (Visco, 103 V-8074/6284) in a mixed aromatic solvent solution of benzene, xylene, and toluene, which is added to the emulsion in a ratio of 1:1 on a volume-to-volume basis. This mixture is poured into graduated centri- fuge tubes and shaken. The tubes are then placed in a heated centrifuge for 5 minutes at 3000 rpm at 800C. This process separates the emulsion into distinct layers of sand, clay, water, and oil/emulsion-breaker mixture. The results of the 24 analyses are shown in Table 6-2. The water content ranged from a high of 91.25 percent to a low of 20.40 percent, 234 \E20P, -,xI 0 E W16\, PORTS L w W2i , PLOUDALME U BREST Figure 6-6. Major affected zones and beach numbering system along the Brittany coastline. 235 IE4(0\j -00 E501 BRIG; OGA Iv, E45 ROSCOFF E60 LOUESCAT Figure 6-6 (continued). 236 EIOO,/ ILE GRANDE TR TEL-PLAGE. E95 E8 E90 PERROS-GUIREC ,E70 PLOUGASNOU LANNION ;E75 S! MICHEL-EN-GREVE PLESTIN- LES-GREVE Figure 6-6 (continued). @U 237 Co FIT Figure 6-6 (continued). w4z.;@ 238 Table 6-1. Beach numbering system of the French Coast Section Beach Topographic Map No. Name Nearest City Name (1/50,000) El Pointe Scoune Kerros Plouarzel - Ile d'Ouessant E2 Ile Longue Kerros E3 Ile Carn Kerros E4 Blockh Dourlannoc E5 Ruscaroc Ruscaroc Plabennec E6 Roc'h Seac'h Lampaul-Ploudalm6zeau E7 Corn ar Gazel Kervigorn E8 Anse de Brouennou Brouennou E9 Roc'h Avel Kerennoc E10 Carrec Adanet Poulloc Ell Roc'h Melen Poulloc Plouguerneau E12 Ile C6zon Quistilhe (Quistillie) E13 Keridaouen Keridaouen E14 Ile Wrac'h Kervezen E15 Kervenny Braz Kervenny E16 Carrec du Bras le Revn (le Run) E17 Anse Lostrouc'h Lostrouc'h E18 Porz Grae I Kelerdut E19 Porz Grae II Kelerdut E20 Porz Guen I Porz Guen E21 Porz Guen Porz Guen E22 la Gr6ve Blanche Penn ar Str6jou E23 Beg ar Spis Penn ar Str6jou E24 an Dol-Ven St. Michel E25 Kergoff East Kergoff E26 Kergoff West Cr4ac'h an Avel E27 ar C'houlm le Zorn E28 Gr6ve du Vougo le Curnic E29 Curnic le Curnic E30 Enez Croaz-Hent le Curnic E31 Nod4ven Nod6ven E32 Port de Tr6ssgny Guisseny E33 Mentoull E34 Loccarec Mentoull E35 Menbr6ac'h Menbr6ac'h E36 Carrec Hir Boutrouille E37 Louc'h an Dreff St. Egarec E38 ar Vorbic Kerlouarn E39 Carrec Menez-Hom E40 Ile de Kerlouan Minioc E41 Pointe de Beg Pol Perros E42 Terre du Pont Terre du Pont E43 Kerav6zan Monbren E44 Gr6ve de Goulven Brignogan St.-Pol-de-L6on E45 Kibell (ar Guibell) Ker Emma E46 Ae'r de Plouescat Pont-Christ E47 Corps de garde Lanndrien E48 Enes Eog Goas-bians E49 Enez NGez St. Eden E50 Kergovara E51 Clos-ar-H61en Kerfieien (Kerfissien) E52 an Amied/an Holen Kervaliou E53 Port Neuf Keraval E54 Dunes de Santec Kerabret E55 Men Rognant E56 le Stavl (le Staul) Men Rognant E57 Roche Blanche Jugan E58 Prateron E59 Port Gare Roscoff E60 St. Sebastien Kerezoun E61 Cr6ac'h Andr6 Tromdal E62 Pempoul St. Pol-de-L4on 7-8 E63 Penz6 Rivi6re Bay Carantec Plestin [email protected] E64 Morlaix Bay Locqugnol6 11 E65 Kern6l4hen E66 St. Samson E67 le Guerit le Diben E68 Pointe de Diben le Diben E69 Primel-Tr6gastel Primel-Tr6gastel 239 Table 6-1. (continued) Section Beach Topographic Map No. Name Nearest City Name (1/50,000) E70 Ker Maria Plougasnou Plestin les-Grbves E71 KerdreTn St. Jean-du-Doigt E72 Beg an Fry Kervourc'h E73 les Charrues Poul Rodou E74 le Moulin de la Rive le Moulin de la Rive E75 Roches d'Argent Locquirec E76 Rocher Rouge St. Efflam E77 Grbve de St. Michel St. [email protected] E78 an Treuzec Tr4drez Lannion E79 Malabri Kerguerven E80 Plage de Notigou Locqu4meau E81 Plage de Porz Mabo Beg-Leguer E82 Plage de Tresmeur Tr4beurden E83 Plage de Por2 Terman Crec'h H6ry E84 Goaz-Trez Kerhell4n Perros-Guirec No. 5-6 E85 Rulosquet Dourlin 11 E86 Ile @ Canton Dourlin E87 Carr Dourlin E88 Pointe de Toul-ar-Staon Dourlin It E89 le Corbeau Porz Gglin E90 Ile Mouton Penvern E91 Ile d'Erc'h Kerdnoc E92 Ile Plate Landrellec E93 Ile Jaouen Bringuiller E94 Ile Tanguy Bringuiller E95 Kerlavos Kerlavos E96 Haren E97 la Gr6ve Blanche la [email protected] Blanche E98 116 Ronde la [email protected] Blanche E99 Beg ar Vir Ile Renote E100 Ste. Anne Ste. Anne E101 Plage de Trestraou Perros-Guirec E102 Anse de Perros St. Quay-Perros Perros-Guirec E103 Feu de Nanthouar Tr4l6vern E104 Port VEpine Keriec E105 Plage du Royau Trdvou-Tr4guignec E106 Anse de Pellinec Penv6nan E107 Anse de Gouermel Ral4vy E108 Baie d'Enfer Kerbors Tr4guier E109 Port la Chalne Pleubian E110 Sillon de Talbert Lanmodez wi Prat L6ac'h-Kerros Kerros Plouarzel-Ile d'Ouessant W2 Portsall .1 W3 Kerdeniel Portsall W4 Mon Repos Portsall W5 Portsall Portsall W6 Barr al Lann Barr al Lann W7 Barr al Lann Barr al Lann W8 Amer Amer W9 Beg ar.Gal4ti Tr6mazan W10 Beg ar Manac'h Tr6mazan Wil St. Samson St. Samson W12 Pointe de Landunvez Kerhoazoc W13 Kerlaguen Landunvez W14 Penfoul Landunvez W15 St. Gonvel Argenton W16 St, Gonvel Argenton W17 St. Gonvel Argenton W18 Presqu'ile du Vivier 'Argenton W19 Presqu'lle St. Laurent Porspoder W20 Melgorn Bihan Porspoder W21 Melgorn Braz Porspoder W22 Rad4noc Porspoder W23 Porspoder Porspoder W24 Poulloupry Porspoder W25 Mazou Porspoder W26 Prat ar Men Porspoder W27 Ile de Melon Porspoder W28 Mentiby Lanildut 240 Table 6-2. Oil and water content of emulsions formed during the Amoco Cadiz oil spill Date Water: Oil Oil: Water Beach No. Collected Clay % Sand % Water % Oil % Ratio Ratio % Water % Oil Wil 20 Apr 78 0.45 7.30 91.25 8.00 11.41 .0876 91.94 8,06 W8 20 Apr 78 0.42 0.42 76.94 22.22 3.46 .2890 77.59 22.41 W5 29 Mar 78 0.74 0.59 57.52 41.15 1.40 .7143 58.30 41.70 E2 19 Apr 78 0.30 0.60 75.10 24.00 3.13 .3195 75.78 24.22 E2 19 Apr 78 0.44 0.57 68.70 30.29 2.27 .4405 69.40 30.60 E6 19 Apr 78 0.25 18.17 56.59 24.99 2.26 .4425 69.37 30.63 E6 29 Mar 78 0.75 3.75 75.50 20.00 3.78 .2646 79.60 20.40 E6 19 Apr 78 0.60 5.25 60.15 34.00 1.77 .5650 63.89 36.11 E6 19 Apr 78 0.42 1.76 65,19 32.63 2.00 .5000 66.64 33.36 AB4 23 Apr 78 64,50 3.00 22,50 10-00 2.25 4444 69.23 30.77 AB4 29 Mar 78 1.76 1.91 75.71 20.62 3.67 .2725 78.59 21.41 E13 21 Apr 78 3.46 3.17 64.78 28.59 2.27 .4405 69.38 30.62 E15 21 Apr 78 1.16 1.58 72.30 24.96 2.90 .3448 74.34 25.66 E15 21 Apr 78 1.20 60.00 20.40 18.40 1.11 .9007 52.58 47.42 E59 29 Mar 78 1.60 0.92 63.28 34.20 1.85 .5405 64.92 35.08 E77 30 Mar 78 1.50 5.63 65.38 27.50 2.38 .4202 70,39 29.61 Table 6-2. (continued) Date Water: Oil Oil:Water Beach No. Collected Clay % Sand % Water % Oil % Ratio Ratio % Water % Oil E77 23 Apr,78, 0.00 65.25 21.75 13.00 1.67 .5988 62.59 37.41 E85 31 Mar 78 1.20 0.60 70.20 28.00 2.51 .3984 7.49 28.51 E85 23 Apr 78 0.90 .0.90 50.20 48.00 1.05 .9524 51.12 48.88 E91 23 Apr 78 2.37 2.00 65.34 30.29 2.16 .4630 68.33 31.67 E96 30 Mar 78 0.60 2.25 73.15 24.00 3.05 .3279 75.30 24.70 E98 30 Mar 78 1..88 1.50 81.62 15.00 5.44 .1838 84.48 15.52 Tr4gastel 23 Apr 78 6.90 3.60 67.50 22.00 3.07 .3257 75.42 24.58 Penahr 29 Mar 78 1.88 5.25 70.90 19.97 3.65 .2740 78.50 21.50 Avg. 2.94 .4379 70.78 29.16 Overall Oil/Water Ratio .41 Over all Water/Oil Ratio 2.43 The oil flowed freely and had a water content 20 percent less than an earlier sample. The results of the analyses to date tend to indicate that emulsions of water-in-oil have a "life history" that can be traced from formation to final deposition or disappearance. Fig. 6-7 indicates possible pathways by which emulsions impact shorelines. The time scale, rates, and even probable pathways are missing because of the lack of knowledge about the fate of water-in-oil emulsions. The behavior of the mousse on the beaches is of extreme importance to cleanup operations, particularly as the mousse moves back and forth with the tide and ultimately becomes stranded at or below the high tide line and as its specific gravity is increased through evaporation of light hydrocarbons and through the entrapment of sand. What starts out as a floating, pumpable, separable material, eventually becomes a rela- tively stable, heavy, nonpumpable material that must be either removed by hand or construction equipment, or left on the shore. OIL RELEASED AT SEA EMUL ION III WIND a WAVES ACT WORKED BY SURFj ON THE OIL TO FORM AN EMULSION WATER CONTENT WITH WATER INCREASES -11_ NO OIL REMAINS AT SEA DOES IS IT IS IT HE MOUSSE YES AP ROACHING STRANDED UNTIL DISPERSED NO T ROCKY IN POOLS, ON ROCKS BY NATURAL FORCES GO ASHORE ROCKY OR SAND ON ALGAE ? AREA SANDY Y"S EMULSION IS STRANDED BY OUTGOING TIDE HAS IS IT EMULSION Is ABOVE NEX EMULSION WATER REFLOATED "NO THE NO HIGH Yf_S CONTENT DECREASES BY OUSSE'S SP. GR. TIDE LINE OUTGOING TIDE EXCEEDED 7 DUE TO WEATHERING 1.0247 YES S IT )IS REMOVED BY UTURE TIDES NO I REMAINS ON/IN BEACH UNTIL DEGRAD ED BY NATURAL PROCESS]ES EMULS' ON No A ER S C T W CT Yf NO 0 NTEN DE REA E DUE To W EATHERIN yes _rS NO Figure 6-7. Possible pathways of oil spilled from Amoco Cadiz. 243 In the Portsall and Roscoff areas the mousse was quite thick on the water surface and amenable to direct removal. In most other areas, however, the oil was stranded on the beach with heaviest concentration in the high tide zone. Typically, the beaches would have a relatively stable oiled area at the top intertidal zone, which might be up to 50 meters wide. This oil would be stranded after the tides receded, and would either stay in place or slowly ooze down the beach front as a result of gravity. Downslope in the middle beach area, the movement of the oil down the beachface was aided by ground water emerging from the sand. Quite often the oil would flow down the beach in rivulets on top of the flowing ground water. The oil that drained down the beach would pool in the lower intertidal zone or at the water's edge and then work its way up the beachface with the incoming tide. For the most part, the mousse tended to bridge over the fine beach sands and did not appear to penetrate them. In rocky areas the mousse would lightly coat the face of the emerged rock and seaweed and would pool in the crevices around and between the rocks, sometimes to depths of 4 or 5 inches. North of Portsall Harbor (W3) the oiled beach at low tide was over 400 yards wide and near a rocky area toward the west end of the Middle Dunes Beach (E2) north of Portsall the oil was 235 yards wide with an average depth of at least 1 inch. Near the high tide mark on some of the beaches, the oil would be trapped by kelp or by rocks and other depressions and would pool to a depth of 2 to 4 inches. Toward the end of the second week, skimmer operators in the Aber Benoit estuary reported that the oil was beginning to remain on the bottom of the estuary when the tide would come in; this was also ob- served in the upper beach deposits that would have 2 weeks to weather and be sanded before the spring high tides returned to the area. In addition, sand deposition created layers of oiled sand or mousse between clean sand layers on many beaches. As with other spills, the nature of the oil to be removed by cleanup is a function of the type of the oil, its development into an oil-water mousse, the trajectory it takes to the shore, the method of its deposition on the beach, the succession of spring and neap tides, the ground water exchange with the beach, the physical and chemical aging of the stranded oil, and the introduction into the oil of materi- als that increase its specific gravity. 6.3 Organization To Deal With the Spill Almost immediately after the grounding of the Amoco Cadiz, it became evident that cleaning up the spill would [email protected]_dthe capacity of the ship owner (Amoco) or the cargo owner (Shell) using available com- pany personnel or contract resources. It was also evident that cleanup 2.44 costs would exceed the resources available under TOVALOP or the Civil Liability Convention, whichever coverage was provided by the ship owner, or under CRYSTAL, the financial fund maintained by cargo owners. Conse- quently, the task of organizing and financing the cleanup operation fell to the government of France, which executed the plan PO 'LMAR, correspond- ing roughly to the National Contingency Plan in the 'United States. A discussion of the development and organization of the plan within the local, regional, and central governmental structure of France will help explain why certain procedures were followed and how certain successes were achieved. It also explains how certain problems arose. 6.3.1 Plan POLMAR In France, the President is advised by the Prime Minister and the Cabinet; the Cabinet guides policies of the nation, directs action of government, and is responsible for national defense. On May 12, 1976, one of the two topics presented at the Cabinet meeting was a report of the status of the fight against pollution and the protection of the maritime frontier ("un bilan de la lutte contre la pollution et de la protection des facades maritimes"). After several months of debate, on November 3, 1976, Monsieur Vincent Ansquer, Minis- ter of the Quality of Life, announced the adoption of measures for the control of marine pollution. On May 5, 1977, the Cabinet accepted a law authorizing the rati- fication of a convention on the prevention of marine pollution by the discharge of waste products. On May 12, a national agency was created to prevent air pollution and was financed by a levy against combustible pollutants. These actions in May 1977 divided the original plan into separate plans for air and for water pollution, with separate policies. The law on marine pollution was adopted in,its second reading on June 18, 1977, by the Assembly, and 6 days later by the Senate. This law was designed to prevent and control marine pollution resulting from intentional discharge of waste products or from accidents. In these ea rly stages the law was referred to as Pollution Marine. Shortly thereafter, it became known as "Plan POLMAR." Governmental authority in France flows from the national level to the local level. Many important government decisions are made in Paris and enforced in the several localities by a network that includes the Ministry of Interior and its staff, who supervise local units, mayors, and municipal councils, and the prefects and subprefects associated with the Department of Interior. Control of pollution was conceived of as a civil matter. Plan POLMAR was the brainchild of the Ministry of the Quality'of Life, but its execution was placed in,the Direction of Equip- ment, which is comparable with U.S. state and local Departments of Public Works, insofar as its primary work is concerned. The Ministry of 245 the Interior retained the enforcement powers. Since there was already a structure of local entities carrying out the policies of central govern- ment, it was reasonable to envision use of the same organizational structure to deal with a marine pollution incident such as a major oil spill. At the time of the Amoco Cadiz wreck, Plan POLMAR had not been tested in a major incident. Immediately following the grounding of the Amoco Cadiz, Vice-Admiral Jacques Coulondres, maritime prefect of Brest, was placed in charge of Plan POLMAR. As time passed, --'t became in- creasingly evident that the fight against the oil spill would have two fronts: the sea and the coastline. Thus, Plan POLMAR was split into Plan POLMAR-Mer (sea activities) and Plan POLMAR-Terre (land activi- ties). Vice-Admiral Coulondres retained control over the sea activi- ties. The land activity was first placed under the responsibility of Monsieur Bourgin, but later passed to Monseiur Marc Bicam, former mayor of Quimper and secretary of the Ministry of the Interior at Paris. However, much of the strategy of the land activities and the details of operation were channeled through the Direction of Equipment offices in [email protected] and C8tes-du-Nord, the two Departments constituting the af- fected coast. On the local level, existing political structures were used for the land activities. The two affected Departments were each divided into four zones, each under the immediate responsibility of an engineer from the Direction of Equipment. It was soon learned, however, that the land activities required a great deal of organized manpower and the Army was called in. Establishing the unforeseen communication links needed between these organizations was a major, time-consuming task. Plan POLMAR had no provision for use of volunteers in the event of a pollution disaster. This resulted in a tremendous problem for the administrators since the disaster occurred during the Easter break of the schools and universities, and many students wanted to volunteer. Eventually the problem was resolved by placing the administration of volunteers under the Ministry of Youth and Sports. A prospective volun- teer first called the local office to demonstrate age, ability, and possession of necessary protective clothing and shelter. The volunteer was then assigned to a [email protected] area under the supervision of a foreman. This allowed for orderly use of the volunteer, protected the volunteer's personal safety and health, and discouraged vagabonds in search of free meals and lodging. The response to the spill was a function of several factors: 1) an untested plan which continuously needed revising to adjust to unforeseen problems such as the two fronts and the volunteers; 2) the weather; 3) the existence of centralized control over local affairs and the execu- tion of national policies through local units; and 4) the existence of certain communication channels and the lack of others. 246 and oil content ranged from a low of 8 percent to a high of 48 percent. There is no trend in the oil and water content with distance from the spill site. In the four cases where mousse samples were collected at the same site (E6) in March and April, there was a significantly higher oil content in the April sample. This indicates that when the emulsion is stranded above current high tide lines and is subjected to sunlight, wind, and other forces, the water evaporates and leaves a material with a higher oil fraction. The water-to-oil ratio evaluation indicates that the samples have an average of 2.43 parts water to 1 part oil. This ranges from 11.4 parts water to 1 part oil in fresh mousse at site W11 to almost 1:1 for weathered mousse at site E85. The average ratio of oil to water is o.41. Samples that gave the most extreme results indicate what happens to emulsions.in different coastal and weather conditions. The sample from W11 was taken in a steep rocky coastal area from a large pool of light brown fresh mousse recently deposited in a natural rock-formed pool by an increasing series of high tides. This location receives very strong wave action, and any oil in the area would be highly emulsified and would have a very high water content. This was borne out by the 91 percent water content of the sample. The two samples obtained from the Aber Benoit estuary (AB4) site indicate how the same site can yield different emulsions on different occasions. The sample taken on March 29 has a ratio of 3.67:1 of water to oil, which would be expected for a fairly fresh mousse. The sample taken on April 23, which showed a ratio of 2.25:1, has an unusually high clay value of 64.5 percent; this value is probably high because more than 25 percent of the clay volume is water. The oil had been exposed to 3 days of clear, sunny skies and warm temperatures, was very fluid, and had a dark black color. The wave action of the tide apparently mixed this mousse with the clay of the banks producing an emulsion having a high clay content. The two samples obtained from E15 and also two from E6 showed that after an emulsion with a high water content has been exposed to the sun and wind, the mousse loses some of its water. When the incoming tide mixes this mousse with suspended sand, the mousse coats the sand, and consequently has a high sand content. This process was also observed in areas where cleanup operations mixed sand into the the emulsion (E6) or where pits were dug intothe sand, filled with mousse, and covered again with sand (E77). The final example of change in an oil/water emulsion is Ile Grande marsh (E85). At this site large quantities of oil were exposed to 4 days of clear sun, and the oil was 12'C (20'F) warmer than the water. 247 6.3.2 Organization in [email protected] The project team became more familiar with the organizational structure of the response in [email protected] as a result of being located at and working with staff of COB/CNEXO, and through information provided by the Office of Direction of Equipment in Brest. The assistance provided by both organizations was outstanding. Fig. 6-8 shows a simplified organizational chart of land activities in [email protected] The linkage with sea activities and the land activities in C6tes-du-Nord is also shown. Each of the sectors was under the direction of an engineer from Direction of Equipment, and also included a Lt. Colonel or Colonel who served as a liaison officer with the mili- tary troops working in the-sector. Each sector was responsible for organizing daily activities in the field, requisitioning supplies, equipment and personnel, and-providing the logistical support to the field activity. The Command Center in Ploudalm6zeau coordinated sector activities, acquired and delivered logistical support, and arranged for ultimate disposal of the material collected in the field. Various supporting activities provided specialized technical advice or dealt with individual technical components of the logistical chain. SECTEUR do SECTEUR do SECTEUR do SECTEUR do SECTEUR do SECTEUR do SECTEUR do ST. RENAN LANNILIS ROSCOFF PLOUGASNOU LANNION ST BRIELIC FINISTERE AT SEA F- EATT ACTIVITIES INISTiRE COAST PC. POL MAR PC.PLOLIOALMEZEAU PC.ZOME RENNES MARINE FINISTERE CbTES-DU-NORD CONSTRUCTION PORT I-, STICS a OF ULTIMATE TIVITI ES THODS SOLID WASTE STORAGE ME SYSTEMS Figure 6-8. Approximate organization of the response effort. 248 Various units dealt with the physical aspects of oil removal. It appears that the initial response was from Civil Defense organizations, fire departments, contractors, and the French Navy. Follow-up response came from volunteers, Army units, public works departments, and addi- tional contractors. In addition to the personnel involved with cleanup operations, the local scientific community--on both an organized and voluntary basis--was substantially involved in determing the short and long range behavior and impact of the spill. 6.4 Strategy of Control and Cleanup From observations of this spill and from a general knowledge of the field, a strategy for spills of this magnitude emerges. The first step is to eliminate the oil or stop its discharge to the environment. In the Amoco Cadiz case, initial attempts were made to bring in pumping equipment to offload the cargo. However, the lead time required for equipment to arrive, the deterioration of the grounded ship, the adverse weather, and the difficulty of providing receiving tankage made elimina- tion by cargo transfer impossible. Related to this step in the strategy was the decision to bomb the ship after some 90 percent of the cargo had been lost, so that the remaining oil would be spilled and would not continue as a pollution source after major cleanup had been achieved. The second step in the strategy is to provide protection to the most environmentally sensitive areas. In this case, the mariculture facilities and the exposed estuaries that open to the west along the coast were considered the most important systems. Large numbers of booms were deployed in an attempt to protect these areas in the early days of the spill. Four days after the spill it was observed that the booms in l'Aber Benoit had been deployed correctly using angle theory, but other booms had failed either because they were damaged or because of entrainment. As the period of spring tide approached, all booms were ineffective because of the strong currents. On the Lannion Peninsula, where there were several days of lead time before the oil reached the area, some resort communities bulldozed the top layer of sand from their beaches and stored it in piles at the high tide lines. The plan was to clean the oil from the newly exposed beach face and, after cleanup was completed, to cover the entire area with the clean sand that had been stockpiled. A third phase is to prevent the oil from reaching shore. Preven- tion methods may include mechanical removal or the use of chemicals. In the case of the Amoco Cadiz, mechanical containment and removal were impossible [email protected]_eof lo-cal sea and weather conditions. Early attempts to use dispersant chemicals near shore were discontinued after the policy was established to refrain from using such chemicals in waters less than 50 meters deep. More than 35 boats ultimately were used to spread dispersants in deeper waters north and east of Roscoff and the Ile de Br6hat and south of Pte. de St. Mathieu. 249 The fourth phase of cleanup is the collection of floating oil 'from the surface of the water in locations where pumping and vacuum equipment can be used. Specific examples of this were in the Portsall and Roscoff areas. The fifth phase is removal of stranded oil. In the Amoco Cadiz case, the priority that apparently was established was to remove stranded oil first from those areas with highest population or with high-use resort beaches.. The first phase of the removal involved collection and pumping of the oil from the beach. This was accomplished by tactics such as the trenching and the digging of pits on the St. Michel-en- [email protected]_e beach, and the use of natural pockets and low points in other beaches. The removal of stranded oil also included washing down stone breakwaters and rip-rap areas that had been coated with water, and flushing the oil either into trenches or behind sand dikes. Several marsh areas were affected in varying degrees. A large marsh in the Ile Grande area was almost entirely covered with oil 2 to 8 inches deep. The only course available to avoid the extended damage as seen in the Espora marshes impacted by the Metula spill in the Straits of Magellan was to remove the oil. Less oiled marshes observed near the Baie de Kernec and near [email protected] de Goulven were probably best left alone since removal of oiled vegetation would probably cause more harm than the moderate oiling. A sixth phase of the strategy is to remove oil-contaminated materi- als. This includes removing oiled seaweed from rock, oiled sand from beaches, and oiled detritus of all sorts. The collected material is now low in oil content, but bulky and difficult to handle. Ultimate dis- posal of this material is a major problem. A seventh phase of the strategy is to handle the collected mousse and detritus material for recovery or ultimate disposal. 6.5 Specific Cleanup Operations A major activity of the Texas A&M team was to document the cleanup activities. During a series of visits to the cleanup site during 5 of the first 6 weeks following the spill, operations were observed visually and extensive photographs and 8-mm movies were taken. During the second project trip from April 15 through April 30, 1978, survey forms were filled out on the beaches at the time cleanup operations were observed. A copy of the form is shown as Fig. 6-9. We believe that the most important part of the cleanup of this particular spill took place ashore where the oil was stranded against or on the beaches and rocky shoreline. Seven unit-process diagrams (Figs. 6-10 through 6-16) document cleanup operations on shore and serve as a 250 OBSERVER DATE/TIME 7. Samples collected(if any) - date time location no. AMOCO CADIZ BEACH CLEANUP OPERATIONS SURVEY 1. Beach Number/Name/Descriptions_ 8. Describe the cleanup operation, sequence of events, usages of equipment, 2. Equipment utilized, size, type, amount, etc. effectiveness, Boom Dump Trucks Vac Trucks-- Tank Trucks----- Tractors______ Fire Engines Skimmers Honey Wagons__ 3. Expendibles, Small Equipment, Sorbents, (shovels, rakes, garbage cans, etc.) Types, How used, Est Quantities: LA ------------ 4. Personnel: (Approx. Number)___________; Laborers____________ Equipment operators [email protected] Type of work force, i.e. contract, volunteer, military, civil defense 6. Air temp @WX. etc. Water temp Wind velocity/direction Tide ( i n-out) /current Wave/swell Physical consistence of Describe terrain, i.e. sandy beach, marsh, etc. 9. Still Photos- Roll# Frame . ..... ----- - 10. Movies, Roll# est.footage. *Weather-sun, rain, partly cloudy - est. percent cloud cover - f0q, et( Figure 6-9. Beach cleanup survey form. guide to the color plates for this chapter. The processes of the Amoco Cadiz cleanup are discussed in sections 6.5.1. through 6.5.7. Also discussed are the other activities that contributed to the success or failure of the cleanup procedures. 6.5.1 Removal of Mousse From Water Surface Through Delivery to Interim Storage A diagram of four unit processes used to collect mousse from the water surface is shown as Fig. 6-10. Much mousse was collected by vacuum trucks (A) at locations where ramps or causeways permitted direct access of the trucks to the oil during high tide periods. The tank trucks were able to pump the mousse directly from the surface because of the thickness of the mousse layer. Plate 6-1 shows vacuum trucks opera- ting from a boat ramp in Portsall. TRANSPORT IN /GISCHARGE INTO PROCESS /.1.11 DECANT MOUSSIE SEAWEED FARM ,A60N OR INTERIM BULK FROM WATER WATER DUMP TRUC X SOLI 0 WASTE A SURFACE WITH VACUUM TRUCK STORAGE WATER MOUSSE WATER $ZAME9D TO SEA SEPARATOR TO SEA 0.1 FROM I MOUSSE MOUSSE TRANSPORT 1. SURFACE WITH DECANT TANK TRUCK INTERIM U53E MONEY '#ROOM WATER STORAGE /.ILE T T ANSFER By COLLECT OIL FROM DECAN C MOUSSE BY HAND HAND TO 30 GAL. GARBAGE CANS WATER IN BUCKETS GARBAGE CANS WITH VACUUM TRUCKS WATER TO SEA COLLECT TRANSFE TO NOUS34 WITH DECANT 0 SIOMM EN TANK TRUCK WATER INTERIM MOUSSE STORAGE WATER RETURN TO SEA Figure 6-10. Unit process: Removal of mousse from water surface.to interim storage. @ [email protected] FA A DUMP W TO BEA T. Al _'@@IWATE A To SEA WAT ER ____jR1 U.. T To A 252 A second method (B) involved the use of farm "honeywagons." Honeywagons are small vacuum trucks of 500 to 1000 gallon capacity, which are normally used to pump farm manure from cesspools and spread it on fields. Honeywagons drawn by tractors could work on the beach sur- face and follow the mousse as.it moved with the tide along the beach. This equipment had the advantage of being able to work during a greater portion of the tidal cycle than could the vacuum trucks, which were restricted to hard surface roads; indeed, this equipment was the most important in the French cleanup effort. Plate 6-2 shows three honey- wagons backed into the mousse on the beach to take on a load. Both of these pumping operations were hindered since skimming devices were generally not available to separate the mousse and the water. As a result, large volumes of water were pumped into the tanks along with the mousse. Part of the mousse would separate out and water. could then be removed from the tank by decanting; nonetheless, large volumes of water were often delivered to the interim storage areas. One report indicated that a tank truck brought 14 parts of water and 1 part of mousse to a storage area. One of the problems encountered in pumping directly from the sea was the presence of large amounts of seaweed in the mousse. Open topped industrial dumpster units 8 feet wide by 20 feet long by 4 feet deep were brought to the scene to use as seaweed/mousse separators. The oiled seaweed mixture was pumped into baskets hanging over the dumpster units; the mousse was strained through the basket and the seaweed re- tained in the basket. The seaweed was then removed by hand and carried away to an interim bulk solid waste storage area. Several separators are shown at the top of the ramp in Plate 6-1. Four Acme skimmers operated in the Portsall area. These skimmers discharged directly into vacuum or tank trucks, which then decanted excess water prior to delivery of the mousse to the interim mousse storage area. These compressed-air-driven skimmers from Tulsaj Okla- homa, are shown in Plate 6-4 and also in Plates 4-9 and 4-19. Initial operations also included the simple bucket brigade whereby a large group of soldiers would scoop the mousse directly from the water surface in small buckets and pass the buckets to shore where the mousse was dumped into 30-gallon garbage cans. The mousse was then sucked into a vacuum truck for ultimate mousse/water separation and transportation to interim storage. This operation is shown in Plate 6-3. 6.5.2 Removal of Stranded Mousse from the Beach and Transportation to Interim Storage During the period of increasingly high tide, mousse was resuspended and carried higher with each tidal cycle. When the spring tides began to recede, the mousse was deposited at each high tide and was not re- moved by the next tide interval. As a result, wide bands of mousse were 253 stranded on the beach and a major activity became that of removing the mousse material. The unit operations diagram for this activity is shown in Fig. 6-11. The first step was to concentrate the mousse where it could be picked up by mechanical equipment. This was accomplished by digging trenches or pits, or by using natural depressions or even squeegee boards to create a sufficient depth so that suction devices of the honeywagons could remove the mousse. Large numbers of soldiers pushed the mousse into these depressions and manned suction hoses. The primary unit operation included concentration of the mousse, loading into the honeywagons, discharge into an oil/water separator-to separate the seaweed from the mousse, and then transport by vacuum truck to the ultimate disposal area. Plate 6-5 shows a group of soldiers concentrating the mousse in a shallow pit and using vacuum hoses from two honeywagons to remove the mousse. This is also demonstrated in Plate 4-5. Plate 6-6 shows the use of a front-end loader wit 'h supple- mental loading by hand to pick up the mousse, which was then loaded in the dump truck in the background to be carried away for disposal. Plate 6-7 shows the collection of seaweed on a beach into piles both-by hand and by mechanical means. The mousse drains away from the seaweed so that it can be collected in pits and trenches for removal. TRENCH us" MOUSSE IN BEACH WITH INTO TRENCHES ROAD GRADER WITH SHOVELS BROOM OR -SOUEGEE NO MOUSSE/ SEAWEED SEPARATOR PIT IN PUSH MOUSSE INTO /F1C. MOUSSE [email protected]"T IN BEACH WITH PIT WITH MOUSSE WITH VACUUM OR FRONT END FRONT END LOADER SEAWEED MONEY WAGON SEPARATOR YANK TRUCK LOADER OR BY HAND BREAK /U.E T..AL PUSH MOUSSE DEPRESSIONS Oft INTO 0 EPRESSION BOA RDS TO CREATE By HAND SUCTIDN P 01 NY PICK UP MOUSSE L WAGON ITH WITH HAND TOOLS CARS OR PICK AND PUT IN UP OIL WITH GARBAGE CANS MONEY WAGON /.E FRONT END DISCHARGE [email protected] LOADER TO LOAD INTO SCOOP UP MOUSSE DUMP TRUCKS W E RIM MOUSSE SWRA09 Figure 6-11. Unit process: Removal of stranded mousse from beach to DISCHARGE _U47. '.T.... MOUSSE STORAGE <t> interim storage. 254 Plate 4-8 shows a front-end loader with a load of seaweed and the farm trailer used to carry the seaweed off the beach. Plate 6-8 shows a trench dug in the St. [email protected] beach to collect the mousse flowing down the beach so that it can be picked up by mechanical means. Plate 6-9 shows a series of pits dug in the same beach to collect the mousse for removal by a honeywagon. The men are using homemade squeegee boards with long handles to push the mousse across the beach into the pits. 6.5.3 Removal of Mousse from Rocky Areas to Interim Storage Large amounts of mousse were trapped in rocky areas, either by the pooling of the mousse in crevices and depressions or by the collection of mousse on algae. The algae on the rocks near the high tide line served almost as a natural oil absorbent. As the tide receded, the Algae became dry as a result of wind and sun action. When the tide returned, bearing a mousse mixture on the surface, the algae became oil coated as the mousse came into contact with algae before it came into contact with the water. As a result, the algae would hold many times their weight in mousse. Plate 6-10 shows mousse absorbed in algae. The removal of mousse from the rocky areas involved both the re- moval of the mousse trapped in the crevices and pools and the removal of the algal mass. Fig. 6-12 shows the unit processes for the removal of the pooled mousse and the mousse drained or squeegeed from the algae. VACUUM No /' MOUSSE C V TO E UIPMENT INTO "RAGE :YENTRA PONT D HAND OR AVAIL. CANS WAGO14 OR LOADER YES NO SEPARATION 7 TA NSP AT DISCHARGE IN VACUUM MOUSSE P-C P F"".SEU 'IT' DECANT SZE WEEK OR IAN, ... WATER 5 R DON TAU IN-"' OR VAC UU" C @1 TG.SA TRUCK WATER MOUSSE TO SEA SEAWEED /TRANSPORT JOISC"A'Re' By DUMP INTO IN ERNA TRUCK OR __ GO,.. WAGON _T. __.E Figure 6-12. Unit process: Removal of mousse from rocky areas to C [CE .y WA.1 @t interim.storage. 255 The process of removing mousse from crevices and pools depended on how close mechanized equipment could get to the rocky areas. In a few cases " it was possible to reach the crevices using a vacuum truck and long suction hoses. Plate 6-11 shows such an operation: a group of seamen volunteers are collecting mousse to be removed from among the rocks with a long suction hose from a vacuum truck. Often this simple solution was not possible and it was necessary to scoop the material from the rocks with a small can or even seashells and then to put the mousse into successively larger pails and finally into a 30-gallon garbage container that could be carried to a receiving point by hand or by farm wagon pulled by a tractor. The process of picking mousse up by hand and placing it in buckets is shown in Plate 6-12. 6.5.4 Removal of Oiled Sand, Seaweed, and Detritus to Interim Storage Fig. 6-13 diagrams the unit processes for collecting and moving oiled bulk material to interim storage. The initial process covers the collection of oiled sand or oiled seaweed and detritus, which is placed in bags. Many soldiers and some volunteers bagged large volumes of oily materials into heavy plastic bags. Most of the bags were apparently designed for commercial fertilizer but were diverted for use in the cleanup. Plate 6-15 shows soldiers picking up and bagging oiled algae. OR OILED SAND IN PLASTIC BAGS .1 AND [email protected],Z TO CARRY BY 1 0 - ONTO WAGON INTERIM -SAG CtA:TNALTO OR FRO NT END STORAGE PO I 'IT LOADER /PL. OILED SEAWEED 0 OETRITUS 1: PL STI CEASS COLLECT SEA We ED By VIA 0 OR BEACH /I. A.. OR /TRANSPORT To DISC" RGE DUN TRUCK ["ERIN BULK INTO INTERIM By FRONT emu SOLID WASTE BULK SOLID /C.LL..T LOADER STORAGE WASTE STORAGE SEAWEED WITH FRONT END WADER /F.C. UP .,LED LOAD INTO SAX0 "I " DUMP TRUCK F CRT END MOEN Figure 6-13. Unit process: Removal of oiled sand, seaweed, and detri- Sol I tus to interim storage. 256 Plate 4-5 portrays the operation of picking up bulk oiled seaweed from the beach. Similar operations included picking up oiled sand from some beaches. 6.5.5 Cleaning_of Walls, Rock Faces, and Cobbles Since the entire coastline in this region is a resort area, the cleaning of rocks, retaining walls, ramps, and boulders was necessary for both safety and aesthetic reasons. In the later stages of the cleanup considerable effort was given to this unit operation, which is diagrammed in Fig. 6-14. The most complete cleaning operation consisted of the delivery of large volume of water to the cleaning area by tank trucks or vacuum trucks, the use of fire department pumping units to increase the pres- sure, and the use of fire for a high pressure stream with sufficient volume to flush the mousse into a collection area. Where the operation was done correctly, a containment area was established to collect the washed mousse and to pick-it up for disposal. However, in many cases where the rocks or walls were washed the mousse was merely allowed to be trapped in sand, or if conditions were favorable, to be carried away with the next tide. Cleaning of rock walls can be seen in Plates 6-13 and 6-14. The unit process diagram (Fig. 6-14) also describes the process of spraying oiled cobbles with dispersant and moving the cobbles to the lower beach zone for cleaning and redeposition. This procedure, shown also in Plate 6-30 is discussed under the topic of dispersants. OILIVE /B.. OIL15" TIES UP DECANT WATE A .FACE WASHED OIL SITE 1:-T... -...T:"-...E WATEMWEITTIR'SAI CO Be ITh BOOM WATER TRUCK TRUCK LLE OR IN DEPPIESSION NO DELIVER WATER IN STOP FIRE OR VACUUM TRUCK SPRAY /A'.. PICK Up TRANSP T AND COUN ON SURF COBBLES WITH ---- DRYING COWLES WITH DISCHARGE AT ACTION TO 013PERS&NT TIME FRONT END LOWER BEACH CLEAN AND LOADER LEVEL RETURN COBBLES P:ck UPH . I IT VACUUM TRUCK Figure 6-14. Unit process: Cleaning of walls, rockfaces, and cobbles. 257 6.5.6 Unit Processes for Cleaning the Ile Grande Marsh The marsh areas at Ile Grande near the northern end of the Lannion Peninsula (E85 and E86) were heavily oiled, with mousse levels of 2 inches or more in grassy areas and levels ranging in depth from inches to feet in pools and channels. Experience gained in the Metula spill indicated that a marsh so heavily oiled would show no signs of life for years; therefore, oil removal, even at the price of vegetation removal and soil surface disruption, was warranted. Fig. 6-15 diagrams the operations observed and those expected to be used. The cleanup consists of the removal of the mousse and oiled vegetation where the mousse has covered the ground and the root stalk system. Where the soil is not covered, oiled grass should probably be left alone. Lightly oiled marshes such as those at [email protected] de Goulven and Baie de Kernec are prob- ably best left alone. Plate 6-16 shows a group of soldiers working with a small group of women volunteers in the Ile Grande marsh. The crane in the picture became bogged down while trying to create a channel to collect the mousse. PICK-UP By LO I ONTO ........ TO HAND FAR. ron DUMP TRUCKS SOLID CUT VEGETATION AT DRAIN GROUND WITH VEGETATION SHOVEL OR MECHANICAL MEANS SQUEESE MOUSSE FROM GRASS IS No PUT TRANSPORT By SEPARATION No MOUSSE IN HAND, FARM AVAILABLE SON OR FRONT SUCK E TS WA EN0LOAD ER MOVE U LOAD INTO HONEY YES K UP By OR MECHANICAL YES OR OIL/OETRITU .U. ON INTO NATOUSSAEL [email protected] WA AND/ SEPARATION =TA C ANNELS By AVAI LABILE VACUUM TRUCKS A . TRUCK HAND WATER TO SEA DIG CHANNELS MOVE MOUSSE NOTES WHERE NEE DED TO INTO CHANNELS I. Arrempr wo ro "A, Orr ArAosm m co*-y AvusSE Hiff DRAIN OIL BY HAND SPRING TIDES BROKE rNE DAN. Z SPRINKLERS WERE USED IN SVWE AREAS rO X&P OIL OPP OF CLEANED ARJEAS, Figure 6-15. Unit process: Cleaning of Ile Grande marsh. SOL" AT 258 6.5.7 Movement of Mousse and Oiled Materials from Interim Storage to Final Disposal Sites The volume estimates calculated in the initial section of this chapter indicated the huge amount of material that must be removed from the beach in such a spill. Since it is not desirable to tie up the limited equipment in transportation over long distances during the critical stages of the cleanup, a large interim storage much be created near the beach. Here mousse and solid materials are stored for periods from a few days to a few weeks, until sufficient equipment can be di- verted from the mousse removal operations to carry the stored material to its final destination. A unit process diagram covering the processes from interim storage through disposal is shown in Fig. 6-16. The primary interim storage devices used for mousse in the Amoco Cadiz spill were dug pits, which were either lined with plastic or left unlined. Plate 6-17 shows a typical group of interim storage pits located near Roscoff. Several honeywagons are unloading into one of the pits and vacuum and tank trucks are loading for transport. In the same region, a series of pits was used with screens placed between two pits (Plate 6-18) to serve as seaweed/mousse separators. Efficient loading requires the decanting of excess water from the tank of vacuum trucks as shown in Plate 6-19. NO SEPARATION LOAD ON TANKER FOR WATER TRANSPORT TO SEA /INTERIM MOUSS TRANSPORT By DELIVER 10 MOO", SEA - 0 VACUUM OR REFINERY .:I STORAGE ANA N TANK TRUCK INCINERAT SEAWEED LOAD ON R.A. TANK CARS MR TRANSPORT LOAD ONTO TRANSPORT LOAD INTO SHIP FOR TO DUMP TRUCKS TRANSPORT BREST FOR TRANSPORT RESIDUE IN IN CHARGE IN MOUSSE LOAD INTO . TI MAT E INTERIM DUMP TRUCKS DISPOSAL PITS STORAGE PITS FOR TRANSPORT BREST HARBOR /IN'T.R.1% a" 43CNARGE 1. STORAGE ULTIMATE DISPOSAL PITS TREMASTLIE +WA ER T To SEA SEA-_ "T" L ]N ITS Figure 6-16. Unit process: Movement of mousse and oiled material from interim storage to disposal. 259 During the early stages of the spill, mousse from the Roscoff area was discharged into a small coastal tanker for transport to an oil re- finery for processing. This tanker and the huge backlog of tank trucks waiting to be unloaded is shown in Plate 6-20. Later in the cleanup operation the mousse was transported by railroad tank cars to a refinery for either reprocessing or incineration. In the later days of the spill, huge volumes of oiled sand, detri- tus, and seaweed were collected. This material also required interim bulk storage. In most cases bulk seaweed and sacked materials were stored on plastic sheets placed on flat ground with the edges built up to prevent any drainage. This material cannot be recycled for oil, nor does it have sufficient fuel value for burning. As a result, it posed a major problem'. In the Department of C8tes-du-Nord, the material is being buried permanently near the town of Tr4gastel. One of the ulti- mate disposal pits is shown in Plate.6-21. In the Department of [email protected] several large storage pits have been constructed on the port property at Brest. Four pits ranging in size, from @ to I acre have been constructed: first, pits with a depth of approximately 10 feet are dug and are lined with clay and then with a thick black plastic liner. Material is discharged into the pits pending future decisions to stabilize the material or use another form of perma- nent disposal. Plate 6-22 shows typicai materials dumped into these storage pits. A problem for future disposal is the.large number of plastic bags that have been used in storing semi-solid waste materials. An attempt was made to use a crane to pick up and drop the bags upon delivery in order to break them. 6.5.8 Results After Cleaning During the period of April 20 through May 1, many of the beaches appeared to be clean. However, in most cases it was found that the view was deceiving and that a considerable amount of mousse had been buried under the sand that was building up on the beaches at this time of year. Plate 6-23 shows mousse that was left in the concentration pits on St. [email protected] beach, which was ultimately covered by sand. It can be seen from Plate 6-24 that extensive working of mechanical equipment over the same beach left behind areas of oiled sand. Plate 6-25 shows layers of oiled sand on the same beach in the area worked by the mechanized equipment. In rocky areas many of the pools of oil and most of the heavily oiled algae were removed. However, at the base of the rocks were many areas where mousse, sand, gravel, and shell combined to form a solid, "moussecrete," which will remain for a long time. The rock walls, and ramps and boulders that were cleaned by water or with water detergent mixures were relatively clean. 260 6.5.9 Other Technologies Booms Many booms were used early in the spill to try and protect impor- tant areas, and later in the spill to aid in the recovery of mousse. The four types of booms used are shown as Fig. 6-17. The most fre- quently used boom was the French made Sycore II, an air-inflatable boom with a 1-meter skirt and the primary heavy-duty boom. It was reported that some 20 kilometers of this boom were available in France to be used for the spill; however, only 11 kilometers in good condition were avail- able. This boom was too light and fragile for the heavy sea environment in which it was used, and the deep skirt created exceptionally large drag forces which damaged the boom fabric and end connectors. The second type is the Acorn boom, which is filled with foam beads and has a shallower skirt. This boom appeared to be much more rugged, and under high wave conditions was observed to be following the wave profile exceptionally well. The boom appears to be more bulky to handle but much more effective in practice. Two types of gamlen booms saw limited service. One is the "hi-sea" fence boom and the other is a small harbor boom with pockets for flota- tion. The latter boom generally appeared to be ineffective in the environment in which it was used. All of the booms placed in the early days of the spill failed to some degree, for a variety of reasons: (1) Structural failure as demonstrated by broken booms in Roscoff, l'Aber Wrac'h, and other areas. (2) Entrainment or the passing of oil under the boom by high velocity as shown occurring in Plate 4-30 and by the oil on both sides of the boom shown in Plates 4-29 and 4-32. (Booms in the first two Plates are Sycores II and the third is the gamlen aluminum harbor fence boom.) (3) Difficulty in anchoring the boom ends so they would work effectively at all tidal levels. (4) Breaks and fouling by debris as the booms went unattended. (5) Trapped oil was not removed and had time to work its way through the booms. (6) Deployment based on equity of protection or shortage of boom was not made in a manner known to be effective. 261 INFLATION HOSE 40crn SLIDE END CONNECTOR CHAIN(TENSION MEMBER a HAIN BALLAST) SYCORES I (INFLATABLE BOOM) CONNECTOR END OF BOOM FOAM FOAM 30cm PELLET FILLED PELLETS 50 CM. TENSION MEMBER SHACKLE ACORN (CURTAJIN BOOM 12 ADDITIONAL FREEBOARD ---HINGE FLOTA ION BAG GAMLEN HI SEA TOW PL STRUTS GUARD CONNII-Wa (FENCE BOOM) b a a 0 a 0 0 0 0 0 0 0 0 0 0 0 C 0 0 0 0 0 0 FABRIC 0 FABRIC 0 TATI ON 0 FLO (ALUMINUNt' 0 FABRIC CONNECTOR CHAIN GAMILEN OIL PLATE ALUMINUM BOOM (FENCE BOOM) Figure 6-17. Four types of booms used during spill cleanup: (a) Sycores II; (b) Acorn; (c) Gamlen Hi-Sea Boom; and IM. W Gamlen small fence boom. T50 TOW -PLau CONNECTOR RIC PLATE 262 Later in the spill, some of these problems were overcome with more boom, marine commandos to tend the boom, increased ability to remove trapped mousse, and more experienced supervision of placement. Removal personnel also learned to use booms on the beaches to collect oil for removal by vacuum trucks or honeywagons. Plate 6-26 shows effective placement of a boom in Aber Ildit. Skimmers Large skimmers generally proved to be ineffective because of the high sea state or lack of mobility. The Chamdis, a barge brought from Le Havre, had four large Cyclonet skimmers attached. It was able to operate only 2 hours over a 2-week period, but did achieve high rates of recoveries of about 40 tons per hour. Two French Navy ships, including the one shown in Plate 6-27, were equipped with Cyclonet units, but again were not able to re,cover much mousse because of high waves. A Vortex skimmer also had little success in the Roscoff area because of lack of mobility, high draft4 and sea state. Three small Oil Mop skimming units were used in the Aber Benoit and Aber Wrac'h areas and proved effective, although they could be used only during high tide periods. Thus total recovery was limited. More small skimmers of the Acme type used in Portsall would havebeen valuable. Use of Dispersants The policy governing the use of dispersants was discussed in sec- tion 6.4. Approximately 30 French and 6 British ships were utilized to spread dispersant. In the later stages of the spill a four-engine DC-4 aircraft was also used to spread dispersant. The primary dispersant used was the British Petroleum No. 1100 which is concentrated dispersant, but few data are available on amounts used or on effectivenss. The effectiveness of dispersants as a major control tool was limited by the broad distribution of oil along the coast, the patchiness of the oil in windrows, and the ability of a ship to cover only a limited area even during the better weather conditions. It is believed that considerabl' 'Y more oil was dispersed in the water column as a result of the high seas and the action of the seas with the rocky areas than was removed with dispersant. Other Methods After the Torrey Canyon spill the French Navy equipped itself to spread chalk on oil as a sinking agent. The method was used in the Amoco Cadiz spill even though numerous recommendations were made against it. Plate 6-28 shows a French Navy vessel discharging chalk on an oil slick southwest of Brest. Other novel methods were used. For example, plaster was used at a site near the beach at Tr6gastal as an absorbent material in an attempt 263 to remove the mousse from the coarse sand beach. The technique.proved effective, but required tremendous amounts of labor to remove both the oiled materials and the chalk. (See Plate 6-29). Spraying dispersant on rock and windrowing the rocks for cleaning and recycling by the surf were discussed earlier and are displayed in Plate 6-30. The use of heavy equipment such as front-end loaders to move the mousse into collection areas on beaches is shown in Plate 6-31. 6.6. Resources Required For Cleanup The authors have been concerned that many individuals thrust into oil spill cleanup activities misjudge-the magnitude of the problem they face. This happens because most on-scene commanders or coordinators are chosen for,some administrative or command talent and not as a result of an expertise in oil spill control. For this reason particular care has been taken in Section 6.1 to explain the magnitude of the spill in terms recognized by a person not familiar with oil transport terminology. In this section, the authors have documented to the extent possible the level of effort in manpower, supplies, and equipment used to deal with the Amoco Cadiz spill and the amount of materials removed from the beaches. the-information source used relative to land activities is good for the [email protected] region, but almost non-existent for C6tes-du- Nord. Logistical information on Navy activities is also sketchy. Although the number of vessels used is specified in the daily reports, information on manpower and use of supplies like dispersants is not provided. It is hoped that a detailed French report on this subject will be prepared and made available to the public. 6.6.1. Amount of Material Recovered The daily pollution reports for [email protected] listed amounts of re- covered oil in three categories. Material Pumped: This category included material pumped directly from the water surface into tank trucks or honeywagons. Material Skimmed: This category included material skimmed from the surface of the beaches or rocky areas by men or equipment and moved off the beach by honeywagons, front-end loaders, or dump trucks. Sacked Material: This category included mousse, oiled sand, oiled .seaweed, and oiled detritus which was put in plastic bags and carried from the beach for disposal. 264 Figure 6-18 shows graphically the amount of oil which had been pumped from the water and the amount of material which had been removed from the surface of the beaches. It can be noted that the amount of oil removed by pumping from the surface and that the amount of oil removed from the beaches peaked in the last days of March and continued at a decreasing rate throughout April; The amount of material being col- lected in the last days of April up through the early days of May fell off considerably, which could be expected when less oil was floating on the surface and as the materials on the beaches became more contamin- ated. Figure 6-19 shows the amounts of materials bagged by the men work- ing on the beach. This includes the oiled sand, seaweed, and the other detritus that has been put in bags to be hauled away to the solid waste material storage areas. This operation began rather slowly because greater priority was put to the removal of the liquid oil, but peaked toward the end of April and the early days of May. 80001 0 7500- 7000- 6500- 6000- 5500- 5000- MATERIAL PUMPED MATERIAL SKIMMED 4500- -----ESTIMATES OF MISSING DATA 4000- Figure 6-18. Volumes of 3500- spilled material pumped from water and removed 3000- from beach surfaces in 2500- [email protected] 2000- 1500- 1000- 500 As CHRONICLE DAY -10 [email protected] 2.0 25 3b [email protected] 4P 45 50 5.5 21 TUE 26.SUN 31. FRI S.WED 10,MON [email protected] 20,THU 25JUE 3%'SUN 5,@Rl 10, WED MARCH APRIL MAY 265 Figure 6-20 shows the cumulative amount of materials removed from the beach. As of the first of May, the total amount-of materials removed was approaching 100,000 cubic meters or approximately 100,000 metric tons. The accumulation of the total mount of material diminished as the oil became more diffuse and the material became more difficult to handle. On the basis of the assumption that a cubic meter of mousse equals approximately a ton of mousse material and that the average oil/water ratio is 2.5:1,.the material was roughly 30 percent oil. It can be estimated that 20,000 to 25,000 tons of oil have been removed from the coastline. If one compares these figures with those shown in Section 6.1, it can be observed that only about 15 to 20 percent of the mousse was removed. This indicates that the delay in removal coupled with the local oceanographic and meteorological conditions caused a large frac- tion of the mousse to be spread into the environment. 6.6.2 Manpower Resources It has been difficult to determine the exact number of men working on cleanup activities. Figure 6-21 shows a count of men reported to be at work in the region of [email protected] The work force on shore in [email protected] included public works personnel,.Army troops, Navy commandos, security civil personnel, police, firemen, and volunteers. Estimates were made for the general level of personnel in the region of Co^tes-du-Nord based on very sketchy figures reported in newspaper articles. This figure was assumed to be 50% of the figures for [email protected] It is hoped that'an accurate figure for this manpower level can ulti- mately be obtained. Navy personnel levels were estimated from Navy reports of the number of ships engaged in dispersant, chalking, or other operations. An average of 35 men per ship was estimated. Table 6-3 is a summary of the estimated direct manpower utilized at different times after the start of the spill. Note that the manpower effort continued to rise for almost two months after the spill. In additon to the direct manpower,,it could be expected that an additional 50% of personnel were needed as part of direct and indirect support roles. During the middle of the spill cleanup, large numbers of volunteers were involved. However, problems of logistics and organization appear to have eliminated their effectiveness as a whole, although individual groups observed appeared to be highly effective. Few volunteers were able to stay for the duration of the recovery operation. 266 I SACK 150 lb. X 0.0682 M 1200- ESTIMATE OF MISSING DATA 1 100 - 1000- 900- 800- cc 700- w 2 600- 2 500- 400- 300- 200- 100 CHRONICLE DAY 5 10 1P 20 25 30 3P 4P 45 50 @5 21 JUE 26.SUN 31. FRI 5-W"D IO.MON '15,SAT 20,THU 25JUE 30.S4JN 5.FMI 10. W ED MRCM APRIL "Y Figure 6-19. Volumes of spilled material bagged on the beach. 100,000- 90,000- 80,000 Ile 70,000 60,000- 50,000- 40,000_ w ESTIMATE OF MISSING DATA 30,000_ 20,000 10,00CL T CHRONICLE DAY - 6 10 1.5 2.0 [email protected] 3b 3 P 4.0 415 510 5.5 El 21 -TUE 26'" 31, FRI5WED 10,MON 15,SAT 20.THU 25,TUE 3QSUN 5.FRI 10, WED "RCH AP RIL MAY Figure 6-20. Total cumulative volume of spilled material removed from the beach. 267 6500. 6000- TOTAL 5500- 5000- 4500. 4000- _Qb. 3500- MILITARY PERSONNEL INVOLVLO IN THE LAND o 3000-1 BASED CLEANUP 2500- ---- ESTIMATES OF MISSING DATA 2000. VOLUNTEERS 1500- 1000- FIREMEN 500- CHRONICLE DAY 5 10 1P io 2p, 3P 3P 40 45 50 5.5 21 TM 24m 34 rFu s, WED 00. MOM M SAT MTHU 25,11UE 306 5. MI 10. WED MARCH APRIL KSY Figure 6-21. Numbers of personnel reported to be working on spill cleanup. 6.6.3 Equipment . In the first section of this report, an attempt was made to relate the amounts of different types of equipment with the total magnitude of material to be dealt with. In this regard it is useful to observe the amounts of different types of equipment that were used in the cleanup operation. This information is shown in Figs. 6-22 through 6-25 which plot the numbers of these pieces of equipment used throughout the time sequence of the spill. Thefigures for the equipment used must be adjusted to include the equipment used in the region of Co^tes-du-Nord. It is expected that the equipment level in Cohes-du-Nord was 50 to 60 percent of that used in [email protected] 6.7 Summary of Observations The cleanup of the Amoco Cadiz is now history. A large number of capable administrators, engineers, sailors, soldiers, public servants, and volunteers have carried out a massive cleanup to an end point con- sidered feasible and reasonable. Memories of the cleanup will remain as a vivid reminder of the practical difficulties of dealing with a massive spill. L 268 Table 6-3. Field personnel involved in the cleanup of the Amoco Cadiz oil spill 3-28 3-29 4-8 4-9 4-11 4-12 4-18 Navy Personnel 455 1085 245 175 280 490 420 at Sea Military Personnel' in Finistbre 1742 1663 4250 4651 4692 5288 5178 Province Military PersonneJ2 871 832 2125 2326 2346 2644 2589 in Cbtes-du-Nord Total Personnel 3068 3580 6620 7252 7528 8422 8187 'Based on reports that give an average of 35 men per vessel. 2Based on reports that indicate a ratio of 2 men working in Finist6re for one man working in Cbtes-du-Nord. Oil spill contingency planners should continuously evaluate their plans in light of the Amoco Cadiz experience. For this reason, it is appropriate to examine the characteristics of the spill and evaluate the response to it to see what lessons have been learned. 6.7.1 The Spill and Its Impact (1) The magnitude of spilled oil is enlarged by the creation of water-in-oil emulsions or mousses. This increased volume must be considered in planning removal activities afloat or ashore. (2) For a major spill near shore, the primary line of defense will be on the coastline. Both the Metula and Amoco Cadiz spills demon- strated that when oil is spilled nearshore, with prevailing winds toward shore, it will reach the beaches quickly. Stopping the oil from coming' ashore by mechanical and chemical means should be attempted, but the backbone of a contingency plan must recognize the necessity of dealing with oil on shore. (3) If the oil is not removed or stabilized, it will spread to uncontaminated coastlines and extend the area of impact. In the case of the Amoco Cadiz, effective oil removal onshore did not begin for almost a week. As a result, much oil that could have been removed remained on the water surface or the beach face. This oil continued to move with the winds along the shore to impact new areas. Later drastic windshifts from the west to the northeast in the third, fourth, and sixth weeks substantially redistributed oil to beaches previously missed. 269 100- 90- so- ESTIMATE OF MISSING DATA 70- 60- 50- w w 2 40- z 30- 20- to- iO [email protected] 3b 3 CHRONICLE DAY 10 [email protected] 4P 4P [email protected] [email protected] 22JUE [email protected]%A 34FM 5,@IED 1O.'MON @SAT 20.TMU Z5.TUE 50.SM 5.FRI 10,WED MARCH APRIL wy Figure 6-22. Numbers of tank trucks (camion citerne) used during spill cleanup. 140- 130- 120- 110- 100- ESTIMATE OF MISSING DATA 90- [email protected] 70 0 60- z 50- 40- 30- 20- 111 \PbAV 10- [email protected] 26 [email protected] 3P 3P 4'0 4' CHRONICLE DAY 110 P [email protected] @5 21 rUE [email protected]" 31.FRI S.WEID 10,MON MSAT 20,TRU 25JUE 30.SUN 5,FRI 10, WED MARCH APR I L MAY Figure 6-23. Numbers of vacuum trucks (camion d'assainissement) used during spill cleanup. 270 300- 280- 260- DUMP TRUCKS 240- 220- --- ESTIMATE OF MISSING DATA 200- 180- > 160- 0 140- 120- z 100- HEAVY MACHINERY BULLDOZERS, so- BACK HOES, FRONT-END LOADERS 60- 40- 20 VAGONS CHRONICLE DAY 10 [email protected] iO [email protected] 3P 3P 4P 4P @O @5 21 T"" 26"RM 31.FRI 5,WED 10' MON 5. SAY MTHIU 25,TUE SO." 5.FRI IO.WM MARCH APRIL MAY Figure 6-24. Numbers of dump trucks, heavy machinery, and railroad wagons used during spill cleanup. 90- so- 70- P\ 60- W _j 50- > U. 0 5 40- In // 30- ESTIMATE OF MISSING DATA 20- 10- PHIAW-NE [email protected] @'ERI HI AC K HI IN LOAD RA 'LR CHRONICLE DAY - 5 10 15 2b 2T5 @O 3,5 4,0 4,5 10 55 I I 1 1 21 TUE 24UN. 31,FRI. 56WED IOPON, 15,SAT 20,THU 25,TUE. 30;SUN 5,FRI IOWED MARCH APRIL MAY Figure 6-25 Numbers of honeywagons (bac) used during spill cleanup. 271 (4) The longer it takes to clean up the spill, the greater will be the loss of oil to the environment and the more sand, seaweed and detri- tus there will be with the collected oil. Figure 6-26 shows an estimate of the fate of oil as reported in the French press and credited to local officials. It indicates substantial losses to the sea-and most likely to the beach sands. Rapid removal of the mousse where it first hits the coast would minimize such losses. Greater dispersion of the spill makes for lighter coatings of more area. Then removal must deal with larger volumes of lightly contaminated material rather than smaller volumes of more concentr'ated material. This not only increases the bulk, but renders the residue less amenable to treatment and/or reclamation. 6.7.2 Organizational Structure (1) Policies necessary to deal with the spill need to be predeter- mined. 76,000 tons 20,000 tons at chemically sea dispersed /6,000 /tons chem. [email protected] 74,000 tons 5,000 tons evaporated deposited on the seabed 25,000 tons disappeared perhans under eac san 80,000 tons went ash re 20, - 25,000 tons recovered 230,000 Figure 6-26. Estimated fate of oil from Amoco Cadiz. Source: local newspapers. 272 It was reported that considerable time was lost in the spill re- sponse while. policies as to who does what, who pays for what (and how), which methods will be used and what chemicals will be used were being determined. Effective response is possible only when such issues have been decided in advance and the response team adequately informed of the decisions. (2) Necessary operational components need to be organized and tested. A large spill response requires that many functional groups such as public works organizations, volunteers, fire departments, sol- diers, and contractors work together. Pilot operations need to be carried out to see how these groups work together and to see what opera- tional problems arise, ranging from lunch schedules and union rules through logistics and communications. (3) Major mobilization including both the military and public works is needed. In the Amoco Cadiz spill, it rapidly became apparent that the attempt to deal with the spill on land as a strictly civil activity was destined to failure. Not only was Army manpower needed, but military communication, organization, logistics, and equipment were needed as well. It is increasingly apparent that both public works agencies and the Army or similar military units are necessary for the unique man- power, manpower training, and logistic support available from each. 6.7.3 Resources Necessary to Deal With a Spill (1) Operational components need to be predetermined and mechanisms for response established. Those responsible for dealing with the spill need to have resources for different levels of response readily available. In addition to the public resources such as the Army and public works agencies discussed previously, this includes contractors, equipment sources, cooperative agreements, etc. (2) A reservoir of equipment ranging from shovels and containers through small skimmers and storage devices needs to be inventoried and made available. It appears that France was able to respond rather quickly to supply the simple needs of protective clothing, hand tools, buckets, etc., but limiting storages were observed in some-beach parties. A critical shortage of small skimmers and storage devices was evident. In many parts of the world, the lack of these modest tools may become a limiting factor in cleanup operations. 273 @ (3) Logistics need to be arranged to maximize the use of equipment during favorable tide and weather. Often the matching of the tides, time of day, and normal workday resulted in extremely short working days for some unit operations. Lunch breaks were observed to shut down some operations during ideal time for removal of oil. Using shifts for the men on the beach and for machine operators could have resulted in much higher removal rates. (4) Equipment and supplies to be used need to be determined be- forehand. Examples were reported of fantastic prices charged where equipment was supplied without pre-negotiation of prices. 6.7.4 Specific Unit Operations (1) Equipment compatible with the tide, current, and weather conditions must be chosen and tested in order to assure utility. The failure of booms and skimmers to serve a meaningful role in the Amoco Cadiz cleanup is a reminder to choose methods of response compat- ible with the oceanographic and meteorological conditions of the area. (2) Oil contained by booms, but not removed, will ultimately be lost to the environment. This old adage of the field was borne out at the Amoco Cadiz spill. Booms that were effective during some tides or for part of the tidal cycle, would ultimately fail since the collected oil was not removed. (3) Booms not tended are likely to fail. Many of the initial boom deployments failed at the ends, by break- ing or by being tripped by debris. Careful tending and mending in the early days of the spill could have lessened the damage in some areas. 6.7.5 Systems Approach to Unit Processes (1) Large masses of simple equipment utilized by many people will be needed in the cleanup operation. The magnit ude of the problem in terms of volume of mousse, also the spreading into rocks, seaweed, and pockets of sand, indicates the amount of hand labor involved in removal of the material, particularly in the middle and.later stages of the cleanup. (2) A systems approach to examining unit processes and unit opera- tions is necessary to eliminate waste and increase efficiency. 274 For efficiency and economy, it is necessary to match men with tools, supplies, and equipment in appropriate ratios, i.e., if 25 men can handle 1 honeywagon, having 100 men on the beach with only 1 wagon accomplishes nothing more. Similarly, if the same 25 men can load three honeywagons in series, then having only one wagon in service and having the men wait between loads is wasteful. Ratios of men to equipment need to be determined either before the spill or early enough in the spill to be adjusted. (3) Levels of resource requirements for spills of different sizes need to be determined and published. The results of the Amoco Cadiz and other spills need to be analyzed to determine guidelines for the level of resources needed to handle spills of different sizes. This will help the on-scene coordinators immediately to assess the size of the response effort that will be needed. 6.7.6 Effective Contingency Planning and Training (1) Overall contingency planning is necessary. An effective contingency plan will contain many of the elements mentioned in this report. The plan must be a working entity, not merely a book on the shelf. (2) Training is needed both before and during the spill. It is essential to train administrators, engineers, and team leaders in oil spill control. In a spill as large as that of the Amoco Cadiz there is also a need for pretraining the manpower to be sent to the field. On-scene videotape methods may prove particularly valuable. (3) All aspects of the plan must be tested periodically for readi- ness. The major drawback of the French response was that the incidents of the Bohleme and the Olympic Bravery had not resulted in a full scale test of the POLMAR plan. The problems with the organizational compo- nents of the plan were the most important. However, all aspects of a contingency plan need appropriate testing. 275 APPENDIX A Chronology of Events March 16-April 20, 1978 The following is a chronology of events surrounding the Amoco Cadiz incident and activities of the U.S. scientific team: March 16 The Amoco Cadiz, carrying a cargo of 216,000 tons of light mideastern crude oil and 4,000 tons of Bunker fuel oil runs aground near midnight on a rock outcropping, 1.5 nmi from Portsall on the northwest coast of France. Three of 13 loaded tanks are emptied on grounding. Seas at the time of grounding are rough with 22- to 28-kn winds from WSW. March 17 Crew evacuated by helicopter at 0530. Vessel-breaks forward of the wheelhouse at the level of the no. 4 tanks at 0600. Weather continues poor with strong W to SW winds. March 19 Vessel continues to leak. Shell Oil in charge of clean- up. Pumps being shipped from Detroit. Six NOAA and NOAA-contract scientists arrive on-scene, contact CNEXO officials, and visit Portsall area. Weather foggy with 12- to 20-kn winds from WNW/NW. March 20 Vessel continues to leak with stern canted toward the east. Weather improves with good visibility in after- noon, 6- to 8-kn winds from the west. 50 tons of dis- persant reportly used to date. U.S. field party conducts observations at Portsall. March 21 Vesselcontinues to leak in 4- to 6-ft seas. Wind 20 kn from W/SW. First U.S. fixed wing overflight reveals contamination extending from 10 km west to 80 km east of wreck site. March 22 Five tanks reported empty or leaking. Eight pumps on- scene with a total capacity of 1500 m3. Nine French Navy ships Are now on-scene with 100 tons of BP 1100 WD dis- persant; five English ships standing by. Beach cleanup operations involving 310 individuals limited to pumping and recovering dense concentrations of oil. Shoreline contamination in varying degrees extends 145 km from Pte. de St. Mathieu to Bay of Lannion. Winds 5 to 15 kn from SW. 277 U.S. team conducts helicopter overflights in connection with shore-based beach and estuarine observations near Portsall. March 23 Vessel stern remains connected to bow. However all tanks appear leaking with 30,000-70,000 tons of cargo estimated to remain on-board. 20- to 30-kn winds gusting to 60 kn from WNW/NW, turbulent seas. 57 tons of dispersant used at sea to date. U.S. team maps coastline and conducts five transects by helicopter from Portsall to Roscoff, obtains oil sample from near vessel. Ground surveys continue near Les Dunes beach. March 24 Vessel stern is shifted to west; new breaks are apparent. Winds 20 to 30 kn gusting to 45 kn. Sea conditions continue turbulent. Shoreline contaminated along 210 km from Pte. de St. Mathieu to Ile de Br6hat. Ten navy vessels and 3 U.K. tugs treating the spill with dispers- ant, with some additional support from helicopters. 450 individuals involved in beach clearlup. U.S. team conducts helicopter and fixed-wing aircraft surveys of impact area, coordinated with beach surveys. Subsurface chemical sampling using a towed fluorometer is conducted in the Aber Wrac'h estuary, extending 6 km offshore. March 25 Vessel continues to leak in poor weather. U.S. team continues transects by helicopter, beach sur- vey, and subsurface chemical sampling in l'Aber Wrac'h. March 26 Close observation of vessel indicates extensive leaking from pipes at about 1 ton per minute. French Navy has opened hatches and valves on #1 tank. Winds 18 to 20 kn from the west. U.S. team obtains oil sample 30 m from vessel by helicop- ter and maps beach area by fixed-wing aircraft. Beach surveys continue near l'Aber Wrac'h. March 27 Poor visibility prevents all aircraft operations. Winds 18 to 20 kn gusting to 35 kn from west. U.S. team conducts beach surveys and subsurface chemical sampling in and near I'Aber Wrac'h. 278 March 28 Ship broken in two with stern offset, bow inclined sharply from point of break. 10,000 to 50,000 tons of cargo estimated to remain on-board. Authorization to blow up tanker is obtained from owners and underwriters. Winds 30-40 kn from SW. Sporadic use of dispersants continuing from 6 English and 20 French ships. 1,420 people now involved in beach cleanup operations. U.S. team conducts helicopter transects to 35 km off coast, encountering large patches of oil moving offshore. Shoreline region is filmed. Beach surveys continue. March 29 Depth charges used to rupture hull. Winds 15 kn from the SW. Beaches appear cleaner; however sheen and large patches of mousse are observed to 60 km offshore. U.S. team conducts helicopter transects, fixed-wing over- flights, and. beach surveys. March 30 Depth charges again used to rupture hull. Vessel now broken in 3 sections; bow is elevated to 450. Sky clear, winds light from SW. Less than 20,000 tons estimated to remain on board. U.S. team conducts reconnaissance by fixed-wing aircraft and beach surveys. Offshore chemical sampling initiated aboard the French research vessel Le Suroit. March 31 Good weather, not much wind. U.S. team occupies 18 beach stations. Substantial kill of cockles and limpets ob- served near Roscoff and Portsall. April 1 Weather remains good. U.S. biologists visit lobster pound at Roscoff and find it must be rebuilt before use. Beach survey team continues second survey of standard beach stations. April 2 Good weather, light wind. U.S. team visits St. Michel- [email protected] to observe massive kill of heart urchins and razor clams. April 3 U.S. scientists meet with CNEXO and UBO scientists to review research efforts to date. Cleanup forces estimate 5000 tons of oil have been cleared from beaches. April 4 Vessel Le Suroit returns to port. U.S. biologists visit oyster culture dealer on l'Aber Benoit, bird hospital in Brest, and alginate factory. 279 April 5 U.S. scientists visit University of West Brittany. April 6 Winds continue from the northeast for fourth day, although only a few areas in the far west appear to have been further contaminated. U.S. scientists continue meetings with University of West Brittany. April 7 U.S. scientists meet with Dr. Cabioch at Roscoff biologi- cal station. April 8 Fixed-wing aircraft observations reveal new areas of impact on western coast and beaches facing northeast due to 6 days of onshore winds. Considerable oil remains offshore. Subsurface beach sands are contaminated in some areas near Roscoff although surface appears clean. Areas above normal high tide are still heavily contami- nated. April 9 Sheen continues to surround vessel. Beaches on southern coast of the Brittany peninsula are clean despite reports of oil offshore. April 11 Vessel Le Suroit returns from second cruise. Scientists indicate substantial bottom sediment contamination near Portsall and in the Bays of Lannion and Morlaix. April 12 Patches of oil sighted off the tip of the Brittany penin- sula. French officials establishing contingency plans for use of dispersants should oil move into Brest harbor area. April 13 Oil shifting toward south. Aerial photographs indicate oil lying offshore of Brest. U.S. scientists discuss impact on kelp industry; growth of kelp appears retarded. April 14 Observations are taken from Roscoff to les Sept Iles; major impact appears to be at Lieue de [email protected] where wind- rows of heart urchins are evident. Recent kills of molluscs are observed. Worker population appears in good health. April 15 Overflight conducted along three transects perpendicular to the coast between the wreck and les Sept Iles. Little or no oil seen on water although some sheen and streamers observed in the vicinity of Pointe de St. Mathieu. April 16 Some sheen reported near COB. Fifty puffins found oiled and dead south of Brest on the Crozon peninsula. Oil reported near the Ile de la Vierge, between Pointe du Raz and Rade de Brest, at Cap Sizun, between Pointe du Raz and Pointe de Lesven, and at Ile de Sein. 280 April 18 Oil at sea now in a number of slicks, two of which have drifted as far as 50 km south of Brest. About 7000 people now involved in cleanup. April 19 French Navy locates 8 km diameter slick north of Ile de Sein and an 8 km x 300 m slick near Pointe du Van. Both threaten the Bay of Douarnenez. a French Naval districts issue first official estimates on fate of oil to date: Confidence Tons level 1. Evaporated 741000 � 20% 2. Amount hitting beach to-date 80,000 � 50% 2a. Amount cleaned off the beaches 25-309000 -- 3. Still at sea 76Y000 � 50% This amount is broken down as follows: a) Treated with dispersant 20)000 � 50%, b) In process of being treated 6YO00 c) In sediment or water column 25yOOO � 50% d) Unknown 25,000 April 20 Two overflights conducted by U.S. scientists. Major concentrations of oil observed near the Bay of Douarnenez and in an area 385 km south of Cap de la [email protected] Sheen continues around wreck site early in the day, but is not evident in the afternoon. 281 APPENDIX B Colored Plates 283 1-1. The Amoco Cadiz on March 21, 1978. 1-2. The Amoco Cadiz on April 3, 1978. P-1 . ......... Yaw-, [email protected]@ 1-3. The Amoco Cadiz wreck is only about 2 km off the coast at Portsall. This sectiiin-of the coast could experience heavy wave activity and frequent storms at this time of year. -dei 4 L AN N (JLE S ffOxAr&-,-b -J, ur N Golf, 'Valo do SI gaie do. r4w- 1411t,11-1111, [email protected], t [email protected] W:O, r o - g . ., I- .. @RE V, I E -WLAINP you.-e @-. . . "' [email protected] 0-, 1p 1-4. Map of the northwest section of France. 21, 5*4 R'A ................ 1-5. The town of Portsall in Brittany. P-3 117 1-6. Beach near Portsall about 2 km east of the wreck on April 2. This area has been heavily oiled repeatedly. There has been a large effort to clean up this beach. The wreck is visible in the background. -U w., @X7X- 1-7. A beach about 2 km west of Portsall on April 2. This beach has received very little oil because it is west of the wreck. P-4 lid 2-1. Heavy mousse concentration in deep water under moderate wind conditions. A 2-2. Mousse and sheen distribution in offshore 2-3. Weathered mousse at sea, 31 March. region under strong wind conditions (40 kn). Le Suroit cruise. [email protected]' [email protected] 45" aliL-A- 47= @14 2-4. Frothy form of mousse seen in surf zone. .0or 01 2-5. Pool of mousse accumulating along shore line. P-7 q [email protected] 01 2-6. Stream of oil moving downwind between rocks. 2-7- Oil moving in along-shore drift being fed by wind-blown sheen and mousse from offshore. III tLZOW M-7 *4 2-8. Oil concentration overflowing a small bay and moving into along-shore drift. P-9 V-I 2-9. Mousse draining down beach face after being stranded by high tide. 2-10. Significant amounts of mousse being washed, or refloated off rock during flood tide. P-10 3-1. Separation of mousse samples into oil and water in the laboratory. 9 Ile ri 3-2. The French research ship Le Suroit loading equipment in prepara- tion for chemistry cruise. P-11 ZT-d low pr ct H. m 0 0) ell LA) 41 pr 010 fD Adkl. .A -46. 11411 r 3-5. Sterile bag Butterfly sampler suspended from a float ring ready to take subsurface water sample. --------------- [email protected] 3-4. Dr. Marchand of COB carrying out hydrocarbon extractions and UV fluorescence scans on board Le Suroit. P-13 3-7. Detergents being used on rocks at Santec. P-14 09 R41, \I 4-1. Heavily oiled marsh behind Ile Grande (AMC-18). This was the most heavily impacted salt marsh in the study area. Detailed studies were carried out in the marsh area left of the bridge. (30 March 1978) P-15 4-2. Oiled marsh grasses and dead polychaete 4-3. Mousse in tidal creek at Ile Grande marsh. worms within a mousse pool on the surface Photograph was taken at low tide. The of the marsh at Ile Grande (AMC-18). The mousse flow is caused by late stage drain- pool is 15-20 cm deep. (2 April 1978) age of the marsh. (2 April 1978) 41W. 4-4. Pitted beach at St. Michel-en-Greve on 2 April 1978. Pits were dug in order that the mousse could be scraped into them with rakes. Oil was then pumped into tanks and hauled to disposal sites. 'n; 4-5. Clean-up in progress at St. Michel-en-Greve (F-55). Filling the pits with mousse in this manner undoubtedly accelerated the rate of pollu- tion of the ground water under the beach. P-17 at j 4-6. Dead heart urchins on intertidal surface at St. Michel-en-Greve on 2 April 1978. The urchins, which floated freely on the water's surface, were distributed evenly over the intertidal zone as the tide receded. 4-7. Clam accumulation at high tide swash line at St. Michel-en-Greve on 2 April 1978. These clams, which were rolled along the bottom by wave-geaerated currents, were deposited at the middle level of swash action at high tide. P-18 4-8. Front-end loader scooping sand at Les Dunes-West (AMC-5). In this case, a considerable amount of sand is being removed from the beach, a practice that should be avoided if at all possible. (31 March 1978) 4-9. Deployment of skimmer at Portsall (AMC-2). (20 March 1978) P-19 J4 4-10. Heavily oiled beach and low-tide terrace near Roscoff. Linear pattern perpendicular to beach is caused by ground water runoff. (21 March 1978) & S,n t*0 A 4-11. Heavily oiled beach near Ile Grande. Note presence of mousse in the surf (low-tide photograph). This mousse moved back and forth across the beach with each change of the tide. (30 March 1978) P-20 A 4-12. Oil swash lines on beach near Kerlouan (F-47). This beach resembles the coarse-sand beaches on Cape Cod. (27 March 1978) '4" 7", 'A 4-13. Oiled beach at St. Michel-en-Greve (AMC-15). The heavily oiled gravel and rocks at the spring high tide level will prove to be very difficult to clean. (28 March 1978) P-21 @A . . ........ 7 it t 4-14. Heavily oiled gravel beach at Pointe de Sehar (AMC-16). This steep gravel beach resembles many gravel beaches in New England and Alaska. (28 March 1978) IA S . 41 IN 2711 4 2 @h [email protected] 40 4-15. Mousse on gravel beach at Pointe de Sehar (AMC-16). (28 March 1978) P-22 7 Pot T_ 77 T, ;g 1. .04 44 4-16. Heavily oiled beach at Roc'h Quelennec (AMC-13). Shovel sits in oil- filled scour pool beside boulder. (27 March 1978) La tnw AW0,10- kv- 77 TrA& A 4-17. Oiled rocks at Roclh Quelennec (AMC-13). Note oil accumulation along bedding surfaces in the rocks. (27 March 1978) P-23 VI OF [email protected]'A F. 7 4-18. Oiled marsh near Pellinic (F-70)-. (29 March 1978) P-24 [email protected] IV--- [email protected] .00 A., a 4' AW v b*A_ 77 TI 40 S 4-19. Oiled seawall at Portsall (AMC-1). (31 March 1978) "4' "lid --7 4nwCA 7-7,7A, A"T 4-20. Crenulate bays. There are several bays of this type in the oiled area. P-26 7' Ink I"W 4e 4-21. Tombolo near I'Aber Wrac'h. These sand spits develop in the lee of offshore islands as a result of wave refraction around the islands. (3 April 1978) MEMO= 4-22. Granite blocks in intertidal zone at Coz Porz. The coast is predom- inantly erosional, a process which leaves these granite blocks exposed as the shoreline retreats. This area is similar in many respects to the coast of Maine. (28 March 1978) t AN A,' AW 4-23. Dune scarp at Les Dunes-West (AMC-5). Dune areas of this type are rare, occurring primarily at the mouths of streams. (31 March 1978) P-28 4-24. Dead amphipods at high tide swash line at Les Dunes-Center. Scale units are 1 cm. (31 March 1978) 1Y W4 AS r-S- JA kr 4-25. Accumulation of dead cockles at the toe of the beach face at St. Cava. The dead cockles were rolled up and down the beach at high tide, fi- nally accumulating at the toe of the beach as the tide receded. (26 March 1978) P-30 WWI-- A.- low.- .ir it 64% - - - ------ - - =ttifimmw 7=41W -fly [email protected], 4-26. Trench though the upper portion of the beach at Cough ar Zac'h (AMC-9) showing the burial of oil layers to depths of 10-15 cm below the sur- face. Scale is 15 cm. (1 April 1978) 4-27. Heavy mousse in surf at Tremazan (F-1) on 20 March 1978. The mousse was gone and the rocks were clean on 31 March 1978. -4 T 6k 4-28. Mousse being kept offshore from rocky areas by reflected waves. Near Roscoff. (30 March 1978) P-32 4-30. Oil (sheens) streaming through the oil boom at the mouth of l'Aber Wrac'h. (21 March 1978) P-33 14 4-29. Boom on sand flat (at low tide) near Kerenoc (F-75). The entire upper portion of the flat was heavily oiled. (29 March 1978) IN 4-31. Heavily oiled beach at Port la, Chaine (AMC-17). (29 March 1978) P-34 S 1-32. Oiled tidal flats at east Roscoff (AMC-8). (21 March 1978) 4-33. Oil on gravel beach at station 6 near Roscoff on March 24. P-35 5-1. Petroleum in "mousse" form mixing with attached seaweeds in rocky intertidal area near Roscoff (March 29, 1978). 5-2. Recently emerged cockle (Cerastroderma sp.) in moribund stage near Roscoff (March 29, 1978).- P-36 -, '41 [email protected] 5-3. Oiled intertidal limpets (Patella sp.) near Roscoff (March 29, 1978). 5-4. Remains of limpet recently eaten by seagull near Roscoff (March 29, 1978). P-37 C. 5-5. Oil in pericardium of limpets near Roscoff. Two recently killed limpets are on sand at base of rock. Limpet on rock was turned over by scientist (April 1, 1978). A ,V AW4 5-6. Nereid worm emerging from sand on beach near St. Efflam (April 6, 1978). P-38 [email protected] 44 5-7. Dead crab in heavily oiled marsh near Ile Grande (March 30, 1978). 5-8. Nereid worms seeking refuge in small pool of water surrounded by oil in marsh near Ile Grande (March 30, 1978). P-39 5-9. Mass mortality of nereid worms in marsh near Ile Grande (April 2, 1978). j oiZ 5-10. Wind rows of subtidal urchins, mollusks and other invertebrates which covered the beach from St. Efflam to St. Michel-en-Greve (April 2, 1978). P-40 X 11,[email protected] -,4w V [email protected]@w Al. W 'v -4 AN e4 7 JP*, ia Ilk 71 @gm Z IL 5-11. Wind rows of urchin tests on beach at St. Efflam (April 2, 1978). P-41 T. 5-12. The number of dead organisms was estimated from counts in several one-square-meter quadrants (April 2, 1978). t-24, z @7 @71 7, [email protected] ?3 5-13. Surface and subtidal organisms alike were impacted at St. Efflam (April 2, 1978). P-42 4c" V 411 LIM, fZ" OU 5-14. Nesting gannet colony on Rouzic Island at Les Sept Iles bird sanctuary near Perros-Guirec (April 2, 1978). P-43 A*@ 5-15. Carcasses of oiled birds being inventoried at bird hospital in Brest (April 16, 1978). 77 N @j7 5-16. Oiled oyster farm being cleaned near St. Pabu on Aber-Benoit estuary (April 4, 1978). P-44 P ,t SO_C @q W '4 4r. :@2 7W. ............ 5-17. Oiled lobster-holding pen at Roscoff (April 1, 1978), and aerial view. P-45 IT a, _IF 7 OA, - 5-18. Inside view of one lobster-holding pen showing extent of oiling (April 1, 1978). P-46 moo,", A -.Xjr.- 4W-- ;Apw xV 04 Air, Al 5-19. Gale force winds coupled with spring tides flung oil into cauliflower fields during harvesting process (March 30, 1978). R6 [email protected] 5-20. Oyster racks off the Brittany coast (21 March 1978). [email protected] ", , @@S' 5-21. Fishing stopped near Portsall after the wreck. Many people in the area fish part-time as a second occupation. P-48 "g 5-22. The common puffin. 77'' 5-23. Some fishes and a crab that were found washed up on the beach in the Portsall area during the first few days of the spill. P-49 Ak 011 Oda '7 A&I 4M RM 5-24. Infrared photos of beach area, used to distinguish healthy vegetation (with red color) from oiled areas. P-50 6-1. Oil is pumped from t