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USNS Potomac Oil Spill Melville Bay, Greenland, August 5, 1977 A Joint Report on Scientific Studies and Impact Assessment by the NPAA-USCG Spilled Oil Research Team and the Greenland Fisheries Investigations, -Ministry for Greenland. August 1979 GC 1121 .G76 A.""IMENT OF COMMERCE 1979 MINISTRY FOR GREENLAND kletwW6 and Atmospheric Administration Greenland Fisheries Investigations .1w- of America Denmark USNS Potomac Oil Spill Melville Bay, Greenland 5 August 1,977 PrOPertY Of CSC Library + A Joint Report on the Scientific Studies and Impact Assessment by the NOAA-USCG Spilled Oil Research Team and the Greenland Fisheries Investigations, Ministry for Greenland C Aamos"', Peter L. Grose and James S. Mattson Center for Environmental Assessment Services Environmental Data and Information Service d: National Oceanic and Atmospheric Administration ENT Of U.S. Department of Commerce C) Washington, D.C. 20235 U6A S . DEPARTMENT OF COMMERCE NOAA 'ERVICES CENTER - COASTAL S Hanne Petersen 2234 SOUTH HOBSON AVENIJ; Greenland Fisheries lnvestigaOMARLESTON SC 2,/ - 413 The Ministry for Greenland -0405 -2 Jaegersborg Alle 1B 0 DK-2920 Charlottenlund, Denmark 8 FIR <rl Major Contributors -'Iry Paul Boehm and David Feist Energy Resources Co. 185 Alewife Brook Parkway Cambridge, MA 02138 Vibeke Jensen, Nis Hansen, and K. Krongaard Kristensen C) Water Quality Institute C Agern Alle 11 DK-297.0 Hoersholm, Denmark Martin Ahnoff and Goran Eklund Department of Analytical Chemistry University of Gothenburg GU-CTH S-41296 Goteborg, Sweden August 1979 Washington, D.C. NOTICE Th6 National Oceanic and Atmospheric Administration does not approve, reeoinmend, or endorse any proprietary product or proprietary material me ntiofiea--i*iCthis publication. No reference shall be made to the National Oceanic and Atmospheric Administration or to this publication furnished by the National Oceanic and Atmospheric Administration in any advertising or sales promotion which would indicate or imply that the National Oceanic and Atmospheric Administration approves, recommends, or endorses any proprietary product or proprietary material mentioned herein, or which has as its purpose an intent to cause directly or indirectly the advertised product to be used or purchased because of this National Oceanic and Atmospheric Administration publication. ~0 PREFACE The spiLL of BunKer-C fueL from the USNS POTOMAC on August 5, 1977, in Me~LviL~Le Bag, Green~L~and~, is among the few oiL spiLLs studied in Arctic waters. This report presents the studies and findings of the N~qOP~qA-USCG SpiLLed ~O~IL Research and Gr~qUnL~ands F~qiskeriunders~qt~q;geLser (GreenLand Fish~q&ries Investigations, Ministry for GreenL~and) teams which responded to stud~g the spiLL. This spi~lL is noteworthy for three reasons: 1) the spiLL occurred In the pristine waters of the Arctic which have ver~qg Low b~acKground LeveLs of p~etroL~eum hydrocarbons and a frag~qlLe ecoLogy, 2) the fu~eL o~qiL~, (a bLend containing 55 percent pitch with a specific gr~avit~qg of 1.054) remained on the surface untiL it weathered suff~qicientL~qy to sin~K~, and 3) a fairL~qy comprehensive ~sampL~qing program was underta~qKen in spite of t~he remoteness and Logistic probLems. which served as the basis for comprehensive studies on the fate and impact of the sp~iLLed ~o~iL. ACKNOWLEDGMENTS This report represents the efforts of many people and organizations without whose support and dedication it could not have been generated. The following scientists participated In the field investigations: P. L. Grose, Physical Oceanographer. NORA; J. S. Mattson, Marine Chemist, NORA; E. 1. Chan, Marine Ecologist, NORA; G. Mueller, Arctic Biologist, University of Alaska; H. Petersen. Environmental Biologist, Greenland Fisheries Investigations (GF); S. 0. Horsted. Fishery Biologist, GF: J. Christensen. Marine Ecologist, Marin ID. The field program was supported by the U.S. Coast Guard Cutter WESTWIND, the MiLitary SeaLift ship MIRFAK, and the Greenland research vessel ADOLF JENSEN. While valuable support was received from all of the personnel on these vessels, specific acknowledgment of assistance is due to: Crndr. D. Super, Captain: Marine Science Technician (MST) Chief L. Pierce: B. Grahm, MST2; and G. Davis, MST3; and Lt. Cmdr. J. Carruthers, Executive Officer. all from the WESTWIND as welt as Captain J. Petersen and the entire crew of the ADOLF JENSEN. Many useful observations and oil samples were received from the U.S. Coast Guard Atlantic Strike Team and the U.FA. Navy Superintendent of Salvage representatives involved in the cleanup effort. The biological samples were sorted and analyzed by R. Maurer and J. Kane of the Narragansett Laboratory of the NORA NationaL Marine Fisheries Service and 0. Norden Andersen of Marin ID, Denmark. Chemical analyses were performed by Energy Resources Co. for the NORA samples and by the Water Quality Institute and University of Gothenburg (Sweden) for the Danish samples. Microbiological studies were performed by the Water Quality Institute. Funding for the studies was supplied by NORA's Environmental Data Service, U.S. Navy Superintendent of Salvage. and the Ministry for Greenland. Publication costs were underwritten by the NORA Hazardous Materials Response Program. IV ~0 TABLE OF CONTENTS PREFACE ......................................................... ~I~I~qI ACKNOWLEDGMENTS ................................................. ~I~V 1.0 INTRODUCTION ..................................................... 1~-~1 2.0 SCIENTIFIC RESPONSE TO THE OIL SPILL ............................. 2~-1 ~2.1 MORA Response .................................................. ~2~-1 2.2 Danish Response ............. ........ 2-3 2.3 On-scene Coordination ....... ........ 2-4 3.0 FIELD PROGRAM ................................................... 3-1 4.0 MOVEMENT OF THE OIL ........... ~qZ~q@~.~q6. ~. 4-1 4 ~1 Cir~cu~Lation And G~en~er~aL CLim~at~o ~9 ~q6~q@ ~qi~q;~q@~q@~qi~q; 4-1 4~q:2 Currents And HorizontaL Advection Of The~'~Oi~L .............. 4-~P 4. 2.I Geo~strophic Currents ......................................... 4-2 4.2.2 Direct Measurements .......................................... 4-4 4.2.3 Wind Stress Currents ......................................... 4-5 4.2.4 Summary of Currents .......................................... 4-~q6 4.2.5 Hor~l~zont~aL ~Advect~ion of ~O~IL ................................... 4-6 4.3 Physi~QaL Observations .......................................... 4-7 4.4 Verti~caL Movement 4-8 4.5 Summary Of OIL Movem~q;~q@~qi~*~'~'~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~'~, 4-9 5.0 WEATHERING OF SURFACE OIL ........................................ 5~-~q1 5 ~1 An~aLy~qtic~aL Procedures .......................................... 5-4 5~q:2 ResuLts ........................................................ 5-7 5.2.1 The Reference S~ampLe ...... ~q5~-~q7 5.2.2 Gas Chromatography of the Sur ~q1 5-8 5.2.3 Spe~ctrofLuorometr~qg~, NO~A~A SampLes ................. .......... 5~-17 5.2.4 Spe~ctrofLuorometry, and Mass Fragm~entography, Danish mpLes 5~-~q1~8 5.2.5 A~sphaLtenes ~5~_~2~0 5.3 Summary For Weat~'~h~*e~'~ri~q@~*g~*~q6~q@~*~q@~4qL~q@~qi~q@~q@~q;~*~q6~qi~q@~*~'~'~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q: 5-22 ~q6.~q0 MICROBIOLOGICAL STUDIES ......... ....... ~q6~-1 ~6.1 Counting And Identification Of Mi ....... ~q6~-1 ~6~.~1.~1 An~a~l~ytic~aL Procedures ........................................ ~q6~-1 ~6.~1.1.~1 T~otaL Count on Agar PLates ~6~-1 ~q6.1.1.2 Yeast and Fungi on Agar ~q6-2 6.1.1.3 ~O~I~L Degrading Bacteria on Agar PLates ~q6-2 ~6.1.1.4 ~O~IL Degrading Yeast and Fungi on Agar ~qP~qL~q@~qi~q;~q;-~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:- ~6~-~2 6.1.1.5 ~O~IL Degrading Microorganisms by Most Probab~Le Numbers ...... 6-3 6.1.2 Identification of IsoLated ~qO~qIL Degr~a~qlding Bacteria ............ ~q6-3 6 1.~3 Re~suLt~s 6-3 ~6~q:2 Degradation 6-5 ~6.2.1 Procedures .................................................... ~q6~-5 ~6.2.2 ResuLts ...................................................... ~6~-~7 ~6.3 Degradation Of ~qO~IL B~qy Iso~t~ated MonocuLture~s .................... ~q6~-11 6.3.1 Pro~Qedure .................................................... 6-11 ~6.3.2 Re~suLts ...................................................... 6~-13 ~q6.4 Summar~qg Of Biodegradation Studies ............................... 6~-13 ~0q7.0 ACCOMMODATION OF OIL INTO THE WATER COLUMN ....................... 7-1 ~0q7.1 S~qampL~qing Procedures ~q7~q-1 ~q7.~q1.1 The Danish S~qampL~qes ~q7.1.2 The N~qO~qA~qA SampLes .......... 7-2 ~q7.~q2 An~qaL~qytic~qa~qL Methods .......... 7-3 7.2.1 Danish SampLes ... 7-~0q3 7.2.1-1 U~qL~q-~qI-SpectrofLuor~q*~qo~0q@~0q;~0qi~0q@~qL~qj~q,~q*~q,~0q:~0q:~0q:~0q:~4q:~4q:~4q:~4q:~4q:~0q:~4q:~4q:~0q:~q.~0q:~0q:~4q:~0q:~4q:~4q:~4q:~4q:~4q:~0q:~0q:~0q:~0q:~0q:~4q:~0q:~4q: ........ 7-3 ~0q7.2.1.2 Gas Chrom~qatogr~qaph~qy~q,~q,~q,M~qass Spectrometry ....................... 7-4 ~q7~q.~q2~q.~q2 N~qOA~qA SampL~qe~qs ~qr~q_~q6 ~q7.~q3 ResuLts 7-7 7.3.1 The Danis~q'~72qW~8q@~8q@~qa~q*~4qi~4qg~q,~8q;~8q;~qs .......................................... ~0q7~q-~0q7 ~qV ~0 TABLE OF CONTENTS (CONTINUED) ~?.3.1.1 Quantitative U~V-Spectro~fLuorometry ......................... ~r~-~r 7.3.1.2 U~V Comparison of the Danish and NOAA S~ampLing Methods ...... 7~-13 7.3.1.3 Mass Spectrometric (MS) An~aL~ysis ........................... 7~-14 7.3.1.4 Comparison of MS -and U~V ResuLts ............................ 7-1~6 7.3.2 The NOA~A ana~t~qgses ......... 7~-17 Gas Chromatograp ~7.3.2.1 hy . .. . . . ......... ~7~-2~0 ~7.3.2.2 U~V-FLuore~scence 7~-25 7.4 Summary Of ~qAccommodatio~q@~*~qin~qio~'The~'Water~*Co~L~q@mn~'~'~* ................. 7-27 ~6.~0 BIOLOGICAL STUDIES ON PLANKTON AND FISH .............. ~q: .......... ~8~-~1 ~8.1 SampLing Procedure .................................. .......... ~8~-~1 ~F~3.1.1 Danish SampLing .............................................. ~6~-1 ~E~3.1.2 U.S. S~ampLing ................................................ ~8-4 8.2 Species Composition ............................................ e-4 8.2.1 The Danish SampLe~s ........................................... ~8-4 8.2.2 The U.S. S~ampLes ~8~-~6 ~6.2.3 White P~articLes on ~qih~'~'e~'~q@~'e~q&~'~*S~q@~0q@~q@~q&~q@~q@~'~*~*~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q: ~8~-~1~0 e.3 ~O~iL Contamination Of ZoopL~anKt~on And Fish ...................... ~8~-1~0 8.3.1 ChemicaL Examinations ........................................ ~8~-10 8.3.1.1 AnaL~qytic~aL Procedure ....................................... ~B~-~q1~0 8.3.1.2 ResuLts .................................................... ~8~-~11 ~6.3.1.3 Discussion ... ...................................... ~B-13 8.3.2 Ph~ysic~aL ~E~xaminati ...................................... ~B-14 ~8.~3.~2.1 Procedure .................................................. ~6~-1~1~4 8.3.2.2 ResuLts ..................................................... 8-14 ~8.3.2.3 Discussion ................................................. ~B~-1~6 ~q8.4 Summary ........................................................ ~B~-1~6 ~q9.~0 MARINE MAMMALS AND SEABIRDS ..................................... ~9~-~1 ~9.~1 Observations Of Marine M~amm~aLs ................................. ~9~-~1 9.2 ~OiL Contamination Of SeaLsKins ................................. 9~-~1 9.2.1 ~An~aL~qytic~aL Procedure ....................................... 9~-~2 ~9.~2.~2 ResuLts ...................................................... ~9~-2 9.3 Seabird Observations ........................................... 9-7 ~10.0 IMPACT ASSESSMENT ~.~q6~.~q@ ........................................... 1~0~-1 ~1~0.1 Fate Of The SpiLL~ed ~i ..... 1~0~-~1 1~0.2 Impact Of The SpiLL~ed ~OiL On Bi 10~-3 10.3 ConcLus~qions .................................................... 10-4 ~1~q1.0 SIGNIFICANT SCIENTIFIC FINDINGS ............................. I .... ~1~1~-~1 1~q1.1 Observations On The Behavior And Fate Of The Sp~qiLLed ~qOiL ....... 11~-1 1~1.~1.1 Sinking of the ~OiL ........................................... 11~-1 11.1.2 Weathering Rates ............................................. 11-2 11.2 BioLogic~aL Findings ............................................ 11-3 11.2.1 Biodegradation ................................................ 11-3 11.2.2 ZoopL~ankton .................................................. 11-4 ~1~1~.~2~.~3 Birds and M~ammaLs ............................................ ~1~1~-~4 ~q11.3 ConcLusions .................................................... 11-5 12.0 REFERENCES ....................................................... 1~2~-1 13.0 APPENDIX 13-1 1~3.~1 Marine Ag~'a~q@~'~'~*~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~,~.~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~q:~*~q:~q:~q:~q:~q:~.~*~q:~q:~"~.~q:~,~.~q:~q:~*~.~q:~q:~q:~q:~q:~q:~q:~q:~q:~q: 13-1 13.2 Agar Substrate ................................................. 13~q-2 13.3 Bunch Substrate (used for MPH method) .......................... 13~q-3 13.4 CoLweL~0qL Substrate (used for MPH method) ........................ 13~q-4 ~qv~qi ~0 LIST OF FIGURES ~1~-~1 ~qUSNS POTOMAC ~oi~t sp~iLL site and surrounding area . ................. 1-2 3-1 Locations of~'WESTWIND sampling stations . .......................... 3-4 3-2 Locations of ADOLF JENSEN s~ampt~ing stations . ...................... 3~-~q5 3-3 Detailed Locations of ~qH~qOAA and Danish stations . ................... 3~-~q6 4-1 Dynamic topography of the sea surface . ............................ 4-3 4-2 Vertical density d~qistr~qibutlon at three stations . .................. 4-4 4-3 Wind runs for 10-12 and 15~-19 August . ............................. 4-5 5-1 Distillation curve for the cutter stock . .......................... ~q5-3 5-2 Analytical scheme for the N~O~PA surface o~qi~l samples . ............... 5-6 5-3 Gas chrom~atogram or ~qf~ql (saturate) fraction or POTOMAC fuel . ....... 5-8 5-4 Gas chrom~ato~qgram o~qf ~f2 (aromatic) fraction or POTOMAC fuel . ....... 5~-~6 5-5 Relative peak abundances of n-~aLkanes from N~qOAA analyses . ......... 5-~9 5-~6 Relative peak abundances of n-a~qkkanes from Danish analyses . ....... ~q5~-9 5-7 A time series of gas chrom~atogr~ams of surface oi~l samples . ........ 5~-11 5-8 GC/MS results for r2 (aromatic) fraction or POTOMAC fuel . ......... 5~-12 5-9 GC~,~/MS results for r2 fraction of 1~8 August surface sample . ........ ~q5-1~q3 5-10 GC/MS results for ~qf2 fraction or 19 August subsurface sample . ..... ~q5-13 5-11 Ratio of nC~q17~xpristane for spilled o~i~l samples . ................... 5~-14 5~-12 Synchronous fluorescence scan or POTOMAC fuel . .................... 5~-15 5~-13 Relation between peak height and fuel concentration . .............. ~q5~-~q1~6 5~-14 Excitation and emm~qiss~qi~on spectra of a surface o~qi~ql sample . ......... ~q5~-~1~9 5~-15 Comparison of concentrations of selected aromatics ................ ~q5~-21 5-1~q6 Change in asphaLte~ne content with time . ........................... 5~-21 G-1 Gas chromato~qgr~ams; from first experiment . .......................... ~q6~-~6 ~q6-2 Gas chromatogram~s from second experiment (control) . ............... ~q6~-9 ~q6-3 Gas chrom~atograms from third experiment (added nutrients) . ........ ~q6~-~1~q0 7-1 Analytical scheme used for NOAA water samples . .................... ~q7~-~6 7-2 ~0qO~qi~0qL concentration as a function of depth at four stations . ........ ?~q-12 7-3 Fluorescence spectra of a sample containing spilled o~0qi~0ql . .......... 7~q-13 7-4 Fluorescence spectra of a sample containing cooling water . ........ 7~q-14 7-5 Fluorescence spectra of uncontaminated water . ..................... ~0q7-15 ~qv~0qi~qi ~0 LIST OF FIGURES (CONTINUED) 7-~q6 FLuorescence spectra of NOAA s~ampLe . .............................. 7~-17 ~q7~-~7 ExampLe of a mass ~qfra~qgmentogr~am . .................................. 7~-19 7-8 ReL~ative aromatic concentrations vs. moLecuLar weight . ............ ~q7~-2~0 7-9 Trimod~aL gas-chromatogram of extract 2, fl fraction . .............. 7-25 7-10 TrimodaL gas chromatogram of extract 2. ~qf2 fraction . .............. 7-25 7-11 Cap contamination gas chromatogr~am of extract 1~0-~2b~, fl fraction. 7-26 7~-12 Cap contamination gas chromatogr~am of extract 1~q0-2b~. f2 fraction. 7-26 7~-13 Gas chromatogram of vi~aL cap. f~qO (unfractionated) . ................ 7-27 7~-14 Low LeveL gas chrom~atogr~am of extract 3~q0-~lb~, f~O (unfractionated). ~. 7-27 ~qB~-1 Comparison of species compositions from neuston and bongo ........ ~qB~-9 ~qB-2 Gas chromatogram of Boreom~q@~qjsi from station 5465 . ................. ~B~-~q1~1 ~q8-3 Gas ~chromatogr~am of Themisto from station 5465 . ................... ~qB-12 ~q8-4 Gas chr~omatogr~am of Cop~epod from station 54~q70 . .................... ~qB-12 ~qB-5 Gas chrom~at~ogram of a Copepod 50 nm~qi from sp~iL~L (station 5477). ~qB~-~q1~q3 ~q9~-~q1 Capture Locations of an~aL~qUzed seaL~s . .............................. 9-3 9-2 Gas chromatogr~am of se~aL I (he~av~qiL~qg oiLed) . ....................... 9-4 9-3 Gas chromatogram of se~aL 2 (he~aviL~qy o~qiLed) . ....................... 9-4 9-4 Gas chromatogram of ~seaL 3 (spots on nec~K) . ....................... 9-5 9-5 Gas chromatogram of seaL 4 (far from sp~I~LL site) . ................ 9-5 9~-~q6 Gas chromatogr~am of seaL 10 (spots on necK) . ....................... 9~-~6 9~-~q7 Gas chromatogram of seaL 13 (far from spiL~L site) . ................ 9~-~q6 ~qv~0qi~0qii ~0 LIST OF TABLES 3-1 Scientific stations occupied during the POTOMAC oiL ~s~qpiLL . ........ 3-2 3-1 Scientific stations (continued) . .................................. 3-3 ~q5~-~q1 Surface o~qiL s~ampLes~-coLLected . ................... ................ 5-2 5-2 Concentrations of n~aphth~aLenes and phenanthrenes . ................. 5~-12 5-3 Concentrations of 2-~. 3-~, 4-~, and 5 ring aromatic compounds . ...... 5~-16 5-4 Characterizations b~qy spectrofLuorometr~qy of surface sampLes . ....... 5~-18 5-5 Concentrations of ten aromatic isomeric gro~.~ups . ................... 5-2e ~q6~-1 Enumeration resuLts from microb~qloLogica~l~ examinations . ............ ~6-4 6-2 BiochemicaL test resuLts for is~oLated strains . .................... ~6~-~q6 ~q6~-~q3 ~qResuLts from GC anaL~qy~ses of experiments with n~aturaL cuLtures~. ~..~.. ~6~-~7 ~q6-4 Growth of natura~qL cuLtures . ....................................... ~6~-1~q1 6-5 Growth of ~IsoLated m~onocu~ttur~es In time and temperature . .......... ~6-12 7-1 Trace impurity concentrations from soLvent in Danish sampLes . ..... 7-5 7-2 List of sampLes for which resuLts are not reported . ............... 7-9 7-3 ~qO~qIL concentrations In Danish water sampLes . ....................... ~q7~-1~q0 7-4 Amounts of interfering substances within soLvents . ................ ~q7~-11 7-5 Extraction efficiency of Danish procedures . ....................... 7~-15 ~q7~-~q6 Resu~qLts of intercomparison samp~qting . .............................. ~7~-1~6 ~q7~-~q7 SampLes anaL~qUzed b~qg mass fragmentogr~aph~qU . ......................... 7-18 ~q7~-~q8 Concentrations of se~Lect~ed aromatic compounds in water s~ampLes. ~.~.. ~q7~-18 7-9 Comparison of GC/MS and UV anaL~qyses . .............................. 7~-21 7-10 Seawater extract ~anaL~qyses, N~qOA~qR . .................................. 7-22 ~7~-~1~0 Seawater extract anaLy~ses, NORA (continued) ....................... ~7~-~2~3 ~q7~-11 Groupings of NO~AA seawater samp~qLes . ........................ I ...... 7-24 ~q8~-1 Summary of Danish b~qio~qlogicaL stations . ............................ 8-2 ~q8~-2 Summary of NOAA b~lo~qlogica~L stations . ..................... I ........ 8-3 ~q8-3 ZoopLanKton enumeration from Danish stations . ..................... ~8-5 ~4q8-4 Fish Larvae coLL~qected at Danish stations . ....................... ~q8~q-~q6 ~4q8~q-5 Zoop~0qL~qankton enumeration from N~qOA~qA stations . ....................... ~qG-7 ~0q8~q-~4q6 Occcurrence of o~4qiL contamination on dominant pLankton groups . ..... ~0qB-15 9~q-~q1 Date and Locations of seaL captures . .............................. 9-2 ~0qI~qx 1.0 INTRODUCTION On the morning of August 5, 1977, the U.S. Navy ship POTOMAC, bound for ThuLe Air Force Base with a cargo of arctic-bLend dieset fueL, was being escorted in intermittent dense fog by the U.S. Coast Guard cutter WESTWIND through the scattered sea ice of MeLviLLe Bay in the northeastern part of Baffin Bay off western GreenLand. The WESTWIND moved into a Large ice fLoe at 9 to 10 Kn. foLLowed by the POTOMAC. When both vesseLs were in the Ice ftoe. a crewman on the POTOMAC sighted oiL on the water at 0430 tocaL time. The WESTWIND was immediateLg informed. The POTOMAC's position at the time of the sighting was 74*52'N, 61*13'W (Figure 1-1). It was discovered that the No 2 Bunker (deep port) tank. containing about 107.000 us gaLLons of Bunker-C fuet, had been nhoted" by an iceberg or "growLer". ALmost aLL of the fueL in the hoLed tank was eventuaLLy spiLLed. CaLm seas with waves of 0 to 2 ft and Light winds of 0 to 7 Kn Kept the aiL from dispersing for severaL days after the spiLl. WhILe the WESTWIND escorted the POTOMAC to ThuLe with a water bottom in her hoLed tank. representatives of the U.S. Coast Guard (USCG) NationaL Strike Force and the U.S. Navy MiLitarg SeaLlft Command fLew to ThuLe aboard a USCG C-130, arriving on August 8. ImmediateLy upon arrivaL. they Left for the scene of the spiLL onboard the WESTWIND. From August 10 to 12, the C-130 fLew over the entire area, carrying its airborne oiL surveiLLance system for mapping the extent of the oiL sLick. Heticopters from the WESTWIND atso participated In the search. The C-130 Located the major concentration of the*oiL on August 12. and directed the Coast Guard heticopters and the icebreaker WESTWIND to the scene. 1-2 90* 80* 70 60* 50* 40' 30- 20' 10, 0. 80* 80o C % 75* 75* S,(0 MELVILLE G BAY 70* 70- ..UMANAK 7 GODHAVEN CHRISTIANSHAAB LL LL 65* AVIS STRAIT' se 65* GODTHAAB 60* 60* 70 60* 50* 400 Figure 1-1. USNS POTOMAC oil spill site and surrounding area. The spill site is marked by + in Melville Bay. ~0 2.0 SCIENTIFIC RESPONSE TO THE OIL SPILL As is standard for o~qlL SPILLS, the scientific response to the POTOMAC o~ql~ql, SPILL was an ad hoc effort b~qg concerned scientists. The U.S. and Danish responses were not fu~qL~ql~qg pr~ep~qt~anned nor were th~e~qg coordinated before ~arr~qiv~aL on scene. This section summarizes the events and p~qL~ann~qin~qg that cu~qtm~qin~ated with their ~arriv~aL on scene and the objectives for their responses. Summaries of the Impact of the SPILL and the significant scientific findings are presented in Chapters 10 and It. 2.1 NOAA Response On August 11 and 12, the Office of the Chief of N~avaL Operations ca~qLLe~qd upon the Office of Environment~aL Monitoring, ~qN~ation~aL Oceanic an~qd Atmospheric Administration (NORA), regarding p~os~s~qIbLe advice or assistance with the POTOMAC ~oiL SPILL. After cons~uLt~at~qion within NORA, the Nav~qg was Informed that the ~qN~qO~qRA-USCG SpiLLed OIL Research Team (SOP) c~ouLd Lend assistance. On August 14, a meeting was heLd at the U.S. N~av~qU M~qILit~ar~qg ~qSe~aL~ql~qft Command In Washington D.C. attended b~qV representatives or the N~a~v~qq Superintendent of S~a~qLv~age~. Chief of ~qN~avaL Operations, and the NORA SOP team. At this meeting a description of the water c~qircuLat~qion In the v~qi~c~qin~qit~qu of the sp~qiLL was presented aLong with the most recent "poLLut~qion report" from on scene. This report stated that there had l~oeen a "~qf~a~qlrL~qg rapid dispersion and breakup considering [the] nature of Ethe ~ciLl ... the rainbow streamers [had~qJ disappeared Leaving chocoLate mousse streamers ... [weather] caLm ... sea conditions have not acceLerate~qd this breakup ... Ethe o~qIL~q3 w~qiLL not ~qfL~oat forever; it wiLL breakup and dissipate through evaporation and ~qE~chem~qicaL3 breakdown with subsequent dispersion Into [the] water co~qtumn~,~" and ~l~lo~qi~qt within streamers on 12 Aug showed 50.000 gaLs of r~qecover~qabLe ~qo~qiL ... a 50 percent rec~qover~2qg w~qouLd be optimistic." The~4qg cautioned against overconfidence, continuing "a [weather] change with ~8qtincreased3 wind couLd disperse the o~4qiL so w~2qf~4qdeL~2qU that rec~qover~8qU ~qc~qou~8qLd be reduced to 1-5,~8q0~8q0~4q0 gaLs.~q" The message finished with, ~q"~2qEc~6ql~qonverseL~8qU, the oiL couLd be pushed ashore contaminating 2~4q0 m~4qiLe~qs or ice and coastLine with 1~8q0-25~q,~8q0~8q0~8q0 gaLs and since "Impact wouLd be in a ~8q2~q-1 ~0 2~2 sensitive es~qk~qiM~o hunting area. ... the sens~qit~qivit~qg of t~qhe incident vs. cost of [a cLeanu~qp~q] response dictates referraL to mission coordinator for appropriate action.- Add~qiti~onaL information for those present at this meeting was contained in a brief summary of t~qUP~qICaL ph~qU~s~qica~qL properties of the sp~qILLe~d rueL; ~I.e., "t~qUp~qIca~qL~l~l ~anaL~qUs~qts as reLa~qged b~qy EXXON: specific gravity 0.9~q74 at ~q6~q0 F ~q1~q0.9~q87 at 30 F3 ... o~qlL wiLL ~qfLoat [rather th~an~qJ sink .... ~1~1 As was to be Learned Later, these ~"t~qUp~qicaL~" properties of the sp~qILLed ~o~qlL were aLL that ~c~ouLd be provided on short notice b~qg EXXON because of a communications strike In Aruba. The N~qOA~qR representatives disagreed with the optimistic predictions In the poLLution report that the mass of the ~o~qiL remaining at the surface w~ouLd .continue to diminish b~qg 50 percent per week, unt~qiL ~l~lresiduaL tarbaLLs remaining after 6 weeks wouLd be 3 to 5 percent or the t~otaL ~spiLL.~" This disagreement was based on 1) the reported specific gravity of the sp~qILLed ~oiL~. and 2) the L~qi~qKeL~qihood that the mass reduction observed in the first week was due to a t~qotaL Loss of the v~oLat~qlLe fraction (b.p.< 250 C) o~qr the "cutter stock". It was their opinion that continued reduction or the mass of the surface oiL was u~n~qLi~qkeL~qU, but that h~0r~qIzontaL dispersive processes w~ouLd quic~qKL~qW Lower the possibiL~qit~qg of recovering the sp~qiLLed ~oiL. Based upon the reported movements of the surface o~qiL during the week that had eLap~sed since the sp~qI~qLL and the an~aL~qUs~qis of the surface water motion In the MeLviLLe Bag - Cape York area, they predicted that within 2 weeks, or b~qg about August ~q27~, the surface o~qlL wouLd be so wideL~qg dispersed that no recover~qg wouLd be po~ss~qib~~qLe. The U.S. Navy MiL~qlt~ar~qg Sea~qLi~qft Command decided to proceed with the ct~e~anup effort even though 9 d~a~qgs had eLapsed since t~qhe spiLL and the~qg agreed that the over~a~qL~qL effort wouLd benefit from a scientific response that wouLd incLude b~qi~qoLoglsts. a ph~qys~qic~aL oceanographer and a chemist. It was decided that four SO~qP Team members sh~ouLd accompany the Coast Guard Strike Team pers~onneL on the C~-5~qA fL~qight to ThuL~e. The scientific mission was thr~ee~qf~oLd: 1) to advise an~qd ass~qls~@t the On~-Scene-Coordinator~. the Strike Team, and the Navy to the maximum extent possibLe~q, 2) to conduct ch~em~qicaL~q, ph~qgsi~caL, and bi~qo~2qt~qo~2qgi~qcaL samp~4qting for a rudimentary assessment of t~0qhe ecoLoglca~0qt Impact, and 3) to assist and c~qoLLabor~qat~qe with the Danish scientists aboard the ~8qR~qIV ADOLF JENSEN. The SOP team arrived in ThuLe at 0900 EDT on August 16. Left for the scene of the spiLL~q.~qaboard the ~8qU~4qSNS MI~0qRF~qA~0qK~q. and arrived at the WESTWI~4qND~q's ~0 position at 1300 EDT on August 17. The NO~qAA ~qf~qIeLd effort was c~ompLeted with the return of the WESTWIND to ThuL~e on August 21. 2.2 Danish Response At 0010 GMT on August G, the Ministry for GreenL~and received a message that 390 tons of ~O~qIL had been sp~qiLLed b~qg the USNS POTOMAC in M~eLv~qiLLe Bag. GreenL~and. The Ministr~qU re~uog~n~qized that this opportunit~qg to study an o~qiL spiL~ql in Arctic water was of partIcuLar~ Interest because or t~he ongoing o~qlL expL~oration off West GreenLand and the importance of hunting marine mammaL~s and birds in this area b~qg native hunters. Moreover, the~qg, wanted the opportunity to exercise and test recent contingency pL~ans for o~qlL spiLL research. The Minsitr~qg, therefore, redirected the research vesseL ADOLF JENSEN from its scheduLed cruise to a spec~qIaL cruise into MeLv~qiLLe Bag to stud~qg the oiL spiLL. During the next 4 da~qgs~. a cruise pLan was generated and the required spec~qiaL equipment was staged onbo~ard the ADOLF JENSEN. The cruise p~qtan caLLed for ph~qUsicaL, chem~qic~aL~. and b~qIoLogi~ca~qL observations an~qd was generated with inputs from the Water ~qQu~a~qt~qit~qy Institute, Marin ID~, the Un~qIvers~qit~qW of Gothenburg. and GreenLand Fisheries Investigations, Ministry for GreenLand. The scientific staff for the cruise, two b~qloLog~qists and a marine ma~m~m~aL ~o~qb~server~o Left Copenhagen. Denmark on August 1~q0 and arrived a~t HoLste~qin~qoorg, GreenLand the same da~qg. In the meanwhiLe, the ADOLF JENSEN had been prepared for the cruise and saiLed from HoLsteinb~org when the scientific part~qg was aboard. Considering that there was onL~qg a weekend between the notice of t~qhe ~sp~qILL and the departure of th~e scientific team, that some or t~qhe scientific gear had to be sent from Sweden to Denmark, that the ADOLF JENSEN had to be directed from an area off Disko I~sL~and to Ho~qLst~e~qinborg~. and that the communications between GreenLand and Denmark were ver~qg di~qf~qf~qicuLt because or a strike at the Gr~eenL~and radio stations. the cruise to M~eLviLL~e Bag couLd hardL~qU have been started earLier. The ADOLF JENSEN arrived at the scene of the ~qspiLL on August 12 and the investigations started imm~qed~4qi~qateL~4qy~q. The cruise terminated on August 23 when the ADOLF JENSEN arrived at Eg~qedesminde~q. Gr~qeenL~qand. ~0 2-4 2.3 On-scene Coordination On August 17, the N~qOA~qR and Danish scientists met O'~nb~o~ard the ADOLF JENSEN to exchange p~qtans and discuss scientific coordination. At this meeting it was agreed that the chemistry sampLin~qg was aLL to be done from the ADOLF JENSEN because of better Logistic support. C~ons~equ~entL~qg~, one of the N~qO~qA~qA team joined the ADOLF JENSEN with the required s~ampLin~qg and anaL~qyt~qicaL equipment. It was aLso agreed that the N~qO~qA~qA team remaining on the WESTWIND wouLd focus its efforts on the movement of the o~qiL and on obtaining neust~on and bongo tows for ~qbi~oL~o~qgic~aL ~sampLe~s at or near the surface. The Danish team on the ADOLF JENSEN wouLd concentrate on the subsurface ~qb~qlo~qL~og~qlca~qL sampL~qin~qg in addition to the chemistry. D~aiL~qg contact was maintained between the two teams to ensure coordination~'and to discuss current findings. ~0 ~q3.~q0 FIELD ~qP~qR~qO~qG~qI~I~I~qA~qM ~qT~i~f~t~e ~qVi~eL~qd ~qP~r~o~qgr~-c~a~i~r~t in response to the ~qU~qS~qH~qS ~'~PO~qT~qO~qM~qn~qC o~qiL sp~qi~qL~qL w~a~s concentrated ~4qn~'~o~n~i August ~q1~q@~q5 to 21 for the vast ~ma~qjo~r~qi~qt~qU of the samp~qL~qin~qg. Fort~qg-s~qi~x ~s~qt~@~it~qi~on~@~3 were occupied from the U.S. Coast Gu~ar~qa cutter ~8qH~qE~qSTWIND and the GreenL~and research vesseL ADOLF JENSEN. The Locations of these stations are presented in ~ql~qa~qb~qLe 3~-~-~q1 and figures ~q3-1 to 3-4. ~qALso noted in T~a~qb~qLe 3-1 are the sampling programs undert~a~qKen at each station. These s~amp~qLing stations were the basis for the ph~qUsic~a~qL. ~chem~qic~aL~, and ~qb~qloLoglcaL studies conducted ~qb~L~qj the NORA and ~qD~j~nl~@~s~qh scientists. In support of the ph~t~qjs~qi~caL studies, 11 temperature pro~qfiLes were obtained to depths of ~e~l~t~qb~qU m using e~xp~end~abL~e bath~L~qjthermog~r-~ap~qhs (~qXBTs)~, eig~,~"~I~qt stations coLL~ected h~qy~qdr~o~qgr~aphic temperature and ~s~aL~qin~qi~qt~qy data using N~ans~en ~qOoi~:tLe~s and reversing ~@~.~'her~i~m~o~m~eter~s, ~and~.~at two stations, e~xpend~abL~e current measuring probes were d~ep~qLo~qyed. ~qThe p~qM~qUs~qlcaL programs were undert~aK~en to determine the movement of ~q@h~e ~O~qIL and ~qa~re contained in Chapter 4. ~qThirt~e~u~n ~s~n~r~q@~dc~e ~oiL s~ampLes were coLLected for studies on the w~e~athe~r~Ing of the s~urfaCL o~qiL. ALiquots of these s~ampLe~s were an~aL~qUz~ed as part of the NORA and Danish programs and are discussed in Chapter 5. TO ~a~S~L~e~i~-t~ain the impact of ~m~qi~cr~ob~qi~oL~ogic~aL degradation of the ~Sp~qI~qLLed ~u ~qi L, ~cu L t~ur~u~s w~er~u grown on var ~qI ~ous subs tr~a t~es ~qf ram samp ~qL es c~o L L e~c~, ~qt~ed a t f ~qi ve stations by ~qD~6~ni~sh scientists-. The resuLt~s of these studies are contained in Chapter 6. Water were cuLL~e~cted at IS stations to determine how much o~qiL was ~a~q=~lm~m~odat~ud into ~qi~:h~u water c~oLum~n~. More than 58 ~sa~mpL~es at depths down to 30 m were obt~ai~n~l~qd. '~L~qbe NORA team c~oLL~ected their s~ampLes using a Nisl~ein ~st~er~qiLe bag ~s~a~i~r~ip~qler w~qk~iiL~e the ~q)~q)~ani~sh team coLLected their s~ampLes with a 1.0 ~qL gL~ass ~8qb~q@~qjttLe ~8qLow~qe~qi-~qu~8qd i~qt~qi ~q@~qi~qr~q, ~q@~q6t~qainLes~qs steeL frame. These ~q1~q3ottLes were fitted with a tefL~qo~qr~qt Lined c~q-~q-~q-~q,~q,~q) ~qwi~q-~qiic~0qh was pierced ~4qb~qij a spi~8qR~qe when a messenger was dropped, aLL~qow~2qi~qng th~qL- ~qi~qj~4qt~8qt~8qt~qe ~8qt~qu be ~4qfiLL~qed~q. ~8qT~8ql~qi~qe ~8qb~qo~4qt~4qt~q:~8qL~qu~q@~qs w~qu~qr~qe riot rese~qaLed before being brought bacl~qe, through the surface. E~qAcept for two reference stations acquired on t~qhe return to ThuLe by 3--~4ql Table 3-1. Scientific stations occupied during POTOMAC oil spill Date Time Vessel* Station Latitude Longitude Map Program supported** Comments 1977 GMT N W fig. X H C 0 M W Z 10 Aug W W-1 750 02' 600 50' 4 0 12 Aug W W-2 750 061 610 43' 4 0 13 Aug 1130 AJ 5460 740 53' 610 10' 3,4 H D Z Stramin & Hensen 2300 AJ 5461 750 10' 610 23' 3,4 H 0 M D Z Stramin & Hensen 14 Aug 1400 AJ 5462 750 25' 610 441 3,4 0 M D 15 Aug 2300 AJ 5463 750 12' 610 23' 3,4 0 16 Aug 1123 AJ 5464 750 12' 610 30' 3,4 0 Z Stramin & Hensen 1155 W X-30 750 13' 610 24' 4 X 17 Aug 0007 W X-31 750 14' 610 26' 4 X 0607 W X-32 750 14' 610 05, 4 X 1215 W X-32 750 14' 610 05' 4 X 1310 AJ 5465 750 10' 600 38' 3,4 Z Midwater Trawl 2100 AJ 5466 750 20' 610 12' 3,4 H 0 N,D 18 Aug 0009 W X-34 750 211 610 05' 1 x 0300 AJ 5467 750 34' 610 09' 3,4 0 M N,D 0634 W X-35 750 21' 610 12' 4 X 1205 W X-36 750 20' 610 10' 4 X 1700 W 1 750 30' 610 02' 2,4 X H 1900 AJ 5468 750 42' 600 15' 3 H M N,D 2100 W 2 750 23' 610 53' 2,4 X H 19 Aug 0500 W 3 750 14' 610 10' 2,4 X H D Z Stramin & Hensen 1448 AJ 5469 750 44' 610 35' 3 H N,D Z Stramin & Hensen 1600 W B-I 750 15' 610 15' 4 Z Bongo 10,15,20 m 1700 W B-2 750 151 610 15' 4 0 Z Bongo 5,10,15,20 m 1830 AJ 5470 750 35' 610 24' 3 H N,D Z Stramin & Hensen 20 Aug 0540 W WW-1 750 16.5' 610 20' 3 Z Neuston 0635 W W-2 750 17.5' 610 15' 3 Z Neuston 0723 W. WW-3 750 18.5' 610 12.5' 3 Z Neuston Table 3-1. Scientific stations occupied during POTOMAC Oil spill (Continued) Date Time Vessel* Station Latitude Longitude Map Program supported** Comments 1977 GMT N W fig. X H C 0 M W Z 20 Aug 0748 W ww-4 750 19.5' 610 10.5' 3 Z Neuston 0827 W ww-5 750 20.5' 610 14' 3 Z Neuston 0850 AJ 5471 750 26' 610 10' H 0 N,D Z Stramin & Hensen 0945 W WW-6 750 22.5' 610 04' 3 Z Neuston 1045 W ww-7 750 18.5' 610 19' 3 Z Neuston 1129 W WW-8 750 18' 610 17' 3 Z Neuston 1200 H A 750 22' 600 30' 1,3 C Bad probe 1300 H B 750 15' 610 00' 1,3 C 2130 AJ 5473 750 16' 610 15 2,3 0 N,D Intercomparison 21 Aug 1300 AJ 5374 750 15' 610 10' 2,3 M D oil waste background 0843 W WW-9 750 26' 620 52' 2 Z Neuston 1600 AJ 5475 740 55' 600 121 2 0 M D 1253 W WW-10 750 45' 650 50' 2 X N Neuston 2200 AJ 5476 740 39, 590 10' 3 D 1600 W WW-11 750 53' 670 58' 2 N Z Neuston - Reference station west of Cape York 22 Aug 0100 AJ 5477 740 21' 580 37' 3 H D Z Stramin & Hensen Reference station 18 Sept Local 750 ? 610 ? 0 1 Oct Local 750 ? 610 ? 0 *W= Westwind AJ = Adolf Jensen H = Helicopter Local Collected by local hunters **Programs: X -expendable Bathythermograph H -Hydrographic data (Nansen bottles) C -Current measurement 0 -Surface oil sample M -Microbiology Lo W - Water samples N-NOAA D - Danish Z -Plankton Tow (Type nets described under comments) ~0 3-4 0~4~q0~8q0 CAPE MELVILL ~q0 76~' ~qSAVIGSIVIK CAPE YORK 0 ~q10 CAPE WALKER CPA ~q9 17 AUG 0 2~qA A ~4q% ~X 7 2 15 AUG 3 B 12 AUG 75~0N ~4q9 XBT ANANSEN ~0q0 SPILL SITE X CURRENTS 640 ONEUSTON 60~' Figure 3-1. Locations of stations occupied by the WESTWIND. Areas where surface oil was found are indicated for three days. the WESTWIND, ~a~qLL the water ~SaM~qpLes were acquired from either the ADOLF JENSEN or from her rubber d~qin~qghu a ~qfe~w hundred meters ~awa~qU to decrease the chance of contamination b~qg waste discharges from the ADOLF JENSEN. The water sampLes were extracted using he~xane as soon as p~o~s~s~qibLe after s~ampL~qing (hours) and were independentL~qU ~anaL~qUzed using uv-~qfLuorescence and gas chrom~ato~qgraph~qu~-m~a~ss spectroscop~qg b~qW both NORA and Danish contractors. T~qhe re~suLts of these studies are presented In Chapter 7. ZoopLan~qKton sampLes were coLLected using four different sampL~qing devices at 22 stations. The NORA team conducted 11 neuston tows with an 0.5 x 1.0 m frame fitted with a ~q0.5~q05 mm mesh net. These tows each S~aM~qpLed 550 sq m of surface area. The~qW aLso conducted two bongo tows with ~q61 cm frames fitted with 0.505 and .333 mm mesh nets. The first tow was for a distance of 0.56 ~8qKm ~0q0 CAPE ~8qW~2qNA~qLK~qER at ~2q20~q, 15. and 1~2q0 m depth each. whiLe the second saM~2qpLed for 0.95 ~4qKm at each depth of 20~q, 15, 10, and 5 m. The Danish team coLLected sampLes with a ~0q2-m-d~6qiameter Str~qamin net r~8qitted with a mesh of 500 threads/m and a Hensen net of 72 cm fitted with No. 3 s~2qiL~2qK mesh at each or their stations. T~4qhe ~4qStram~8qin 3-5 62* 61 60* 59* 58* 57* 76* - 9 760 It 95469 : -/--, 0 546a 5470 0 05467- 17 AUG'**C@p VOIA 54620 95471 C, 5466 12 AUG --P.-%-5%4-73 V-0-- 15 AUG 5464 V@474 005463 0 v 0 0 5472 5461 5465 75* - 75* 5460 05475 0 SPILL SITE 0 5476 Qeb ;v ;@C 00-1 05477 62' 61* 60* 59* 58* 57* Figure 3-2. Locations of stations occupied by the ADOLF JENSEN. 3-6 620 40' 20'=Mm*#& 6 o 40' 20' I Psi 17 AUG C@ 30' 5471 5462 17 AUG WW-6 A 2 0 ww- X-35 @ 10 * X-34 20' WW-4 *OX-36 20' 12 AUG WW-3 0 5466 15 AUG WW-7 * % 0 WW-2 0 ww-1 x 0 WW-8 5473 X-31 05 74 0 131, 2 9 *1 X-30 : 3 X-32, 33 * 5463 5464 5465 10, 0 10, 5461 W2 0 wi 75*N 75*N 6475 5460 SPILL SITE 62* 40' 20' 61 40' 20' w Pigure 3-3. Detailed locations of NOAA and Danish stations in the area of highest oil concentration. See Table 3-1. 1 @G\ 5 -34 6 @ 5, 3 ~0 3-7 net performed ~obLique tows from 200 m depth for about 30 minutes at 1.5 ~qKn speed, wh~qiLe t~qhe Hen~sen net was hauLed vert~qicaLL~qU from 50 m at 0.33 ~m/s. The resuLts of the species composition and contamination studies are contained in Chapter 8. L~qim~qIted obs~e~q@~rvations an marine m~amm~aLs (~seaLs~q) and seabirds were made during the stud~qg period. ~qOiLed sK~qins of se~aLs, shot Later in the ~qU~ear b~qg ~Loc~aL EsKim~o hunters, were made avaiLibLe to the Danish team for ch~em~qicaL anaL~qUses. These studies are presented In Chapter 9. As with an~qu ad hoc scientific response, not aLL the desired information was coLLected during the fieLd program. In retrospect, there sh~ouL~qd have been more direct measurements of the surface currents using the current probes, and it wouLd have been d~esira~qbLe to have conducted the zoopLan~qKton sampL~qing to account pr~operL~qU ror dIurnaL var~qla~qU~qlL~qit~qU~. ~qFr~o~qD~abLy the most important data not c~aLLected were numerous sampLes of the subsurface o~qlL for weathering studies. However, given the short notice before departure. It.is probabL~qy significant that the s~ampL~qing was as c~omptet~e as it was. ~0 4.0 MOVEMENT OF THE OIL To assist the On-~scene-Coord~qinator and to assess eco~qLo~qg~qica~qL effects, It was necessary to determine and predict the movement of the SPIL~qLe~qd o~qt~qt. ~q1~q7~1~q1~qt was done b~qy both direct measurements and modeL~qing. The h~orizont~aL advection of ~qspiL~qled o~qi~qt is in~qfLuenced b~qy the ~qgeneraL c~qircuLation or permanent currents upon which the Lo~qcaL effects of wind stress and waves on the o~qi~qt are superimposed. These Loca~qt effects tend to move the o~qlL independ~ent~qtW of t~qhe surrounding wa~qt~nr~. ~q7~qTe approach used was to determine separ~qite cont~qibut~qions for the three time scaLes of motion -- days for the permanent currents, hours for wind stress, and minutes for the wave Interaction -- an~qd then draw concLusions based on their reLat~qive magnitudes. Extensive use was made of a report by Muench (1971) and supporting data from U.S. Coast Guard Icebreaker cruises in 19~q6~q8. 1969. and 1970 ~q(Muench at aL.. 1971~; Moynihan and Muen~ch. 1971~; and Muench, 1972). 4.1 C~qircuL~ation And G~eneraL C~qL~qiMat~oL~o~qg~qg Of Baffin Bay Baffin Ba~qy is a sem~qiencLosed body of water with Limited access to the Arctic Ocean to the north and to the ~qAtL~ant~qic Ocean to the south through Davis Strait. The waters in the bay consist of four Layers: a surface Layer extending to a depth of about 5 to 10 m generated b~qy ice meLt~. a c~o~qL~qd subsurface~-LaWer ~q(< 0 C) from 20 to 10~q0 m deep generated from the mixing of Arctic water and ~qAtLanti~c water~.~'a deeper Lager of warm water ~6q0 ~q0 C~q) from 150 to 4~q0~q0 m deep originating from the ~qAt~qLant~qic, and a bottom La~q@er or co~qt~qo water ~q(< ~q0 C) beL~ow 500 m. The circuLat~qion of MeLv~qILLe Ba~qy is dominated b~qy the West Gr~een~qt~an~qd Current, which fLows to the north aLon~6qg the west coast of GreenL~qand. This current appears to be driven pr~2qimar~2qiL~2qW b~6qy runoff and Ice meLt as the c~2qt~2qimatoLogicaL winds are not very strong. The current pr~2qimar~4qIL~2qU is contained in the upper Layer of the ba~8qy (down to 20 m). 4-1 ~0 4-2 4.2 Currents And HorizontaL ~qAdvect~qion Of The ~qO~qIL 4.2~.~q1 Ge~ostrophic Currents H~qistor~qicaL data (Mu~ench. 1972) Indicate that the predominant surface currents in MeLviLLe ~qBa~qy are roughL~qg paraLLeL to the coast. In the area of th~qe spiLL, the current is to the northwest. changing to west off Cape YorK. T~qh~qe geo~strophIc currents roLLow t~qhe contours or ~qa~ql~qlnamic topography s~qnown In Figure 4-~q1. Since these currents are based on is~oLated h~qUdrographic stations acquired before 1971. the geo~strophic currents were estimated during the ~sp~qILL from three h~qUdrogr~aphic stations occupied an August 18 and 15 b~qy the WESTWI~qND. ~qAt~"these stations. temperatures and s~aL~qinities were measured with Hansen b~o~qt~'t~qLes and reversing thermometers at seven depths from the surface to 150 m. The Locations of the stations are shown In Figure 3-4. The primary purpose of the stations was to define the density structure at the top and bottom of the ~s~u~qb~.surf~ace Arctic water as an aid in predicting the Location of the oiL in the water coLumn in the event the oiL san~qK. Thus the acquired data did not adequateL~qU define the major density structure at the surface required for geo~1p~ophic c~aLcuL~ations. ~qAdditi~onaL ~qLeveLs were interpoLated for. based on the temperature-saLin~qit~qU reL~ationship derived from the Hansen casts and the temperature structure derived from XBTs at each station. The density struc~-ture~,w~a~s found to be near~qL~qU constant b~eLow 40 m (Figure 4-2). in accord with historicaL data. and the surface currents were computed reL~at~qive to a depth~,~of 40 m. The caLcuL~ati~ons indicated a westerLy ~qfLow (2~q6~q0~0T) at 3 ~cm/~s~, which is onL~qg a crude estimate because of the int~erpoLation used to suppLement the. Hansen data and the LacK of s~qUn~apt~qicit~qg. The error bounds for the speed were estimated to be -3 to +5 cm/s and ~+/- ~8qM degrees for direction. Since the.~origin of the Lighter surface water is ice m~eLt~. the derived current is ~k I consistent with the greater concentration of ice near the shore. Sever~aL h~qudrogr~aph~qic stations were occupied by the Danish researchers from the ADOLF JENSEN, but simuLt~a~neous XBT data were not av~aiLibL~e to aLLow interpo~~qLati~on of the required additionaL LeveLs to define the density structure. ~2qALso, ~qaLL but one of the ADOLF JENSEN stations were more than 3~8q0 nmi from the area of the spiL~8qL or were separated in time by more than 36 hours from the WESTWIND stations. The one comp~qar~qab~4qLe station (Station 546~4q6) was consistent with the three WES~4qTWI~4qND stations. 4-3 wo 70* wo 600 40 C= 1928 STATIONS X 1940 STATIONS 0 0 0 .80 75' 75* % 0 0 1454.70 .75 x 0 x 14 .70 700 *0 700 .75 .75 00# 0 Y.80 .80 .85 .90 .95 65* wo wo 70' wo Figure 4-1 Dynamic topography of the surface with respect to 1,500 decibars (from Barnes, 1941). Contour interval is 0.05 dynamic meters (from Muench, 1972). 4-4 3 10- 2 20- 30 - 40- 50@ I 24 25 W 27 DENSMat Figure 4-2. Vertical density distribution at three -hydrographic stations. Nine additional XBT stations In the area indicated that the top of the subsurface Arctic water (0 C isotherm) was between 10 and 30 m deep. However, as the sensity at temperatures near 0 C are dominated by salinity effects, these XBT data did not yield any further information for estimating the geostrophic current. 4.2.2 Direct Measurements On August 20. an attempt was made to measure surface currents directly with three Richardson current probes depLoUed from a helicopter. Only one was partially successful; the other two fatted to release any subsurface floats. From the single float released from the one partially successful probe, the surface current was computed to be approximateLU 8 cm/e In a soutnw@sterLij direction (2200T). This current would correspond to the currents at 1 m depth and is relative to the net transport of the entire water column. Based on measurements of the elongation of the dge patches caused primarily by Stokes drift and only slightly by windage. the uppermost surface waters (5 cm) were calculated to be moving at 2 cm/s relative to the water at a depth of I m and at a right angle to it (1250T). ~0 4~5 4.2.3 Wind Stress Currents A second method for assessing the magnitude of the surface currents Is to m~odeL the currents from wind observations. The wind modeL indicates that the wind driven surface currents were directL~qU downwind with a speed of about 3 percent of the wind speed. Wind observations were made on t~qMe ~qP~qJE~qSTWIND at ~6-hour int~ervaL~s WhiLe the ship was In the vicinit~qU of the sp~qILL. These wind data and v~qi~su~aL estimates of wave heights are contained in Mattson and Grose Figure 4-3 shows the wind runs for the two periods when the WESTWIND was 15 AUG. I No ~W~a 12 AM ~WQ~G ~QMT ~4~0 ~W~A ~12~8~' TRUE Is ~A~U~G. ~O~D~W ~qW~r 0 ~I~O~A~U~G~.~0~0~0~0~0~qW 19 AUG. IWO G~Kr 12 AUG. ~I~O~W ~O~qW \\ ~q) ~I~q. I I ~A~UG. 0000 G~k~Tr 40~5 NM 3~4~W T ~I~O~A~qW~.~W~W~G~qW Figure 4-3. Wind runs for 10~-12 and 15~-19 August. The nominal position is 75'15~1N, 61~*W. at the scene of the sp~qILL. From these runs, one can m~odeL that the ~oiL wouLd have moved onL~qU 12 nmi in a nortwesterL~qU direction ~q(34~q0~0T) from August 10 to 12 and about 12 nm~2qi in a southwesterL~8qU direction (12~8q0~q0T) from August 15 to 19. ~-~0~3~q- ~I~q-~qME Oi~4qt ~8qtoc~qations for August 15 and 17 (Figure 3-4) indicate a net drift or 4 nmi to the northwest (31~8q0~q"T)~q, and (for this time period) the mod~qeL predicts a drift of 2 nmi to the south ~4q(~8q1~8q6~8q0~q0T~4q) at an average speed of 2 cm/s. From this difference between the sLicK ~qI.oc~qati~qons and the wind modeL resuLts, one can 4-6 Infer a general circulation of 6 cm/s In a northwestertU direction (3200T). 4.2.4 SummarU of Currents Estimates or the three time scales that contribute to the Local surface current are as foLtows: I-GeneraL circulation. a-HistorIcal values or Less than 29 cm/s to the west. b-Geostropic currents of 3 cm.,Is to Me west (2600T) measured reattive to 40 m depth. c-Inferred currents from the wind modeL of 6 cm/s to the northwest (3200T) 2-Surface currents at I m. a-Current of 8 cm/s to the southwest (2170T) measured with Richardson probe. b-Average currents of 2 CM/S from wind stress in various directions. 3-Surface currents at 5 cm (measured Stokes drift of 2 cm/s). 4.2.5 HorizontaL Advection of OIL Large errors, on the order of a factor of 2, are associated with all the measurements described above. However, there Is no doubt that the surface currents are of Small magnitude. The two shorter time scales probabLg contribute Less than 5 cm/s and tend to average to 0 because of the random ,directions. The Long-scaLe motions appear to be westerLU at about 5 cm/s. which indicate that the OIL was not transported far from the site of the spill. i.e.. less than 40 nmi over a 2-weeK period. The elongated stIcK pattern was probaDLU caused bW spILLage over a period of time (1-hr duration at 8 kn = 8 rimi Length). Once generated. this pattern was then advected bg LocaL currents in random directions. depending primarily on winds with a net set to the northwest from the permanent currents. OIL observed In neuston tows northwest of the main spill site during the return to Thule on August 20 probabLU stemmed from continued Leakage bU the USNS POTOMAC as she made her waW to the same port via the same route, because the observed currents were not strong enough to have carried the principLaL spill that far. Advection of the OIL bW the surface currents did, however, alLow a Large surface area to be exposed to the OIL at one time or another. The exposed area 2 weeks after the spill was estimated at 500 sq mi based on OIL Locations ~0 4-7 and current measurements. 4.3 Ph~qUs~qIcaL Observations ShortL~qy after the ~sp~qiLL. the ~O~qIL was reported to be In the form of ~sma~qt~qt. pancakes 10 to 25 cm in diameter and 0.5 ~cm thick. which were organized in windrows about 3 m, wide presum~abL~qU from wind-induced L~angmu~qir circuLatl~on. Sheen, a visibLe but thin stick, was seen emanating from these pancakes, and major concentrations were easy to spot from the air. B~qy August 10~, 14 days after the sp~qiLL, the ~O~qIL was no Longer not~qicea~qbLe from the air. ~qWes~seLs at the site stiLL reported some pancakes I to 13 ~cm In diameter on the surface, in streamers or rows sever~aL hundred meters Long ~and~'at~iout ~q71~qD m wide. Less than I percent of the surface in these windrows. however. was covered with o~qiL. One windrow observed on August 20 was estimated to contain Less than 350 ~gaL In an area of 4.0~q00 sq m. Elg~qht~qg percent of the pancakes no Longer were surrounded by sheen. and more than ~_~q5 percent of the area of the individuaL pancakes was submerged. Many pieces the size and shape of c~orn~qfA~aKes were observed at the water surface and in the water coLumn~. On the previous da~qy. a Large number of subsurface ~qrLa~qKe~s were aL~so reported. B~qy this time the surface o~4~.L had become spongy in texture. but it was not undergoing w~ater-in-oiL emuLsif~qic~ation or "mousse" formation. Even after severa~qt days of weathering, Less than 5 percent water was found in t~qhe surface ~O~qIL after it had been heated to ~q8~q0 C. The spiLLed ~O~qIL did not reach shore during the ~sp~qILL response. Icebergs in the vicinity of the spiLL were examined by the U.S. Coast Guard to see if OIL ~was adhering to them. It was noted that t~qhe ~O~qIL staged away from ~qt~qhe icebergs pro~qbabL~qg because they were activeL~qU meLting. Over the next 8 months, isoL~ated reports of ~O~qIL ~elght~qings and sampLes were received from bioLogists an expeditions (E. Born and T~. ~qKr~qistensen. per~son~aL communication to H. Petersen, 197~q3) and from LocaL ~qMUnt~ers. One ~O~qIL ~ampLe (October 1) was confirmed as coming from the POTOMAC and some of the seaL skins (Chapter 9) may have been contaminated b~2qy POTOMAC ~qO~4qIL. whether this contamination occurred ~8qt~qocaLL~8qU where captured or during their passage through MeLviLLe Bay is unknown. OIL cLumps or t~qar~4qb~qaLLs were ~qaLso reported to have been t~qa~4qRen ~4qin seat nets north of T~0qhu~4qLe at N~qor~0qlussaq (Figure 9-1) during the Autumn of 197~2q7 and during ~4qApriL or May of 19~8q7~4q6. A GreenL~qander hunting poL~qar ~0 bear in MeLv~qiLLe Bag (southeast of S~av~qigs~qiv~qi~qk) reported o~qlL above and beLow the sea ice. This hunter noted that the o~iL was coming up through cracks in the ice. With the exceptions noted, none of these reports were confirmed as coming from the POTOMAC spi~qL~ql by chem~ica~qL anaL~qWsis because the Green~L~anders did not coLLect sampLes. However, for Lack of another source. they ma~qy ver~qg L~qi~qKe~qL~qU have come from this spiLL. WhiLe the evidence (next section) strongL~qU indicates that most of the o~qlL sank, it is apparent that at Least some of the ~oiL remained on the sea surface and may have been advected to distant pL~aces over the next few months. 4.4 V~ertic~aL Movement, The initiaL specific gravit~g (s.g.) of the spiLLed oiL was 0.976 which was a bLend of 55 percent pitch with a s.g. of 1.054 and 45 percent cutter stock with a s.g. of 0.883. As the cutter stock Lost its Light fractions through evaporation, the s.g. of the remaining oiL increased. A computation based on the percent n-~aLkanes remaining (54 percent) In a surface s~amp~Le acquired on August 18 and the dens~qit~g of the orig~in~aL cutter stock (~q0.~8~83) indicated that, after 13 da~qgs of weathering, the s.g. had increased to 1.~q002~. On this date sm~aLL ~qfL~akes of oiL were observed beneath the sea surface. The water coLumn in the area can be considered a two Lager f~Lu~qld system as seen in ~qPigure 4-2 with the top Layer being 10 to 20 m thick. The ~s.g~. of the two Layers were 1.023 and 1.027 respectiveL~qU. The s~.g. of the buL~qk weathered oiL (~q1.002) indicates that it shouLd stiLL have been ~qfLoat~qin~qg and Indeed It was s~ampLed from the surface. It is h~qUpothesized that the skin of the o~ql~qL pancakes was even more depLeted in Light fractions and, through an e~xfoLi~at~qi~on process not fu~qLL~qy understood, separated from the pancakes In fL~a~kes ~an~d sank because the s.g. was greater than 1.023. C~a~LcuL~ations s~qim~qiL~l~ar to those mentioned above indicate that when ~q73 percent of the cutter stock had evaporated, the residue bLend wouL~qd have a s.g. of 1.023 and w~out~qd start to sink. It cannot be assumed that the s~-~qg~- stopped increasing (because weathering stopped) as soon as the o~qiL sank beLow the surface; chem~qic~a~qt ~qan~qa~8ql~0qUsis of the one subsurface (bongo) ~qsampLe (Chapter ~4q5.2.2) indicated that weathering in fact increased through di~qssoLuti~qon of the ~qsp~qarin~4qg~4qL~0qg ~qsoLubL~qe aromatic fractions. It is beL~0qlev~qed that a gre~qpt ~qa~qr~qw~q)~qu~qn~qt of ~qth~qm~q. ~qw~q2~qa~0qth~qar2d ~qo~0qiL ~0 4-5 ~q(67 percent of the 1~q07~,~q0~q0~q0 gaLLons S~qpiL~qLed) eventu~aLL~qU sank to t~qhe bottom in the area where the spiLL was observed. ~qB~eLow 20 m~. sinking whouL~qd have been acceLerated by the greater compressib~qiL~qit~qU Of the ~O~qIL compared with the water and b~qy the ne~arL~qu uniform dens~qIt~qU of the Lower Layer. HI~stor~qIcaL ~qgeostroph~qic current data indicate that the veLocities are Low (2 percent of the surface currents) in this deeper Layer which actuaLL~qU consists of three water masses as noted e~artier~. Thus once the ~O~qIL had sunk beLow 20 m~. it wouLd not tend to move hor~qiz~ontaLL~i~qj during the severaL weeks that it wouLd~~aKe to rea~c~n the bottom about 1000 m beL~ow. ~qAt a mean ~qfaLL veLo~c~qIt~qU of 1 cm/m~qin~, It wou~qLd take Less than ~q50 days for the o~qiL to reach the bottom In most areas of MeLv~qILLe Ba~qy. 4.5 Summar~qU Of ~qO~qIL Movement The sp~qiL~qled ~O~qIL was transported on the sea surface by var~qlabLe winds and a sLow c~qircuL~at~qion to the west or northwest. T~qhe var~qlabLe winds pro~qb~abL~qU caused L~qittLe.or no net movement Wh~qiLe the sLow circuLat~qi~on transported the ~qO~qIL a maximum distance of 40 nmi. The surface ~O~qIL impacted appro~x~qimateL~qg 500 s~qq mi of Me~qLv~qILLe Bag. and a smaLL pLume w~as Left in the wake of the POTOMAC from continued Ligh~-t Leakage whiLe she proceeded to ThuLe. After sufficient evaporation of the cutter stock (about 33 percent of the tot~aL v~oLum~e)~, it is expected that a great amount of the residue sank in the form of sm~aLL (I cm) ~qfL~akes (~smaLL ~qfLa~qkes were observed sinking) to the bottom of MeLv~qiLLe Bag. The water depth in the area of the spiLL was about 1.000 m and the detritaL residue was scattered over a Large area ~q(-5~q0~q0 s~qq m~qi). It Is expected that this petr~oLeum detritus w~qiLL remain ~qInder~qIn~qIteL~qU in t~qhe bottom sediments. 5.0 WEATHERING OF SURFACE OIL Both the Danish and the NOAA teams anaLUzed a time-series of surface oiL ("tar") sampLes (TabLe 5-1). with the objectives of determining-the degradation rate and the uLtimate fate or the spilLed bunker fueL. Bunker fueL is usuaLLy a very heavy materiaL and in this case the fueL was comprised of a bLend of 55 percent-pitch (s.g. = 1.054) and 45 percent "cutter stock" (s.g. - 0.883). The pitch originates from the residuum of the refinery distitLation process and wouLd not be usabLe as ship fueL in its unbLended form. Cutter stock is added to the pitch in order to reduce the viscosity of the bLend sufficientLy to aLLow it to be pumped, after heating, from the ship's fueL tanks to the burning orifices. Cutter stock can originate anywhere in the refining process and wouLd normaLLU be a distILLate materiaL. exhibiting compLete voLatiLization over a discrete temperature range. In the case of the POTOMAC's spiLLed fueL. the cutter stock voLatiLzed compLeteLu over a temperature range of 154 C to 388 C, as shown In Figure 5-1. Because of its distiLLate nature, the cutter stock component of the Bunker fueL wiLL evaporate, partiaLLy or entireLy, on exposure to naturaL weathering processes at the sea surface. In measuring this process for the POTOMAC spiLL, both teams empLoWed a combination of gas chromatography (GC) and gas chromatographg,-,mass spectrometry (GC/MS) in their efforts to address the foLLowing questions, among others: I-How did the composition and density of the surface oiL vary with time? 2-Did the Low temperature and caLm sea state produce sLower evaporation than one wouLd expect In temperate zones and rougher seas? 3-What was the "cutoff point" for the evaporative process in terms of reLative vapor pressures or boiLing points, e.g., did n-aLkanes with bolLing points of up to 250 C exhibit measurabLe evaporative Losses? 300 C? 350 C? 4-Did dissoLution of the Low moLecuLar weight aromatics occur at a measurabLe rate? CouLd it be distinguished from evaporation if Losses 5-1 t-n Table 5-1. Surface oil samples POTOMAC oil spill 5-August 1977 Date Time Station Latitude Longitude Comments 1977 GMT No. N W 7 Aug Thule From holed bunker - (not spilled oil) Retain From Exxon Refinery Aruba, V.I. 10 Aug W1 750 02' 600 50' Taken by J-,JESTWIND personnel 12 Aug W2 750 06' 610 43' Taken by WESTWIND personnel 13 Aug 2330 5461 750 10' 610 23' Pancakes, 25 cm diameter 14 Aug 2000 5462 750 25' 610 44' Oil slick with concentrated pancakes 15 Aug 2300 5463 750 13' 610 23' Pancakes, 15 cm diameter 16 Aug 1130 5464 750 12' 610 30' Pancakes, 15 cm diameter 17 Aug 2100 5466 750 20' 610 12' 18 Aug 0300 5467 750 34' 610 09' 18 Aug 2100 WW 750 18' 610 16' Collected from skimmer 20 Aug 0635 WW-2 750 17' 610 15' Collected from Neuston Tow #2 21 Aug 1600 5475 740 56' 600 12' Taken in an area with 2 cm flakes 18 Sept 750 ? 600 ? Taken by local people in Melville Bay 1 Oct 750 ? 600 ? Taken by local people in Melville Bay 10 90 80 70 60 W Ir W > 50 0 LU a: 40 30 - 2 Ad 10 - 0 L40iIwmdN!!%.N"01f L 150 200 250 300 350 400 TEMPERATURE CELSIUS Figure 5-1. Distillation curve for the cutter stock of the Bunker-C fuel spilled from the USNS POTOMAC. were observed? 5-Did microbial degradation taKe place to ang noticeable extent? Could microbiaL degradation have occurred at all In this relatively "pristine" environment? 6-DId the OIL sinK? Where did it go? 1/0001 The USNS POTOMAC oil spill studies did provide answers to most of these questions. In some instances the answers were surprising, and in all instances the answers were welcome and provided field confirmati.on of one or another model of oil spiLL weathering processes. This chapter describes both the Danish and the NOAA approaches to these questions. ~0 5-4 5.1 AnaL~qyt~qicaL Procedures The ~qN~qOA~qA team entered into a contract with Energy Resources Company, Inc. (ERCO) of Cambridge, Mass., for the ~an~aL~qyses of its POTOMAC sp~qiLL sampLes. The principaL Investigator on the ERCO contract was P. Boehm. and the coauthor of ERCO~'s report to NOAA was D. Feist. GreenLand Fisheries Investigations had arranged with the Danish Water QuaL~it~y Institute and the University of Gothenburg, Sweden, for the ~anaL~Uses of their oiL sampLes. ERCO used simiLar procedures in ~an~aL~qyzing both the seawater extracts (Chapter 7) and the surface oiL samp~qtes~. The Latter were anaL~Uzed by siLic~a geL~,~-aLum~in~a ~C~oLumn chromatography, g~t~as~s cap~ILLar~qy gas chromatography~, mass spectrometry. spectrofLuorometr~qy~. and determination of ~asphaLt~ene content. The si~qtica geL/~aLum~qina c~o~qtumn chromatography procedure was the same for both the surface oiL and the seawater extract sampLes, except that 1.0 g of copper metaL powder was Layered on top of the coLumns used for the surface o~qlL ~sampLes to remove eLementaL suLfur from the ~ci~qL. The s~qiLica g~eL (7.5 g) ~,~,aLumina (~q2~.5 g) coLumn was then eLuted with 18 ML of he~x~ane and 25 mL of benzene to ~qUieLd saturated (f~ql) and unsaturated (f2) fractions of each oiL and water sampLe. The fractions were evaporated b~qy rotary evaporation and an aLiqu ~ot was subsequentL~qU weighed on a Cahn eLectrobaLance. The column chromatography fractions were then characterized by gLass c~apiL~qt~ar~qy gas chromatography using a HewLett P~ac~Kard M~ode~qt 584~q0A gas chrom~atogr~aph equipped with a fLame Ionization detector and Interfaced to a PDP-1~q0 computer. SampLes were anaL~qy~zed on a 15 m SE~-30 coLumn, with temperature programed from 5e to 260 C at 3 C/min. Retention Indexes (~qRI) of ~qIndividu~aL components of each fraction were c~aLcuLated b~qy comparing observed retention times with the retention times of n-aLK~ane~s In a standard mixture. The Danish Water QuaL~qlt~y Institute (Hansen, et ~aL.. 1978) emp~Lo~qyed both SCOT (Support Coated Open TubuL~ar) and pacKed coLumns on a HewLett P~acKard ModeL 5830A and 5840A gas chrom~atogr~aphs, respectiveL~qU. The SCOT coLumn was 56 m Long, p~acKed with OV-1~q01, and was temperature programed from 85 C to 275 C at 4 C~/~Im~qin. None of the surface oi~qt s~amp~qLe~s ~qana~4qt~0qUze~0qdb~0qg Danish researchers were fractionated prior to injection Into the gas chromato~4qgraph~q. 5-5 Selected spitted oil aromatic fractions (f2) were analyzed by ERCO by GC/MS using a Hewlett Packard 5700A chromatograph interfaced to a 5980A mass spectrometer with an electron ionization source and a 5934A data system. The gas chromatograph was equipped with a 15 m SE-30 glass capiLLarW column and was temperature programmed from 80 C to 250 C at 4 C/mIn. Mass chromatograms were reconstructed from mass fragments characteristic of particular compounds, and peaks were electronically in:egrated to yield absolute concentrations. Unfractionated surface stick and selected f2 column chromatography fractions also were characterized by ERCO using spectrofLuorometrW with a Farrand MK-I spectrofLuorometer equipped with corrected emission and excitation modules. Two types of spectra were obtained. Emission spectra from 2eo to 480 nm. with excitation of the sample at 254 nm, were used for "matching" with the Bunker fuel carried by the POTOMAC (Jademac, 1977). Synchronous scans, from 250 to 500 nm emission wavelength and 225 to 475 nm excitation wavelength, were used to examine compositional changes in the fluorescent compounds of the oil (WaKeham, 1977). Sample concentrations used for the fluorescence spectra ranged from 3.1 mg/mL for synchronous scans to 20.0 mg/mL for emission scans. The analytical procedures used by ERCO for the surface oil samples are shown in Figure 5-2. AsphaLtenes were determined by ERCO using ASTM Standard Method D893-G9, except that hexane was substituted for pentane. One gram subsampLes of oil were repetitively dissolved in le mL of hexane and centrifuged at a relative centrifugal force of.600 to 700 g's. Approximately 10 washes were required to completely remove the hexane-soLubLe components of the oil. The residual "asphaLtenell was dried at 110 C and its final weight was expressed as a percentage of the initial weight of the oil. The Gothenburg University (Ahnoff and Eklund, 1979) analyzed oil samples and surface water samp(es suspected of containing oil particles or films. Fluorescence spectra were recorded using an Aminco-Bowman SPF SpectrofLuorometer. For the qualitative comparison of different samples, intensities at three wavelength combinations were measured, 230/340 nm. 270,/3GO.nm, and 310/4oe nm, respectively. The Bunker-C fuel and one surface oil sample were further Investigated by mass fragmentographg, employing glass capillary gas chromatography combined with a computerized mass spectrometer 5-6 SURFACE OIL SLICK @AMPLE WEIGH A SUBSAMPLE; DISSOLVE IN DETERMINE CYCLOHEXANE; ASPHALTENES WEIGH ALIQUOT BY ASTM METHOD DISSOLVE IN ON CAHN BALANCE DICH LOROM ETHANE; WEIGH ALIQUOT ON CAHN BALANCE I TOTAL OIL EXTRACT ASPHALTENES (CYCLOHEXANE) TOTAL OIL EXTRACT (HEXANE) MAKE UP A SOLUTION OF KNOWN CONCEN- TRATION; FINGER- PRINT TOTAL EXTRACT BY EMISSION AND FRACTION ON A SYNCHRONOUS SPEC- SILICA GEU TROFLUORESCENCE ALUMINA COLUMN FRACTION 1 (f,) FRACTION 2 (SATURATES) (AROMATICS) I I ROTARY EVAPORATE WITH N,; ROTARY EVAPORATE WITH N,; WEIGH ALIQUOT ON CAHN WEIGH ALIQUOT ON CAHN BALANCE; FINGERPRINT BY BALANCE; FINGERPRINT BY SE-30 GLASS CAPILLARY SE-30 GLASS CAPILLARY GAS CHROMATOGRAPHY GAS CHROMATOGRAPHY Figure 5-2. Analyt4cal scheme for the surface oil samples used by ERCO for the NOAA samples. ~0 5-7 (Varian Mat 112 - ~Spectr~~~gstem 100 M~S). Mass fragment~gr~~p~M~g was used to determine the concentrations of SeLected aromatic ~qM~qUdrocarb~ons. Due t~qo the high s~en~sitivit~qg of the mass spectrometer when used in the n~onsc~anning mode, the same technique couL~qO be used to an~aL~qgze subsurface water ~sampLes. TechnicaL detaiLs are contained in Chapter 7.2.1.2~, as weLL as an e~xampLe of a mass fr~agmentog~ram (Figure 7-7). 5.2 ResuLts 5.2.1 The Reference Samp~qLe A sampLe of the BunKer-C fueL carried b~qg the ~qUS~qH~qS POTOMAC was suppL~qied ~qb~qu EXXON from the originating refinery. Both groups used the EXXON s~ampLe as a standard. From this sampL~e two fractions were prepared b~qg ERCO~; an rl containing the saturated h~qUdr~ocarbons (aL~qK~anes) and an ~qf2 containing n~aphth~eno~ar~omatic and aromatic h~qgdrocar~qO~ons. These were ~anaL~qUzed b~qg gL~ass capiLLar~qy gas chr~om~atogr~aph~qg~. The chrom~atogr~ams, shown in Figures 5-3 and 5-4. indicate that the f~qt fraction is dominated by a series of norm~at and branched a~qL~qkanes from n~-Cll to n-C3~q0~. with a maximum abundance at n-C~q16 and by a significant proportion of unre~s~oLved components with ~s~qim~qiL~ql~ar ~qbo~qlL~qing range and maximum detector response. The observed n-aL~qRan~e composition is quite sim~qi~qti~ar to an anaLysis of BunKer-C oiL pu~qO~qLi~shed b~qg CL~ar~qK and Brown (~ql~qe77). The f~q2 fraction is dominated by an unresoLved compLe~x mixture (UCM) with onL~qy smaLL re~qLative proportions of re~soLv~ed components. The major res~oLv~e~qd components as determined by GC/MS are meth~qUL- and dim~eth~qy~qL~-naphth~aLenes~, phenanthrene, and meth~qyL and dimethyL phenanthr~anes. A ~sampLe of the Bunker fueL from the damaged tank was coL~qLected by the Danish Laison officer at ThuLe ~sh~ortL~qU after the POTOMAC arrived in port. Det~aiL~s of ex~actL~qU ho~w and where the sampLe was obtained within t~qhe tank are not ~cL~e~ar~. This ~"Thu~qLe ~s~a~m~qpLe~" was ~ana~qL~qgzed toy t~qhe Water Qu~aL~qlt~qg Institute and found NOT to compare with either the EXXON s~ampLe or the s~ampLes co~qtLected from the sea surface of MeLv~qI~qLLe Bag. The difference in composition between the ~q"Thu~2qLe~ql~ql and other oiL samp~8qLes may be due to weathering of the oi~4qL which remained in the tank during the transit from the spiLL site. which is unLi~8qkeL~8qg~q. or. more prob~qabL~4qU, the ~qoiL s~qampLed from the tank was a residue from a previous fu~qe~4qL carried in the tank which had coated the tank sides. 0 0 0 in Figure 5-3.. Gaa chromatogram, of fl (saturate) fraction of the spilled fuel. 0 0- Figure 5-4. Gas chromatogram of f2 (aromatic) fraction of the spilled fuel. 5.2.2 Gas ChromatographW of the Surface OIL SaMPLes The gLass capiLLarg gas chromatograms of the spitted OIL sampLes are quite simiLiar. except for some variabILItU in the reLative abundance of the more voUtLe and soLubLe components. The abundance of the n-aLkanes In the fl fraction for each spitted OIL sampte was normaLized to that of n-C20, aLLowIng one to compare reLative changes in the chemicaL composition of the Spitted Olt 5-9 2.5 o---o BUNKER C FUEL 10 AUGUST 12 AUGUST 2.0 o-- -0 14 AUGUST Uj X- 18 AUGUST 01, Z D I gap 04 (6. *4 M Uj 1.0 Uj cc do 0.5 x 0.0 + 12 14 16 18 20 22 24 26 n-ALKANE CARBON NUMBER Figure 5-5. Relative peak abundance of n-alkanes for spilled oil samples analyzed by ERCO. 2.0 Cx w C20 +-+ BUNKER C FUEL () 1.8 - Z 0----0 10. AUGUST < 1.6 - 0 &------ a 14. AUGUST Z D 1.4 - 20. AUGUST 00 + x 1.2 - X-X 1. OCTOBER < 1.0 - w w 0.8 - 0.6 - w 0.4 - 0.2 0 11 12 13 14 15 16 17 18 19 20 -21 22 23 24 25 26 n - ALKANE CARBON NUMBER Figure 5-6. Relative peak abundance of n-alkanes for spilled oil samples analyzed by Water Quality Institute. ~0 sampLes over time under the assumption that the concentration of n-C~q2~q@ was constant. Since the pr~qim~ar~qg'sh~ort term weathering mechanisms, evaporation and d~qi~ssoLuti~on, pr~qeferent~qiaLL~qU depLete Lower moLecu~qLar weight compounds, norm~aLizat~qion to a reLat~qIveL~qU high M~oLe~cuLar weight compound Is reason~ab~qLe. A graphic representation of the n-~aL~qKane reLat~qive pe~aK abundances r~or SeL~eCte~qd sampLes is given in Figures 5-5 (ERCO) and 5-6 (Water ~qQuaL~qIt~qU Institute). The scatter of the points for n-aLKanes Less than n-C~qI8 Is much greater than for those components above n-C~qI~qS and shows a trend of depLet~qion of Lower moLecuLar weight compounds as function of t~qi me. The observed depLet~qion of the Lower moLecuLar weight n-~aLk~anes with time Is the resuLt of seLect~qive evaporation and d~qisso~qtutlon of the Lower weight ~aLK~an~es with vapor pressures greater ~~q(bo~qiL~qin~qg points Less) than that for n-C~qI7~. The c~oLd surface temperature (3 to 4 C), Light winds ~2qU to 3 m/s). and the r~eLat~qiveL~qy thicK (ca. ~q6 m~qf~n) form of '.the panc~a~qKe~s sh~ouLd tend to s~qL~ow evaporation rates reLat~qive to warm water sp~qtLLs, thus suggesting Losses of onL~qU the Lightest compounds. This was not the case, however, as Figures 5-5 and 5-6 in~qd~qI~c~ate. In fact, n-aL~qKanes with b~o~qi~qLin~qg points~.of up to 300 C (n~-C~qI~q7~; b~oiLin~qg point = 303 C) showed measurabLe Losses after 2 ~L~-~jeeKs of weathering (Figure 5-7). The s~m~a~qLL amounts of res~oLved components in the gas chr~omat~ogr~ams of the f2 fractions of the sp~qiLLe~qd o~qIL samples made ERC~2qO's quantification or ~qin~qd~qiv~qidu~aL components d~qi~qf~qf~qicu~qtt ~qb~qg GC/~qr~qIS~. and mass chrom~atograms were reconstructed t~o.qu~antif~qU individ~quaL compounds. ~qAbso~qtut~e concentrations were caLcuLated bW normaLization to an internaL standard. Five aromatic isomeric groups of compounds. meth~qUL naphthaLenes (M/E 142). d~qimeth~qUL naphth~aLenes (M/~qB 192). phenant~qhrenes ~q(~qM~.~,~,E 178). met~qM~qyL phenanthrenes (M/E 192). and d~qimeth~qgL phenanthrenes ~q(M/E 206) were quantified in the Bun~qKer-C ~qfueL and In t~qhe sp~qILLed o~qIL sampLes co~qt~qLected on August 17 an~qd ~9. The resuLt~s~1p~ shown in Figures 5-8. 5-~q3, and 5-10 and In Ta~qO~qLe 5-2. The August 18 surface sampLe (Figure 5-8) is depLeted In meth~qUL n~aphth~aLenes and d~qimeth~qUL naphthaLenes~. as one ~w~ouLd expect from the Known reLativeL~qg high vapor pressure and soLubiLitW of these compounds. ~qRbs~oLute concentrations or ph~qenanthrenes and meth~8qU~8qL phenanthrenes in the o~4qiL ~qsLic~0qK sampLes appeared to increase sL~4qightL~4qU with time. The evaporation and dissoLution Losses of the Lower bo~8q!Ling compounds prob~qabL~4qU accounts for the apparent increase in the meth~6qU~8qt phenanthrenes~q. POTOMAC fuel (6 August) 10 August ,@@^POT'OMAC #f(uel (6 August) k/ 21 August I October L Figure 5-7. Selected gas chromatograms from surface oil samples analyzed by Water Quality Institute. 5-12 Table 5-2. Concentrations of naphthalenes and phenanthrenes in selected oil samples analyzed by ERCO. Concentrations (,ug/mg oil) M/E Compound group Reference August 18 August 19 fuel slick sample bongo sample (01-32) (01-23) (01-30) 142 Methyl naphthalenes 1.7 0.5 0.0 156 Dimethyl naphthalenes 6.1 3.2 0.9 178 Phenanthrenes 1.7 1.7 1.7 192 Methyl phenanthrenes 3.3 3.8 3.8 206 Dimethyl phenanthrenes 3.5 5.6 4.9 Concentrations reflect the sum of all isomers of the compound group. TI h -SS 40 45 5@1 Figure 5-8. GC/MS total ionization current for the,Bunker-C fuel, f2 (aromatic) fraction. Labels refer to alkyl-napthalenes (N) and phenanthrenes M. 5-13 TI try"' ''Tit' 111261 1 1 'a's' 14101 11 1461 1 1 Vol 1 1 1SIS' 1 1 Figure 5-9. GC/MS total ionization current for the August 18 surface sample, V (aromatic) fraction. TI S 10 is 22 Pr- 11136111-111111461 11 14161 1 1-Tsre-r-r'"s-T s Figure 5-10. GC/MS total ionization current for the August 19 subsurface sample, f2 (aromatic) fraction. The bongo net sampte of oiL (Figure 5-10), coLLected on August 18 during a bioLogicaL tow. shows simiLiar but more extensive Loss of the methUL and dimethyL phenanthrenes. The n-aLKane ratios from the fl fractiaii gas ~0 5~14 chrom~t~gr~m for this sample are s~im~lH~r to those of the ~Rugust 1~6 surface sample. Thus. the more extensive Loss of the substituted naphthalenes in this sampLe is not explained b~qg evaporation alone. Boehm and Feist suggest that. once broken into smaller particles and dispersed into the water Column, the spilled oi~ql weathered more r~apidL~q9 than surface oi~ql. pr~qimar~qiL~qg due to dissolution of the aromatic compounds. 2.5 2.0 ~4qx ERCO ~qx ~0qM ~qx 1.5~, ~qx 0 ~C~L 0 ~qW ~0qz WATER QUALITY INSTITUTE ~qM 1.0 ~4q0~.~q5 0.0 15 0 5 10 NO. OF DAYS AFTER SPILL Figure 5-11. Ratio of n~-Cl7/pristane for the surface oil samples. ~q(*~q) sample from October 1 --56 days after the spill. Because microbial degradation of ~oi~ql results In a depletion of n-aL~qK~ar~es relative to branched ~aLKanes (ZobeLL~. 1569). the ratios of n~-~qC~q17/pr~qistane and ERCO ~4q@~6q@W~2q@ATER Q~4q@UA~qLITY ~4q@IN~qSTI~8q@TU~qTE L n~q-Cle/ph~8qUt~qane can be used to monitor b.~8qioch~qem~4qic~qaL degradation processes ~0q(BLumer and Sass. 1572). The n~q-~8qC~8ql~8q?~q,~q-prist~qan~qe ratio for the spilled o~8qi~8ql samples shows ~qst~qat~2qistic~qaLL~2qg significant fLuctuat~8qion~qs but does not show a consistent trend with time. The Danish SCOT column data show the same con~qsi~qstanc~4qg over almost ~0 2 months. Both sets of data are shown in Figure 5-11. If bl~ochemicaL degradation of the ~spiLLed oiL was extensive, the n~-~qC17~/prist~ane ratio ~w~ouLd show a significant decrease with time. The absence of m~qicrobiaL degradation of the ~o~qiL over severaL weeks after the spiLL is consistent with sLow in~qiti~aL microbi~aL activity because of the Low water temperature and ~a~qLs~o because of the smaLL surface ~are~a/voLume ratio of the ~o~q1L pancakes. Both of these factors inhibit Large-~sc~aLe microbi~aL degradation. It ~qi~s diff~qiCULt to sa~qy how Long the October 1 sampLe was actu~aLL~qU exposed to a potent~qiaLL~qU degrading environment, as we do not know the precise circumstances of its coLLect~qion. Suffice it to sag. though. that no m~qicr~obiaL degradation took pLace for the first 2 weeks after the ~spiLL~. and it Is pr~o~qb~abLe that none took pLace for the ~qinit~qi~aL 4 to 8 weeks. Further discussion of mtcrob~q!aL biodegradation is contained in Chapter 6. 250~q- ~q300 350 400 450 500 ~qz ~U~j ~qz 250 300 350 400 450 500 WAVE LENGTH (NM) Figure 5-12~q. Synchronus fluorescence scan of POTOMAC fuel by ERCO. 5-16 Table 5-3. Concentrations of two-, three-, four-, and five-ring aromatic com- pounds in selected spilled oil samples Sample Concentration Relative peak height Gg/ml) 307-nm 365-nm 405-nm (2-ring) (3- and 4- ring) >5-ring) Bunker C fuel 2 8 102 100 83 10 August 3.9 98 100 83 12 August 3.3 102 100 82 15 August 3.2 107 100 78 18 August 3.5 105 100 77 20 August 3.4 114 100 76 The analysis was done by measuring peak height maxima on a synchronous fluorescence scan from 250- to 500-nm emission with excitation at a wave- length 25 nm shorter. 60 . 307nm (2 RING) x 385nm (3.4 RING) 0 405nm (;-)-S RING) X 50 40 30 20 10 0 0.0 1.0 2.0 3.0 4.0 CONCENTRATION (pg/ml) Figure 5-13. Relationship between peak height and Bunker-C fuel concentration for synchronous fluorescence scans. 5.2.3 SpectrofLuorometrW, NOAA SampLes Unfractionated spiLLed OIL sampLes were dissoLved-in cycLohexane (2 to 20 yg/mt) and characterized by emission and synchronous fLuorescence scans by ERCO as described earLier. As the spiLLed OIL weathered. the emission scans showed a sLight enhancement of the concentration of aromatics fLuorescing at waveLengths shorter than the maximum emission and a diminuation of those fLuorescing at Longer waveLengths. This trend is consisteht with weathering patterns observed by U.S. Coast Guard investigators in oiLs with an emisson maximum between 240 nm and 400 nm (Eastwood, 1977). The synchronous scans (Figure 5-12) are considerabLy more detalLed quantitativeLU thus providing more chemicaL information than singLe waveLength emission scans. One can theoreticaLLy discriminate between one-, two-, three-, four-j and five-ring aromatic compounds based on discrete fLuorescence bands for each compound type (I.LoUd, 1971). Synchronous fLuorescence bands are 280 to 290 nm for benzenes, 310 to 330 nm for naphthaLenes. 340 to 380 nm for three- and four-ring compounds. and >405 nm for five-ring compounds. The reLation between peak height and the Bunker-C OIL concentration Is Linear for the peaks corresponding to two--, three-. four-. and five-ring aromatic compounds over a concentration range of 0 to 4.0 pg/mL of OIL (Figure 5-13). The reLative concentrations of three- and four-ring compounds and five-ring compounds appeared to decrease about 10 and 20 percent faster, respectivety. than two-ring compounds over a period of 2 weeks (TabLe 5-3), a resuLt which appears anomaLous. This trend contradicts the observations by GC/MS (TabLe 5-2) and University of Gothenburg fLuorescence anaLuses (TabLe 5-4) that two-ring aromatics (naphthaLenes) decrease at a greater rate than three-. four-, and five-ringaromatics. In Light of the observation that no bloLogicat degradation took pLace during the same time period (Figure 5-11), these synchronous scan fLuorescence resuLts cannot be expLained away as being due to the formation and dissoLution of poLar-substituted three-, four-, and five-ring aromatics. Hence the quantitative aspects of synchronous scan fLuorescence anaLWses must be considered suspect. 5-18 5.2.4 Spectroftuorometrg and Mass Fragmentography of Danish Samples OIL samples and surface water samples, found to contain oIL In amounts indicating the presence of particles or fILms. were characterized bg spectrofLuorometrg and mass fragmentography. Fluorescence Intensities at the three waveLength combinations, 230/340 mn. 270/360 nm, and 310/400 nm. were compared with the reference oil. Complete agreement wouLd yieLd relative intensities of 1.0, 1.0. and 1.0 respectiveLy. The results are shown in Table 5-4. Table 5-4. Characterization by spectrofl'uorometry of surface samples analyzed by the University of Gothenburg. Sample Relative intensities* 230/340 270/360 310/400 Bunker C fuel 1.0 1.0 1.0 10 August 0.92 0.99 1.0 13 August 0.87 0.96 1.0 14 August 0.75 0.99 1.0 18 August 0.83 1.0 0.99 20 August** 0.74 1.0 0.96 Intensities are given relative to the Bunker C fuel and are normal- ized so that the highest value of the three is set to unity. See also Figure 5-14. A tgpIcaL set of spectra is shown in Figure 5-14. WMiLe intensities at the Longer wavelengths staged aLmost constant during the 15 dags of weathering. a gradual decrease down to about 0.75 relative intensitu Is seen at the shortest wavelength combination of 230/240 nm. This Is interpreted as a Loss of the Low molecular weight components and Is in accord with the more specific mass fragmentographic anaLWses carried out on the reference fueL and one surface oiL sample collected on August 10. Ten aromatic isomeric groups of compounds were quantitated. The concentrations found in the two anaLUzed samples are Listed in Table 5-5. A comparison of these two sampLes is shown graphicaLLy in Figure 5-15. It Is seen that. whiLe the concentrations of dimethUL naphthalenes (M/E 156) and Lower compounds have decreased, the concentrations of aLL other groups Lie verg near those In the BunKer-C fuel. 5-19 ----- ----- -- . ....... ........ -- ------- IWARV ------ -... . . ...... .... 2=4 3or .......... to.: -i- 4- 4 ....... - ------ 7**, N, Figure 5-14. Excitation and emission spectra of a surface oil sample collected at Station 5473 on August 20 generated by University of Gotheaburg. Intensities at 230/340 nm, 270/360 nm and 310/400 run were used for qualitative comparison of the different samples. A good fit between a spiLL sampLe and a reference oiL can be taken as a strong indication of the origin of the spiLLed oiL as has been shown bg GrahL-NieLsen (1976) in connection with another spILL Incident. 5-20 Table 5-5. Concentrations of naphthalenes, phenanthrenes, and dibenzothiophenes in two oil samples analyzed by the University of Gothenburg. Concentrations (pg/mg oil) WE Compound group Reference August 10 fuel slick sample 128 Naphthalene 0.44 0.085 142 Methyl naphthalenes 0.90 0.20 156 Dimethyl naphthalenes 2.90 0.90 170 Trimethyl naphthalenes 1.30 1.25 178 Phenanthrene 0.28 0.25 184 Methyl phenanthrenes 0.51 0.48 192 Dimethyl phenanthrenes 0.80 0.80 198 Dibenzothiophene 0.20 0.21 206 Methyl dibenzothiophenes 0.55 0.50 212 Dimethyl dibenzothiophenes 0.65 0.60 Total 8.09 5.19 % 0.81 0.52 Concentrations are not corrected for a few percent of water present in this sample Naphthalene excluded 5.2.5 AsphaLtenes . AsphaLtenes were measured gravimetricaLLg as the hexane-insotubLe fraction of the oiL by ERCO. in contrast to shipboard estimates of asphaLtenes made by the SOR Team, the Laboratory data show no consistent changes over time. A sLight decrease in the percentage of asphattenes from 15 to 13.9 percent after 7 days fotLowed by a graduaL Increase to 15.5 percent after 16 days were noted (Figure 5-15). No major changes in the asphaLtene content are suggested by the data. AsphaLtenes woutd not be expected to separate out by gravity settLing since their density is approximateLU 1.0 and their surface activity tends to keep them dispersed in the oit (MiLgram. 100% 0 PHENANTHRENES 0 DIBENZOTIORHENES 50- NAPHTALENES I 1 9 lmw 100 150 200 250 Figure 5-15. Comparison of concentrations of selected aromatic hydrocarbons in the surface oil sample collected August 10 with the POTOMAC Bunker-C fuel. Horizontal axis is molecular weight. Vertical axis is the ratio of the sample to the Bunker-C fuel in percent. 25- 20- LL 0 10- 5- L 0 0 5 10 15 40. OF DAYS AFM SPILL Figure 5-16. Change in asphaltene content of surface oil samples as a function of time. ~0 5-22 5~.~q3 Summary F~o~i~, Weathering of Surface ~qO~qIL Gas chromatography, mass spectrometry, and spectr~o~qfLuor~ometr~qg have been used to fingerprint and to investigate chemicaL changes in the sp~qILLed ~O~qIL s~amp~qtes. Both gas Chromatography and spectro~qfLuoromet~r~qg confirmed that aLL of the ~sampLes consisted of ~O~qIL carried b~qy the F~qOT~qOM~qRC. The pr~i'm~ar~qU weathering mechanisms for the first 2 wee~qKs are evaporation and disso~qtut~qi~on~. N-aL~qK~anes with b~o~qiLing points Less than that of n~-~qC17~. and substituted n~aphth~a~qL~enes~, are depLeted b~qy 5~q0 to 10~q0 percent after 15 days of weathering. DissoLution ma~qy pLa~qU a significant roLe In weathering once the ~O~qIL is dispersed In the water ~C~oLumn; a subsurface.s~ampLe coLLected from a bongo net contained ~sign~qi~qficantL~qy ~smaLLer amounts of meth~qU~qL an~qd d~qimet~qn~qu~qt n~aphthaLenes than did a surface sL~qI~c~qK ~s~ampLe c~oLLected at apro~ximateL~qy the same time that contained simiLar amounts of h-aL~qK~ane~s with bo~ql~qLing points simiL~ar to those of the aL~qR~qUL n~qapht~qMa~qtenes. The synchronous scan fLu~qore~sce~nce data on the ~qM~qO~qA~qR s~ampLes ~qfa~qi~qLed to corrober~ate the GC/MS and singLe w~ave~qtength ~qfLuoresc~ence data and hence the quantitative aspects of this anaL~qys~qis method must be considered suspect. MicrobiaL degradation of the o~lL appears to proceed ~sLowL~qy~. If ~at~-a~LL, since the n~-C~ql~q?~/pristane ratio varied onL~qU sL~qIghtL~qU with time. There seems to have been no significant change In ~qt~qhe ~asph~aLt~ene content or t~qhe ~O~qIL s~ampLes 15 days after the ~spiLL. ~qAsph~aLt~enes did not appear to have been preferent~qiaLL~qU ~s~ettLing from the sp~qiLL~ed OIL. The tar fLaKes observed to be ~settLing in the water coLumn ~ma~qy have been ~"s~qLoughing off" of the highL~qU weathered ~I~'s~qKin~i~n that is ~qXnown to form at the alr-o~ql~qL interface of th~qic~qK Lenses of ~O~qIL (p~anca~qKe~s). 6.0 MICROBIOLOGICAL STUDIES Sterile water samples were coLLected by the Danish team and sent to the Water Quality Institute where microbIoLogicaL studies were undertaKen to determine the presence of OIL degrading microorganisms at the spiLL site and their effect on the spilled BunKer-C fueL. Three studies were completed. The first was to determine which microorganisms were present In the area and whether their abundance was increased by the spILLed OIL. The second study was to-determi@,e the rate of degradation of OIL by the naturaL cuLture found at the site while the third was to study the rate of degradation for each component of the natural cuLture. 6.1 Counting And Identification Or Microorganisms Surface water samples coLLected In the spiLL area on August 14 and 21 were used as the basis of this study. The sampLing procedure IS described In Chapter 3. WhiLe it was realized that the Lag time for growth of OIL degrading microorgantsms wouLd not be compLeted during the 1-weeK Interval, an attempt was made to determine whether or not the naturaL populations were enhanced by the spilled OIL. FiVe different counting techniques were used to measure the abundance of microorganisms and SeveraL tests were performed on each sample to isolate and identify the oiL degrading microorganisms. 6.1.1 AnaLWticak Procedures 6.1.1.1 TotaL Count on Agar Plates Total counts were measured.bg culturing the water sampLes on marine agar (Dtfco Bacto marine agar 2216). The composition of this substrate Is given In the Appendix. Sterile phUsioLogIcaL sodium cMLorIde soLution (9 g NaCL disoLved in I L of water) was used for the preparations of the ditutions of the seawater sampLes. I mL of the diluted sampLes was transfered to sterlLe petri dishes; then Liquid marine agar. cooled to 45 C. was added to each dish and incubated for 7 days at 20 C. 6-1 ~0 6.1.1.2 Yeast and Fungi on Agar ~qP~qtates Counts ~o~qf yeast and fungi were performed using marine agar as the substrate. Bacteria were inhibited b~qy the addition of ~qStreptom~qycine and Tetr~ac~qUcL~qine (both at equ~aL concentrations of 50 ug/mL) and the pH was adjusted to 5.0. The substrate and incubation were ident~qicaL to that used for the TotaL Count described above. 6.1.1.3 ~qO~qIL Degrading Bacteria on Agar PL~ates Counts of oi~qL degrading bacteria were measured an CoLweLL~'s MPN-me~qd~qlum soLidified b~qy the addition of 1.5 percent agar. CoLweL~qt's medium was modified b~qy reduction of the amount of MgS~q04,7H~q20 to avoid precipitation of phosphate. The composition of the actuaL substrate used is contained in the Appendix. She~q[L V~qitrea o~qlL 27 was used as the s~qingLe carbon source for these cuLtures (~q0.5 percent on a v~oLumetric basis ~q)~. SheL~qL~. Vitrea o~qlL 27 is free from detergents and has a composition of 7~q0 percent aLKanes~. 24 percent c~qycLoaLKanes~.~.and ~q6 percent aromatics. A ~spec~qi~aL technique as described by Baruah et aL. (1967) was used to Insure that the o~qiL was h~om~ogene~ousL~qu incorporated into the substrate. This technique caLLed for ~qd~qisso~qLv~qing 5 g of the o~qiL in 1~q5 mL of eth~qWL ether and then carefuLL~qU mixing with 5 g of ~s~qIL~qIc~a (Cab-~qO-S~2qM In a m~orter. The ether was then evaporated In a rotary evaporator and the remaining powder (si~qLic~a and oiL) was ea~s~qiL~qU distributed homogene~ousL~qU on the substrate. Fung~qi~z~one (at the rate of 10 ~qpg/mL) was added to suppress yeast and fungi growth. Base agar (without the oiL) was produced and used as controL. Both o~qiLed and unol~qled p~qt~ates were Incubated at 20 C and counted after 14 and 2~qS days. ~q6.1.1~.4 ~qO~qIL Degrading Yeast an~qd Fungi on Agar PLat~es Counts of oiL degrading yeast and fungi were made using the same substrate as for bacteria described above except that strept~om~qU~c~qlne and t~qetrac~qUcL~qlne (50 ~qpg/mL each) were added to inhibit the bacteria and the pH was adjusted to 5.0. As with the bacteria counts. SheLL Vitr~ea o~qiL 27 was added as the singLe source (0.5 percent b~qy voLume) and incubation was at 20 C. Counts were made after 14 and 28 days. ~0 ~6.1.1.5 ~qO~qI~qL Degrading Microorganisms b~qy Most ~qPr~obabLe Numbers Counts of ~qO~qIL degrading microorganisms b~qy Most Pro~qbabLe Numbers ~q(~qM~qPN method) were made using two mediums. The two mediums are described b~qy Bunch and HarL~and (1976) and M~qiLLs, Brezi~qL~, and CoLweLL (1978) and are contained In the Appendix. The amount of MgS~q04~.H~q2O in CoLweLL~'s medium was reduced as mentioned ~earLi~er~. Portions of these mediums (5 mL) were distributed Into screw cap tubes. After ~steriLiz~ati~on, 50 uL of o~qlL (SheLL V~qitre~a o~qlL 27) or paraffins were added to each tube. The substrates were tested b~qy the f~o~qLLowing petr~oLeum degrading microorganisms: N~oc~qar~qd~qia~, Pseu~qUomon~as~, ~Arthr~ob~acter, Stre~qv~@tomuces, Gra~i~oh~qiLum~. Pent~amuces, and Candid~a. Both were found to be su~qlt~abLe for MPN Investigations. Of the two. t~qhe CoLweLL medium was preferred. In ~aLL t~qhe ~qM~qPN Investigations, tr~qipL~qicate tubes were pLaced In a rotary shaker at 100 rpm during incubation at 15 C. The tubes were read wee~qk~qL~qg for six wee~qK~s. ~6.1.2 Identification of Iso~qt~ated ~qO~qI~qL Degrading Bacteria ~qQuaL~qitat~qive examinations of the ~qIsoL~ated bacteria were carried out for identification using the ~qf~oLLow~qing tests: Haem~oL~qU~s~qts, pigmentation, c~qWtochrome o~x~qU~qd~as~e, c~at~aL~ase, twe~en 20. tw~ee~qM 80, geLatIne, ~qO/F test, Simmon's c~qitrate, m~otiL~qlt~qU (S.I.M.)~, ~qIndoLe (S.~qI.M.), H2~q3 ~q(~q5.1.M.~q), I percent tr~qgpt~one, I percent trypt~on~e with 4 percent ~qNaCL. I percent tr~qUpt~one with 7 percent NaCL, V.P. broth, ~argin~qine, ~qt~qys~qine~, ur~ea. nitrate. ar~ab~qinose, ceLLoblo~se, Lactose, sucrose, gL~L~qjcer~oL~, starch, ~x~qU~qLose, ch~qit~qin, veaL Infusion broth with I percent NaC~q[ at ~q5 ~qC, 1~q0 C~, 15 C. and 30 C~. antibi~otlca test (pt~evidine), and gram staining. ~qA~qL~qL the reactions were read da~qiL~qU over a period of I to 7 days. UnLess stated above, ~aLL the incubation temperatures were at 20 C. ~6.1.3 ~qResu~qLt~s The resu~qtts from the microbioLog~qicaL examinations are presented In TabLe 6-1 for aLL five counting methods. In ~aLL cases and for aLL sa~mpLe~s the observed counts are ~smaLL. The concentrations of ~O~qIL degrading micro~org~an~qism~e estimated by the MPN method are Less than 15~qe~qO per Liter, which corresponds to Less than I percent of the tot~qaL count. As indicated by the vaLues from Station 5474. the tot~qaL count as weL~2qL as the numbers of oiL degrading bacteria do not appear to be a function of depth. G-4 Table 6-1. Results of enumerations from microbiological examinations of water samples. Number of Number of Number of Number of Station Depth Date Total oil oil oil bacteria of degrading degrading degrading on base collec- count micro- bacteria yeast and agar tion organisms on agar fungi on plates (MPN-method) plates agar plates no. M day/mo. per ml per liter per liter per liter per liter 5462 0.0 14/8 50 < 300 < 5 < 5 < 5 5462 0.0 14/8 2 < 300 < 5 < 5 < 5 5466 17/8 560 700 85 5468 0.1 18/8 5 < 300 30 < 5 55 5474 0.0 21/8 4 < 300 < 5 < 5 < 5 5474 0.2 21/8 2200 < 300 < 5 < 5 5 5474 1 21/8 370 700 10 < 5 10 5474 3 21/8 3700 < 300 5 < 5 5 5474 5 21/8 240 < 300 < 5 10 < 5 5474 10 21/8 10 1500 < 5 5 10 5474 30 21/8 2300 1500 205 15 340 5475 0.0 21/8 14 400 30 Water surface with visible layer of oil No examination The number of oiL degrading bacteria an oiled agar plates was the same order of magnitude as the number of bacteria on the unolLed plates. This result corresponds to other studies conducted on water samples coLLected from Greenland waters and indicates that the MPH method must be preferred to the agar plate method. ~0 ~6-5 An increase In either the t~otaL count or the number was not found in the sampLes taken on August 21 reLat~qive to the vaLue~s from the s~ampLes taken on August 14. This indicated that the sp~qILL~e~qd ~o~qiL was pr~obab~qt~qy not s~qign~qir~qicantL~qy biodegraded. This resuLt confirms the findings from the gas chromatography performed.~on the surface ~o~qIL saM~qpLes (Chapter 5.2.2). The resuLt~qs of the identification tests for aLL the ~qJ~D~acterla ~qIs~oLat~ed are presented in Ta~qo~qte 6-2. Tentative Identification of the isoLated strains are as ~qfoLL~o~ws: I-Strain ~q80~q0 seems to be the genus ~qP~qseud~omonas. ~q2-Strains 801~, and ~q8~q0~8q4~, seem to be ~qZa~qt~qe~qj~q:~qp bact~er~ica , but are unt~qgp~qic~aL I in the ~qcataLase test.' 3-Stra~qins 802~, 803. and 804 seem to be the genus Corune~q0~acter~qlu according to tentative Investigations performed ~qOU Dr. R.~qR~ ~Cn~qLweLL. The reactions Indicate that these strains ~aLL couLd be ~qIndenti~qfied as the species C~orun~eb~acter~qtu Pseu~qdod~qi~p~qhth~qer~qi~qae. 4-Stra~qin ~q812 does not seem to fit into an~qy Known t~a~xonom~qicaL group. ~q5-Str~a~qin ~q812a ~c~ouLd not be pLaced in a taxonom~qic~aL group based on the tests conducted. It shouLd be emphasized that none of the is~oLate~qd strains couLd be identified as either fish or human pathogenic bacteria. 6.2 Degradation Rates B~qy NaturaL CuLtures Of Microorganisms Three~*experiments were performed to determine the rate of degradation of ~~ql~qL b~qy the natur~aL ~CuLtures of microorganisms found In the MeLv~qILL~e Bag area. The experiments were started on August 27, 1977 using seawater sampLed ~steri~qt~aL~qU at Station 5475 c~oLLected on August 21 and a surface ~O~qIL ~sampLe co~qLLected on August 10. The first experiment was intended to determine the rate of oiL degradation using the sampLes as ~CoLLected. Vie second was a controL experiment mea~s~qWrin~qg the change of the o~qiL In the absence of microbi~oLo~qg~qicaL activity (contr~oL). The.th~qlrd experiment was to determine the rate of degradation of t~qhe s~ampLes with t~qhe addition of nutrients. 6.2.1 Procedures For aLL the experiments. ~6q50 m~6qL of the water sampLe was mixed with 0.250 g of oiL in a c~qon~6qicaL ~2qfLasK~q. To prevent bi~0qoL~qog~2qicaL activity for t~8qhe second experiment. 0.25 percent ~4qf~qormaL~8qdeh~8qWde, ~4qb~8qg vo~4qL~qume, was added. For the third experiment I g/L of K2HPO4 and 2 g/L NH4N~2qO3 were added as nutrients. MuLtipLe 6-6 Table 6-2. Biochemical examinations of strains isolated from substrates using oil as the single carbon source. All reactions read within 7 days. Strain No. Tests 800 800 1 801 2 802 803 804 812 812a Haemolysis + - - - - + - Pigmentation Cytochrome oxydase + + Catalase + - + + + Tween 20 + - + + + + + Tween 80 + - + + + + + Gelatine + - O/F test Ox F F gl- gl- gl- gl- gl- Simmon's citrate + + motility (SIM) Indol (SIM) HI)S (SIM) 1% tryptone + + + + + + + 1% tryptone + 4% NACL + + + + + + 1% tryptone + 7% NACL (+) (+) (+) + V.P. M M M M Arginine Lysine UrRa + + + + + + NO-' M + + + + + M + Arabinose M - M M M M M Cellobiose M - M M M M M Lactose M + M M M M M Sucrose M M M M M M Glycerol + Starch M M M M M M Xylose Chitin Veal infusion broth + + 1'/. NACL at 50C Veal infusion broth W + 1% NACL at 100C Veal infusion broth + M M M M M + M + 17. NACL at 150C Veal infusion broth + + + + + + + + + 1% NACL at 300C Antibiotica test - - + + + + + W (Pteredine) Gram 9- 9- 9- 9+ gr-F gr-F 9- gr+ rod rod rod rod rod rod rod rod M = test not carried out Ox = oxidative degradation F fermentative gl = glucose negative M = weak reaction 6-7 flasks were prepared for each experiment; these were maintained at 15 C and carefully shaken (100 rpm) for the 8-weeK duration of the experiment. At weekly intervals chemical and microbiological examinations were performed on one of the flasks for each experiment. For the chemical examinations, the total mixture of oil and water from one flask was extracted three times with CCL4. The combined extract was diluted to 25 mL with CCL4. A few microliters were then injected into a gas chromatographic coLumn. The gas chromotography Was performed using a 5COT column as described in Chapter 7.2.1.2. The microbioLogicaL examination were performed by the MPH method as described in Chapter G.I.I. 6.2.2 ResuLts The results from the gas chromatographic analyses on the SCOT column are presented in Table 6-3. The relative amounts of n-C17/pristane and n-CIGxphytane were determined and are shown in these tables. As previously mentioned. the n-aLKanes such as C17 and CIS are degraded faster than pristane and phytane and thus their ratios can be used as indicators of biodegradation. Some of the chromatograms are included as Figures 6-1 to 6-3. Table 6-3. Relative amounts of n-C 17 /pristane and n-C 18 /phytane determined by GC analyses of natural cultures. Date Incubation Experiment 1 (1) Experiment 11 (2) Experiment 111 (3) time C /Pri C /Phy C /Pri C /Phy C /Pri C /Phy 1977 (weeks) 17 18 17 18 17 18 Sept 14 211 1.45 1.78 1.27 1.77 0.62 0.85 Sept 21 31-2 1.28 2.12 - - - - Se-3t 28 02- 1.33 1.85 1.39 1.80 0.41 0.49 Oct 5 51-2 1.39 1.72 - - - - Oct 12 6;@ 1.45 1.74 - - - - Oct 26 81-2 1.29 1.67 1.36 1.76 0.14 0.29 (1) = Water and oil (2) = Water, oil, and formaldehyde (control) (3) = Water, oil, and nutrients 2 weeks 8 weeks Figure 6-1. Gas chromatograms of oil degraded by natural cultures. From Table 6-3 it is seen that the n-C17/pristane and n-CIS/pMgtane ratios do not indicate degradation of the oil for the first two experiments where oil and water and then oil. water. and formaLdehUde were cuLtured. in contrast, the third experiment with oil, water. and nutrients show a remarkable degradation of the oil after 2.5 weeks. The oil degradation continued during the incubation period. The resuLts of the micronioLogicaL examination are presented In Table 6-4. These results aLso indicate a much faster propagation of the oil degrading microorganisms in the experiments with the added nutrients. The 6-9 2 weeks X 8 weeks Figure 6-2. Gas chromatograms from the second oil degradation experiment (control). first experiment indicates that the propagation of OIL degrading microorganisms without added nutrients Is a verg sLow process. The propagation rates In the MeLviLLe BaU area where the SpILL occurred WOULd have been even sLower as the ambient temperature there was about 4 C rather than the 15 C used In the experiments. 6-10 2 weeks 413 4 weeks 8 weeks Figure 6-3. Gas chromatograms from the third oil degradation experiment which had nutrients added. Table 6-4. Growth of natural seawater cultures as a function of time. Incubation Experiment 1 (1) Experiment 11 (2) Experiment 111 (3) time A B A B A B (weeks) 1 15-,800 - - 14,800 - 2 720,000 300 - <300 4.5xlO 6 460,000 3 4.1xlO 6 900 120,000 3,900 17.x1O 6 2.lxlO6 6 6 6 6 4 19.X10 110,000 1.2xlO 24,000 21.x1O 2.4xlO 6 22.xlO 6 460,000 6.3x106 46,000 24.xlO 6 24.xlO6 8 25.xlO 6 9.3x1O 6 8.8x1O6 210,000 26.xlO 6 1.lxlO9 A= Total count per ml B= Oil degrading microorganisms per liter (NPN method) (1)= Water and oil (2)= Water, oil, and formaldehyde (control) (3)= Water, oil, and nutrients 6.3 Degradation Of OIL BU IsoLated MonocuLtures G.3.1 Procedure ALL the oiL degrading strains isoLated from the naturaL cuLtures (TabLe G-2) were tested for the abiLitU to degrade the foLtowing mixtures of hydrocarbons: I-Mixture of cycLopentane, cycLohexane. and cUcLoheptane (cUcLoaLKanes) 2-Mixture of benzene. naphthaLene, and phenanthrene (aromatics) 3-Paraffins (aLkanes) 4-SheLL Vitrea oiL 27 (aLkanes, cUcLoaLKanes, and aromatics) These investigations were carried out in screwcap tubes. The CoLweLL medium with reduced MgSO4,7H2O content was used as the medium with a I percent hydrocarbon concentration (50 ;jL hydrocarbon with 5 mL of medium in each tube). The tubes were pLaced in a rotary shaker (100 rpm) during the incubations at 5, 10. and 15 C. The reactions were foLLowed weekLU for 6 weeks. 6-12 Table 6-5. Growth of isolated oil degrading strains in various petroleum hydrocarbon mixtures as functions of time and temperature. Times are in weeks. Bacterial 50C 100C 150C strain 2 3 6 2 3 6 2 3 6 ALKANES 800 - - - - - - X X 8011 8012 - - 802 - - X X X X X X 803 - - X* X X 804 - - X* X X 812 - X X X X X X 812a - CYCLOALKANES 800 - - - - - - - - 8011 - - - - - - - - 8012 - - - - - - - - - 802 - - - - - - - - - 803 - - - - - + - - - 804 - - - - - + - - - 812 - - - - - 812a - - - - - AROMATICS 800 - - - - - 801, - - - - - 8012 - - - - - 802 - - - 803 - - - 804, 812 812a SHELL VITREA OIL 27 (ALKANES + CYCLOALKANES + AROMATICS) 800 - - - - - X X X 8011 - - - - - + X X X 8012 - - - - - + 802 - - - - - X X* X X 803 - - - - - X* X X 804 - - - - - X X X 812 - - - - X X X 812a - - - - = no growth + = doubtful growth X = visual growth X* = visual growth after 1 week ~0 6~13 6.3.2 Re~uLts ~esu~qLt~s of the studies on m~onocuLtures are presented In T~a~qb~qte 6-5 ~qfor each hydrocarbon mixture. Strains 802, 803, and 804 appear to be very active o~qiL degrading strains, especi~aLL~qU in the biodegradation of paraffins and SheLL V~qitrea o~qlL 27. After on~qL~qU I week at 15 C~. these strains grow in mediums with o~qi~qL as sin~qgLe carbon source. ~qOnL~qy two strains, 802 and 812, degraded o~qiL (paraffins) at 5 C after 6 weeks. In most cases the Lag phase at tow temperatures seems to be more t~qMan 6 weeks for the monocuLture~qs and depends on the species and composition of o~qlL. However, in the n~atur~aL environment the Lag phase c~ouLd be quite different from that determined from the monocuLtur~qes in the Laboratory, because the toxic constituents norm~aLL~qU produced couLd be removed from the oiL/w~ater interface at the sea. 6.4 Summary Of Biodegradation Studies The number of microorganisms found In MeLv~qIL~qte Bay water was sm~aLL~. and oiL degrading microorganisms constituted Less than I percent of the t~ot~aL amount. Eight different micr~obiaL strains were ~qIsoLated In the water sampLes using oiL as the onL~qU carbon source. No Increase In tot~aL num~qoer of the o~qlL degrading microorganisms was found In sampLes c~oLLected 16 days after sp~qI~qLL as compared with sam~qpLes c~qoLLected 8 days after the sp~qI~qLL. ALL the mi~cr~ob~qloL~ogi~caL examinations snow that in situ biodegradation w~ou~qtd have been very stow. The resu~qLt~s from the degradation studies with seawater and o~qlL show that, unLess nutrients are added. o~qlL degradation Is a very stow process. The gas chromatographic ana~qt~qyses dld~*not indicate ~oi~qL degradation during an 8 week period, and the m~qicro~qb~q!~o~qLo~qg~qicaL anaL~qgses showed a stow propagation of oiL degrading microorganisms during the same period. This seems to indicate a Lag period of more than ~8q8 weeks and, consequent~4qL~2qW~q, a stow degradation process. ~0 6~14 The addition of nutrients to the ~~IL and water Increased the OIL degradation ~strongL~qg. Both the gas chromatography and the M~qlCr~O~q0I~OL~O~qgicaL ~anaL~qyses show that. after I to~-2 weeks, a high o~qiL degrading activity was ~aLread~qg present. In this case, the Lag period was found to ~qbe Less than 2 weeKs. The resuLt~s from m~o~qnocu~qtture experiments showed that onLy two strains, 802 and 812. w~ou~qLd degrade paraffins at 5 C after 6 weeKs incubation. ~0 7.0 ACCOMMODATION OF OIL INTO THE WATER COLUMN Subsurface water sampLes were coLLected after the POTOMAC spiLL to determine the amount and composition of o~qiL accommodated into the water coLumn. These water ~sampLes were coLLected b~qy both the Danish and N~O~A~R teams, the former using a-brown bottLe In a ~sta~qinLess steeL frame that was opened via a messenger puncturing a TefLon seat, and the Latter using a Gener~aL Oce~anics Inc. "SteriLe Bag" sampLer. ~qAnaL~qy~se~s of the ~sampLe~s were carried out using U~qV-fLuorescence spectrometry (U~qV). g~qas chromatography (GC), and gas chrom~atograph~qg/m~ass spectrometry (GC~.~/MS), by Ahnof~f and EkLund (1978) for the Danish s~am~qpLes and b~qy ERCO (Boehm and Feist, 1978) ~qfor the N~qO~qAA ~samp~qtes. 7.1 SampLi~n~qg Procedures 7.1.1 The Danish SampLes The Danish water sampLes were acquired with a noncommerciaL sampLer. This device was actu~aLL~qy constructed and suppLied b~qy M. Ahnoff and G. E~qkLund of the Department of AnaL~qWticaL Chemistry~, University of Gothenburg, Sweden (~qAhnoff et a~t., 19~q74). The sampLer consisted of a I-Liter, wide-neck brown bottLe heLd in a st~a~qin~qLes~s steeL frame. The bott~qte was seated with a Te~F~qton sheet pL~aced under the screwcap. After Lowering the s~ampLer to the desired depth. a messenger was used to operate a mechanism which punched a hoLe In the TefLon sheet through a hoLe in the screwcap. The sampLer was retrieved without recLosing the opening. Prior to the cruise. ~aLL s~ampLin~qg b~ottLe~s were washed with tap water. di~stiLLed acetone, and purified n-he~x~ane unt~qiL the he~xane showed no traces of contamination using uv-spectrofLuorometr~g. During the cruise in Me~qLviLLe Ba~qy, bottLes were rinsed with purified n-hexane between sampLing~s~, but there was no opportunity to controL the bottLes~. Throughout the sampLing program, dupLic~qate sampLe~qs were taken on separate Lowerin~4qgs for separate ~qanaL~4qUsis~q. The sampLes were extracted In the s~qampL~4qing bottLe b~8qy adding 10 mL of n-he~qxane and a magnetic stirring bar, stirring for 45 minutes. and then transferring 2 to 4 mL of the organic phase to test tubes se~qaLed with Te~0qrL~qon Lined ~qscrewc~qaps. ALL the test tubes had been quaL~0qit~0qy controLLed b~8qy ~0q7~q-~0q1 7-2 spectrofLurometrU prior to use. Sample extracts acquired from Station 5471 and subsequent stations were stored in glass vials supplied by NOAR. These samples were used for analyses by UV-spectrofLuorometrg only. 7.1.2 The NOAA Samples The NOAA team used a commercial sampler made by General Oceanics,'Inc. of Miami Florida. This sampler, called a "Sterile Bag Sampler", consists of a pair of hinged metal plates that, when triggered by a messenger, open a sterile polyethylene bag. The bags are used only once and, after being opened at depth, are resealed after fitting. When fitted and reseaLed. the bags contain between 0.8 and 2 Liters of water, averaging about 1.5 Liters. Each water sample was taken as a "double replicate", in that each depth was sampled twice (on separate towerings) and two 500 mL aLiquots were taken from each bag. Each aliquot was extracted In a separatory funnel with 10 mL of UV-spectroquaLity hexane. No filtration of the samples was attempted before extraction. The extracts were stored in prerinsed gL-ass vials seated with aLuminum foit. and screwcaps. Considerable difficulty was experienced because of the closures on the HOAA samples. For those samples which were not seaL6d tightly. the extract suffered from either spillage or evaporation causing the Loss of some samples. Other vials which had been seated too tightly suffered from contamination when the aluminum foil tore and allowed the solvent to extract the waxes in the normal cap Liner. Because of the difficulties experienced, the NOAA team recommends that no substitutes for Teflon cap Liners be used for any extract containers In the future. Subsequent Laboratory experiments (Boehm and Feist, 1978a) indicated that the polyethylene bags adsorb oil from the water sample and Leach pLastisizers into the sample. Indicat-ions are that the bags are inappropriate for water samples with oil concentrations Less than 100 ppb or when the sample is held in the bag for much more than 15 minutes. ~0 7-3 ~q7.2 ~qAn~a~qL~qgti~c~aL Methods The water sampLe~s coLLect~ed in MeL~ViLL~e Ba~qy were ~an~aL~qUzed b~qy UV-~spectrofLuorometr~qg (U~qV)~. gas chromatography (GC), and gas chromatography mass spectrometry (GC/MS). ~q7.2.~q1 Danish SampLes According to Ahnoff and E~qkLund (197~q9), the reasons for choosing the UV technique for determination of petroLeum hydrocarbons are that 1) the sensitivity Is sufficient for measuring very Low concentrations, down to ~"natura~qL~l~' background ~qLeve~qts and 2) the technique Is fast so that ~a~qL~qL samp~qLes can be an~aL~qUze~qd within a few days after their arrivaL at the Labor~ator~qW. GC/M~qS, using a gLass c~apiL~qLary co~qtumn~. was empLo~qged for the ~qfo~qLLow~qing reasons: 1) the high ~se~qtect~qivit~qU of the technique permits an unambiguous determination of singL~e petroLeum hydrocarbons; ~q2) the ~qInstrumentaL ses~qit~qiv~qi~qt~qy, is sufficient to measure concentrations down to ~"natur~a~qL~l~' b~acKground LeveLs~; and ~q3) compounds to be measured can be ~seLected. By measuring aromatic hydrocarbons. high seLectiv~qit~qU can be obtained reL~ative to blogenic hydrocarbons found n~aturaL~qL~qU In water. The procedures had been designed to be as simpL~e as poss~qIbLe to obtain Low contamination of the ~s~ampLes~. For ~exampLe, the number of transfers of the sampL~e between different vi~aLs was Kept at a minimum. to minimize exposure to surfaces and atmospheres that couLd cause contamination. GL~assw~are and soLvents were checked before use b~qy UV~-s~qpecro~qfLuorometr~qic measurements an b~qtan~qks~. ~q7.2.1.1 UV~-~-SpectrofLu~orometr~qy ~qO~qIL fLuoresces when exposed to U~qV-L~qIg~qMt. ~qF~qLu~or~e~scence Is the emission of Light b~qy prev~qiousL~qU excited eLectrons. ~qFLuorescenc~e In petroLeum is dominated by aromatic m~oLecuLes and is extrem~eL~qy compLe~x because of the OIL's compLexit~qU. A COM~8qPLet~qe characterization of an OIL ~0qO~8qU spectro~0qfLuorome~0qtr~8qg wou~0qLd ~4qIncLude registration of ~8qfLuore~qsce~qnce intensities at a Large number of e~qxcit~qation/~qemi~qssion-waveLength combinations and caLcuL~qation of a three dimensionaL map of corrected fLuorescence intensities. Such a procedure ~2qUieLds more information than is necessary when the object is to screen LeveLs ~0 7-4 of ~O~qIL in a Large number of s~amp~qtes. It Is time-consuming, requires special equipment, and cannot ~qbe emp~qto~qyed on samples containing OIL In trace a~m~oUnts. On the other hand. a procedure consisting of measuring the fluorescence ~qinten~sit~qU at a s~qin~qgLe excitation/emission combination reduces the information LeveL s~qi~qgnificantL~qg and makes quantitative evaluation difficult. A procedure which empLo~qUs more than one excitatlon/em~qission combination Is rapid and gives apprec~qiabL~qU more Information than a sin~qgLe point measurement. Measurements at 230/340, 270/360, and 310/400 nanometers (nm) were empLo~qged b~qU the Swedish chemists. The qu~aL~qltat~qive information obtained from this procedure can be used to evaLuate each measurement for quantitative determinations. The combination of measurements should Indicate whether the fLuorescence~.character~qistics of the sa~mpLe appear re~ason~abLe or if contamination has occurred. Intensities at the different w~aveLength combinations were compared with corresponding intensities of a standard soLution made from the reference OIL. A bLan~qK correction was made for the contamination found In the solvent used for extraction. 7.2.1.2 Gas Chromato~qgr~ap~qM~qU/Mass ~qSpectrometr~qU In this technique~j g~qt~ass-cap~qiL~qtar~qy gas chromatography is used to separate voLatiLe petroLeum h~qUdroc~ar~qbons which are then ~SeLectIveL~qU detected with a mass spectrometer. The technique is sim~qiL~qiar to that described b~qg GrahL-~qNieLs~on (1976) aLthough he empLo~qWed a quadrUPoLe Instrument. Masses to be monitored were those of naphthaLenes, ph~enanthrene~s~, and d~qibenzothiophene~s. These aromatic h~qUdrocarb~ons have Low enough mo~qtecuLar weights to be s~oLubLe In seawater but ~suf~qficientL~qU high m~oLe~cuL~ar weights so as not to read~qiL~qU evaporate. These compounds are known to be b~qi~c~qLo~qg~qic~aL~qt~qu active, as the~qg are eas~qIL~qW absorbed ~qb~qU Living organisms where t~qMe~qW exhibit toxic and other detrImentaL effects. Two m~qILL~qiL~qiter aL~qIquo~qt~s of hexane extracts of water samp~qLes were concentrated to about 50 ~qpL under a stream of purified nitrogen. Five n~qano~2qgrams of 1-bromon~qa~0qPht~4qMaLene were added to each extract to serve as an internaL standard. The bacKground LeveLs of the se~4qLected aromatic h~8qgdrocarb~qons in-the n-hexane used for extraction were determined from a ~2q1~0q0 ML ~qsampLe concentrated to 50 ~4qJ~qJ~0qL (TabLe ~4q7-1). ~0 7-5 Table 7-l.--Background concentrations in Danish water samples due to trace impurities in the solvent used for extraction. Compound nanogram per liter Naphthalene 1.3 Methyl naphthalenes 1.0 Dimethyl naphthalenes 0.30 Trimethyl naphthalenes 0.15 Phenanthrene 0.21 Methyl phenanthrenes 0.24 Dimethyl phenanthrenes 0.20 Dibenzotiophene 0.05 Methyl dibenzotiophenes 0.06 Dimethyl dibenzotiophenes <0~.03 Total (naphthalene excluded) 2.3 A combination of a CarLo Erb~a Fr~act~ovap 2101 gas chrom~at~ograph and a Varian MAT 112 mass spectrometer aL~ong with a Spectr~os~qUstem 100 ~qMS was used. the gas chromatogr~aph was equipped with a sp~8qUtL~e~ss Injector. The extracts were ~an~aL~qUzed on a 4~q0~-m b~qg 0.33-mm (inside-diameter) OV~-101 gL~ass cap~qi~qtL~ar~qg ~coLumn. The foLLowing conditions were chosen: injector bLocK at 250 C. the oven temperature programmed from 1~q00 C to 240 ~qC at 4.5 degre~e~s/~mInut~e after an init~qI~aL isotherm~a~qt period of 5 min at 25 C~. and the carrier gas ~q@He) at a ~qfLow rate of 2 mL/min at ambient temperature. Two m~qicr~oL~qiter~s of the concentrated extracts were injected without stream ~spL~qitt~qing with a spLi~qtLes~s period or ~q6~q0 The amount of the seLect~ed aromatic h~qUdroc~arbons was quantitated re~qL~at~qi~ve to a standard mixtut~-~6qZ containing 0.1 ppm n~ap~qMthaLene, phen~anthrene~q. dibenzothioph~qene~q, and 1-bromonaphthaLene~q. For the quantitat~0qion of the aL~8qN~8qUL~qat~qed n~qaphth~qaL~qene~qs~q, phen~qanthr~qenes, and ~0qd~4ql~0qb~qenzothi~qophenes, the t~qot~qaL ton current per m~qo~8qL~qe ~qwas assumed to be the same for these compounds as for their nonaLk~8qgL~qated h~qom~qo~4qt~qO~8qgU~qeS. From mass ~qsp~qectr~qaL data on pure substances, It was known how Large a fraction of the tot~qaL ion current ~qwas made ~qup b~8qg the 7-G measured fragment Ion. Thus the amount.of each setected aromatic hydrocarbon was caLcuLated. The sum totaL of seLected aromatics was atso caLcuLated. An equivaLent amount of reference oit was estimated by muLtiptWing.these vaLues by a factor obtained from measurements on reference olL sampLes. This factor expresses the ratio between totaL weight and weight of the seLected aromatics in the reference oit. It must be pointed out that, while the vaLues for the seLected aromatics are true vaLues, the equivaLent amount of reference oiL is a theoreticaL vaLue that may produce deviations between the totaL amount of petroLeum hydrocarbons reported and the amount actuaLLW present in the water sampLes. The precision in mass spectrometric determination of the seLected aromatic hydrocarbons was.determined by Injecting the sampLe from each station five times and caLcuLating reLative standard deviations of the measured amounts. The precision is highLW dependent on the magnitude of the ion current from the measured ionic species. Since the ion current from the more branched aromatics is distributed between severaL peaks, the magnitude of ion current is Lower and hence the precision is poorer. The reLative standard deviation is I to 5 percent for naphthaLene, methULnaphthaLene, and phenanthrene; 8 to 12 percent for dimethyLnaphthaLene, trimethgLnaphthaLene, methULphenanthrene, dimethULphenanthrene. and dibenzothlophene; and 20 percent for dimethy(dibentothiophene. The detectabiLitg of aromatics in seawater by mass spectrometry is Limited by the background LeveLs In the extraction soLvent and by contamination from gLassware. The detection Limit is Low, about 0.1 picogram injected or 5 picograms; per Liter of seawater for a singLe compound. The overaLL contamination of sampLes during sampLing.and processing couLd not be preciseLU determined.. The Lowest vaLues of the sum of the seLected aromatics was about 20 ng/L. They are probabLU cLose to the detection Limit set by the procedure used. 7.2.2 NOAR SampLes ERCO (Boehm and Fiest, 1978) perfomed the analyses on the NOAA water .sampLes using procedures simiLiar to those for the surface oiL sampLes. The detaiLs of these procedures are contained In Chapter 5.1 and wILL not be repeated here. In summarU,.the hexane extracts of seawater were dried over sodium suLfate. weighed, and setectivetU characterized by slLica geL/aLumina coLumn chromatography, gLass capiLLarg gas chromatography, and UV spectrofLuorescence. A bLock diagram of the procedure is presented as Figure 7-1. 7.3 ResuLts 7.3.1 The Danish AnaLgses 7.3.1.1 Quantitative UV-SpectrofLuorometrLj The spiLLed oiL contained high amounts of heavy aromatic hydrocarbons giving rise to fLuorescence at Long waveLengths. Its fLuarescence characteristics differed significantLU from those of Lighter,oiLs such as dieseL and Lubricating oiLs, and aLso from the pattern found in apparentLU unpoLLuted water. Therefore. fLuorescence patterns having characteristics simiLiar to the spiLLed oiL couLd be found in many sampLes. even though the concentrations were quite Low. The fLuorescence patterns of the contaminated sampLes. incLuding those sampLes with the highest concentrations. deviated significantLy from that of the spiLLed oiL. DissoLution and weathering processes produce a different composition of the petroLeum hydrocarbons in the water coLumn within a few days of the spiLL. Since fLuorescence at Long waveLengths (310/400 nm) was considered tWpicaL for the spiLLed oiL,.it was used as an indication that the petroLeum hydrocarbons originated with the spiLLed oiL.. SampLes which contained petroLeum hydrocarbons in amounts above the baseLine LeveL. but did not show the characteristics tgpicaL of the reference oiL, were considered not to contain oiL spiLLed from the POTOMAC. In at Least one sampLe, the fLuorescence spectrum was simiLiar to the spectrum of the cooLing water from the ADOLF JENSEN. Of the 76 subsurface sampLes that were taken. three were Lost and five were considered as contaminated. These eight sampLes that were not anaLgzed are Listed in TabLe 7-2. For the corresponding sampLing points, resuLts from quantitative spectrofLuorometric (UV) measurements are based on singLe sampLes. For the other 30 sampLing points. dupLicate sampLes were anaLyzed. 7-8 HEXANE EXTRACT OF 500 ml SEAWATER DRY OVER SODIUM SULFATE; EVAPORATE TO 0.2 ml UNDER NITROGEN CONCENTRATED HEXANE EXTRACT WEIGH A 20 ml ALIQUOT ON rAHN BALANCE FRACTION ON A FINGERPRINT BY SE-30 SILICA GEL/ GLASS CAPILLARY GAS ALUNINA COLUM CHROMATOGRAPHY TOTAL EXTRACTABLES 01g) FRACTION 1 (fl) FRACTION 2 (f2) (SATURATES) (AROMATICS) T ROTARY EVAPORATE WITH N2; ROTARY EVAPORATE-WITH N2; WEIGH ALIQUOT ON CAHN WEIGH ALIQUOT ON CAHN BALANCE; FINGERPRINT BY BALANCE; FINGERPRINT BY SE-30 GLASS CAPILLARY SE-30 GLASS@CAPILLARY GAS CHROMATOGRAPHY GAS CHROMATOGRAPHY Figure 7-1 Analytical scheme for hexane extracts of seavater used by ERCO for NOAA samples. 7-9 Table 7-2. List of samples for which results are not reported. Station Depth Code Cause 5460 10 m 1 a 5461 5 m 8 a 5466 1 m 16 a 5468 5 m 29 a 5470 1 m 39 b 5470 20 m 45 c 5471 20 m 52 a 5477 5 m 71 b a ; Strong indication of contamination of sample. Comparatively high levels of oil with fluorescence characteristics strongly deviating from those of the spilled oil. ; Screwcap on sample vial was not sufficiently tightened. c ; Not-delivered As a rough test for simiLiaritW to the spiLLed oiL, a vaLue of at Least 0.5 for the foLLowing reLative fLuorescence intensitU (r) was required: r - c310/400 c270/3GO . Here, c310,,1410 and c270/360 are fLuorescence intensities at the Indicated waveLengths expressed in reference oiL equivaLents of pgzL. The resuLts of these tests are shown in TabLe 7-3. Quantification was made with the reference oiL from EXXON's Aruba refinerW as the standard. ALL vaLues are mean vaLues from the dupLicate sampLes, except for the sampLing points Listed in TabLe 7-2. The resuLts. corrected for interference from the soLvent, are shown in TabLe 7-4 expressed as equivaLent concentraions of the reference OIL in )jg/L Some profiLes of concentration of petroLeum hUdrocarbons as a function of depth are contained as Figure 7-2. FLuorescence spectra of different tupes of water sampLes are shown-in Figure 7-3 (contaminated bg Bunker-C fueL), Figure 7-4 (contaminated bg cooting water from the ADOLF JENSEN). and Figure 7-5 (apparentLg uncontaminated water). 7-10 Table 7-3. Petroleum hydrocarbons in subsurface water samples, quantitated as the amount of reference oil that gives rise to the same fluorescence intensity at chosen wavelength combination Station Depth microgram per liter Spectral (m) measured at (nm) similarity to reference oil 230/340 270/360 310/400 5460 1 0.91 0.53 0.27 + 10 0.22 0.14 0.049 5461 1 4.9 3.5 2.5 + 5 0.74 0.57 0.41 + 10 0.53 0.40 0.29 + 20 0.56 0.32 0.13 5462 1 1.0 0.50 0.30 + 5466 1 1.5 0.90 0.48 + 5 0.54 0.36 0.35 + 10 0.48 0.32 0.19 + 20 0.32 0.21 0.082 5467 1 0.41 0.22 0.081 5468 1 0.48 0.23 0.11 + 5 0.59 0.40 0.20 + 5469 1 0.28 0.16 0.038 5 0.36 0.26 0.13 + 10 0.28 0.20 0.11 20 0.28 0.18 0.065 + 5470 1 0.31 0.14 0.043 5 0.20 0.12 0.032 10 0.24 0.11 0.032 20 0.29 0.12 0.028 5471 1 0.24 0.15 0.041 5 0.74 0.34 0.11 10 1.0 0.49 0.25 + 20 0.23 0.12 0.026 5473 1 0.47 0.27 0.13 + 5 0.91 0.64 0.43 + 10 0.56 0.24 0.10 20 0.53 0.25 0.11 30 0.37 0.25 0.12 5474 1 0.87 0.32 0.11 5476 1 1-.7 0.77 0.19 5477 1 1.3 0.73 0.28 5 0.47 0.27 0.072 10 0.63 0.28 0.083 20 0.63 0.19 0.079 7-11 Table 7-4. Amounts of interfering substances in solvents used for extrac- tion, quantitated as micrograms of oil per liter of water sam- ple. Bottle Used at stations micrograms per liter 230/340 270/360 310/400 (nm7 5460 - 5468 0.27 0.052 0.031 11 5469 - 5473 0.30 0.056 0.033 ilia 5474 - 5477 0.75 0.19 0.047 a American hexane The reLative difference between dupLicate sampLes, catcuLated as (cl - c2) / 0.5(cl + c2), ranged between 2 and 103 pet-cent. The median vaLue was 40 percent and the arithmetic mean difference was 55 percent. The concentrations Found at different sampLing points ranged from 0.03-0.04 jig/[ at Station 5470 to 2.5 )jg/L at Station 54G1 at I m depth. Thus significant differences couLd be seen between different stations and between different depths, aLthough the precision was reLativeLU poor. The deviation between dupLicates is due partLU to the fact that recentLU poLLuted water is not homogenous: thus, the dupLicate sampLes do not necessariLy contain equaL amounts of oiL. Judging from the fLuorescence characteristics of the subsurface water sampLes, none of them contained oiL which was identicaL in composition to the POTOMAC oiL. Therefore, there wiLL be a systematic error when the spiLLed OIL is used as a reference for quantitative evaLuation. This Is not unique for the fLuorescence technique but is a generaL probLem when o1L is to be anaLyzed at the I ppb LeveL. Each technique which can be empLoyed at this concentration LeveL suffers from the drawbacK that it does not have equaL sensitivity for aLL components of the oiL. The UV-fLuorescence technique is sensitive to aromatic hydrocarbons in oiL and has the property of generaLLg being more sensitive to Larger moLecuLes. Therefore, if the composition of the oiL in the sampLe is shifted towards the Lighter part of the reference oiL. the totaL concentration can be underestimated. This can be partLy overcome by choosing excitation and emission waveLengths that are tWpicaL of the Lower aromatics, e.g., the naphthaLenes and phenanthrenes. 7-12 STATION 5470 20/8 microgram/liter 590W 61 W 1.0 0 A-, 76 0N to-?, 0 5470 5471 C 20 5466 C (V. 5461 0 4%, % 750N STATION 5471 20/8 SPILL L microgram/liter 0.5 1.0 STATION 5466 17/8 5 1@0 microgram/liter & 5 1.0 to J 5- 20 10 M STATION 5461 13/8 201 1 microgram/liter 0.5 1.0 2.0 3.0 5- to- M 20- Figure 7-2. Concentrations of petroleum hydrocarbons at four stations as 42@4> a function of depth. Concentrations by UV-Spectrofluorometry. Values from duplicate samples are indicated. Spectral wave- lengths: excitation 310 nm, emission 400 nm. ~0 ~7~1~3 ~4qE~0qW~qt~2qLd~4qo~4qn ~6qX~2qU~g~qg~8q3~4qo~,~q0~0q7~0q0~"~0qB~ql~0qo ~8qX~6q1~4q0 ~8qU~4q0 400 Figure 7-3. Fluorescence spectra of an extract of subsurface water collected on August 13 at Station 5461, 1 m depth. Left: excitation spectrum from fixed emission wavelength, Right: emission spectra from different excitation wavelengths (see also Table 7-10.). A simpLe recovery test was made to check the efficiency of the Danish extraction procedure. Tap water was added to a s~ampLi~ng bottLe, adjusted to a ~s~aLinit~qU of 30 g/L~. and 10 ~q)~jg of the reference ~oiL dis~soLv~ed in ~1~0 ~qpL of dichLoromethane was added. The water was stirred for 3e min, extracted with hex~ane, and anaL~qUzed using the norm~aL procedure for the water sampLe~s. The recovery was cL~ose to In percent as is seen in TabLe 7-5. However, ~Ahnoff and EKLund~'s experience (1979) from reaL seawater sampLes that have been extracted in two consecutive steps indicated that extraction is not 100 percent but somewhere between ~q80 and 100 percent and that the extraction efficiency is affected by the particuL~at~e Load of the water. 7.3.1.2 ~qU~V Comparison of the Danish and NORA SampLing Methods At Station 5471, water sampLe~s were taken using both the Danish and NORA procedures. Two of the NORA s~ampLes which had been extracted by the NORA team were ~qanaL~qUzed b~0qy Ahnoff and EKLund. A comparison of these two samp~qLes with the Danish s~qamp~0qLes taken at the same depths at this station Is presented In TabLe 7-~0q6. Spectra of these sampLes are shown in Figure 7-~q6. The fact that the emission spectra Look the same, independent of the excitation w~qaveLength 7-14 .. .. .... . ..... 6,: AA ....... . ......... . ...... .... . .... ...... ........ ... M T Figure 7-4. Fluorescence spectra obtained from a surface water sample, station 5474, that contained waste cooling water from the ADOLF JENSEN. (for explanation see Figure 7-3.) is atUpicaL of oiL and suggests the presence of onLU one or a few simiLiar fLuorescing compounds, possibLW naphthaLenes. 7.3.1.3 Mass Spectrometric (MS) AnaLUsis TabLe 7-7 Lists the surface oiL and water coLumn sampLes that were anaLyzed using the MS method in Sweden. The concentrations of different aromatic hydrocarbons found in these water sampLes as determined by 111S anaLWsis are given in TabLe 7-8. According to UV anaLUses, three or these contained Less than I pg./L totaL petroLeum hydrocarbon concentration as noted in this Latter tabLe. These sampLes contained aromatic hydrocarbons in amounts bareLU above the practicaL detection Limit of the MS method. This Limit was not set by instrument sensitivity, but rather by the amount of contamination introduced into the sampLes during the anatgticat procedure. Conta mination interfered more strongLg with the MS than with the UV anaLLjses. :514 6 ......... ..... ...... ..... . . ......... .. 000 WA Ot Figure 7-5. Fluorescence spectra obtained from a surface water sample, Station 5469, collected well to the north of the spill area. The vertical scale is more expanded than in Figures 7-3 and 7-4. Table 7-5. Recovery of Melville reference oil from synthetic seawater using hexane as extractant. Excitation/emission 230/340 270//360 310/400 wavelength (nm) Recovery M 96.1 98.7 96.9 1 Table 7-6. Comparison between samples taken by NOAA and Gothenburg Uni- versity sampling methods. Station Depth Method microgram per liter 230/340 270/361) 310/400 (nm) 5471/1 0-0.5m NOAA 6.2 2.1 0.20 Om GU 0.59 0.31 0.20 5471/2 0-0.5m NOAA 10 2.8 0.40 Om GU 0.24. 0.15 0.042 The sampLe at I m depth from Station 54G1, which contained a few pg.,,L of petroteum hydrocarbons, showed 50 ng/L of seLected aromatic hydrocarbons (TabLe 7-8). Mass fragmentograms are shown in Figure 7-7. In Figure 7-8, the concentrations of different aromatic hgdrocarbons are compared with the concentrations found in the surface oiL sampLe coLLected on August 10. It can be seen in this figure that, for each type of aromatic hydrocarbon, the reLative concentrations decrease with increasing moLecuLar weight. This is in accord with the Lower soLubiL-itLj of the higher weight compounds. For the naphthaLenes. evaporation of the Lightest naphthaLenes from the oiL can aLso contribute to the differences seen In Figure 7-8. 7.3.1.4 Comparison of MS and LJV FesuLts The seLected aromatic hydrocarbons make up approximateLg 1 percent of the totaL weight of the originaL POTOMAC fueL which was spiLLed (TabLe 5-5). Assuming that the same reLation between the seLected aromatics and the totaL amounts of petroLeum hydrocarbons exists in the water sampLes (obviousLy this is not true), vaLues of totaL petroLeum hydrocarbon concentrations can be caLcuLated. TabLe 7-9 presents such concentrations for the sampLe at 1 m from Station 5461. ObviousLU, these vaLues must be maxima since the seLected aromatic hydrocarbons beLong to the most water sotubLe components of the oIL and thus wouLd be expected to be present in high reLative concentrations. The LJV anaLUsis shows Lower reLative concentrations. Compared with the MS technique, the LJV method measures a broader spectrum of aromatic hydrocarbons. Higher waveLengths are more seLective for the heavy aromatic components, and they 7-17 "A# ------- - ---- --- at --------- ------------- -- ........ ..... .. -4- . .......... :7.3 ,------- --- OkA . ..... - -- ----- .... .. T- Figure 7-6. Fluorescence spectra obtained from a water sample collected in a polyethylene bag by NOAA at Station 5471 just below the surface. aLso gieLd Lower concentrations. VaLues from measurements at 310/400 nm can be regarded as minimum concentrations. Consequentty. it can be concLuded that there is good agreement between the MS and the UV determinations on at Least this sampLe. 7.3.2 The NOAA anaLUses The NOAA hexane extracts were anatgzed bg ERCO. and a compLete report of their findings is contained in Boehn and Feist (1973) from which the foLLowing materiaL was extracted. 7-18 Table 7-7. Samples analyzed by mass fragmentography. I "Thule oil" acquired from tank of the POTOMAC. 2 Reference oil Bunker-C retain acquired from EXXON refinery at Aruba where POTOMAC last loaded with fuel 3 Surface oil sample collected on August 10, 1977. 4 Station 5460 1 m code=4 5 Station 5461 1 m code=5 6 Station 5461 5 m code=7 7 Station 5469 5 m code=33 Table 7-8. Concentrations of naphthalenes, phenanthrenes, and dibenzothiophenes in subsurface water samples. Compound 5460 (1m) 5461 (1m) 5461 (5m) 6569 (5m) nanogram per liter Naphthalene 4.3 5.7 5.5 6.6 Methyl naphthalenes 3.2 7.2 1.8 3.4 Dimethyl naphthalenes 0.9 12 1.5 3.3 Trimethyl naphthalenes <2.0 8.4 1.8 4.2 Phenanthrene 5.8 5.5 1.1 1.5 Methyl phenanthrenes 2.3 5.3 0.9 0.6 Dimethyl phenanthrenes o.7 4.4 <0.1 <0.1 Dibenzothiophene o.6 1.9 0.2 0.3 Methyl dibenzothiophenes 0.2 2.7 0.4 0.7 Dimethyl dibenzothiophenes <0.1 2.5 0.5 0.9 Total (naphthalene excluded) 14 50 10 15 Spectrofluorimetric analysis 230nm/340nm 930 4900 740 500 270nm/360nm 560 3200 570 350 310nm/400rm 240 1900 41.0 180 M/0 156 212 Is M/0 142 RVG 206 x M/0 206 M/0 128 M/0 192 x M/0 198 nya 127 In,% 178 rn/e 184 x /.170 L AL 10 15 retention time 151 111, ......... @ i 0 0 7"r .t..t7 on X me Figure 7-7. Mass fragmentogram reconstructed from a water sample collected at Station 5461 at I m depth. 7-20 0 2XIO-8 NAPHTALENES 0 \0 DIBENZOTIOPHENES 'MW 100 150 200 250 Figure 7-8. Comparison of concentrations of naphthalenes, phenanthrenes, and dibenziothiophenes in the subsurface water sample from Station 5461 at I m depth with the surface oil sample collected on August 10. Vertical axi@; is-'the concentration in the water sample divided by the cqf!Fentration in the-surface sample. Concentrations of the water sample have been corrected for background effects by subtracting out the mean concentrations found in three other water samples (see Table 7-8). Horizontal axis is molecular weight. Fiftg-six hexane extracts were characterized by totaL extractabLes (TabLe 7-10), after which 36 extracts were characterized by either GC or GC-MS depending upon the concentration LeveLs. The goaLs of the anaLgees were 1) to characterize the chemicaL fractionation of the oiL incorporated into the water coLumn and 2) to estimate the quantitU of oiL incorporated into the water coLumn. These goaLs were achieved onLg partLy, because severaL of the extracts prepared in the fieLd were either contaminated or evaporated because of fauLty cLosures. 7.3.2.1 Gas Chromatographg Where coLumn chromatography preceded gas chromatography, two fractions of the hexane extract were anaLyzed: an fl fraction containing saturated hydrocarbons and an f2 fraction containing naphthenoaromatic and aromatic hydrocarbons. In the case of sampLes containing smaLLer concentrations of totaL extractabLes, ~0 7~21 Table 7-9. Comparison between mass fragmentographic and spectrofluori~qmetric analysis on a subsurface water sample (Station 5461 at 1m) microgram per liter (ppb) Sum of selected aromatic hydrocarbons 0.050 Total concentration of petroleum hydrocarbons assuming that selected aromatics constitute 0.81% of total 6.2 Fluorescence intensities in reference oil equivalents Excitation/emission (n~qm) 230/340 4.9 270/360 3.1 310/400 1~.9 onL~qW the unfr~actionated ~(~qf~qo~q) extract was ~a~na~l~.~qgze~qd. The sa~m~qoLe~s were grouped into three broad cL~a~sse~s as shown in TabLe 7-11. Three water extracts, ~s~ampLes 1. 2. and 3~, coLLe~cted 12 da~L~qjs.a~fter the spi~qLL at Stations 5466 and 5467 contained high concentrations of t~otaL e~tract~ab~qLes ~4q0~q15oe ~qpg~z5o~qem~qu. Their GC spectra contained a trim~adaL distribution of high moLe~cuLar weight unres~oLved components in the fl fraction (Figure 7-9) and a characteristic distribution of res~oL~ved components with a reLative index (RD between 1400 and 17eo in the ~qf2 fraction (Figure 7-10~). The gas chrom~atogr~ams of these three s~ampLes were rem~ar~RabL~qy s~imiLiar to each. other but not to the spectra from the POTOMAC ~OiL (Figures ~q5-3 and 5-4~q). This indicates that the ~o~qiL in these sampLes came from a source other than the POTOMAC. Fifteen other ~sampLes were characterized b~qy varying concentrations (gener~a~2qU~qg 100 to 500 ~q)~jg~q) of a suite of n-~aL~ql~@anes from RI 2100 to 31~q0~q0~.~ with the maximum at 2500 in the fl fraction (Figure ~q7-11~) and ~aLso by a bimodaL unre~qsoL~qved compLex mixture (UCM) in the ~qf2 fraction (Figure 7~q-12~q). These GC patterns are ~qat~4qUpic~qaL of ~4qBun~0qker-C fu~qeL but match a he~qxane extract of a cLe~qan sampLe viaL cap (Figure 7~q-13). The contamination of ~qsampLe~qs in this group from the wax coating on the v~4qi~qaL caps precLuded measurement of o~0qiL in these 7-22 Table 7-M Seawater extract analyses, NOAA Lab. Vial Total f 1 f 2 GC I.D. I.D. extractables 01g) (ug) f f Total GO 1 2 08-81 MCB H-1 138 87.5 277.9 X X 08-105 1 22,500 7280 8112 X X 08-106 2 15,380 5175 7315 X X 08-107 3 16,120 3465 5210 X X 08-99 4a 759 318.4 163 X X 08-97 6a 114 08-98 5 16 23.5 25 X X 08-96 7b 202 32.0 64 X L 08-95 8b 46 08-94 9 23 08-93 10 33 X 08-92 11 874 201 227.9 X X 08-85 12 548 145.4 106.1 X X 08-86 13 112 X 08-87 14 435 34.4 24.6 X X 08-88 15 284 26 52 X X 08-89 16 88 08-66 5469-@a 55 X 08-67 5469-@b 108 08-77 5470-OA 100 X 08-76 5470-@B 35 08-75 5470-la 224 115 79 X X 08-72 5470-lb 0 08-65 H-la 0 08-64 H-lb 35 X 08-63 H-2a 249 81 74 X X 08-62 H-2b 286 X 08-61 1-la 1700 665 560 X X 08-60 1-lb 204 X 08-115 1-2a 63 X 08-114 1-2b 20 X 08-68 5-la 63 X 08-69 5-lb 83 08-70 5-2a 41 X 08-71 5-2b 78 Table 7-10. Seawater extract analyses (continued) Lab. Vial Total f1 f 2 GC I.D. I.D. extractables (11g) (jig) f f Total 01g) 2 08-113 10-la 17 08-112 10-lb 29.4 X 08-84 10-2a 67 08-83 10-2b 418 163.2 189.4 X X 08-111 20-2a 5 08-110 20-2b 6.4 X 08-109 20-4a 23 X 08-108 20-4b 40 X 08-100 30-la 0 08-101 30-lb 19 X 08-102 30-2a 0 08-103 30-2b 35 X 08-79 10-0a 12 08-78 10-0b 153 X 08-74 11-0a 51 08-73 11-Ob 98 X 08-90 11-10A 108 X 08-91 11-10B 185 X 08-82 Fisher 765498 118 72 60.9 X X 08-80 MCB Blank 254 149 108.6 X X L = Lost X = Wed sampLes. Three of the four proceduraL bLanks were simiLiarLU contaminated, and the fourth contained smaLL amounts of hUdrocarbons (<5 jig) confirming the contamination. The 14 remaining sampLes were not contaminated bg the viaL caps but contained onLy minor amounts (<10 pg/500ML) of a few resoLved components in the unfractionated sampLe (Figure 7-14). The smaLL number of resoLved components, usuaLLy one or two, argues against gross contamination bw the POTOMAC oiL and suggests a biogenic origin of these components. In no case was major contamination of the water CoLumn with POTOMAC o1L observed. SeLective dissoLution shouLd resuLt in a series of substituted naphthaLenes, and gross incorporation of oiL into the water coLumn shouLd resuLt in an fl 7-24 Table 7-11, Groupings of seawater samples NOAA Sample Date Station Depth Group I.D. (August) No. W 1 17 5466 1 T 2 18 5467 0 T 3 18 5467 0 T 4a 18 5468 1 C 5 18 Blank - C 7b 18 5468 0 LL 10 18 5468 1 LL 11 18 5468 1 LL 12 18 5468 1 LL 13 19 5469 0 LL 14 19 5469 0 LL 15 19 5469 0 LL Oa 19 5469 0 C Oa 19 5470 0 C H-la 19 5470 1 C H-lb 20 5471 0.2 C H-2a 20 5471 0.2 C H-2b 20 5471 0.2 C 1-la 20 5473 1 C 1-lb 20 5473 1 C 1-2a 20 5473 1 LL 5-la 20 5473 5 LL 10-lb 20 5473 10 LL 10-2b 20 5473 10 C 20-2b 20 5473 20 LL 20-4b 20 5473 20 LL 30-lb 20 5473 30 LL 30-2b 20 5473 30 LL 10-Ob 21 WW-10 10 C 11-Ob 21 WW-11 0 C 11-10a, 21 WW-11 10 C 11-10b 21 WW-11 10 C T = Trimodal unresolved envelope. C = Cap liner contamination. LL = Low level concentrations (< lOpg/500 ml). pattern simiLar to that for the whoLe otL (Figure 5-3). Neither of these patterns was observed in any of the NOAA water sampLe extracts anaLUzed by GC techniques. 7-25 Figure 7-9. Gas chromatogram of the fl (saturate) fraction from extract 2 showing the trimodal group. Analysis by ERCO. 61 C4 Figure 7-10. Gas chromatogram of the f2 (aromatic) fraction from extract 2 (trimodal group)- Analysis by ERCO. 7.3.2.2 UV-FLuorescence Three f2 fractions of water extracts, incuding members of the trimodaL aLKane group, the cap bLank group, and a shipboard bLanK, were anaLgzed by synchronous-scan spectrofLuarometrg and compared with an f2 fraction of the reference oiL. No concLusions couLd be drawn from the resuLts because of the simiLarity of peaK shape and concentration of the two water sampLe extracts and the bLank. 7-2G ri C4 10 Figure 7-11. Gas chromatogram of the fl (saturate) fraction from extract 10-2b showing cap liner contamination. Analysis by ERCO. 6) 4 Q !t Figure 7-12. Gas chromatogram of the f2 (aromatic) fraction from extract 10-2b showing cap liner contamination. Analysis by ERCO. 7-27 0 V) 0 M0 co Figure 7-13. Gas chromatogram of a sample vial 'cap liner (unfractionated). tj T Figure 7-14. Gas chromatogram of the unfractionated extract 30-1b showing the low level group. Analysis by ERCO. 7.4 Summary Of Accommodation into The Water CoLumn UV-spectrofLuorometry, gas chromatography, and mass spectrometry were used to anaLgze the Danish and NOAA hexane extracts of water sampLes to investigate chemicaL changes of the spiLted oiL incorporated into the water coLumn. Use of these techniques was hindered by contamination of some of the sampLes. both during coLLection and during storage. Some of the extracts showed gas chromatography patterns atypicaL of the oiL spiLLed by the POTOMAC. ~0 7~28 Most of the remaining s~ampLes contained ~sm~a~qLL amounts of resoLved components ~q(~q<~q2~q0 ~qPg~.~/~m~ql~q) ~. U~qV-spectrofLuor~ometr~qg was used to screen the hor~qiz~ont~aL and vertic~aL distribution of oiL in MeLv~qiLLe Bag. Petr~o~qLeum h~qgdr~oc~arbons were found in the Danish sampLes at concentrations from ~q0.~q03 ~q)~jg~.~/L up to above 2 ~j~ug~.~/L~. using spec~qtr~aL waveLengths t~qypicaL for quantification of the sp~iLLed ~o~qlL~. Using different waveLength~s for quantitation~. the maximum concentration found was between 2.5 and 4.9 ~q)~jg~/L. The spiLLed oiL couLd be traced b~qg UV techiques down to about 0.1 ~q)~jg/L. Depth pro~qf~qlLes, taken 8 to 12 d~a~qg~s after the sp~i~qLL occurred, showed maximum concentrations near the surface (I m depth) and a rapid decrease down to 10 to 20 m depth. Pr~ofiLes taken 13 to 15 d~a~qgs after the spiLL showed maximum concentrations at 5 to 10 m depth corresponding to the bottom of the surface Lager (Chapter 4.1). The petr~oLeum hydrocarbons In the water coLumn contained higher reLative amounts of the L~ow-moLecuLar-weight aromatic compounds than the reference oiL and surface o~qtL sampLes. Mass spectrometric anaL~qgsis was used on a sm~aLL number or the Danish water s~ampLe extracts as a comparison with their UV-spectro~qfLuorometric ~anaL~qUsis. Good agreement was found between the two techniques. WhiLe Lar~qge-~scaLe dispersion of the ~o~qi~qL Into the water coLumn might have occurred during the ~q8 d~a~qgs before the first water samp~q(es were c~oLLected, no gross accommodation of the sp~qiLLed oiL into the water coLumn was found in ~an~qg of the water sa~6qPp~qLe extracts anaL~qUzed. ~0 ~q8.0 BIOLOGICAL STUDIES ON PLANKTON AND FISH S~ampLes of z~qQopLanKt~on and fish were collected In the v~qic~qin~qit~qg of the ~sp~qiLL as weL~qL. as in reference areas to examine the Impact of the oi~ql (Tables ~q8-1 and ~q8-2)~. The Danish samples were forwarded to the Water Quality Institute ~qfor h~qUdrocarb~on ~anaL~qUsis, to Marin ID for analysis of the composition of species and identification. and to Greenland Fisheries Investigations (GF) for examination of contaminated pLan~qRton~. The 13 U.S. biological samples were forwarded to t~qhe ~qPL~a~qhKt~on E~coLog~qg L~aborator~qg~. National Marine Fisheries Service, Narragansett. ~qP.I., for an~aL~qgsis of species composition. abundance, and contamination of pLanKton. ~q8~.1 Sampling Procedure ~q8.1.1 Danish Sampling PLan~qkt~on samples were collected with a ~qStramin net (2 m diameter. mesh 500 thre~ads/m hauled from 200 m to the surface at 1.5 ~qKn over a period of about 30 min) and Hen~sen net (7~q2 cm~ diameter, No 3 s~qIL~qK hauled vert~qicaLL~qU at 0.3 ~m/s from 50 m to the surface.) (Table 3-1.) One pLanKt~on sample was collected with the Str~am~qin net at the spill site (Station 5460) and two samples were CO~qLLect~e~qd in areas with oi~ql p~ancaKes on the surface; at Station 54G~qI~. the Str~am~qin net ~qoro~qK~e t~qhe surface within the oiled area and at Station 5464. the Str~am~qin net bro~qKe the surface outside of the oiled area after hauling inside the oiled area. Three samples were collected on a Line north of the center of t~qhe oiled area (Stations 54G9~. 5470, and 5471). One s~ampLe was collected In an area with subsurface o~qi~ql fL~qa~8qKes (Station 5473) and-one in a reference area (Station 5477). Samples were also collected with the Hensen net at Stations 5460~q, 5469~q, 5471. and 5477 (Figure 3-2). The volume of the pL~qan~4ql~qet~qon samples from the ~8qStram~0qin net were measured immedi~qateL~2qU (Table 8-1) and the pL~qanKt~qon were examined for o~8qi~4ql contamination. ~4q3~q-1 Table 8-1. Summary of Danish biological stations including plankton volume. 00 I Date Time Depth Volume Total Oil Present Gear Station Position 1977 GMT m wet ml number visible analysis Stramin 5460 74053'N 61010'W 8/13 1325 0-225 3000 143680 no yes of 5461 75010' 610231 8/14 0201 0-225 2000 IM pancakes yes 11 5464 75012' 61030' 8/16 1123 0-225 900 31826 pancakes nm if 5469 75044' 61035' 8/19 1448 0-225 1300 132224 no no ff 5470 75035' 61024' 8/19 1830 0-225 1300 nm no ? It 5471 75026' 61010' 8/20 0851 0-225 3000 150264 no ? it 5473 75016' 61015' 8/20 2137 0- 1 150 nm flakes yes il 5477 74021' 58037' 8/21 0207 0-225 2000 57472 no no Hensen 5460 '75053' 61010' 8/13 1325 0-50 nm 15065* if 5469 75044' 61035' 8/19 1448 0-50 nm 5713*. of 5471 75026' 61010' 8/20 0851 0-50 nm 8367* it 5477 74021' 58037' 8/21 0207 0-50 run 13093* Pelagic 5465 75010' 60038' 8/17 1310 ca 250 nm trawl nm = not measured ? = uncertain results = total number per m 2 Table 8-2 Summary of U.S. biological stations including plankton volume. Date Time Surface area Wet volume Filtered volume Wet volume Gear Station Position 1977 GMT. (M2 (ml/1000m2) (M3) (ml/lo()m3) Newston 1 75016.5'N 61020'W 8/20 0540 550 50.7 if 2 75017.5' 61015' 8/20 0635 550 46.2 If 3 75018.5' 61012.5' 8/20 0723 550 200.9 it 4 75019.5' 61010.5' 8/20 0748 550 34.2 it 5 75020.5' 61014' 8/20 0827 550 36.0 it 6 75*22.5' 61004' 8/20 0945 550 3.6 if 7 75018.5' 61019' 8/20 1045 550 5.4 of 8 75018' 61017' 8/20 1056 550 13.5 it 9 75026' 61052' 8/21 0843 550 45.0 It 10 75047' 65050' 8/21 1253 550 10.8 it 1.1 75053' 67058' 8/20 1600 550 8.1 Bongo/0.333 1 75015' 61015 8/19 1600 722 29.11. Bong'0/0.505 1 it ff 11 It it 28.2 Bongo/0.333 2 75015' 61015' 8/19 1700 964 47.4 Bongo/0.505 2 it if It it 40.1 00 ~0 8-4 Samples of the dominant groups ~(C~pep~ds, ~Par~them~ist~. and ~F~terop~~cs) were selected and kept frozen for h~qUdroc~ar~qbon analysis. ~qT~qhe remainder of each sample was preserved in 4 percent Form~aL~qin ~qf~or identification, counting. an~qd further examination for oi~ql occurring as external smudges or Ingested into the gut. 8.1.2 U.S. Sampling Neuston samples were coL~qLe~cted at 11 stations with a 0.5 b~qg 1.0 m rectangular frame fitted with a 0.505 mm mesh net. Tows of 10 min duration were conducted at speeds of 3.3 ~qRm/hr, eff~ectiveL~qU sampling a surface area of 550 s~qq m. In addition, at Stations I and 2, stepped o~qbL~qique tows were made with a ~q61 cm bongo sampler fitted with 0.505 and 0.333 mm mesh nets. At Station 1. a 45 min tow was conducted which sampled at 20, 15. and 10 m depth each for 15 min. At Station 2. the tow was for I hr and sampled 20, 15~, 10, and 5 m depths each for 15 min. ALL sampLes were preserved In 10 percent FormaLin. ~qP ~summar~qg of these tows Is contained In Table 8-2. 8.2 Species Composition ~q6.2.1 The Danish Samples The ~qStramin net ~samp~qLe~s were reduced to an ~a~t~iquot of ~a~Dout 3~q000 specimens with a sampLe ~a~qlv~qid~er and Identified to t~he Lowest possible taxa~. The Hense~r net samples were totaL~qL~qU counted and identified (Table ~q8-~q3). The fish Larvae from a~qLL the samples were identified (T~a~qULe ~q9-4). The ~copepods were the dominant group In the pL~an~qkton. ~q@~.~a~qLanu~-~s h~qUperb~areus was the dominant species In aLL the S~qtram~qin net ~Sa~m~qpLes accounting for 37 t~qb 82 percent of the specimens. CaLanu ~aL~aciaLi w~a~o the second most numerous species and occurred at aLL stations. At ~qt~qhe r~el~qfer~ence station, Metridi~a ~q1~6q2~qa~6qo was the dominant species, but on~qL~qU a ~qfew or no specimens were present at the other stations. In the Hen~s~en net samples, the sm~aLL copepod Pseudo~c~aL~qanu minutus was the dominant species. po~ss~qibL~qy because of t~qhe smaller mesh in this net. Because of the Known daily vert~4qic~qa~0qL migration of plankton, natural variation present in the ~qsamp~0qL~qe~qs made comparison ~4qOetwe~qen samples collected at different times uncertain. 8-5 Table 8-3. Results of zooplankton enumerations for Danish stations. Station number 5460 5464 5469 5471 5477 5460 5469 5471 5477 Type of netand depth S 200, 225-0 m, 30 min haul 0,45 ml Hensen, 50-0 m Sarsia princeps 64 8 70 Leukartiara breviconis 64 Aglantha digitale 5440 2040 4960 3238 128 61 63 54 67 Clione limacina ad. 704 72 1216 70 5 1 It it 3uv. 8 4 6 5 Limacina helicina ad. 704 24 2144 141 64 3 1 3 11 If juv. 9 4 4 20 Hiatella ap.juv. 1 Conchoecia sp. 1 Calanus hyperboreus 50880 3920 39360 665"20 26880 120 19 86 36 11 V 54720 7600 42240 49984 44720 124 4 109 93 it IV 9600 3040 20800 5280 10880 44 9 71 51 it 111 960 320 1280 - - - - Calanue glacialis T 7680 1040 1280 5280 9600 96 3 27 28 If it a 80 It it V 5120 2840 3200 6688 52480 376 21 103 354 it If IV 4 8 4 12 Calanus finmarchicus q 320 3200 60 6 is 50 it 11 (1 3 11 it V 320 640 192 14 49 114 it it. IV I Calanus copepodits IV 856 96 364 819 Calanus nauplii 192 312 196 30 Pseudocalanus minutus 9 280 36 68 75 1. 1, V@ 568 390 444 845 it If va 368 228 188 510 it IV 2084 132 832 1170 If 111 552 560 492 265 Pareuchaeta glacialis 152 141 320 If If V? 88 141 128 1 it it VdT 1 70 256 1 1 it iv@ 1 1 It Iva 320 70 2 111 80 1 2 2 Metridia longa 32 70 64000 4 33 543 If V? 1 4 30 if ve 640 2 5 30 Oithona similis 112 44 80 10 Microsetella norvegica 6 Harpacticida sp. 640 4 Parathemisto libellula 192 352 710 64 2 4 4 3 Epicarida sp. I Pandalus borealis juv. 66 Ophiura sarsi 16 16 Ophiocten sericeum 5 4 3agitta elegans 256 2112 1280 1420 6144 3 4 21 Bukrohnia hamata 6848 8280 14720 7040 5824 37 27 35 34 Pritillaria borealis 4 8 27 Oikopleura vanhobffeni 2 316 102 84 Total 143680 31826 132224 150264 227888 6149 2332 3415 5344 ~0 ~8~~6 Table 8-4. Fish larvae collected at Danish stations. Fish larvae Station 5460 5461~ 5464 5469 5470 5471 5477 Liparis sp. 7 ? 16 6 ~q1 7 2 Boreogadus I The lack of available background data from the spill area ma~qKe comparisons of numbers and species of z~oopLan~qKton with t~qhe ~"n~orma~qL~" situation difficult, and conclusions about impact of the o~qi~ql on the plankton community at the s~qpiLL area cannot ~qbe firmly drawn. An investigation in 1928 ~q(~qJ~e~spersen, 1934) found CaLanus ~qf~qinmarch~qicus and CaLanus hu~qper~qboreus to be t~qhe predominant c~opep~qods In the upper water Layers, but Metr~qid~qia Lon~qga also appeared. Generally, the same species of copep~ods were found during the Investigations of both 1928 and 197~q7. ~ery few fish Larvae were found In the ~qStramtn net samples (Table 8-4). A~qLL of these were Lipar~qis sp. except for a single Bore~ogadu~s sald~a. A 1-hr midwater traw~qL (Station 5465) resulted in only 11 adult ~qR~0q2~6qn~qg~6q2~q@~qL~adus ~s~a~qld~a being collected. 8.2.2 The U.S. Samples Analysis of the U.S. sam~qp~.Les was performed by R.Maurer and J~.~qKane at the Narragansett Laboratory of the Nation~aL Marine F~qis~qMer~qies Service (Maurer and Kane, 1978). Plankton biomass was measured at each station by determining t~qhe displacement volume of each sample (Table ~q8-2). VoLumes were recorded to the nearest milliliter following the method described b~qy ~qAhLstrom and Thr~aLK~qiLL (19~q6~q3). When necessary. plankton samples were reduced to an ~qaL~8qiquot of approximately 350 to 500 specimens using a modified Mo~0qto~8qda box~q-t~8qgpe spL~8qi~8qtter~q. Zo~qopL~qan~8qkters were identified to the lowest possible ta~qxa, counted. and examined for o~2qi~2ql contamination (Table 8-5). Table 8-5 Resull-a of zoopl@Lnktqn enumerati n 'or U.S. stations NEUSTOM BONGO Station R01MOO .1@2 WG/1000 M3 Species 2 2 4 5 5 7 Q, 10 1@ lt(Oe333) ](0.505) 2(0.333) 2(0.505) Z5 M 2 is 7 36 so 1@ 13252 14049 25908 21192 Calanus OIC23 1@3 58 t5 30 13 459 47 73 56 40 ?906 2061 3056 5510 1 'Calanus 1189 15 58 14 11 105 is 510 78 9 7490 399 10895 731 fl-n-m-archi cus Pseudocalanus - - - - - - - 44 8997 133 13685 - g, nu -fus Oithona - - - - 7 709 44 531 S i mi B's Calanus sp. - - - - 98 - - - Metridia lonqa - - - 4 - - - - - - Parathemisto 4712 5236 21990 2843 4989 80 229 147 4632 22 - 355 244 266 -T,-6-CTTu-Ta- Limacina 116 116 58 175 58 105 149 196 80 11 133 89 44 - - helici Clione limacina, 15 - 7 29 - - - 44 5 2 266 M 266 199 Conchoecia 5P. 15 - 7 - - - 2 - - - - - - Eukrohnia hamata - - 4 - - 11 - - - - - @Saqitta sp. - - - - - - 133 66 TomOteris SP. - - 7 - - - - - .Polychaeta - - - - - - Siphonophora - - 73 73 7 - - - - - 44 - 133 Gymnosomata - 15 175 - - - - 5 - - 2 - - - - Coclenterata - - - - - - - - - - - 266 Hydromedusa - - - - - - 4 - 7 - 00 Total number 5479 5469 22339 3135 5207 223 975 423 4938 248 346 ~0 Large C~aL~a~ncid c~opepods strong~qL~q9 dominated the p~qLan~qKt~on In the 0.5e~q5 mm mesh Bongo samp~qtes. C~a~ql~anu huperbor~eus~, one or the Largest known caL~ano~qlds and one which occurs pr~qim~ariL~qg in Arctic waters, accounted for ~appr~o~ximate~qL~qg 77 percent of the t~ot~aL ~z~o~o~qpLan~qKton numbers at Stations I and 2. C~@~qL~qanu ~qaLaci~aLis and ~qCa~qt-anu ~qf~qinmarc~qr~i~ql~cus, smaLLer, morpho~qtog~qI~c~aLL~qy ~sim~qi~ql~qlar~, and congeneric species, occurred at both stations but were not numerous enough to be considered dominant. It shouLd be noted that ~qP~ar~at~qh~emlsto L~qIbeLLuLa. a h~qUperid amphipod~, and smaLLer c~opepods were not ranked high ~qI~n the 0.505 mm mesh bongo ~s~a~m~qpLes. C~. hu~qperboreus aLso dominated t~qhe smaLLer mesh (~q0.333 mm~q) bongo sampLes (T~abLe 8-5). The noticeabLe difference In species composition between the sm~aLLer and Larger mesh s~ampLes was the increase In numbers of sm~aLLer species. P. minutus and O~qlthona ~s~qim~qiL~qls~, In t~he sm~aLLer mesh sampL~es. ~qP. minutus was ranked second in numeric~aL Importance for these s~ampLe~s. ~qNeuston sampLe~s taken In the v~qi~c~qin~qIt~qU of the sp~qILL (Stations 1 to ~q8) were dominated b~qg~-~0qE~. ~qt~qibeLLuL~a. In the c~ontro~qt area (Stations ~q@~q@~. 10. and 11). P. ~6qUbeLLu~qL~a was ~aLso dominant. The composition of communities In the neuston (surface) and bongo (water coLumn) s~ampLe~s are compared in Figure 8-1. The two dominant species appear to be ~a~qtmost mutuaL~qL~qU excLus~qive. The neuston sampLes are strongL~qU dominated b~qW ~8qE, ~qL~qIbeLL~uLa (~q01 percent) white C. ~qMu~qner~qboreus (76 percent) dominates the bongo ~s~ampLes. C~aL~anus ~qgLacia~qL~qi ~. C. ~qf~qinmarchicu~s~. and L~qim~acin heLicin~a were of Less importance in both bfot~opes. Sar~s ~q(~i~qO~2qM reported that P. Lfbe~qtLuL Is a good Indicator of the Arctic water and occurs in ~qt~arge numbers at the surface. PopuL~at~qion~s are ~qRnown to be composed ~qprimariL~t~qi of juv~eni~qtes, as the Large aduLt ~qInd~qividu~aL~s are seLdom encountered. Si~m~qlLarL~qU~, in this surve~qg the popuLat~qi~on was d~qi~sprop~ort~qion~ateL~qU juveniLe~s. From 9~q3 to 100 percent of P. LibeL~qLuLa at ~an~qg one station were juveniLes. Hyperid ~amphip~ods are known to ~qbe e~xtremeL~qU strong swimmers. cap~qabL~qe of extensive vert~8qic~qa~4qt movement and ~8qP. L~8qIbeLLuL~qa has been reported from the surface to 2,500 m. Examination of the diurna~0qt occurrence of ~8qP. Li~0qbuLLeLa in the neuston s~qampL~qes during this surve~2qg Indicates that this species Is from 100 to 1.000 times more abundant at the surface during the Arctic night and tw~8qiLight periods. B-9 BONGO NEUSTON ........... ........................ ............... CALANUS HYPERBOREUS I * '' *. ................................... .................................... CALANUS GLACIALIS CALANUS FINMARCHICUS LIMACINA HELICINA PARATHEMISTO LIBELLULA 80 60 40 20 0 20 40 60 80 PERCENT NUMBERS Figure 8-1. Comparison of the species composition of communities in bongo (0.505 mm mesh) and neuston (0.505 mm mesh) samples. Stations I and 2 were combined for the bongo samples. If a sLick was present, as at station 2, then the pLanKton movement into and out of contaminated waters wouLd provide a pathway for hydrocarbon compounds to enter major pLanKton and fish communities in the water coLumn. Amphipods, because of their numericaL importance, are considered as a major food resource for fish species and the ringed seaLs. Whether or not there is a food chain magnification of hgdrocarbon compounds as has been shown for other poLLutants, e.g.. pesticides and heavU metaLs, has yet to be determined. However, the potentiaL for significant impact exists if these compounds are transferred to the more sensitive deepwater environments. CharacteristicaLLY, these Low productivity regions are inhibited by Cong-Lived sLow-growing species with Low LeveLs of fecundity; therefore. the carrging capacity for such poLLutants in these environments wouLd be expected to be minimaL. Fish Larvae were virtuaLLU absent in the pLankton during this survew. The onLy specimen coLLected was a radiated shanny, 2tichaeus punctatus. ~0 ~9~~1~0 8.2.3 White ~qPart~qic~qtes on the Sea Surface ELeven ~qC~qa~qUs after the SPILL, SM~aL~qL White p~a~rt~qicLes were observed ~qfLo~at~qin~qg on the sea surface. Some of the p~art~qIcLes couLd be Identified as the remains of dead zo~opLankt~on (copepods~q).~. These white part~qicLes appeared to be gLobuLes of white fat or o~qlL~. It is suspected that no re~qtat~qion exists between dead p~qLanKton and the ~qSpiLLed oiL. as the White part~qIcLes were observed both within o~qlLed areas as weLL as in areas that the sp~qi~q[Led ~oiL did not reach. Furthermore, dead p~qtankton have been reported in this area during 1928 as a n~atur~aL phenomenon of~'the c~o~qpe~qpod Metr~qid~ql Long (Jespersen, ~ql~qS~r34). T~qhe most prob~abLe reason for the association of the dead pL~anKt~qon and the oi~qt Is that they Were both concentrated b~t~qj convergent processes such as Langmu~qir c~qlrCUL~atlon. This expLanation does not however pre~cLude an adverse effect of o~qIL on pL~an~qKt~on which cou-Ld c~once~qiv~abL~qU contribute to pLan~qKt~on mortaLit~qU~. ~qO~qIL Contamination Of ~qZ~oopL~an~qKt~on And Fish 8.3.1 Ch~qem~qicaL Examinations Ten ~sa~m~qpLes of zoo~qpL~ankton and fish from Danish hauLs Were chem~qic~aLL~qU examined for petroLeum h~qUdrocarbons b~qg the Water ~qQuaL~qit~qy Institute (Hansen et ~a~qL., 197~q13). 8.3.1.1 AnaL~qUt~qIca~ql Procedure In ~qgeneraL~, the procedure of Farrington an~qd Tripp (1975) and Farrington an~c~qr Mederias (1975) was app~qt~qled for extraction and ~qIsoL~at~qion of the h~qUdrocarbons between n-C~q12 and n-C~q3~q6. An amount of 2 to 20 ~qg (wet weight) of ~qb~qioLog~qic~a~qt materiat was used for each anaL~qWsis. After homogenization in a bLe~n~qd~er~. the s~ampLe was re~qfLuxed for a few hours with 40 g KOH per Liter or ~q30 percent meth~anoL~. After c~o~oL~qing. the mixture was ~qf~qi~qLtered with ~suct~ql~on If s~oL~ql~qd materiaLs were present. The residue was washed off the ~qf~qlLt~er with a ~sm~aLL voLume of pent~qane. The saponification mixture, If ~4qfi~4qL~.tr~qatlo~qn was neces~qsar~2qg~q. was extracted three times with pent~qane~q. The extract was evaporated with a rot~qar~2qg evaporator unt~8qIL I to 2 mL remained. CoLumn chr~qom~qatograph~2qU of the extract ~qWas perrormed ~0qb~qt~2qj using a ~qco~4qLumn of equaL amounts of a~2qLum~8qin~qa (~2qAL203) packed on top of siLic~qa (~8qS~8ql~2qo2)~q. The aLumina ~0 and ~s~qIL~qIc~a were activated overnight at 250 C and 150 C~, re~spect~qive~qL~qU~, and both were subsequentL~qg deactivated with 5 percent of water. The ratio of coLumn m~ater~qiaL to non~sap~oni~qfiabLe L~qip~qid had to be 100:1 or more for the an~aL~qy~s~qi~s to continue. The coLumn was eLuted with 1~.5~- coLumn voLumes of pent~ane + benzene (~q8~q0 percent + 50 percent by voLume). The eLuate was evaporated to near dryness on a rotary evaporator and then re~qd~qissoLve~qd ~qin a sm~aL~qL v~oLume of CC~qL4. A few microLiters were Injected Into the gas chromatographic coLumn~. A standard n-~aL~qK~ane mixture of Known concentration was used to measure the detector response per unit weight of aL~ql~,~@~ane. The ~qInternaL standard used was n-C22. Gas chromatography was performed on a SCOT c~a~qtumn as described in Chapter 5.1. 8.3.1.2 Re~suLts The resuLts from some of the gas chromatographic ~q(G~qC) ~anaLyses on the SCOT coLumn are shown in Figures ~q8-~q2 through ~qB-5. In ~aLL the c~qMromatogr~ams a few Figure 8-2. Gas chromatogram of Boreomysis from station 5465. ~2q@~qi ~8q4~qt~0qi~0qj ~4qi~l~0q/ very strong peaks dominated, showing the presence of ~8qO~8qlogen~4qic hydrocarbons. One of these, prist~qane. has been found In ~qaLL the sampLes. Most of the sampLes ~qaLso show the presence of a comp~4qL~qe~qx mixture of petr~qo~8qteum hydrocarbons. The amounts of petro~4qLeum hydrocarbons are Low 8-12 f -4 Figure 8-3. Gas chromatogram of Themisto from station 5465. Figure 8-4. Gas chromatogram of a Copepod from station 5470. ~0 8-13 Figure 8-5. Gas chromatogram of a Copepod from station 5477. Reference station located 50 nmi southeast of the spill site.' compared with the amounts of the biogen~qic h~qUdroc~arbons. PetroLeu~m h~qUdr~ocarbons were found even in the reference sampLe from Station 5477 (Figure ~q8-5). ~qOnL~qu two s~am~qpLes seemed to be uncontaminated with petr~oLeum h~qUdr~ocarbon~s. ~q8.3.1.3 Discussion The copep~o~qd ~sampL~e from Station 5477 was taKen as a reference ~sam~qpLe far from areas contaminated b~qg the POTOMAC ~o~qIL. The sm~aLL amounts of petr~oLeum h~qUdroc~arbons found b~qg GC ma~qg indicate inadvertent contamination either during samp~qL~qin~qg or anaL~qUsi~s. However. the an~aL~qUt~qicaL method couLd not distinguish between intern~aL or e~xternaL oiL on the organisms. As a wh~oLe, the Largest amounts of petroLeum h~qUdrocarbons were round In c~opepo~qds~. which have a rather high ~qL~qip~qid content, and the ~qtowest amounts were found In pter~apod~s, which have Low ~2qL~8qIp1d content. This Indicates that ~qonL~8qg part of the petroLeum hUdroc~qarbons found are r~qeL~qate~8qd to contamination either during s~qampL~0qing or anaL~2qU~qs~6qi~qs. ~0 8~14 No correLati~on was found between the water ~anaL~qUs~qi~s performed b~qy fLu~qorescence and the zoopLankton analyses performed b~qy GC. This could ~qbe the result of the fact that t~qhe amounts or petroleum hydrocarbons found In the z~oopLan~qKt~on are relatively Low and dependent on other factors such as ~8qUp~qId content or the fact that the resu~qLts indicate the possibility of contamination during either s~ampLing or analysis as mentioned above. Earlier investigations (Johansen et ~aL 1977) In the area off West GreenLand which studied invertebrates. fish. and sediments, showed no presence of petroleum hydrocarbons. 8.3.2 ~qPh~qU~qsIcaL Ex~am~qinat~qidns ~q6.3.2.1 Procedure The Danish p~qLan~qKton samples were examined under a dissecting microscope for the presence of o~qi~ql. The contamination was classified as 1) external ~qr~or o~qi~ql adhering to the cuticle and adhesion to appendages or 2) internal for ingested ~o~qIL. Specimens suspected t~qo be conItam~qinated In the gut with o~qi~ql were cLe~are~qd with Lactic acid. 8.3.2.2 Results The occurrence of contamination is shown in TabL~e ~q8-~q6. Station 54~q60: The sample was Collected at the spill site where no ~o~qi~qL was visibLe~, but increased h~qUdr~oc~arbon Levels were found in the water. ~qT~qhe highest percent of oi~ql Ingestion was found at this station. The number of pL~an~qKton with algae in their guts was also high. Station 5461~:~-The sample was COLLected in an area with o~qi~ql p~anca~qKes on the surface and the ~qpL~an~qRt~on net retained both o~qiL and pLan~qKton organisms. Many of the organisms had o~qiL adhering to their exos~qKeLetons~. but It was impossible to determine whether or not the o~qi~ql was present before they were caught In t~qhe net. It was rem~ar~qk~abLe that the mandibles were often contaminated. No o~qi~ql was seen as ingested. and very few organisms had ingested algae. Station 5464: The sample was ta~2qR~qen in an area with ~qo~8qIL p~qanca~8qKes on t~4qhe sea surface; however an attempt was made to avoid oiL contamination of the pt~qan~2qKton net. Even so, contamination of the pL~qan~0qKton after capture cannot be excluded. About I percent of the c~qopep~qods were round contaminated with o~4qi~4ql Table 8-6. Occuirence of oil contamination on dominant plankton groups. Station Plankton Examined Contaminated Type of Contamination No. No. % External Ingested 5460 Copepoda 1739 62 4 5 57 5461 Copepoda 2005 N - N 0 5464 Copepoda 1044 11 1 9 2 Parathemisto 19 2 11 1 1 Chaetognatha 715 2 0.3 2 0 5473 Copepoda 355 1 0.3 N I Parathemisto 520 4 0.8 N 4 N Many individuals were observed with external contamination. These were not counted because oil particles were also caught in the net and the contamination may have occurred after collection. and two specimens were found with oiL in their guts. Of the 19 Parathemisto in the sampLe. one was contaminated externaLLy and another internaLLU. Stations 54G9. 5470, and 5471: These Stations were acquired weLL to the north of the oiLed area. No oiL contamination in the gut or on cuticLe was found. Mang of the copepods had aLgae in their guts. Station 5473: Both oiL fLaKes and pLanKton were contained in the sampLe so the number of externaLLU contaminated specimens was not determined. No oiL at aLL was found in the guts of pterapods and onLU two specimens of arrow worms were externaLLU contaminated. The oiL particLes found in the guts of the copepods were examined with a fLuorescence microscope but no fLuarescence was seen. OiL was ccLLected together with pLanKton in aLL of the.NOAR sampLes. The aLimentary tracts of individuaLs that appeared darK were removed, cLeared, and examined to determine whether or not oiL had been ingested. No oiL was found in ang. of the aLinentary tracts examined. ~0 8.3.2.3 Discussion The percentage of pLan~qkton~qic organisms affected by o~qiL was smaLL and thus there was probabL~qU no major effect on the pL~ankton po~qpuLation. The percentage of ~qIndividuaLs with o~qiL in their guts was sm~aLLer than that found at the ARGO MERCHANT o~qiL sp~qILL (Maurer. 1976). The s~ampLe coLLected at the spiLL site (Station 5460) was the onL~qW one with a high percentage of copep~od~s having oiL in their guts. Furthermore, the s~ampLes which had o~iL coLLected in the net did not show a high incidence of c~opepods with o~qiL in their guts. The number of Parathemisto ~qLibeLLu~qLa was gener~a~qtLy Low except at station 5473 and the neuston stations: however. the percentage of ~IndividuaLs which had Ingested oiL was higher. This may be the resuLt of differences in the size of the oiL particLes avaiLibLe for consumption. Parker (1969) found that cop~epods with smaL~L particLes ~of a BunKer-C oiL in their guts did not show signs of distres~q@~. However, Larger o~qiL particLes might cause a bLocKa~qde of the guts with fataL effects for the ind~iv~idu~aL specimens. In cases of both internaL and externaL contamination. the growth and reproduction of individuaLs, if not their very survivaL. may be affected. E~xos~keLeton contamination may inhibit sensitive chemo-receptive pores used for positioning during reproduction (FLeminger, 1973). Adhesion of oi~t to appendages ~c~ouLd aLs~o interfere with the feeding currents and food hand~ting. In addition. those ~qindividu~aLs which were contaminated to the extent that they cou~td not make quick escape responses wouLd be more vuLnerab~Le to predation. 8.4 Summary Two separate and distinct pLanKton communities were present In M~eLv~iLLe Bay during the post-spiLL ~samp~Ling period. The surface Layer, was st~rong~qL~qy dominated b~qy the h~qyper~qid amphipod Parat~qhem~qisto L~qIbeL~LuLa, wh~qiLe the water coLumn pL~an~qkton were dominated by the copepod CaLanus h~quperboreu~s. White p~art~qicLes. which were determined to be the re~qi~q@~ains of dead copepods in some cases. were observed fLoat~qing in Long streamers In parts of MeLviLLe Bay after the sp~i~qLL. This phenomon~a appears to be n~atur~aL and not reL~ated to the oiL spiLL. As~q.evidenced b~0qy gas chromatography of seLected zo~qopLan~qKton, Low LeveL~qs of petroLeum hydrocarbons were found in most of the s~qampLes incLu~qd~qx~qr~q.~q@~q.~.~ql ~qt~q-h~q-~q,~q3s~qe ~0 ~6-17 c~oL~qLected at a reference station which ~shouL~qC not have been Impacted or exposed b~qy oiL from t~qhe USNS POTOMAC. This Indicates that either t~qhe ~sampLes at the reference station were inadvertentL~qU contaminated b~qy the gear used or were contaminated b~qy the ADOLF JENSEN cooLing water. V~qisibLe oiL contamination was observed on 11 percent or the P~arathemisto at one station. Copepod contamination did not exceed 4 percent at an~qy station. Ingested ~oiL was the dominant contamination onL~qU at the sp~qILL site (Station 5460); at the other stations. externa~qt contamination predominated. The effects of this vi~s~qIbLe contamination. either internaL or extern~aL~. on the ~urvivaL or reproductive behavior Is not known. Since onL~qU a sm~aLL portion of the tot~aL zoopLan~qRton popuL~at~qion of MeLv~qiL~qle Bay was beLleved to be affected b~qy the oiL spiLLed from the ~qUSNS POTOMAC. there was prob~abL~qU no major effect on the z~o~opL~ankton P~OPULation from this sp~qiLL~. 9.0 MARINE MAMMALS AND SEABIRDS 9.1 Observations Of Marine MammaLs Marine mammals were observed from the ADOLF JENSEN by J. Christiansen of Marin ID. In the area north of UpernavlK over the period from August 12 to 20, 43 ringed seats (Pusa hispid ), 4 hooded seats (Cystophor cristata), I bearded seat (Erianathus barbatus), and 7 unidentified seats were observed. During two heLicopter fLights on August 16 covering most of MeLviLLe Bag. scientists from the ADOLF JENSEN observed onLU 2 seats. Of the 43 ringed seats, 32 were observed in association with winter ice and 25 of these 32 were observed before reaching the.spiLL site while passing through a beLt of pack ice. The remaining 7 were observed amongst and on rotten ice near Thoms IsLe (75*43'N 6.0035'W). The other seats were observed in open water. often near icebergs. In an oited area. 4 seats were observed together near an iceberg. but nothing unusuaL was observed about their behavior. The sightings of most of the seats near sea ice rather than in open water was quite normaL and agreed with investigations made in the area two years earLier. The smaLL number of seats observed in the oiLed area can be expLained by the Lack of ice in the area without recourse to an avoidance behavior of seats for oiLed water. No deaths or abnormaLities of seats were reported except for some instances of oiL contamination on their skins. 9.2 OiL Contamination Of SeaLsKIns White no seats were captured during the spiLL response, a LocaL hunter did report oited seaLsKins about one month after the spILL. In totaL, about as. oiLed skins were reported. The skins of IS seats. aLL shot or captured in nets, were deLivered to Denmark for anaLysis (Figure 9-1 and TabLe 9-1). Seven of the seats were heaviLy c6ntaminated with oiL on their backs with Lesser amounts on their necks (seats 1, 2, 4, 8, 9, 11. and 13). Three seats had spots of oit on their backs or necks (seats 3. 6. and 10). On eight of the seats it was not possibLe to either see or smeLL oil. (seats 5. 7. 12, 14, 15, 16, .17, and 18). Ten samptes from olted skins and four sampLes from seats 9-1 ~0 9-2 Table 9-1 Date and Location of Seal Catchings. Seal Date Location Position no. ~q1 9/29/77 Moriussaq 76048~'N 70005'W 2 9/15/77 Kuvdlorssuaq 74034~' 57020' 3 11~q/23/77 Tasiussaq 73~020' 56~005' 4 1/26/78 Godhaven (Parry Sk~z~er 69010' 53040~' 5 - 12 Jan-Feb 78 Upernavik area 72035~' 560 13 April 78 Niaqornarssuk 68015' .52050' 14 - 18 Mar-Apr 78 ~qVpernavik area 7203511 .560 with no visible OIL were anaL~qUze~qd b~qg the Water Quality Institute to determine whether or not an~qg OIL originated from the USNS POTOMAC spill. 9.2.1 ~qAna~qL~qutica~qL Procedure The o~qiL was mech~an~qicaLL~qu~*~qiso~qlated from the hair ~an~c~qr the fat. For one sampLe (seat 1). the Isolated ~O~qI~qL was dissolved in a small volume of CCL4 and a few microliters were injected Into a gas chromatographic c~rLumn. For aLL other samp~qte~s, a cleanup procedure was neces~s~ar~qg to Isolate t~qM~e h~qg~qdroc~ar~qoon~s from Interfering components. The cleanup procedure was Similar to that described in Chapter 9.2.2 ResuLt~s Gas chrom~ato~qgrams were obtained on a SCOT column an~qd a ~qf~ew examples are presented in Figures ~q0-~q2~1 to 5-7. It was not poss~q1~q1~3~qLe to detect petroleum h~qWdroc~arbon~s on seats 5~, 7, 12, or 14 confirming the visual a~nd oL~qfactor~qg examinations. Petroleum h~qWdrocarbons were detected In the extracts made from sea~Ls 1. 2, 3~, 4~, ~q6, ~q8, 9~, 10. and 11. The compositions of the h~2qUdrocarbons from seals 1 and 2 (Figures 9-2 land 9-3) were similar to the composition of the ~0qh~8qg~0qdroc~qar~4qbons collected on the sea surface at the sp~8qiLL site. In these cases it seems probable that the contamination ~qa~qf, these two seats originated from the POTOMAC spill. 9-3 90, 80' 70* 60' 50* 40* 30* 20* 10* 0o 80, 80o MAO 75* 75o OAF N(ORY, 2 3. UPERNAVIK 5-12 70- 70' 14-18 UMANAK GODHA CHRISTIANSHAAB 13 LL U- 65* 65* DAVIS STRAIT GODTHAAB 60' 60* 70o- 60* 50* 40' Figure 9-1. Capture locations of the analyzed seals. See Table 9-1. 9-4 Figure 9-2. Gas chromatogram from seal 1. Heavily oiled on back. Collected north of Thule, Greenland on September:29, 1977. @igdre' 9-3. Gas chromatogram from seal 2. Heavily oiled on back. Collected east of the spill site on September 15, 1977. The compositions of the hydrocarbons from seaLs 4 (Figure 9-4), 6, 9, 10 (Figure 9-5). and 13 (Figure 9-6) were different from the surface oIL sampLes. The sharp peaks found In the surface oit sampLes (Figure 5-4) were Lacking in the chromatograms from the S2aLs. This difference miu be due to biodegradation. and it shoutd be considered that these petroLeum hydrocarbons night have originated from the POTOMAC spiLL. 0@1 The missing peaks are aLso evident in the chromatogram rrom seaL 3 (Figure 9-7). Furthermore, the composition of the hydrocarbons In sampLes 9-5 Figure 9-4. Gas chromatogram from seal 3. Spots of oil on neck. Collected southeast of the spill site on November 23, 1977. Of '@'igure 9-5. Gas chromatogram from seal 4. Heavily oiled on back. Collected well south of spill site on January 26, 1978. Figure 9-6. Gas chromatogram from seal 10. Spots of oil on neck. Collected southeast of the spill site in January 1978. Figure 9-7. Gas chromatogram from seal 13. Heavily oiled on back. Collected well south of the spill site in April 1978. ~0 ~9~~7 from ~s~eaL 3 showed more n-~aL~qk~anes with carbon numbers above 20 than d~qi~qd the surface ~O~qIL sampLes. Some n-aL~qNanes with carbon numbers above 20 were aLs~o found in extracts from se~aLs 8 and ~qI~qI. The presence of these n-aLKanes couL~qd be due to a contamination source other than the POTOMAC. It was not po~ss~qibLe to determine if the other hydrocarbons on these seaLs came from the POTOMAC oiL ~spiLL, because the anaL~qUt~qicaL procedure was not definitive enough to distinguish between the ~seaL contamination and the USNS POTOMAC SL~qI~cK sampLes. H~qist~oLogica~qL examinations were conducted on the skin underneath the ~oiLe~qd areas on some backs of the seaLs. No damage was seen during these examinations. In contr~qo~qt~qte~qd experiments with heav~qIL~qU o~qiLed seaL~s (EngeLhar~qdt~, 1~q97~q8). the ~on~qt~qy Long term effect of OIL contamination found was the appearen~ce of cornea Lesions. ALt~qhough the seaLs were tot~aLL~qg coated with ~O~qIL during EngeLhardt's experiment, they were compL~eteL~qy cLean after 6 days in an ~O~qIL free environment. The persistent extern~qaL contamination or seaLs from the West Coast of GreenLand after the POTOMAC OIL sp~qiLL might be attributed to differences in the composition of t~qhe contaminating ~o~qiLs~. ALL the ~O~qiLed seaLs reported were either shot or caught in nets; however, it is not certain whether or not the ~oiLed ~seaLs ware more suscept~qi~ql~3~qLe to capture. 9.3 Seabird Observations Observations of seabirds were routineL~qy conducted from the ADOLF JENSEN. Very few birds were observed in the ~O~qiLed areas during the August study period. Apart from a few ~qfLoc~qRs of Litt~qte ~qAu~qKs (PLotu ~a~qL~qLe) and ~qKittlwa~qkes ~q(~2qR~ql~qg~qs~qa ~qt~qr~qld~act~L onL~qy ~s~oL~qttaru birds such as Gu~qLLs (L~aru~s ~q2~4qE~.), Gu~qi~qt~qtemote (~8qS~qp~q2~q2hu~s gr~qy~qLLe)~, an~qd FuLmars (FuL~m~aru~s ~qg~qL~ac~qIaL~ql ) were observed. Some of the birds were seen f~qLo~ating on the sea surface and observed to take off In areas where an ~O~qIL ~qf~qiLm covered the surface; however, no smudged birds were observed and the birds in the oiLed areas behaved ~qident~qic~aLL~qU to those ~qin un~o~qlLed areas. Birds were not observed In direct contact With OIL pancakes nor were an~qy tr~oubLed or dead birds observed. Furthermore, observations from heLicopters did not Indicate an~2qy effect of the ~qO~4qIL on the birds. Except near b~6qir~2qdcL~2qi~2qf~2qfs~q, none of which were Located In the vicinity of the spiLL, very few birds were observed either In t~8qhe sp~4q!~8qt~4qL area or aL~qong the crufse track to the south. The stomach contents of a s~4qingLe FuLmar. shot In the sp~2qILL vic~2qinft~2qg~q, showed no signs of petroLeum hydrocarbons With ~8qga~qs ~0 9~~8 chromatographic analysis. A ~qW~oung Gull with black Legs and breast was reported on October 2. 1977 at Sav~qigs~qiv~qi~qk (760 ~q02~'N ~6~550 00~'W) ~q(-92 nm~qI to the northwest of the spill site). As the v~qic~qin~qit~qg of the spill area Is generaLL~qU deserted. it Is understandable that rew oiled birds were reported. The spill occurred in a Location and season such that no harm to birds was observed. However, during another season or near b~qir~qUcL~qi~qrrs~. a spill or the same size as that of the POTOMAC might have caused extensive damage, e~spec~qiaLL~qU when ~qUoung birds might be Leaving their nests. ~0 10.0 IMPACT ASSESSMENT 10.1 Fate Of The SPI~qLLed OIL On August 6, 1977, ~approx~qim~ateL~t~qj 107,000 U.S. gaLL~ons ~q(~-38~q0 tons) of ~qBun~qker-C fue~qL from the USNS POTOMAC was ~sp~qI~qLLed Into Me~qLv~qILLe Ba~qy, Green~qt~and after a fueL tank was ~"hoLed~" b~qy a sma~qLL Iceberg. This ~qfueL was a bLen~qd of 55 percent pitch (specific gravity 1.~q0~q54)~.and 45 percent cutter stock of No. 2 fueL (specific ~qg~qe~q%~iv~qi~qt~qy ~q0~.~q8~q8~q3) Which ~qInit~qiaLL~qU remained on the sea surface because its specific gravity Of 0.976 Wa~s Less than that of the surface seawater, 1.024. The ~qfLoating ~O~qIL was a~qO~vected to the north and west by the sLow gener~aL c~qircuLat~qion in the area. H~qi~qgh~qL~qQ var~qlabLe Light winds tended to disperse the ~O~qIL over a Large area. Based on various measurements, ~qit Is estimated that the ~O~qIL was not ~advected more than 40 nmi from the sp~qi~qL~ql site, with the ~qin~qit~qia~qL direction being north then shifting to the west after one week. The traces of surface ~O~qIL found In neuston tows during the return to ThuLe~. GreenLand of the USCG icebreaker WESTWIND are beL~qleved to nave originated by continued Light Leakage from the hoLed ~qfueL tank as the POTOMAC continued to~'~qIts destination at ThuLe. The return path of the W~qESTWIND was identicaL to that of the POTOMAC so that these ~sa~m~qpLes wouLd have been taken where the pro~q0abiLit~qU of finding ~O~qIL from continued Leakage was highest. During the two weeks ~qfoLLowing the sp~qILL~, the composition of the ~O~qIL on the sea surface changed through evaporation such that. b~qy August 20, ~aLmos~qt ~aLL of the~.L~ow b~oiL~qlng point fraction of the cutter stock~; components up to n-~qC~q17 (b~o~qlL~qing point 300 C), had disappeared. This evaporative Loss amounted to about 33 percent of the t~otaL ~sp~qiLt (35~.~q00~q0 ~qgaLL~ons~q). It Is estimated that a great part of the remaining ~O~qIL (~q6~q6 percent of the tot~aL) sank 1,000 ~qm to the bottom over a Large area ~q(~-5~q00 s~qq m~ql) of MeLv~qILLe Ba~qy~, because of the Increase in specific gravity of the ~qO~2qIL remaining after evaporation. Sinking was confirmed b~6qy the visuaL observation of sM~qaLL ~4qfLaKes (I cm diameter) within the water coLumn after August 1~2q8. It is hypothesized that the ~8qrLaKes were or~8qiginaLL~8qg the skin of ~qO~8qIL Lenses which. after depLet~4qion o~8qf~q,the more v~qoL~8qit~2qiLe components, were sL~qoughed off or ex~2qfoL~8qiated from the pancakes. ~8q1~2q0~q-~8q1 Bg August 20, only small amounts of oft were observed on the sea surface in the spiLL area. The oft was in the form of small pancakes (maximum diameter of 5 cm) which had Lost almost all of the sheen which had surrounded them earlier. These pancakes were found In windrows severaL hundred meters Long and a few tens of meters wide with a mean spacing of I or 2 meters between pancakes. The total volume of oft in each of these windrows (300 m by 30 m size) was estimated to be about 20 gallons. On August 21 windrows of oft were sighted at 74"55'N, 60*12'W from the ADOLF JENSEN. These were the most southerly observations of the oft. Some. If not aLL, of this oft mag have remained on the surface until it biodegraded or moved out of MeLviLLe and Baffin Bags and into the North Atlantic Ocean. Scattered sightings of oil were received from the region over the 9 months following the spiLL. One sample collected on October 18. 1977. was anaLgzed bg GC and appears to be identical to the POTOMAC oft. Since Melville Bay should have started freezing over bg Late September, six weeks after the spill. whatever oft remained on the surface would have been trapped into sea Ice where It might have become highly visible. Also. the end of the shipping season arrived in early September. effectively removing the possibility of ang subsequent sources of spitted oft. Thus it Is reasonable to assume that any OIL sighted during the next.9 months came from the one Known Large spill. that ofthe USNS POTOMAC. Low concentrations of USNS POTOMAC oft were found In the water column with maximum reported concentrations being between 2.5 and 4.9 ppb. OIL was also found adhering to and injested bg some zoopLanKton. At the Low water temperatures of 4 C, there was virtuaLLg no biodegradation of the oft over the duration or t6e major part of the spill (2 to 3 w2eks) as indicated bg microbiological studies and chemical analyses (n-C17 / pristine and n-C18 / phytane ratios). Despite the high asphaLtene content (15 percent), the spitted oft did not form a water-in-oiL emulsion (mousse). This can probably be attributed to the small amount of mixing energg avalLibLe (wave heights were tUpIcalLU Less than 30 cm) and to the oil temperature being quite close to the pour point for the unweathered Bunker-C fuel. In summary. the fate of the 107.000 gallons (380 tons) of spitted Bunker-C fuel was that 33 percent (-35.000 gallons) evaporated; the major part of the remaining -71,000 gallons seems to have sunk In 1,000 meters of water ~0 o~Ver a Large area of MeLv~qiLLe Ba~qy and a sma~4qU part remained on the surface as SM~aLL panc~a~qNes (Maximum diameter of 5 ~cm). A very s~amLL amount of the o~qlL was accommodated into the water ~coLumn. 10.2 Impact Of The SpiLLed OIL On ~qBl~ot~a Me~qtviLLe Bag is not a hIghL~qU bi~opr~oduct~qive area in terms of fisheries. aLthough it is important as a native ~se~aL~qing area. ~qAn~aL~qgses of pLan~qKton ~~ampLes acquired during Danish tr~awLs indicated that there was ~o~qlL ingested b~qg some c~opepods and amphipods. Four percent of the copepods at the ~spiLL site (station 54G~qO) were found to be intern~aLL~qy contaminated with o~qiL~. with Lesser amounts observed at other stations. Extern~aL contamination of pL~ankton ~L~u~l~as ~~qLs~o observed but, because the nets a~qtso coL~qLected o~qiL~. it was not p~o~ssibLe to determine whether this contamination occurred before or after the pL~an~qkter~s were caught. The actu~aL impact of zo~opL~an~qkton cont~:~Dmin~ation is un~qKnown~; however, the consensus of the concerned r~qi~sher~qie~s ~q0~q1~OL~og~qists Is that there wouLd be no Lasting effect for two reasons: first, the totaL occurrence of the contamination was Low. with onL~qy 4 of 15 stations reporting any occurrence of ~internaL contamination and second. the contamination was observed onL~qW during two weeks of t~qhe more than 12 wee~qR ice-free period. As a worst-case estimate, a maximum of 0.2 percent of the tot~aL se~ason~aL ~qpL~an~qKton might have been contaminated. ~qFLo~ating white particLes~. some of which were identified as remains of zoopLan~ql~,~.ton~. were observed within windrows in the MeLv~qILLe Bay area. It is ~beLieved that these were a natur~aLL~qg occurring phenomona and not reLat~e~qd to the spiLL~H~qd ~oiL as the~qg were ~aLso observed in nono~qlLed areas and had been report~e~(~q; in the hist~or~qic~aL Literature. There was o~qiL contamination on the s~ql~@~qins of some se~a~qLs ~qKiLLed b~qg native hunters after the ~spi~qLL incident. Some of this contamination m~a~qg have come from the U~qS~qM~qS POTOMAC. It is impro~qb~a~qbLe that these instances or o~qI~qL poLLUt~qIon had any effect on the he~qa~4qLth or activities or the se~qaL~qs. Sea birds were rare i~qr ~08qU~q-~q1~qe vicinity of the o~8qiL ~qsp~4qILL, and no not~qice~qa~0qt~ql~8qLe impact was observed on the few ~4qindiv~8qiduaL~qs studied. ~0 10-4 1~q0.3 C~oncLusl~ons The ~oiL ~sp~qiLted from the USNS POTOMAC s~qigni~qf~qicantL~qg contributed to the p~oLLuti~on of MeLvi~qLLe Bag which n~ormaLL~qy has very Low petroLeum h~qUdrocarbon ~qtevet~s in its surface waters. This incident prob~abL~qg had no Lasting effect on the ec~oLo~qg~qy of the region. It Is estimated that the greatest part of the sp~qi~qLLed ~o~qiL sank to the bottom where it Is expected to remain indefin~qiteL~qg. 11.0 SIGNIFICANT SCIENTIFIC FINDINGS During the course of the USMS POTOMAC spill, response and the subsequent analysis. there were several findings which are worth isolating either because theg were significant with regard to the behavior and rate of the spilled oil or were of interest for ecological reasons. 11.1 Observations On The Behavior And Fate Of The Spilled OIL Significant were made concerning the sinking of the oil and the weathering rates,in the Arctic environment. 11.1.1 Sinking of the OIL In terms of the observed behavior or the fuel SPILLed from the USNS POTOMAC. the sinking of the oil was probably the most Important. Eleven days after the spill, flakes of oil were observed within the water column. These flakes were from 5 to 10 mm on a side and about I mm thick. resembling soggy breakfast cereal @LaKes. Two possible mechanisms can be hypothesized for their origin. Either theg'were the residual of weathered tenses of once floating oil or they were pieces of the skin of oil Lenses. Since the pitcM component of the blended BunKer-C fueL was significantly denser than seawater. after 73 percent of the cutter stock (33 percent of the original blend) Mad evaporated. the density of the residuat would be high enough to sink. The evidence points to exfoLiation of the skin, rather than total weathering of small Lenses. as being the origin of the subsurface fLaKes. This evidence is Indicated by the small size of the subsurface fLaKes as weLL as the asphaLtene anaLyses of the surface oil. Total weathering of Lenses should have produced a size range of subsurface flakes which corresponded to the original Lens sizes; however, only small subsurface flakes were observed. The asphaLtene anatUses are somewhat anomalous. but they do Indicate a differential process as the origin of the flakes. It was observed that the asphaLtene content of the floating oil remained constant during the first 15 days or weathering. During this same time period. the Lighter fractions of the cutter stock were being preferentially removed, presumably by evaporation. To retain the constant Levels of asphaLtene in the remaining floating oil. the asphaLtenes 11-1 ~0 11-2 wouLd have to be removed at a rate pr~oport~qion~aL to t~qhe Lighter fractions. Evaporative Losses of the asph~a~qLtenes appear unreas~on~ab~qLe because of their high moLe~CUL~ar weight. However, the ~asphaLtenes m~a~qg have become enriched in the surface Lagers of the ~qfL~o~ating Lenses b~qg a mechanism such as cr~qg~staLLiz~ati~on or precipitation as the Light fractions evaporated. Since the mobiL~qit~qU of the h~qUdrocarbons within the buL~qk ~oiL Is Limiting for weathering processes (as opposed to the evaporation rate), it Is re~a~son~ab~qLe to expect that the surface skin c~ou~ld be rap~qid~qt~qg depLeted in the Lighter fractions and become s~qignificant~qL~qU denser than the buL~qK oiL of each Lens. Given sufficient mech~an~qicaL energ~qg to peeL the the skin from t~qhe Lens. the skin shouLd be dense enough to sink. The exfoL~qlation process m~a~qg have been augmented b~qg t~qhe pL~ate-Like structure of the pitch which formed the Larger component of the ~qorig~qin~aL bLen~qd. The exfoL~qlat~qlon e~xpLanat~qion for t~qhe origin of the ~qf~qLaKe~s couLd have been confirmed If the a~sp~qhaLtene content of subsurface ~qfL~a~qkes had been measured; however, the one fL~a~qKe which was coLLected was too sm~aLL for this t~qUpe of ~an~aL~qgs~qis. A further caution Is that actuaL instances of exfoLiation in the fieL~qd were not observed. But some mechanism must ~qdepLete the aspha~qttene~s in the bu~qL~qK oiL; and the exfoL~qlat~qion of weathered skin. which is enriched in asph~aLt~enes~. is one which appears v~ql~a~qOLe. The significance of the sin~qR~qing is that the causative process was not sedimentation but a process p~oss~qIb~qL~qg more compLex than simpLe evaporative weathering. If the h~qgpothesiz~2d e~xfoL~ql~at~qion of Lens skin was the ~a~ctuaL process, then a reLativeL~qU new sinking process is brought to Light which can potenti~aLL~qg cause rapid breakup of oiL Lenses and ~q(poss~qibL~qg) sinking. The exfoLi~ati~on process shouLd be investigated further. 11.1.2 Weathering Rates Over the course of the eight d~a~qu~s of ~qf~qleLd observations, it was noted that the sheen surrounding Lenses of thick (ca. G mm) o~qiL decreased In area to the point that. b~qg the 14th d~a~qg after the sp~qILL~. t~he sheen was no Longer visibLe. Ch~emi~caL anatyse~s of the ~O~qIL remaining In the ~qfLoat~qing Lenses indicated that ~qaLmost a~8qLL of the fractions which had GC retention times Less than n~q-C12 were Lost. ~8qALso~q, fractions between n~q-CI~8qZ and n-C~4q17 were substanti~qaLL~2qU depLeted with Losses decreasing as the carbon number got Larger. These Loss rates were surprising in Light of the coLd temperature ~0q(4 C)~q, Low wind speed (maximum of 4 m/s~q: average of 2 m/s), and the thickness or the 11-3 tenses. The toss of sheen at the same time that the Lighter fractions vanished suggests that the sheen was composed predominately of these Lighter fractions. Thus the generation of sheen serves to deplete the bulk oil (thick Lenses) of the Lighter fractions bg phUsIcaL fractionation. The Increased surface area of the sheen. attributable to the Lower surface tensions of the Lighter fractions, would allow for increased evaporative Losses. The maximum concentration of petroleum hydrocarbons actually found within the water coL'umn appeared on August 13, the first day on Which water samples were collected. It amounted from 2 to 6 pg/L, depending on the method used for quantification. 11.2 Biological. Findin gs Biological findings Included the potential for biodegradation of the Spitted oil and further information on some aspects of the ecology of MeLviLLe Bay. 11.2.1 Biodegradation Specific Studies using both natural and Isolated monocuLtures or microorganisms were conducted to investigate the potential for biodegradation of the spitted oil. From the collected water samples, eight microbiological. strains were found which degraded oil. These represented less than I percent of the total organisms found. Of these eight, two were found to degrade paraffins (aLKanes) at a temperature or 5 C. At these temperatures, no strains were found which wouLd degrade cUcLoaLKanes or aromatics. As expected at this Low temperature of 5 C, the observed degradation rates were slow as evidenced by no increase In the total numbers of oil degrading microorganisms in water samples collected in the oiled area 8 dags apart. The Lag period for cultured growth appeared to be In excess of 8 weeks using Melville Bag seawater at 15 C temperature. However, the addition of nutrients (I g/L of K2HPO4 and 2 g/t of NH4NO3) induced more rapid growth at 15 C. With the adde- nutrients. the Lag period was found to be Less than 2 weeks. 11-4 11.2.2 ZoopLankton ZoopLankton sampLes coLLected in MeLviLLe BAW were dominated by copepods (CaLanus huperboreus and C. gLaciaLis) in trawLs integrating the upper water coLumn from 250 meters to the surface. These two species aLso dominated the Bongo tows taken between 5 and 20 meters deep, white an amphipod (Parathemisto LibetLuLa dominated the surface neuston tows. TemporaL spacing of the sampLes precLuded more quantitative verticaL zonation because of known migration habits. Ingested oiL was found In up to 3 percent of the examined copepods at ang one station and up to 5 percent of the amphipods. At severaL Locations within MeLviLLe Bag. white particLes (opaque fat gLobutes) were observed in windrows where they had been naturaLLy concentrated. In some instances these white particLes had remains of copepod tissue associated with them which Identified their origin. It is feLt that these kiLLs were a naturaL phenomona and not reLated to the olL spILL because theg were found in areas which shouLd not have been affected by any oiL from the USNS POTOMAC. 11.2.3 Birds and MammaLs Birds and seats were not abundant in MeLviLLe Bay during the AuiSust fieLd study period. A few fLocks of Auks and KIttIwaKes were observed as weLL as a few soLitary GuLLs and FuLmars. None were observed to be infLuenced bg the oiL. Fiftg-five seats were observed. 43 of which were ringed seats. Twenty-five of the seats were spotted weLL south of the spILL site. OnLy 4 seats were seen in the oiLed area; however, no unusuaL behavior was observed. Starting in September. 5 weeks after the spILL. the first of 29 reports of oiLed seaLskins surfaced. ALL of these reports came from native eskimo seaL hunters. Eighteen of the 29 skIns were deLivered to Denmark for anaLyses. Ten of the 18 were surficiaLLU contaminated bg petroLeum hydrocarbons, white the remaining 8 were cLean. Seven of the contaminated skins mag have contained oiL from the USNS POTOMAC. No damage to the skin underneath oiLed hair was observed during histoLogicaL examinations. ~0 11-5 11.3 C~oncLus~qlon~s WhiLe the BunKer-C fue~qt ~sp~qI~qL~qL by t~qhe USNS POTOMAC was an unfortunate accident. the incident did produce an opportunity to study the behavior and fate of oiL spiLLed in the Arctic environment. ExceLLent cooperation among the ~operationaL and scientific pers~onneL from t~qhe United States, GreenL~and, and Denmar~qK aLLowed~' for a comprehensive study of this ~sp~qI~qLL w~4qNch not on~qL~L~qJ Led to a better understanding of the fate of oiL in t~qhe coLd marine environment but a~qL~so its impact on Arctic marine ecoLogy. ~0 12.0 REFERENCES ~qAh~qLstrom, E.H., and V.P~. Thra~qIL~qK~qILL, 19G3: ~"PLan~qKton ~qVoLume Loss With Time of Preservation," CaL~qiforni~a Cooperative Oceanic Fisheries Investigations Report 9~, p 57-73. ~qA~qhno~qff, M. et aL. 1974: "A S~qim~qpL~qified Method .or the Determination of DissoLved P~etroLeum H~qgdrocarbon~s In Seawater." Report on the Chemi~str~qg of Seawater XIV. Department of An~aL~qUticaL Chemistry, Unlvers~qit~qg of Gothenburg. Sweden. pp 4-~q8. (unpubLi~shed manuscript). ~qAhnoff.M.~. and G. E~qKLund. 1979: ~"~qO~qIL Contamination of Me~qLv~qiLLe Bag Water After the POTOMAC Accident in August, 19~q7~q7.~1~' Report on the Chemistry of Seawater XX. Department of ~qRn~aL~qgticaL Chemistr~qg, Universit~qg of Gothenburg. Sweden (unpubLished manuscript). Barua~qh~. J.N., Y~. ~qALr~o~qy~. and R.I. MateLe~s, 19G~q7: ~"Incorporation of Liquid H~qgdroc~arbons into Agar Media." ~qAppL~qied M~qicr~ob~qioL~og~qy~, v~q15~, p 9G~qI. ~qBLumer, M.M.~, an~qd J. Sass, 1972: "OIL P~oLLutlon: Persistence and Degradation of SpiLLe~qd FueL ~qO~qIL.~" Science. v~q17~q6~, pp 1120~-1122. BLumer, M.M~.~, M. ~qEr~qh~.~ardt, and J.H. Jones, 19~q7~q3: "The ~qEnv~qironmentaL Fate of Stranded Crude OIL," Deep-Sea Research, v2~q0~, pp 23~q9-25~qD. Boehm, ~qP.~, and D. Feist. 1978: ~"F~qinaL Report for ~qAnaL~qysis of GreenLand ~qO~qIL SpiLL SampLes,~" NOA~qA Contract 78~-4050, January 197~q9. Energy Resources Company, Cambridge. Mass (unpu~qbLi~shed manuscript). Boehm. P., and D~. Feist, 19~q7~q8~a~: "~qAnaL~qy~ses of the Water S~ampLes From the TSESIS OIL Sp~qiLL and Laboratory Experiments on the Use of Nis~qX~qin B~acter~qioLog~qicaL ~qSter~qiLe Bag SampL~es," NO~qAA Contract 03~-~qAe~ql-~qB-417~q8~. Energ~qg Resources Compan~qg, Cambridge, Mass (~L~inpubL~qIshed manuscript). Bunch. J~.N. and ~qR.C~' H~arL~and, 197G: "Biodegradation of Crude PetroLeum b~qy the Indigenous Microb~ql~aL FLor~a of the Beaufort Sea," Technic~aL Report' 10 (unpubL~qished manuscript). CLar~qk~. ~qR.~qC., Jr.. and D~.W. Brown, 1977: ~"Petr~oLeum: Properties an~qd AnaL~L~qises of Biotic and Ablot~qI~c Systems,~" In chapter 1 In Effects or PetroLeum on Arctic and Subarctic Environments and Organisms. VoL 1. Nature and Fate of PetroLeum, Academic Press, Inc., New Yor~qK~, 321 pp. Eastwood. D~., 1977: Per~son~aL communication with P. Boehm. U.S. Coast Guard Research and DeveL~opment Center, Avery Point. Groton. Connecticut. EngeLhardt~. F.R.. 1978: "PetroLeum H~f~qjdroc~arbons in Arctic Ringed Se~aL~s. ~qE~qU~qs~4qa h~i~pid~a, FoLLow~qing ExperimentaL ~qO~qIL Exposure," Proceedings of Conference on Assessment of E~c~oLogIc~aL Impacts of OIL Sp~qiLL~s, Ke~qgst~one~. C~oLor~ado~. June 14~-17. 1978. American Institute of B~qloLog~qic~aL Sciences. Farrington, J~.W~.~. and B.W. Tripp, 1975: "A Comparison of An~aL~qy~sis Methods for H~qgdrocarb~on~s In Surface Sediments," ~qA~qCS Symposium Series, No 18. Marihe Chemistry in the C~oa~st~aL Environment, pp 267~-284. Farrington, J.W. and G~q.C. Mede~4qiros~q. 1975: "E~qvaL~qu~qat~4qion of Some Methods of An~qaL~2qWsis for PetroL~qeum H~2qgdroc~qarbon~qs in Marine Organisms.~q" Proce~qp~8qd~8qlngs of the 1975 Conference on Prevention and Contro~4qt of ~8qO~8qIL PoLLuti~qon. American PetroLeum Institute, Washington, D.C. pp 115~q-121. FLem~8qinger~q. A.. 1973~q, "Pattern, Number, V~qari~qabiLit~2qy. and Taxonomic Significance of ~4qintegumenta~8qt Organs (Sen~qs~4qi~4qL~4qLa and G~8qLandul.ar Pores) In the Genus Eu~qc~qaL~qanus (Cop~qep~qoda C~qaL~qano~qld~qa~0q)~q,~ql~ql Fishery BuLLetin~q. v7~0q1~q. n4~q, pp. 9G5-1010. GrahL-~4qN~4qIe~0qLson~q. 0~q.~q, 1976: Proceedings of 12th Nordic ~4qS~2qgmp~qos~4qtum on Water P~qoLLution, Nord~4qfor~qs~4qK, H~qeLs~4qin~8qk~8qi. ~0 12~2 Hansen~.N.. V.B. Jensen, and K.K. Kr~qist~ensen, 19~q78: "The OIL SPILL in MeL~v~qiLLe Bag, Green~qLand: ResuLts of t~qhe ChemicaL and M~qicro~q0~qioLogicaL Studies. Draft Report M~a~qg 1, 1578. Water ~qQ~u~aL~qit~qg Institute, HorshoLm, Denmark. 55pp. ~q(~qUnpubLished manuscript). Ja~qdemac, R., 1977: Personal communication. U.S. Coast Guard Research and DeveL~opment Center, Aver~qg Point, Groton. Connecticut. Jespersen~. P.. 1934: "The Godthaab Expedition 192~q8~,~1~1 MeddeLeLser on Gron~qLand, v79~. n~q1~q0~. Copenhagen 1934. Johansen. P~.V. ' B. Jensen and A. Buchert, 1977: H~qgdroc~arbons in Marine Organisms and Sediments off West GreenL~and~.~1~1 (edited b~qy R.G. AcKm~an), Fish. Mar. Serv. Tech. Rep. 729. 33p. I.L~o~qg~qd, J.B.F., 1~q971: "The Nature an~qd Evidenti~aL VaLue of the Luminescence of Automob~qlLe Engine ~qO~qIL and ReLated Mater~qiaLs --I. Synchronous Excitation of F~qLuorescence Emission," J~ourna~qL of the Forensic Science Society, vll, pp. 83-94. Mattson, J.S., an~qd F.L. Grose, 19~q7~q8: "Impact Assessment of the USNS POTOMAC ~O~qIL spiLL, Me~qL~v~qI~qlLe B~a~qW~o GreenLand. August ~qG~. 1977.~1~1 Interim Report, N~at~qionaL Oceanic and Atmospheric Administration, Envtr~onment~aL Data and Information Services, Center for Env~qironm~ent~qIL Assessment, Washington D.C. Ma~qg 1978. ~q(unpubL~qi~Shed manuscript). Maurer, ~qR~.O., 1976: ~1~1 A ~qPreLim~qinar~qg Report of ~qZoopL~an~qkton In the ~qV~qic~qin~qit~qu of the Argo Merchant Oil SPILL," In "The Argo Merchant ~qO~qIL SPILL: A PreLim~qinar~qy Scientific Report", (Grose, P.L. and J.~qS. Mattson, editors) NORA Sp~ec~qlaL Report, N~atlonaL Oceanic and Atmospheric Administration. U.S. Department of Commerce, Washington. D.C.. 275 pp. Maurer. ~qR.~. and J. Kane. 1978: ~"Z~o~o~qpLan~qkton in the ~qV~qlc~qlnit~qg of the USNS Potomac ~qO~qIL SPILL (Baffin Bag. August ~q5~. 19~q77)~." Laboratory Reference No. 78-07. N~ation~aL Marine Fisheries Service, Northeast Fisheries Center, Woods HoLe, Massachusetts, 17 pp. MiLgram, J.~. 1977: PersonaL communication with P. Boehm, Department or Ocean Engineering, Massachusetts Institute of Techn~oLog~qy~. Cambridge. Massachusetts. MiL~qts. A.L.~, C. ~qBreziL and R.R. C~oLweL~qt~. 1978: ~"Enumeration of Petr~oLeum Degrading Marine and Estuarine Microorganisms by the Most Prob~abLe Number Method," (in press). Mo~qUn~qih~am, M.J., and R.D. Muench~. 1971: "Oceanographic Observations in Kane Basin and Baffin Bag. ~qMa~qy and August-October 19G9~.~1~1 U.S. Coast Guard Oceanographic Report No. 44, CG 373-44, Washington. D.C. Muench. R~.D~., 1971~, "The Ph~qu~s~qi~c~a~qL Oceanography of the Northern Baffin Ba~qy Region," Baffin B~a~qg-North Water Project Report No. 1, Arctic Institute, Washington. D.C.. 105 pp. Muenc~ql~i, R.D., 1972: "Oceanographic Conditions in the Northern Baffin Bay Region. JuL~qU-~qPu~qgust ~0q0~q0~.~1~1 U.S. Coast Guard Oceanographic Report No. 54~, CG 373-54, Washington, D.C. Muench. ~qR.D.. M.J. ~qr~-l~o~qyn~qtham. E.J. Tenn~qgs~on, Jr.. W.G. Tldmonsh~. and ~qR.D. Theroux~, 1971: "Oceanographic Observations In Baffin Ba~qy during ~qJu~qL~qg~- September 19~q6~q8~.~" U.S. Coast Guard Oceanographic Report No. 37. CG 373-37. Washington. D.C. Par~qKer~q. C.A., 1969: "The ULtim~qate Fate or Crude OIL at Sea Interim Report No. 5: Uptake of ~0qO~8qIL by ~4qZ~qoopLankt~qon~q.~q,~q" ~0qA.M.L. Report No. ~4qB/198 (M)~q, Ad~qm~8qIraLt~6qg MateriaLs L~qabor~qator~2qg~q. PooLe, EngLand. 16 pp. ~0qS~qar~0qs~q. G.~2qO.~q. 1~0q890: "An Account of the Crust~qacea of N~qorwa~2qU: Amp~4qt~qiip~qor~4qj~qa vo~2qtume 1. Univers~8qitets~4qf~qorLaget, Bergen and ~4qOsLo. Norway. W~qaKeh~qam, S.G., 19~2q77: ~q"Sunchronous FLuorescence Spectroscopy and Its ~8qAppL~8qic~qat~2qi~qon to Indigenous and P~qetroLeum-D~qerived Hydrocarbons in Lacu~qstrine Sediments." Env~4qironmentaL Science and TechnoLog~4qg, vll, pp. 272-27G. ~0 12~3 Z~oBe~ql~ql, C.E., 1~q9G~q9: ~"Microbial Mod~qif~qicti~on of Crude Oil In the Sea," Conference on Prevention and Control of ~qO~qIL Sp~qiLLs, American Petroleum Institute. New York. pp 317~-326. 13.0 APPENDIX 13.1 Marine Agar Bacto-peptone 5. 9 tacto-ueast extract 1. 9 FeCL3 0.1 NaCL 19.45 g Na2SO4 3.24 g M9CL2 8.8 9 CaCL2 1.8 9' KCL 0.55 g NaHCO3 0.16 g KBr 0.08 g SrCL2 0.034 g H3BO3 0.022 g Na2SIO3 0.004 g NaF 0.0024 g NH4NO3 0.0016 g Na2HP04 0.008 g Bacto-agar 15. 9 To rehydrate the medium, suspend 55.1 g In 1.000 mL or dIstILLed water and heat to dissoLve the medium COMPLeteLy. SteriLize In the autoctave for 15 min at 121 C. Adjust pH to 7.6. 13-1 13-2 13.2 Agar Substrate NACL 24. g MgS04,7H20 0.5 g KCL 0.7 g KH2P04 2.0 g Na2HP04 3.0 g NH4NO3 1.0 g Agar 15. g To rehydrate the medium, suspend 4G.2 g in 1,000 mL of distiLLed water and heat to boiLing to dissoLve the medium compLeteLU. SteriLize for 10 min at 115 C. Adjust pH to 7.1. After CoLweLL (MiLLs et aL.. 1978) 13-3 13.3 Bunch Substrate (used for MFN method) NaCL 5.53 g MgCt2,GH20 F.54 g KCL, 0.1 g CaCL2,2H20 0.37 g Tris buffer (Sigma) 7.69 g NH4NO3 1.0 g K2HP04 0.1 g Add 1.0 ML cheLated SoLution of metaL saLts (betow). The compounds are dissoWed in 1.000 mL distiLLed water. The PH is adjusted to 7.5. After Bunch and HarLand, (1976). CheLated soLution of metaL saLts CoCL2,GH20 0.004 g CuS04.5H20 0.004 g FeCL3.6H20 1.0 g ZnS04.7HRO 0.3 g MnS04,H20 0.6 g Na2MoO4,2H20 0.15 g E.D.T.A. 6.0, g These compounds are dissoLved in 1,000 mL distMed water and the PH adjusted to 7.5. 13-4 13.4 CoLWeLL Substrate Cused for MPN method'. NaCL 24. 9 MgSO4,7H20 0.5 g KCL 0.7 g KH2PO4 2.0 g Na2HP04 3.0 g NH4NO3 1.0 g To rehUdrate the medium, suspend 31.2 g In 1,000 mL distILLed water and heat to boiLing-untiL the medium is dissoLved compLeteLU. Steritize for 10 min at 115 C. The pH is adjusted to 7.1. After MILLs et aL. (1978). 17268 *U-S- GOVERNMENT PRINTING OFFICE: 1979 DATE DUE -1 F- GAYLORDIN.. 2333 4;;!Tl B:;! U S A 3 6668 14106 851 2 NOAA--S/T 79-202