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Coast3azoep2. intorma""' 2 Center2 Aip S~~~~~~~~~~~~~~~~T T. P. a 6~~~~~~~~~~~~~~~~~~~~~~~~~ MISSISSIPPI UL 7 175 SUPERPORT STUDY ENVIRONMENTAL ASSESSMENT U.S. DEPARTMENT OF COMMERCE NOAA COASTAL SERVICES CENTER 2234 SOUTH HOBSON AVENUE CHARLESTON, SC 29405-2413 Prepared by Charles K. Eleuterius PROPERTY OF THE UNITED STATES GOVERNMENT NA-f:ONAL OCt.ANIC AND ATIA; SPHJ2RIC ADMiiN:STRAl ON -or Reend;ion When no ilonger needed, please return to: Technical Processes Branch - D823 For OFFICE OF SCIENCE AND TECHNOLOGY OFFICE OF THE GOVERNOR STATE OF MISSISSIPPI X,3r dg LD DR. T. P. BANKSTON, DIRECTOR EASTAL ZONE INFORMATION CENTER ftoperty of CSC Libraay ACKNOWLEDGMENTS in the preparation of such a comprehensive report, it was necessary to depend on the work of many other researchers. The style adopted for this report precluded the acknowledgment of their contributions in the text; however, the sources referenced are listed in the Sources Referenced section of the report. These individuals and their efforts have made this assessment possible. I wish to thank Mr. Paul Poole for his very capable handling of the compu~ter programming required. Mrs. Joyce Randall Edwards worked tirelessly in the rewriting, typing, proofing, and general preparation of the report. Her contributions are deeply appreciated. TABLE OF CONTENTS Page ACKNOWLEDGEMENTS iii LIST OF TABLES v LIST OF FIGURES vi LIST OF PHOTOGRAPHS xi INTRODUCTION 1 ENVIRONMENTAL SETTING 3 GEOLOGY 9 Physiography of Gulf of Mexico 9 Geological History of Area 19 Geological Formations and Their Relationship to the Conditions of the Land Surface 21 Tectonic Behavior of the Subject Area: Movements in Past; Possible Movements in Future 25 Geological Cross Section Between Head of Bayou Casotte and West End Petit Bois Island 29 HYDROLOGY 34 Gulf of Mexico Circulation 34 Shelf Circulation 47 Tides of the Gulf of Mexico 61 Winds and Wind-Driven Circulation 64 Surface Circulation as Inferred From Surface Drifters 81 Wind Rose Projections 93 Wave Height Statistics 109 Wave Refraction 116 Water Characteristics ofGla~f of Mexico 122 Mississippi Sound and Subsystem Circulation 133 CLIMATOLOGY 161 General Controlling Meteorological Conditions 161 Air Temperature 162 Precipitation 162 Humidity and Fog 163 Thunderstorms, Thundershowers, Extratropical Cyclones, Waterspouts 163 Tropical Storms and Hurricanes 164 BIOTA 177 Marshes 177 Submerged Vegetation 186 Oyster Reefs 189 Commercial and Sport Fisheries 195 SUMMARY AND RECOMMENDATIONS 205 SOURCES REFERENCED 246 iv LIST OF TABLES TABLE NO. PAGE NO. I. Formations of Mississippi Gulf Coast. 33 II. Discharge, Pascagoula River at Merrill, Mississippi. 146 III. Discharge, Biloxi River at Wortham, Mississippi. 147 IV. Discharge, Tchoutacabouffa River at Tuxachanie Creek. 148 V. Discharge, Wolf River near Lyman, Mississippi. 149 VI. Discharge, Jourdon River at Santa Rosa, Mississippi. 149 VII. Discharge, Pearl River near Bogalusa, Louisiana. 150 VIII. Poisson Distribution of Tropical Cyclones Affect- ing the Mississippi, Louisiana, Alabama Coast, 1901-1963. Kolmogorov-Smirnov Test. 171 IX. Poisson Distribution of Tropical Cyclones Affect- ing the Mississippi, Louisiana, Alabama Coast, 1901-1963. Chi-Square Test. 172 X. Poisson Distribution of Tropical Cyclones Reach- ing the Mississippi, Louisiana, Alabama Coast, 1901-1963. 173 XI. Mammals of the Study Area. 211 XII. Reptiles and Heaptiles of the Study Area. 213 XIII. Birds of the Study Area. 216 XIV. Fish and Other Macrofauna of the Study Area. 224 v LIST OF FIGURES FIGURE NO. PAGE NO. 1. Location Map, Area of Proposed Superport. 4 2. Proposed Site of Superport. 5 3. Bathymetry of Gulf of Mexico. 15 4. Physiographic Provinces of Gulf of Mexico. 16 5. Conceptual Presentation of Sea Floor Relief 17 6. Geology of Pascagoula - Bayou LaBatre Mainland 27 7. Sediment Distribution, East Mississippi Sound 28 8. Geological Cross Section, Bayou Casotte to West Petit Bois Island. 32 9. Loop Current Streamlines, February, 1962. 39 10. Loop Current Streamlines, June, 1966. 40 11. Loop Current Streamlines, June, 1967. 41 12. Loop Current Streamlines, August, 1966. 42 13. Loop Current Streamlines, October, 1966. 43 14. Loop Current Streamlines, December, 1965. 44 15. Distribution of Surface Density, 11-14 January, 1965. 52 16. Distribution of Surface Density, 31 March - 9 April, 1965. 53 17. Distribution of Surface Density, 10-12 April, 1964. 54 18. Distribution of Surface Density, 10-14 May, 1965. 55 19. Distribution of Surface Density, 24-31 May, 1964. 56 20. Distribution of Surface Density, 29 June - 3 July, 1964. 57 21. Distribution of Surface Density, 19-24 July, 1965. 58 22. Distribution of Surface Density, 31 August- 5 September, 1964. 59 vi LIST OF FIGURES (Continued) FIGURE NO. PAGE NO. 23. Conceptual Representation of Currents of Shelf Area. 60 24. Gulf of Mexico Tidal Regimes. 63 25. Wind Direction and Speed, January. 68 26. Wind Direction and Speed, February. 69 27. Wind Direction and Speed, March. 70 28. Wind Direction and Speed, April. 71 29. Wind Direction and Speed, May. 72 30. Wind Direction and Speed, June. 73 31. Wind Direction and Speed, July. 74 32. Wind Direction and Speed, August. 75 33. Wind Direction and Speed, September. 76 34. Wind Direction and Speed, October. 77 35. Wind Direction and Speed, November. 78 36. Wind Direction and Speed, December. 79 37. Wind Direction and Speed, Year. 80 38. Surface Drift 11-14 January, 1965. 85 39. Surface Drift 31 March - 9 April, 1965. 86 40. Surface Drift 10-12 April, 1964. 87 41. Surface Drift 10-14 May, 1965. 88 42. Surface Drift 24-31 May, 1964. 89 43. Surface Drift 29 June - 3 July, 1964. 90 44. Surface Drift 19-24 July, 1965. 91 45. Surface Drift 31 August - 5 September, 1964. 92 vii LIST OF FIGURES (Continued) FIGURE NO. PAGE NO. 46. Wind Rose Projection, January. 94 47. Wind Rose Projection, February. 95 48. Wind Rose Projection, March. 96 49. Wind Rose Projection, April. 97 50. Wind Rose Projection, May. 98 51. Wind Rose Projection, June. 99 52. Wind Rose Projection, July. 100 53. Wind Rose Projection, August. 101 54. Wind Rose Projection, September. 102 55. Wind Rose Projection, October. 103 56. Wind Rose Projection, November. 104 57. Wind Rose Projection, December. 105 58. Wave Height Distribution, January. 113 59. Wave Height Distribution, February. 113 60. Wave Height Distribution, March. 113 61. Wave Height Distribution, April. 113 62. Wave Height Distribution, May. 114 63. Wave Height Distribution, June. 114 64. Wave Height Distribution, July. 114 65. Wave Height Distribution, August. 114 66. Wave Height Distribution, September. 115 67. Wave Height Distribution, October. 115 68. Wave Height Distribution, November. 115 viii LIST OF FIGURES (Continued) FIGURE NO. PAGE NO. 69. Wave Height Distribution, December. 115 70. Wave Refraction Diagram for Wave Oriented 00. 119 71. Wave Refraction Diagram for Wave Oriented 3150. 120 72. Wave Refraction Diagram for Wave Oriented 450. 121 73. Dissolved Oxygen Profiles, Gulf of Mexico. 126 74. Water Temperature Profile, Average and Extremes. 127 75. Salinity Profile, Average and Extremes. 128 76. Density Profile, Average and Extremes. 129 77. Surface Temperature, Mississippi Sound, 23 May 1973. 151 78. Surface Salinity, Mississippi Sound, 23 May 1973. 152 79. Surface Temperature, Mississippi Sound, 14 June 1973. 153 80. Surface Salinity, Mississippi Sound, 14 June 1973. 154 81. Surface Temperature, Mississippi Sound, 26 June 1973. 155 82. Surface Salinity, Mississippi Sound, 26 June 1973. 156 83. Conceptual Representation of East Mississippi Sound Currents. 157 84. Physical - Chemical Parameters of East Mississippi Sound from Mainland to Mid-Sound. 158 85. Physical - Chemical Parameters of East Mississippi Sound from Mid-Sound to Islands. 158 86. Hurricane, Tropical Storm and Depression Statistics 1901-1961. 174 87. Mississippi - West Alabama Marshes. 184 88. Marshes of East Mississippi - West Alabama. 185 ix LIST OF FIGURES (Continued) FIGURE NO. PAGE NO. 89. Submerged Vegetation of Mississippi Sound. 188 90. Mississippi Oyster Reefs. 191 91. Mississippi Shucked-Oyster Production 1950-1971. 199 92. Mississippi Canned Oyster Production 1950-1972. 199 93. Mississippi Shrimp Landings 1950-1971. 200 94. Mississippi Menhaden Fishery 1950-1971. 201 95. Mississippi Red Snapper Fishery 1950-1971. 202 96. Mississippi Industrial Fishery 1956-1971. 203 97. Mississippi Combined Fish and Shellfish landings 1950-1970. 204 x LIST OF PHOTOGRAPHS PHOTO NO. PAGE NO. 1. NASA Satellite Photograph of Study Area. 7 2. Offshore Oil Rig and Support Ship. 45 3. Nesting Pelicans on Chandeleur Islands. 107 4. Contrasting Mississippi Sound and Gulf Waters. 131 5. Compact Grass Ellipsoids Created by Hurricane Betsy, 1965. 159 6. View of Typical Mississippi Salt Marsh. 175 7. Mississippi Shrimp Boat Dwarfed by Menhaden Boat. 193 xi INTRODUCTION By the year 1985, the energy demands of the United States are expected to reach the equivalent of 60-million barrels of petroleum per day. Domestic sources of energy including petroleum, natural gas, nuclear power, coal, and hydroelectric power are pro- jected to meet only three-fourths of the national requirement. In order to meet the 1985 energy requirement, the United States will need to import 52 percent of its crude oil requirements to supple- ment production from its dwindling domestic energy sources. Supertankers of 100,000 to 300,000 DWT (dead weight tonnage) must be employed to economically and expediently transport the large quantities of required crude. The utilization of the deep- draft supertankers requires an approach channel and port depth of 120 feet. Presently, no ports on the Gulf of Mexico or on the Atlantic seaboard can accommodate such vessels. The depth con- straint and the economically impractical and environmentally undesirable massive dredging required to achieve and maintain the required depth make the employment of single point mooring systems (monobuoys) a feasible alternative with several definite advantages over conventional ports. The purpose of this report is to bring into focus the various natural forces and factors that should be addressed in the judi- cious planning for the construction and operation of a Superport monobuoy to insure not only the successful operation of the port but also the continued integrity of the marine environment. No good purpose would be served, indeed, in destroying the vitally important marine environment and thus the marine dependent in- dustries of commercial fisheries, tourism, and their ancillary services in the pursuit of supplying anothter essential resource. A combination of information gathered from both published and unpublished sources and data gathered on hydrographic cruises in support of this effort make up the basis of this assessment. The information from various sources was synthesized and integrated to depict a comprehensive picture of the environmental factors that must be considered. Because the environmental forces and factors that must be considered do not recognize any imaginary boundary that might be placed about a particular area of interest, it is necessary to study the larger dynamic system, the Gulf of Mexico; and with this perspective, concentrate upon the specific area of interest. In a closer inspection of the specific site location, approximately 25 miles south of Pascagoula, Mississippi, a more detailed dis- cussion of the physical, chemical, and biological factors will be 'instituted. 2 ENVIRONMENTAL SETTING A relatively shallow, oceanic-type basin, the Gulf of Mexico has a surface area of 1.602 million k2(0.619 million square statute miles) and a maximum depth of approximately 3,788 meters (2,080 fathoms). Together, the Gulf of Mexico and the Caribbean Sea are termed the "American Mediterranean." The sub- tropical climate resulting from the presence of the "Bermuda High" and the heat capacity of the oceanic Gulf waters provides ideal conditions for year-around commerce on the contiguous land areas. The site proposed for the employment of a Superport monobuoy is situated in the Gulf of Mexico (Figure 1, Figure 2) on the continental shelf northeast of the Mississippi River Delta and north-northwest of the Yucatan Straits. The proposed site is approximately 25 miles south of the port city of Pascagoula, Mississippi, which in 1973 with a gross tonnage of 14,035,325, ranked twentieth in U. S. ports. Within a radius of 30 miles of the site are five major waterw'ays: Mississippi River, Tennessee- Tombigbee, Intracoastal, Pat Harrison, and Pearl River. Figure 2 depicts the proposed site of the monobouy (single point mooring system), the pumping platform approximately four miles to the north, and the route of the pipeline into Mississippi Sound through Horn Island Pass paralleling the existing ship channel to the Bayou Casotte Industrial Park. Both the monobuoy and pumping platform sites are removed from the shipping lanes and any existing drilling sites or lease areas. 3 GULF OF MEXICO NsMl SS MOBILE FLA LALA 4 pr LA~~~~GULF OF MEXICO FIGURE 1. LOCATION MAP, AREA OF PROPOSED SUPERPORT. 40' 30' 00' 10' 8g. s o, 40' 30 2 0' I n - 880 50' 40' 30, PIPELINE Il PMINGPAFR I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 4~~~~~~~~~~~~~0 PUPIGPLTFR 40. 30' 2 0' 0' 890 50' 40' 30' 30 10' 800 50 0 30 FIGURE 2. PROPOSED SITE OF SUPERPORT. Geology Physiography of Gulf of Mexico The bathymetry of the Gulf of Mexico (Figure 3) is basin- like with the deepest portion of the basin (Sigsbee Abyssal Plain) located in the southwestern section. Compared to average Gulf depths, the entrances to the Gulf are relatively shallow; the Yucatan Straits having a maximum depth of approximately 2,103 meters (6,900 feet); and Florida Straits having a maximum depth of approxi- mately 997 meters (3,270 feet). The widest continental shelf areas lie off the coasts of east Texas; Louisiana, west of the Mississippi Delta; and Florida, south of the panhandle. The intrusion of the isobaths in a northeast direction south of Mississippi and Alabama constitutes the submarine DeSoto Canyon. The relatively narrow shelf area in this section of the Gulf provides access to waters in excess of 183 meters (600 feet) within 52 kilometers (32 miles) of the proposed Superport site. The Gulf of Mexico consists of seven distinct geological provinces (Figure 4): (1) the South Florida Platform, a carbonate bank, depicts a previous basin located on the west Florida con- tinental shelf; (2) the Yucatan Platform and Campeche Bank appear to be an extension of the carbonate platform of south Florida that was bisected possibly by erosion; (3) the Isthmian Embayment possesses thick Tertiary sediments, and vertical salt movement is the major geological process of the province; (4) the continental shelf and slope of east Mexico consist of a bottom relief of folds parallel to the shoreline and caused by the extrusion of salt from 9 beneath the continental land mass; (5) the Gulf Basin consists of an oceanic crust and a thick overlying layer of sediment; (6) the northeastern Gulf continental shelf and slope are subsiding car- bonate banks; (7) the main feature of the northwestern Gulf is the Gulf Coast Geosyncline which extends into the Gulf as far as the Sigsbee Scarp. The sediments comprising the continental shelf and slope of south Florida become thicker and increasingly carbonaceous toward their southward extent. The sediment type and depositional history imply that the area was once a closed basin whose barriers were drowned upon subsidence of the carbonate platform. The Campeche Bank is a large, plateau-like carbonate bank bounded by the Yucatan Straits on the east and the Tabasco-Campeche Basin on the west. The western boundary of the Campeche Bank expresses a gradual transition from carbonate to primarily terrigionous material. A sequence of mountain building, down faulting, and salt depo- sitions resulted in the geological evolution of the Bay of Campeche and the Isthmian Embayment. The seaward topography of the Bay is comprised of a series of long ridges parallel to the perimeter of the basin; this topographic feature purportedly being caused by the extrusion of salt from beneath the continental land mass upward vertically through the overlying sediments. The East Mexico Continental Shelf and Slope encompass the whole western border of the Gulf of Mexico south of the Rio Grande River. A series of folds parellel to the shoreline, characterizing 10 the topography of this area, extends seaward with the outer edge buried beneath the sediments of the shelf and upper continental slope. The crest-to-crest distance of the folds is approximately 5.5 miles with a vertical distance measured from trough-to-crest of approximately 457.2 meters (1,500 feet). The series of folds in the area has served to pond sediments being transported sea- ward from Mexico. When sediment deposition into the interior of the impoundment, formed by the first fold and the shoreline, exceeds the maximum elevation of the fold, the sediment spills over into the next more seaward impoundment. The entire series of ridges in the area is the result of salt being squeezed from under the con- tinental land mass. The Mississippi Cone, the continental rise, and the Sigsbee Abyssal Plain comprise the three divisions of the Gulf's central basin. The Mississippi Cone which extends toward the southeast from the Mississippi Trough consists of thick sediments with a seaward gradation finally mixing with the sediments of the abyssal basin. The continental rise is primarily a build-up of sediments transported south. The absence of such a rise adjoining the Campeche Bank and Florida Platform, which display instead steep escarpments,'is due to the lack of sedimentary material being transported into the basin from the east or south. With a slope of 1:8000, the Sigsbee Abyssal Plain is fre- quently termed the flatest piece of the Earth's surface. The thick, level sedimentary layers are the result of the occurrence of frequent turbidity currents originating at the edge of the continental shelf along a stretch from the Mississippi Delta westward to the present Atchafalaya River, the old route of the Mississippi River. Turbidity currents are caused by a failing of the sediment structure built at the edge of the shelf by deposition of silt and sands carried into the area by the river outflow. Initiation of the "failing" or "slumping"' can be caused by one or a com- bination of several factors: continuous'sediment build-up exceeding the load bearing capacity; storm surges accompanying hurricanes or tropical storms; local or remote earthquakes; and even normal tidal action when the load bearing weight becomes critical. Turbidity currents, the result of "land slides,"' contain tremendous amounts of silt, sand, clay, and other material in suspension and traveling at speeds (computed from measurable occurrences) in excess of 80 kilometers per hour (50 miles per hour). Protruding through the otherwise level sedimentary bottom of the Sigsbee Abyssal Plain are knolls and domes which have defi- nitely been shown to be salt diapiric structures. The continental shelf, delta, and estuarine bathymetry are depicted in Figure 5 where the sea-bottom topography is deliberately exaggerated in the vertical by a factor of 20 in order to emphasize the pertinent geological features. In the right hand corner of the picture, which would be southeast of the proposed site, the DeSoto Canyon is depicted extending northeast toward Pensacola, Florida. The rather abrupt, cliff-like feature in the central portion of the picture and paralleling the bottom edge of the picture is the 12 continental slope frequented by a significant number of commercially valuable but unexploited marine species such as large isopods, clawless lobsters, and the famous "Royal Red" shrimp. The bird foot type delta of the Mississippi River depicts the multitude of passages that have passed through a sequence of being active, inactive, and then finally abandoned. The platform- like structure comprising the delta proper is the result of con- tinuous "upbuilding" and "outbuilding" from sediment deposition. The outer edge of the steep slope along the outer deltaic plat- form is unstable due to the unconsolidated nature of the sediments; deposited sediments exceeding the critical "overbearing" weight limit; and continuing decomposition of organic-detritus deposited throughout the platform. This area, subject to frequent hurricanes and associated storm surges, is particularly vulnerable to slumping and resulting turbidity currents. The salt diapirs appear as conically shaped hills throughout the area covered in the illustration. These diapiric structures correlate highly with the presence of oil bearing subterranean geological structures. It appears from present seismic reflection data that the DeSoto Canyon is the eastern extent of these salt formations indicating a thinning of the salt layer. The broad, scoured trough and surrounding area occupying the central portion of the illustration are predominately covered by mud-sand, well-consolidated sediments. The deepest portion of the upper reaches of this trough is the proposed site of the monobuoy; this location being centrally located and accessible to 13 major water routes to the interior (Mississippi River, Tennessee- Tombigbee, Pearl River, and Pat Harrison Waterway) and along the coastal perimeter (Intracoastal Waterway). On the mainland side of the barrier islands lie extensive, valuable estuarine areas. The bays and sounds serve as nursery areas for the young of many economically important marine species. At the top-center of the illustration behind the series of barrier islands lies Mississippi Sound. It is proposed that the path of the pipeline from the monobuoy to the mainland transverse Mississippi Sound along a route west of Petit Bois Island and parallel to the existing ship channel reaching the shoreline at the Bayou Casotte Industrial Park. The following discussion deals with the geology and physiology of Mississippi Sound and coastal zone in general and specifically with the eastern portion of Mississippi Sound from Bayou La Batre, Alabama, to Pascagoula, Mississippi. 14 990 980 970 960 950 940 930 920 910 900 39 0 880D 870' 860 850' 840) 830 820 810' 800 3 0 0~.''v~ 300 N ~~~290 29'22%~~ 2802c 270 "~ ;~. 270 260 6 250 250D 20 230 230 2 20 220 210 2 2oo -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 200 180, 180. ;.~ 990D 980 970 960 950 940 930 920 91'D 900l 890 330 870 860 350 840 830 820 810 3Q0, FIGURE 3. BATHYMETRY OF GULF OF MEXICO. 310980 970 960 950 940 93, 92' 910 go, 89 0 880 870 860 850 840 8330 820 810 so, 790 30 310 ...ASLOUISIANASHL LRD 28 280... 3~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~030 281 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~... . . . . 2 .. .**.~.**.*. ...*. .. .*. . .............. . FIUR 4.E PYOGAHCOPROVNCENAStO- UFOFMXC K'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 FIGURE 5. CONCEPTUAL PRESENTATION OF SEA FLOOR RELIEF.~~~~~~~~~~ Geological History of Area The oldest surface desposits in the study area date back to Mid-Pliocene times when a coalescing apron of fluvial-deltaic deposits covered the entire region and laid down the Citronelle Formation. Subsequent regional uplift and erosion resulted in the elevation and partial removal of these deposits during Pleistocene times. Earlier Pleistocene fluvial sediments were deposited later immediately north of the study area and probably also under the present Mississippi Sound. Erosion, following this sedimentation period, again removed much of the earlier Pleistocene sediments. Toward the end of the Pleistocene Epoch, marine transgression covered up the region of the present Mississippi Sound and the southernmost fringe of the mainland coast. The nearshore, occa- sionally lagoonal Biloxi Formation formed during this marine influx. At the same time, fluvial sedimentation was responsible for the deposition of the Prairie (Pamlico equivalent) Formation along the ancient seashores. Beach-dune barrier ridges formed east and west of the subject area (Gulfport Formation) on the shore. Round Island, southwest of Pascagoula in the Mississippi Sound, appears to be one remnant of the Late Pleistocene coastal barriers. Withdrawal of the Late Pleistocene sea was followed by con- tinued fluvial deposition as the seashore retreated southward (Prairie Formation) and eroded. The coastal streams cut their valleys into the Prairie and the underlying formations; and at the peak of the last glacial period (Wisconsin), the seashore was located probably 90-120 miles south of the present shoreline. 19 With the return of the sea, toward the very end of the Pleistocene and during early Holocene times (16,000 - 4,000 years ago), the excavated fluvial valleys filled first with freshwater sediment and later with brackish marine deposits. Marshes and swamps developed behind the shores as waters were dammed back. In addition to the Pascagoula River, which occupied about the same position it does today, the Escatawpa River was the second major � river in the area, but followed a course different from its present- day course. A complex system of meanders near Orange Grove and Pecan and south of these locations indicates that the Escatawpa River flowed due south-southeast and emptied into Grand Bay. Bayous Cumbest and Heron are remnants of the main Escatawpa River channels which built a sizable delta into Grand Bay and Portersville Bay. A number of islands (South and North Rigolets, L'Isle Chaude, Long, Big, Barton, Marsh, Isle aux Herbes, et cetera) are remnants of this deltaic plain. The deterioration of these islands started when the Escatawpa River switched course and became the tributary of the Pascagoula River. Miniature sandy barrier islands developed along the deteriorating and retreating abandoned Escatawpa delta front (Grand Batture Islands) but repeated hurricanes destroyed most of them. At the same time, the marshy delta-remnant shores also suffered serious erosion and retreated northwestward (South Rigolets Island). Holocene sedimentation in the Mississippi Sound resulted in the formation of lagoonal deposits 12-36 feet thick. In the zone along the southern margin of the present Mississippi Sound most 20 exposed to the waves of the open Gulf, shoals and barrier islands developed (Horn, Petit Bois, Dauphin Islands). The islands, capped by beaches, dunes, and marshes were and are in constant migration. In addition, storm erosion periodically reduces the island ends to shoal only to be rebuilt later in fair weather conditions. Geological Formations and their Relationship to the Conditions of the Land Surface The Citronelle Formation (Figure 6) consists of brick red, yellowish brown, pale yellow silty sands, sandy silts, sandy conglomerates, and minor amounts of clay. The Citronelle is wide- spread between the Mississippi River and the Atlantic Coast and is widely used for construction purposes. Total thickness of the well consolidated but not cemented Citronelle Formation varies generally between 40-120 feet. In the study area, a Citronelle area lies only 1-2 miles north of the shores of Grand and Portersville Bays. The east-west length of the Citronelle expo- sure is about seven miles. A gently rolling surface at about a 50-70 foot elevation above sea level caps the Citronelle. This surface is disected by fairly steep-walled gullies and valleys. Oval-shaped, gently sloping minor depressions are common in the undisected Citronelle surface areas. The Citronelle block rises abruptly from the flat coastal area of the Grand Bay Swamp, 6-8 degree slopes being common on this escarpment. Consolidated silty sands and sandy silts form most of the Prairie Formation. Near and on the surface, because of oxidation, the original grayish color changes into characteristic pale yellow, 21 pale brownish yellow. The Prairie usually is 10-35 feet thick. In the subject area, it forms an evenly sloping, almost flat, undisected surface usually at 5-15 feet above sea level. Pascagoula, Moss Point, the Bayou Casotte Industrial Park, and Bayou La Batre are all located on the dry Prairie surface. Along most of the coast of the subject area, the Prairie surface is covered by a relatively thin layer of marsh-swamp deposits of Holocene age. Under the Mississippi Sound, presence of the Prairie Formation has been established in a number of coreholes between Pascagoula and Petit Bois Island. Although the Biloxi Formation does not crop out in the subject area, it has been found under the Mississippi Sound in coreholes. It is a gray, muddy-sandy, sandy-muddy unit, usually rich in microfauna and well consolidated. In this area its thickness was only about 19-20 feet. Depths below sea level: 36-53 feet; below Sound bottom: 27-50 feet. The fringes of the mainland and the central areas of the barrier islands are covered by wetland deposits of Holocene origin. The greatest width of this facies is five miles but at few locations is the width of the wetland zone less than one mile. One of the few such locations can be found south of Pascagoula where between Lake Yazoo and Bayou Chico, no wetlands skirt the mainland shore for a distance of about two miles. Due to the very gentle slope of the underlying Prairie surface, it may be assumed that the thickness of the wetland deposits does not exceed 15-20 feet over most of the area and is less than 10 feet in the northern parts. 22 Swamps (tree vegetation) and marshes (without trees, mostly grasses and reeds) are intricately intertwined along the mainland coast. The largest salt-marsh area is found between the Bayou Casotte Industrial Park and the Mississippi-Alabama state line. Northward, the salt marsh grades into freshwater marshes and swamps, the largest swamp area being Grand Bay Swamp north of Grand and Portersville Bays. Fringed by salt marshes along bay shores, this 1-1.5-mile swamp has extremely dense vegetation with the water cover, except in natural channels, not exceeding 2-3 feet. Sediments of marshes and swamps are rich in woody-peaty organic material and muddy deposits. Due to sandy source areas, the sediments in the subject area contain a larger-than-average proportion of sand fraction. Both deposit types are unconsolidate, highly compactible, contain a large propdrtion of water, and represent the poorest engineering soil types for foundation purposes. Due to the low energy conditions, most of the mainland shores lack sandy beaches. The best developed sand beaches are found northwest and northeast of Point aux Chenes but even there the beach width does not exceed 30-40 feet. Miniature sand dunes cap the backshores behind the beaches. High energy conditions and active littoral sand drift helped to develop the offshore barrier islands. Petit Bois Island, in the southern part of the subject area, contains well developed beaches, especially along the Gulf shore. However, along the low-energy Sound shore, the 23 beaches are much narrower. Dune elevations on this island range between 5-18 feet. Remnants of the Holocene Escatawpa delta in the Mississippi Sound, being better exposed to waves, developed beaches on small sandy islands (Grand Batture Islands) but more recent erosion has eliminated most of them. The high energy environment which created-and maintained the Mississippi Sound offshore barrier islands also maintains sandy shoal areas (Figure 7) between the islands and behind them (Horn Island and Petit Bois Passes). Remnants of the Grand Batture Islands and the shoal area in front of them are also outlined by sandy-bottom sediments. Coastal recession and the winnowing of the muddy sediments also resulted in remnant sandy-bottom zones around the Point aux Pins Peninsula, the southern end of Isle aux Herbes, and south-southeast of Bayou La Batre. The greatest clay-mud concentrations are found in the deepest parts of the Mississippi Sound least disturbed by wave and tidal current activity. The muddy-bottom zone between Petit Bois Island and Point aux Chenes; and Dauphin Island and the Bayou La Batre mainland area is 4-7 miles wide at its greatest. Zones of mixed sandy-muddy bottom deposits up to two miles wide exist between the predominantly sandy-bottom and the pre- dominantly muddy-bottom areas. They are found along the margin of the sandy belt skirting the mainland shore and along the sandy- bottom zone north of the barrier islands and the intervening sandy shoals. This bottom category is due to the mixing processes by wave activity and bottom currents. 24 Tectonic Behavior of the Subject Area - Movements in Past; Possible Movements in Future The Mississippi-Alabama coastal zone has experienced upward movement in the past. The fluvial-delatic deposits of the Citronelle and the Prairie Formations have been elevated to higher positions than they originally occupied in the past. During their original deposition, these formations were laid down close to sea level. Such subsequent movements usually occur along a fault line. The coastal zone of the central-eastern Gulf of Mexico is character- ized by the predominance of east-west, southwest-northeast, and southeast-northwest trending "coastwise" faults, along which movements have been going on since the Cenozoic Era. Some faults are shown by geodetic measurements and the tracing of earthquake hypocent~ers to be active at present. One very likely surface expression of a fault line exists along the southern margin of the Citronelle area, north of Grand and Portersville Bays. The southward-facing surface scarp of the Citronelle belt, with a maximum 6-8 degree slope inclination, strikes completely straight for a distance of 7-8 miles in an east-west direction. Similar scarps, also suggestive of fault origin, are located along the Citronelle area north of St. Louis Bay and along earlier Pleistocene deposits north of-Biloxi and Ocean Springs, Mississippi. Tectonically, the subject area is much less active than the adjoining coastal Louisiana area, but the possibility of slow (long-term) or sudden (earthquake-related) movements is not excluded. A minor (Mercalli-Scale V-VI) earthquake occurred in the 25 central part of the Mississippi coast during the decade of 1955-65. A similar-sized quake happened at the same time near Baton Rouge, Louisiana. 26 26 _____ _____ _____35' 88030' 5 20' 5 mhh~~~~~~~~~~~~~~~uE~~~~~~~~~~~EhE ~~~~~~ ~ ~ _ ElS..LL EARLY-MIDHOLOCENIEE ATAWPA- OW 25' MOSPIT- ')25' "A ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~AO - BEACH AND BARRIOR ISLAND SANDSANDBA PR~~~~~~~~~AIE FORMTIO ~~~~~~~~~~~~PLICE AUX CHENBES M~~~~~~~~~~~~~3YBAHADBRIRISLANDPP SOUNDS 40~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~ELN - ~ SWMSAN AS 200 ( H O L O C E N E - R E C E N T ) 2 0 '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~RII OMTO 'B' 4,~~~~~~~~~~~~~~~~~~PLOEE ~~~~~~~~~~~~~~~~~~~~~~~~~~DUHN ISLAND- 35' 88030' 25' 20' 15' FIGURE 6. GEOLOGY OF PASCAGOULA - BAYOU LA BATRE MAINLAND. ~5-L_- 88030' 25' 20' 15' ~~~~~~X~~~~~~~~~~7 ~~~~~~~~~~~~~~ ~~~~MISS! ALA CENTRALIZED MAP OF BOTTOM SEDIMENTS IN SUBJECT AREA 25' ~~~~~~~~~~~~~~~~~~~~~~~~~~(MODI FlED AFTER UPSHAW AND 25'~ ~ ~ ~ PREDOMINANT MUD BOTTOM fCLAY & SILT) OTHERS, 1966) 25 armMUDDY FINE SAND BOTTOM MEDIUM-FINE SAND BOTTOM 4 EEIMEDIUM SAND BOTTOM o "II ,~!t ~I I I AYOU ,~.G~*~AAATRE PASCAGOULA ~i~~iC 20' 15' FIGURE 7,i~''i; SEDMEN DSTRBUION EST ISISSPP SOND20' P uA~ ~ ~ ~iiiijiiiij~ C~~LES "~~~~iiiiiiiiiiii.......... womwwmw iiiii jii nz, 0~~~~~~~~~~~~~~~jjiiijiiiii~ iiiiiiiiiiiiiiiijiii~~~~~~~~~~~~~~~~~~~~~~vayig X.-~~~~~~~~~~~~~~~~~~~~~~~~~~iiliiiii ........ Jerry',~~~~~~~~~~~~~~~~~~~~~~~~~~jijjjiii .......... ...............~~~~~~~~~~~~~~~~~~~iiiiii ..........~~~~~~~~L~iiiiiii ..........................~~~~~~~~~~~~~~~~~~~~~iiiii ........................... .............~~~~~~~~~~~~~~~~~~~~~~~~iiii 111~~~~~~~~1~~~~ ~ ~ ~ iijijiiiiiiiiiiiiiiiiiiiiiilitiiiiiiiiii w~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~5 sell, ...........iiiiiiiiiil i ~~iitiiiiii~iiiiiliiiiiiiiiiiiiiiiiiiijX. iPPI SOUND iii E ::::::/:/: :i:::--:--:-i - ~~~iiiiiiii~~~~~~~~~~~~~~i~~~~~~:~~~~:~~~~:~~~~~~iiiiiiiiiiiiiiiiiiiiiiiiiliiii~~~~~~~~~~~~.. .. .. .... ... ... .. ~~i~iii ~ ~ iiliiii~~ ,............:....:::::::::::::::::X., ........ 35'~~~~~~~~~~~~~~~~~~~~~~~~~~~;:1::1:1~lilll~llli~~~~~i~~ii-:~::::::::::::::::: 88030' 2 5' 20' 0 is,~~~~~~~~~~~::::: j:::j:j:,,:::,:,:: FIGURE 7. SEDIMENT DISTRIBUTION, EAST MISSISSIPPI SOUND.~~~~~~~~~~~~~~~~~~~~~~~:-::��-��-��::��:�::��::��: Geological Cross Section Between Head of Bayou Casotte and West End Petit Bois Island The cross section (Figure 8) has been prepared from assorted drilling data gathered and compiled by Gulf Coast Research Laboratory and from a U. S. Geological Survey published report on Jackson County, Mississippi. The Gulf Coast Research Laboratory informa- tion from four drillholes is, at the present time, far from complete but still serves as a guideline to the stratigraphy of the offshore areas between the mouth of Bayou Casotte and the west end of Petit Bois Island. The northenmost drillhole, P-i, was located 1.3 miles south of the mouth of Bayou Casotte; and the southern- most drillhole, P-4, on the north shore of the west tip of Petit Bois Island. In the following, the lithology of the encountered geological formations along the cross section line is discussed in some detail. The Pascagoula Formation (Miocene) consists of greenish gray, well consolidated, stiff clays; silty, sandy, and occasionally with shell fossils. Sand content occasionally is higher; and at greater depth, sand lenses and layers are intercalated with the silty clays. The surface of ~the Pascagoula is uneven due to erosional disection after deposition by streams in Citronelle times. One major erosional channel, shown at the north end of the cross section, can be attributed to an ancient Pascagoula River channel. Reddish and yellowish-brown sandy gravels, gravelly sands, silty sands make up the Citronelle (Mid-Late Pliocene) and earlier Pleistocene deposits on land with plant fragment inclusions being 29 not uncommon. U. S. Geological Survey data indicate a large Citronelle channel-fill is present at the mouth of Bayou Casotte. Some of the muddy-sandy, sandy-muddy deposits in drillholes P-1, P-2, and P-3 above the Pascagoula surface, in all likelihood, belong to one or both of these deposit types. Found only in drillholes P-1 and P-4, the Biloxi Formation (Late Pleistocene) is greenish-gray, gray muddy sand, sandy muds with occasional sand inclusions; usually moderately to well con- solidated, although not as well as the Pascagoula clay. Macrofossils (shells, gastropods) are occasionally abundant; microfossils (foramninifers) are common. The absence of the Biloxi from the central Sound areas, in all probability, is due to fluvial erosion during Prairie times, streams having excavated the pre-existing Biloxi beds during a regressive period. Light olive gray, grayish blue-green mud, muddy sand, sandy mud, the Prairie Formation (Late Pleistocene) is moderately con- solidated. Toward the surface of the unit, grayish-orange, orange streaks were occasionally -found, this being evidence that the top few feet of the unit were exposed to oxidation before the Holocene transgression. Plant fragments occasionally are also found in this fluvial-alluvial unit, formed in flood plains and river channels. The surface of the Prairie is a gently undulating plain except where major stream channels have excavated it during the very end of the Pleistocene and during the early Holocene times. Such a stream channel probably did not cross the line of cross section but was definitely present west of it in the 30 continuation of the Pascagoula River and, in all probability, also to the east following the early Escatawpa course. Holocene sediments are represented by unconsolidated, water- soaked gray-greenish gray muds and sandy muds in drillholes P-l, P-2, and P-3. Further to the south, in drillhole P-4, sand pre- dominates. In the top section of-P-3, muddy sand forms the uppermost Holocene-Recent unit at 20-25 feet below sea level. The presence of Petit Bois Island nearby is responsible for the presence of a medium-fine sand unit between 3.5 and 26.5 feet in P-4, underlain by clay and muddy sand, probably also Holocene. Macrofossils (shells, shell fragments) and microfossils (foraminifers, ostracods) are common in the soft Holocene sound- bay deposits. 31 HOLOCENE DEPOSITS SFMICONSOLIDATED. UNCONSOLIDATED MUD & SAND ,.PRAIRIE FORMATION BILOXI FORMATION MODERATELY-TONWELL CITRONELLE AND EARLY PLEISCOCENE DEPOSITS CNOIDAE 2S PASCAGOULA FORMATION SCAL NORTH - - P 2 ~~ ~ ~ ~~~~~P 3 P 4 PETIT MISSISSIPPI SOUND BOIS ISLAND GEOLOGICAL CROSS SECTION ACROSS MISSISSIPPI SOUND BET WEEN HEAD OF IBAYOU CASOTTE (NORTH) AND PETIT BOIS FIGURE 8. GEOLOGICAL CROSS SECTION, BAYOU CASOTTE TO WEST END PETIT BO01S ISLAND. ISLAND WEST END (SOUTH) TABLE I FORMATIONS OF MISSISSIPPI GULF COAST Age Formation Thickness m (ft) Lithology and Depositional Facies Recent -- Not applicable Unconsolidated sands, silty sands, gravels, muddy sands, dark muds, peats (mainland beaches, barrier islands, inter-island shoals, sounds, bays, estuaries, river channels, swamps, marshes, oyster reefs) Holocene -- 0-15 m (0-45 ft); mostly Same as Recent and sands of mainland barrier ridge 5-10 m (16.5-33 ft) (Maxi- complex (S. Hancock County) mum: under islands, Missi- ssippi Sound, bay-entrance channels) Pleistocene (Sangamon Inter- Prairie 3-10 m (10-33 ft) Semiconsolidated silty sands, fine and medium sands, glacial-? Early sandy gravels, silts, peats (fluvial-alluvial complex) Wisconsin Glacial) (Sangamon Inter- Gulfport 3.5-8 m (12-27 ft) Fine and medium sand, muddy fine sand dunes, beaches, glacial) shoreface mainland barrier ridges (Sangamon Inter- Biloxi 4-16 m (13-53 ft) Semiconsolidated, often fossiliferous muddy fine sands, glacial) clayey fine sands, sandy muds (shallow nearshore marine) Earlier Pleistocene Not defined 20 m (66 ft) (?) Silty sands, clayey sands, muddy sands, sandy muds, fine (Interglacial? sands, some clay and peat (fluvial-alluvial complex) Glacial?) Pliocene Citronelle 12-48 m (40-160 ft) Sandy gravels, silty sands, fine and medium sands (-Preglacial (fluvial-alluvial complex) Pleistocene?) Miocene Pascagoula Maximum over 490 m: Consolidated clays, silty clays, silty sands, fine ("Graham Ferry" not (1300 ft) (?) sands, sandy muds (estuarine, fluvial and lagoonal considered a separate complex) formation above Pas- cagoula Formation) Hydrology Gulf of Mexico Circulation The circulation in the Gulf of Mexico is complex and not fully understood. The large scale circulation in the Gulf of Mexico is attributable to four major factors: Yucatan Current, tides, winds, and river discharges. There is considerable variability in the magnitude of these four factors, their acting in harmony to reinforce each other or in opposition to cancel each other's influence; and superimposed upon this interaction and varying in scale are transient phenomena that may abruptly change the existing circulation pattern. An assessment of the circulation and environmental conditions in the northeast Gulf area where it is proposed that a Superport monobuoy be located, must first be considered in terms of its relationship to the total Gulf circulation. The Loop Current, *a major feature of the eastern Gulf, is a continuation of the Yucatan Current which has its beginning in the western Cayman Sea. Entering the Gulf of Mexico through the Yucatan Straits, the Loop Current penetrates some varying distance into the Gulf then turns in a clockwise direction and exits through the Florida Straits. The Current exhibits great variability seasonally and annually in both magnitude and course. After entering the Gulf, the Loop Current advances in a north-northeast direction sometimes almost reaching the Mississippi River Delta. A series of hydrographic cruises has revealed a 34 northward progression of the Current from the southeastern Gulf in mid-winter to the edge of the continental shelf off the Mississippi River Delta in August. Direct current measurements taken during spring and summer indicate speeds up to 250 cm sec-1 in the core of the Current. The path of the Loop Current appears to be directed to some degree by the topography of the Gulf basin. The vertical extent of the Current entering the Gulf is dictated by the relatively shallow sill depth of 2,103 meters (6,900 feet) of the Yucatan Straits. This non-steady flow of the Current is characterized in the development of meanderings of the Current. Large eddies, frequently formed from the meanderings of the Current, separate and drift into the western Gulf and decay over periods of three to six months. No significant permanent or semi- permanent currents exist in the western Gulf with the exception of a southerly-oriented boundary current along the west Louisiana and Texas coasts. Figures 9 through 14, illustrating the surface streamlines and the corresponding current magnitude, depict the waxing and waning of the Loop Current and the subsequent formation of eddies. It should be pointed out that a specific volume of water is being transported between adjacent pairs of streamlines; thus where the distance between the lines narrows, the current of necessity in- creases in order to account for the continued transport of the specified volume. The opposite is also true; i.e., where the dis- tance between the lines widens, a reduction in current speed is pro- duced. 35 Figure 9 shows that by February the Loop Current intruded far into the Gulf with its influence being felt even further north. A small eddy appears to have formed off the northwest extent of the Loop Current. On the east side of the Yucatan Straits evidence of a counter-current along the west Gulf-side of Cuba exists that, in actuality, is the formation of an eddy which will become in- ternal to the Current as it intensifies. On the west Gulf-side of the Yucatan Straits the bathymetry rises sharply to a relatively shallow depth. As the Yucatan Current (Loop Current as it enters the Gulf) confronts the steep slope, there is an upward movement of the deep waters to override this barrier. A strong upward movement of the water or 'upwelling" is produced bringing nutriently rich material from the bottom. The enrichment of the surface and water column by the upwelling process attracts numerous marine species. The Campeche Bank has long been established as a rich fisheries area as a result of the upwelling process. In June 1966 (Figure 10) the Loop Current intruded as far north as 28'30' north latitude. Current velocities in the core of the Current reached 3.5 knots (4.03 mph). Northwest of the Yucatan Straits located at about 26'45'N, 90'15'W, a clockwise eddy that separated from the Loop Current is shown. The pattern of streamlines in Figure 11 shows that in June 1967, the Loop Current weakened leaving a well-developed eddy. The difference in stage and intensity from the 1966 situation dis- plays the considerable annual variability. The configuration of streamlines from the August 1966 36 hydrographic cruise (Figure 12) is an excellent illustration of a number of processes taking place. The Loop Current appears to follow the bottom topography of the Campeche Bank bending in a westerly manner after entering the Yucatan Straits. The northerly extent of the Current parallels the continental shelf of east Louisiana, Mississippi, Alabama, and west Florida. An eddy which will eventually drift into the western Gulf is in the process of being formed as evidenced by the narrow constriction below the broad oval-shaped upper extent. The Current is declining in in- tensity and is in the process of moving to the southeast. From the streamlines constructed from data collected in October 1966 (Figure 13) a pattern similar to August 1966 is shown but the orientation of the axis is more to the northwest. The northern extent of the Loop Current again follows the continental shelf from west of the Delta northeast into the DeSoto Canyon and then turns abruptly to the south. Figure 14 is a composite picture constructed from three different cruises. The resulting streamlines show a large eddy situated over the Mississippi Cone. The Loop Current in its weakened or "relaxed" state enters through the Yucatan Straits and immediately turns east and exits through the Florida Straits. The appearance of ripples, scour marks, and lineations in the sediments from photographs of the bottom taken in the area of the Mississippi Cone evidences the existence of significant bottom currents. Current speeds up to 19 cm sec-1 were obtained from current meters mounted near the bottom. The existence of 37 substantial currents was suspected as biological samples taken prior to the use of cameras and current meters contained sessile organisms that depend upon currents to transport food to them. Insufficient information prevented an attemp~t to determine the orientation of the current. It should suffice here to state that data substantiating the existence of bottom currents in the abyssal depths of the Gulf of Mexico have been collected. 38 980 970 960 950 940 930 920 910 900 890 880 870 860 850 840 830 820 810 80� 31o - 310 MISS iALA LOUISIANA 300 30� TEXAS 290� 290 FLORIDA 28� 0 / \ i\ 280 27� 270 260'2 260 25� ,. 250 240 240 230 e 23 0 200� MIVEXICO %. J YUCATAN 1 ~y 200 STREAMLINES IN FEBRUARY 19 / / APPROXIMATE SPEED IN KNOTS 190 180 0 08 980 97 960 950 940 93 92 91 90 89 88 87 86 85 84 830 82 810 800 79 FIGURE 9. LOOP CURRENT STREAMLINES, FEBRUARY, 1962. 980 970 960 95� 940 930 920 91� 900 890 880 870 860 850 840 830 820 810 800 310o I "- i3i m r 310 MISS iALA 3 1 0 LOUISIANA . 300 30 TEXAS i 291 290 FLORIDA 280 280 27 \ \ 270 260 260 2501 25 \0 \ 2 240 240 23 - 23� CUBA 220 220 210� 210 20� MEXI YUCATAN 200 STREAMLINES IN JUNE 190 a' / APPROXIMATE SPEED IN KNOTS 19o 18 I I 18 980 97� 96� 95� 94� 93� 92� 910 90� 89� 88� 87� 86� 85� 84� 83� 82� 81� 80� 79� FIGURE 10. LOOP CURRENT STREAMLINES, JUNE, 1966. 980 970 960 950 94a 930 920 910 900 890 880 870 86, 850 840 830 820 810 800 310 M ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ISSAAn-310 3Q0 300 TEXAS 29029 FLORIDA 280 280 2-70 270 260 260 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~250 5 240 240 23023 22022 210 1 200 M r-X N ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~200 STREAMLINES IN JUNE 19 C APPROXIMATE SPEED IN KNOTS 094 180 18 980 970 960 950 940 930 920 91a 900 890 880 870 860 as0 849 83' 820 810 800 790 FIGURE 11. LOOPCURRENTSTREAMLINES,JUNE, 1967. 980 970 960 950 940 930 920 910 900 890 880 870 860 850 84� 830 820 810 800 310 om - - 310 MISS ALA , . LOUISIANA - -. 300 300 TEXAS 290 290 28 280 270 270 26� 9 260 F231IGURE 12.~ LOOP CURRENT STREAMLINES, AUGUST, 2 240 240 230' 23� 220 220 210 21 20�) MEY NLI YUAA 20� STREAMLINES IN AUGUST ~~~~~19,~~~~ APPROXIMATE SPEED IN KNOTS 19, 180. wom et- . . . . '180 980 970 960 950 940 930 920 910 900 890 880 870 860 850 840 830 820 810 800 790 FIGURE 12. LOOP CURRENT STREAMLINES, AUGUST, 1966. 980 970 960 950 940 930 920 910 900 890 880 870 860 850 840 830 820 810 80� MISS 'A AL' 98=; = _ $ -n 30� LOUISIANA 30 0 30 TEXAS A' 290� 290 FLORIDA 280 280 270 270 250 260 2 ~~~~~~~~~~~~~~~~~~24 ~~~~~~~~~~~~~~~~~~~0 ~240 23 0 23o 22 01 W CJJ~--~~ U 222 21�0 21 18 21 080 : . . - . . . . .ill -18� 980 970 960 950 940 930 920 910 900 890 880 870 860 85� 84� 830 82� 810 80� 790 FIGURE 13. LOOP CURRENT STREAMLINES, OCTOBER, 1966. 98� 970 96� 95� 94� 93� 92 910 90 890 880 870 86� 850 840 830 820 810 800 310 - 8 310 MISS ALA LOUISIANA 300 300 TEXAS 290 290 FLORIDA 28� 280 270 270 260 260 250 ' f ~ 25� 240 2 240 23 23e l / / _ 230 220 22� 21 � 21� 20� MEXICO \ I YUCATAN 200 STREAMLINES IN NOV.-DEC 19I APPROXIMATE SPEED IN KNOTS 190 180 I18 98� 970 960 950 940 930 920 910 900 890 880 870 860 850� 840 830 820 810 80� 790 FIGURE 14. LOOP CURRENT STREAMLINES, DECEMBER, 1965. PHOTO 2. OFFSHORE OIL RIG AND SUPPORT SHIP. Ch~rres K. ius E li T I r~~~~~~~~~~tw ~ ~ ~ ~ ~ ~ ~ .. PHOTO 2. OFFSHORE OIL RIG AND SUPPORT SHIP. Charles K. Eleuterius Shelf Circulation From 1961 through 1966 a hydrographic study was conducted over the northeast Gulf continental shelf from west of the Mississippi Delta to east of Pensacola, Florida, to determine the major circulatory features and distribution of physical properties. A characteristic of the circulation over this region of the shelf is its short-term variability. The area shows strong salinity gradients especially in the vicinity of the Mississippi River Delta where in a distance of 10 miles from the Delta, surface salinities range from near 0.0 parts per thousand to 36.0 ppt. High-salinity cells appear to be permanent features in the area during the winter with an in- trusion of low-salinity waters which spread eastward over the shelf during late spring and early summer. The near-shore shelf area experiences a general freshening earlier due to the earlier occurrence of the peak discharge period of the independent streams and smaller rivers governed by local climatic conditions. Convergence lines identified by strong salinity gradients and sharp color discontinuities are detected 60 to 70 miles east of the Delta during spring. On at least one occasion the dis- charge and mixing of the Mississippi River waters with those of the open Gulf were so intense that a distinguishable vertical difference in elevation was observed along a long stretch of the convergence line. During summer, surface temperatures decrease seaward ranging from 33C in the nearshore legions to 29C in the area near the 47 continental slope. During the winter this trend is reversed with temperatures rising in the seaward direction. Winter surface tem- peratures range from INC in the nearshore area to 22C at the edge of the continental shelf. Because horizontal differences in water density are possible only in the presence of currents, water density is especially useful in delineating current patterns. In Figures 15-22 isopycnals, lines of constant density, are depicted based on calculations of the anomaly of potential density from measurements of temperature and salinity. The isopleths are labeled showing the appropriate density values with the larger numbers corresponding to the greater density. In addition to the labeling of the isopleths, the gradients are emphasized by employing shades of color. While in most instances the heavier water is denoted by the darker shade, this does not hold true throughout the figures due to the occurrence of strong gradients requiring more intervals than available distin- guishable shades. In the outer shelf areas it can be assumed that the currents are nearly geostrophic; however, this assumption cannot be ex- tended to the -nearshore regions that are tide dominated and subject to the influence of river discharges. In January (Figure 15) a tongue of lighter water is seen moving offshore in a southeast direction. A flow of heavier sea water is shown flowing westward over the shelf west of DeSoto Canyon. The presence of this heavier water mass over the shelf appears to be a semi-permanent feature during the winter. 48 The high rate of freshwater discharge from the Mississippi River and its extent of influence on the hydrography of the shelf are obvious in the data collected during the spring (Figure 16). The heavier, high-salinity water is shown moving westward north of the lighter water and then southward almost severing the elongated tongue of lighter water. The movement of the lighter water to the east is probably due to the drag placed upon it by the heavier water that moves approximately parallel to the shelf. The hydrographic cruise of April 1964 (Figure 17), while limited in coverage, does show the northward deflection of the Mississippi River outflow through Pass a Loutre. T1~e extent of the heavier water intrusion over the shelf is clearly shown but because of lack of data, the presence of the nearshore westward flow is not determinable. The westward flow over the shelf from the DeSoto Canyon area was again present during May 1965 (Figure 18). A narrow tongue of lighter water projects eastward from the area of Chandeleur Islands and turns counterclockwise to a northeast orientation. The spatial distribution of density during May 1964 (Figure 19), while similar to the May 1965 pattern, was obviously affected by higher rates of freshwater outflow. The westward flow of the heavier, saline water moved southward offshore and was separated from the mainland by lighter, fresher waters from Mobile Bay and Pascagoula River moving eastward along the shore. The paths of the isopycnals also show that there was considerable outflow from Mississippi, Chandeleur, and Breton Sounds. 49 The surface isopycnals for June-July 1964 (Figure 20) depict an eastward flow of the Mississippi River discharge from Pass a Loutre somewhat aligned with the shelf. An arm of heavier water intrudes over the shelf from the area of DeSoto Canyon separating the outflow of the Mississippi River from that attributable to Mississippi Sound, Mobile Bay, and Pensacola Bay. The arm turns in a cyclonic (counterclockwise) fashion encircling the lighter river water. The elongated tongue of fresh water from the northern mainland extends east-southeast beyond DeSoto Canyon and over the Florida Shelf. To the north of this outflow and moving in a westward direction from east of Panama City, Florida, is a mass of heavy, high-salinity water. An isolated lens of heavy water located due south of Mobile Bay is discernible. The density isopleths constructed from the July 1965 data (Figure 21) show a cell of lighter water southwest of Panama City, Florida. The discharge from South Pass and Pass a Loutre projects eastward, then turns cyclonically as it is entrained by the heavier water that has flowed westward along the northern mainland, then turns encircling the lighter water. The cyclonic eddy that is portrayed here appears to be a semi-permanent feature of the shelf area south of the states of Mississippi and Alabama. The eddy was not present over the shelf during August- September 1964 (Figure 22). The discharge from the Mississippi River was deflected to the northeast combining with an outflow from the west end of Mississippi Sound. The lighter waters east of DeSoto Canyon are apparently continuations of the Mississippi 50 River outflow that have been bisected by the intrusion of the heavier water mass moving northward following the Canyon. The semi-permanent cyclonic eddy, the Mississippi River discharge, and the presence of the Loop Current parallel to the shelf are conceptually depicted in Figure 23. 900 40' 20' 590 40' 20' 8810 40' 20' 870 40' 20' 6 40' 20' LA lv 100 :MLMA-. PENSACOLA--. -- . . FLA 2O'~~ -~ GULFPORT MOBIE - .--2 - PONTCHARTRAIN., 0 0 ' 300.> $%-O~~~'.Z.~~W <2130 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~40'- ago~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~--20 20'- 7 ..2 40'_- DISTRIBUTION OF SURFACE DENSITY 40' -. ~~11-14 JANUARY 1965 40,'I 9Q0 40 20' 590 40' 20' 880 40' 20' 87' 40' 20' 860 40' 20' FIGURE 15 DISTRIBUTION OF SURFACE DENSITY, 11 -14 JANUARY, 1965. g00 40' to' 890 40' 20' 881 40' 20, 870 40' 20' 860 40' 20' LA ` M ISS 'A L A PENSACOFLA GULFPORT 1 L P .. PASCAGOULAna.~l MOBILE., LAKlft ' nL uq o r .- - 2 .PONTCHARTR0 PANAMA. 30" --40' 20,- -.�0 ago.- ~' ~ 4 V 40' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.~~~_0 20'-- 4 0 ? 40'-- .'20' r,~~~~~~~~~~~~~~~~~........ Pao~~8i~ ~~~~~~~~~~~~31MRH- 9 PRI 16 900 40 ~~20'l ggO 40' 20' Sao 40' 20' 870 40' 20' 860 40' 20' FIGURE 16. DISTRIBUTION OF SURFACE DENSITY, 31 MARCH -9 APRIL, 1965. 900 40' 20' ago 40' 20' 880 40' 20' 870 40' 20' 860 40' 20' LA m~GLPR MISS ALA' PENSACOLA'~> -r .'-.. FLA . GULFPORT. PASCAGOULA ~ MOBILE.. : .- ~-2 LAKE'1t *PNM. - ..- -PONTCHARTRAINcg' ..' . PAMA * ~~~~ ~~~~~~~~~~........... 40'-~~~4 4 -30' - /eo ~ ~ e 20'-- t -240 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~40 DK 280~ Ole. '& . .8 40' . ~~~~~~~~~DISTRIBUTION O FSRAEDENSITY "', "* .40' 10-1 2APR IL 1964 g0O 40 20' 890 40' 20, 880 40' 20' 870 40' 20, 8 60 40' 20' FIGURE 17. DISTRIBUTION OF SURFACE DENSITY, 10 - 12 APRIL, 1964. 900 40' 20o 890 40' 20' 880 40' 20o 870 40' 20' 860 40' 20' i , . . i . . I 'MOBILE ' ........' FLA - M t LA M :ALA. (,PEN,,[OL: FLA - GULFPORT MOBILE. eol�. �~~~~~~~~~~~~~~ B~~AY ~I--20' 2o,--% t... LAKEN m, AMA-. -PONTCHARTRAIN.o - . .. �... . N 0 L.... .... . . C ITY 30~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~' '':. t"~:'.' o '" 40'-- ' -40' ,.., . , "- -"': o-- %h .;.:-BL--<. 2.. 290.1 i - 40'-- ,, ~~~~~~~~~~~~~~~~~~~~~~~~--40' 2.- ",.. M A 1 _0 .0j.' 89 4'20',8,s, 40'~ 20X.. -:' 8 7 0 402. . . ,40 o FIGURE,. . D TUNSI,-.M Y 1. 0, � ~o'-~~~~~~~~~~~~~~~~~I*- ..."-... --�40' 100 ~\S ,. ,.. ,: .~<rn - - ""o'~� ' ' 280 - '~54~41 -of ~y/t'cxieo - -. - -.* -- 28o 40'-. i, ~~~~~~~~~~~D ISTR IBUT ION O F SU RFACE DENSITY - -..1. 40' �..�.��. 10-14MAY 1965 ~.� I~~ ~ ~~~~~~~~~~~~~~~~~~ ,"�. -I 900 40' 20' 890 40' 20' 880 40' 20' 870 40' 20' 860 40' 20' FIGURE 18, DISTRIBUTION OF SURFACE DENSITY, 10- 14 MAY, 1965. 900 40' 20' 890 40' 20' 880 40' 20' 870 40' 20' 860 40' 20' LA GULFPOR M ISS 'ALAI PENSAC LA' FLA GUFPRTMOBILE. .�PASCAGOUA 20'-'~ ~~~~t .. C- SAY c6.00 20 LAKEt " "' . - -r-c01 -PONTCHARTRAI NA M A . :"ol~Y 3O- 4 0'- t"cg~O , i --40' 6*0292 40'-- 400 H 40' 280.- * '-. -. *.-.DISTRI1BUTION OF SURFACE DENSITY 24-31 MAY 1964 go,, 40' 20' 890 40' 20, 8830 40' 20' 870 40' 20' 860o 40' 20' FIGURE 19. DISTRIBUTION OF SURFACE DENSITY, 24 -31 MAY, 1964. 900 40' 20' 890 40' Po, 880 40' 20' 870 40' 20 860 40' 20. LA m Iss A L A l ~~~~~~~ENSACOLA'FL * .<'. ~~~~~PASCAGOUL MOIL A 40'-- 20- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~290 K N 40'--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-4 2~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0' 20'-- ...... lot~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~280 40,--, ~ ~ ~~~DISTRIBUTION OF SURFACE DENSITY - 0 'K' ~~29 JUNE - 3JULY 1964 900 40' go, ago 40' 20' 8980 40' 20' 870 40' ?0' 86 40' 20, FIGURE 20. DISTRIBUTION OF SURFACE DENSITY, 29 JUNE -3 JULY, 1964. 900 40' 20' 890 40' 20' 880 40' 20' 870 40 20' 80 40' 20' LA GULEPORT MISS I A (PENSAC&OLA"' *. FLA LAKE \.*AAMA, 99- ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~~~~~~~~~~~~9 40'--' -40 * ~~~~H 28o~~~~~~~~~~~~ "* *. ~~~~~~~~~~~~~~~~280 40t- . ~~~~~~~~DISTRIBUTION OF SURFACE DENSITY 40 19-24 JULY 1965 900 40' 2.0' 590 '40' 20 SS 40' 20' 570 40' 20, 860 40' 20' FIGURE 21. DISTRIBUTION OF SURFACE DENSITY, 19-24 JULY, 1965. 900 40' 20' 890 40' 20' 880 40' 20' 870 40' 20' 860 40! 20' LA 7 GiFl PASCAGOU FLA _. APSqAGOULA MIOB~ILE L. ~~~~BAY -0 201~~~~~~~~~~~~~.tE~~~~~~~~~~~~~ s;~~~~~ ~~~2 LAKIi_ I ~ _ - ~ ~�'�, PANAMA PONTCHARTRAIN-0 ,,y/' -~~Gt 4o~ 0 2~,~:~�~~0 30 .3 - 40' -f t, :6--40' U' 20' ? 290--, 40-- 28* MS0 i~~~~~~~ c~ ~ ~ DSTIBTONOFSRFCEDNSTY. 40' .: '�� �� � �. ...~ ~ '� �� --704 DISTRIBUTION OF SURFACE DENSITY - 0 31 AUGUST - 5 SEPTEMBER 1964 9Q0 40' 20' 890 40' 20' 880 40' 20' 870 40' 20' 860 40' 20, FIGURE 22. DISTRIBUTION OF SURFACE DENSITY, 31 AUGUST - 5 SEPTEMBER, 1964. goo ago 880 870 860 850 ::::::::::::-::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::�.��'�� ������'������'`'::::::::::::::::: ::::::-::::::-:::-::-:::::::-.:::::-:::::::::::::::::: ::::::::-:::::-:::::: ::-::::::::: i:-:-:-:::~: :: : :: : :: i i :::::: :: ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::: ::::::::: ::::::c~j~iiiiiiiiiiiii :-::-:: :: --::: :-::::::: --::--:-:::: :::-:::-: -:::: ::::: :::::::: ::-::::::-::::--::--::::-::-:--::::- ::-:::--:::::--::::::-:-::::-:-::::-::::::-:-::-:::-:-::::::: :::::::::::: ::::::"8~r ::::::: ::-::: :-:::-:::::-::-: :-:-: ::-::: ::-: 300 .'~i' '~" "~~~~~~~~~~ ~ ~ ~~~~~~~~~~~:,: .'. ..'........ :---:--::-:: :::-::::: -:: : -::--:--:::::-:: ::: ::: ::: : :::: :::::: : :::-:-:-:::::: :-:-:: ::-:: :-:-:-:: ::: ::ii~i:I - 'i- ir i,~~~~~~~;"" :iliiiiiiiii!!!i'"~'~--~ : :: :::~:���� ::.:::;::::: :.: :::::: : : ISS ::: ZF.L. :::::::::::::::: ::::::: :::::::::::::: -i ::::::::::::::: ::::::::::::::::: ..~~~~~~~~~~~~~~~~~~~~~~~~~~.......... .... ............. :::: :-~~~~~~.::":"--::::' " ' *: ": '--: .. ... . :~~~~~~~ z .....~~~~~~~~~~~~~~~~~~~~~~~~~~~~~...��� .......-�: : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~........... ...... 31029� .......:-: :-::-::- -:-:-:::. -::--::-:::'-:::-:-::- :-- :::::-:::E@:::::::-:-:--::::::-:::-:----::: ::::::- ::-.::::~:|::::--- -4 : -:-�: -::---::--:-w:--:::J(::-:------ 1t3 '~ , I , 90� 89� 88� I' O 19 ...::.::,' i'.�.:'.:. REPRESE-'.-.'?'-..-'.'&'... 'F CURREA.... uv 89 88� ~~~~~~~~~~~87� 86� 85� FIGURE 23. CONCEPTUAL REPRESENTATION OF CURRENTS OF SHELF AREA. Tides of the Gulf of Mexico The tides in the Gulf of Mexico are moderate in range but diverse in character. Across the Gulf the tide changes abruptly and assumes the following forms: diurnal, semi-diurnal, and mixed. While there is still much controversy surrounding the cause of such a complex tide regime, it is generally believed that the tides of the Gulf are cooscillating with those of the Atlantic Ocean. The tides of the Atlantic are semi-diurnal in nature, i.e., there are two highs and two laws per lunar day. These semi-diurnal tides are dominant at both the Yucatan Straits and Florida Straits (Figure 24). Progressing in a counterclockwise manner around the Gulf perimeter, the tides become mixed on the southwest Florida coast from approximately Key West to Cedar Keys. From Cedar Keys to Cape San Blas the tides are semi-diurnal again. The tides are dominantly diurnal from Cape San Blas to Vermillion Bay, Louisiana. From this point in Louisiana to Rio Grande, the tides are again mixed. The entire Gulf Coast of Mexico experiences diurnal tides. Variations in barometric pressure and winds result in changes in sea level over short periods of time. A reduction in barometric pressure will result in a corresponding rise in sea level, and a rise in barometric pressure will be followed by a fall in sea level. The diurnal tidal components of primary importance in the Gulf of Mexico are the components K Iwith a period of 23.93 hours and 01 with a period of 25.84 hours. The principal semi-diurnal components are N2 with a period of 12.42 hours and S2 with a period of 12.00 hours. 61 The average tidal range in the area proposed for location of a Superport monobuoy is 1.8 feet. In the nearshore regions, tidal currents in excess of one knot have been observed during periods of tropic tides which have a large tidal range. Analytical studies of the open Gulf tides in this area to determine the phase and magnitude of the tidal currents have not been undertaken. 62 980 970 960 950 940 930 920 910 90� 890 880 870 860 850 840 830 820 810 800 31 310 LOUISIANA azi | TEXAS X 83�� _ _ URNAL SEMI DIURNAL 2~~~~~9~~~ _ DIURNAL FLORIDA . 280 280 260 _______ 260 ~~~~~~~~~~~~~~~~~~~~~~~~~~25 0 } j u g >> 1~~ 2 50 24� 240 SEMI DIURNAL 230 23c 01C 0 _ DIURNAL _ / X 20� MEXICO \ _ YUCATAN 20� SEMI DIURNAL 190 9 1 0 18 980 970 960 950 940 930 920 910 900 890 880 870 860 850 840 830 82� 810 800 790 FIGURE 24. GULF OF MEXICO TIDAL REGIMES. Winds and Wind-Driven Circulation Wind-driven circulation is produced by the drag of the wind passing over the water. This wind stress, applied at the sea surface and affecting the subsurface waters through frictional coupling, drives the surface waters at a 45-degree angle to the wind vector in the Northern Hemisphere. Due to this direct effect upon the water circulation, it appears necessary to discuss-the wind fields of the proposed site area at this point. The wind statistics used in this report were computed from 20 years of continuous records collected at Keesler Air Force Base, Biloxi, Mississippi. The wind gauge, located at 30024'N, 88'55'W at a vane elevation of 36 feet, is approximately 32 statute miles north-northwest of the proposed site. Wind data from this particular site were selected for utilization in this assessment for three reasons: the records provide a sufficiently long time series; the location of the gauge is the closest and most-reliable weather station to the proposed site; and the wind data from ship logs are especially scanty in this area. The length of the vectors depicted in Figures 25-37 represents the percent of time the wind blows in a particular direction. The corresponding table located in the lower right corner of the illustration provides the wind speed, for 16 directions and calm, as a percent of time for a particular range in speed. Totals of the percentages appear in the bottom line of the table. For example, a north wind is depicted as a vector pointing south with the percent of time it was encountered corresponding to the 64 magnitude of the vector. The wind speeds associated with this north wind will be found in the table under the proper direction des-. ignation, N. The appearance of zeros in a tenths position in the table implies that there was a small percentage of time when the wind attained such speeds. The indsof anuar (Figure 25) are primarily from the north and northeast with an average speed of 7-10 knots and on rare occasions, less than 0.1 percent of the time, reaching a maximum of 28-33 knots. Overall, the source of the winds during the month is dominately from the eastern sector from 00 (north) to 1800 (south). Considering all winds, 38 percent of the time the wind speed ranges between 7-10 knots. Winds exceed 21 knots less than I percent of the time. Over 11 percent of the time there are no winds. During February (Figure 26) the distribution of wind di- rections and wind speeds are similar to January with the winds primarily from the eastern sector. Wind speed, for all winds, ranges from 7-10 knots over 40 percent of the time and less than 17 knots over 96 percent of the time. There is no wind during 10.5 percent of the time. During March (Figure 27) the wind pattern shifts so that the winds are primarily from north-northeast and south-southeast. Over 41 percent of the time the winds are between 7 and 10 knots, and less than 17 knots over 96 percent of the time. Winds are nonexistent over 9 percent of the time. 65 In April (Figure 28) the winds are predominantly from the southeast quadrant. Winds attain or exceed 17 knots less than 3 percent of the time. The dominant winds have an origin between east-southeast and south-southwest during May (Figure 29). The wind speeds diminish significantly from April with winds less than 17 knots occurring 98.7 percent of the time and winds less than 11 knots prevailing 82.9 percent of the time. Included in these two percentages are the periods of calm (no wind) which amounts to 11.1 percent of the time. There is a slight shift in dominant wind direction to the southwest during June (Figure 30) from May with an additional de- crease in wind speeds. Winds attain or exceed 17 knots less than I percent of the time. Over 88 percent of the time, the winds, including the 12.5 percent designated as calm, possess speeds less than 11 knots. The primary source of the winds shifts to the southwest quadrant during July (Figure 31). The winds continue to diminish compared to the previous month as reflected by the increase in the percent of time denoted as calm. Winds attain or exceed a speed of 17 knots less than I percent of the time. The winds are less than 10 knots almost 93 percent of the time. In August (Figure 32) the winds diminish to their lowest point for the year. The direction of the wind during this month originates primarily in the northeast and southwest quadrants with the latter occurring more frequently. Calm prevails almost 17 percent of the time. 66 The winds are predominantly from the northeast quadrant during September (Figure 33). Winds from the western sector are minimal over the month. There is a shift in the winds to a more northerly course during October (Figure 34) with the major source of the winds coming from the northeast quadrant. The wind speeds are less than 11 knots more than 87 percent of the time. Even though the primary source of November winds (Figure 35) remains from the northeast quadrant, there is a significant per- centage of time when the winds are from the southeast. The winds are below 11 knots more than 82 percent of the time during November. The winds have speeds in excess of 17 knots less than 3 percent of the time. The pattern of winds for December (Figure 36) is very similar to that of the previous month. Winds with speeds less than 11 knots still account for over 82 percent of the time. Figure 37 is a composite depiction of wind information for all months. Winds with sources in the eastern sector clearly dominate the wind regime. It is of particular interest to note that the percentage of time when calm or winds to 3 knots pre- vail is 13.8. Winds less than 7 knots account for over 32 percent of the time; winds less than 11 knots for more than 72 percent; winds less than 17 knots, more than 94 percent. The time thus attributable to winds of 17 knots or greater is less than 6 percent. 67 40' 00 20 I0 as. 60' 40 30, 20' 0' 08 a 0s 40' 300 40' ~nl 0 ~40 WIND SPEED MO BILE S A TI3E LA ~~~~~~~~~MISSISSIPPI SOUND QP~~~~~~~~~~~~~PE 3cp 30 i 1.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 D~~~~~~~~~~~~~DR WIN) 131RECT1N PERCENT OF' TIME3 : J~~~~~~~~~JNUARY 10, 29-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~9 WIND SPEED (PERCENT OF TIME) SPEE) 50 Ni~~~~~~~~~~~~~~ITS) 1-3 4-6 7-10 U1-16 17-21 22-27 28-33 34AlO 41-417 qS-55 56 DIR, Pi 11 1.0 2.3 4.6 3.3 .5 I .0 40.0 .8 2.1 3.6 2.2 .5 I. 12 i .7 1.7 2.8 1.6 .2 Ii EI7 17 1.6 1.9 .4 .0 4 E 1 6 1.4 2.4 .6 .0 + ESE I .4 .9 2.9 1.7 .1 SE .3 I1.0 2.8 1.6 .2 SSE .4 1.5 3.0 1.41 .1 .0 s . 7 2.1 3.2 1.2 .0 . 5501 .4 1.5 2.6 1.0 .1 .6 S u .3 1.1 1.5 .3 I .o i 0 !1j .2 1.5 1.0 .4 I. .D 4 1. .4 .7 .9 .3 .o 20' 404 1i.3 .6 1.0 .5 ,2 .01,0 Ml 1.6 1.0 1.3 .9 .3 .0 I.I .5 1.1 2.3 1.3 .4Ii 1 .0 CALM0 I I I I I 1 TOTAL CA.1%l 11.2 16.2 121.1 138.0 118,1 13.0 .5 .0 I 1 40 30 00 10' 89 50' 40- 30' 20' 10' 88" 50' 403 FIGURE 25. WIND DIRECTION AND SPEED, JANUARY. 40' 30' 20' 10' , 90 50' 40 30' 2(0 icy 880 s 0o 40' 30' 40,~~~0 0 0Y,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 MOBILE SAY 20'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 210 20, 20'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 290 WIN IRECTN (PERCENT OF TIME) 101.~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~00 100 0 7 2.3 4.4 2,3 .6 .1 .E 8 2.0 '4.4 1.5 .3 .1 00 I 2.8 2.7 . 5 .0 .0 4G'~ ~ ~ ~ ~ ~~~~~~~~~~~~~~~~~1 E[ .5 1.6 2.1 .4 .0 .0 40' E .5 1.3 1.0 .6 I 1 .0 ESE I .3 .9 2.2 1.9 .2 .0 SE I.3 1.0 2.5 1.4 .1 .0 SSE I .4 1.7 4,1 1.4 .2 .0 30, ~ ~ ~~~~~~~~~~~~~~~~~~S .6 2.0 4,8 1,3 .0 .0 .0 SS1W .5 2,6 3.2 1,2 I0 .0 . S I .4 1.0 0.0 1,0 .I 60 .2 .6 1,0 .6 .1 . 2(Y~~ ~ ~~~~~~~~~~~~~~~~ w .3 .0 1,0 .3 .0 .0 43.w .2 .7 0.1 .6 . .0 .0 20' .4 .7 1 2 . .2 .0 tN .4 1.1 1.5 1.2 .4 .1 . C'WTI 'I ~~~~~~~~~~~~~~TOTA CU 7% =10.5 .1 7.4 21,4 40.2 17.2 2.8 .4 .0 I 40 3 2 10, B90 0 40' 3D' 20' 10' , 0 40' 40' FIGURE 26. WIND DIRECTION AND SPEED, FEBRUARY. W 30' 20' I n 90 50' 40' 30' 240 10' 080 50 40' 30' 30' MISS.IAA MOBILE BAY 3( 00� 2 WIND DIRECTION (PERCENT OF TIME) MARCH WIND SPEED (PERCENT OF TIME) SPED (WTS) 1-3 4-6 7-10 03-16 17-21 22-27 28-33 34-40 42-47 48-55 �51 .50, ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~DIR.. N 1.0 I2.1 3.8 I1.8 .4 .0 .0 tE0 - 7 I2.1 3.7 I1,4 .2 .0 N E .7 I1.5 2.0 .4* .0 . 4^00 ME I5 1.1 1,7 .3 .0 40 E . 1.1 1 .7 .7 .1 .0 I ESE -3 I1.1 3.3 1.7 .2 .5 SE AI . 1.1 3.8 2.1 .1 .0I SSE .4 1.8 5.3 2.4 .3 .1 30,~~ ~ ~~~~~~~~~~~~~~~~~~~ S .6 2,3 4.7 1,8 .2 .0 0 oo I .1 ,6 1.0 .5 .1 . .1 7.4 22.1 41.5 1 8.2 2,8 .5 I .0 I I a 40, 30 2 00' 10' ag. s o, 4 0' 30' 2 0' 10' 000 50' 40' 30' FIGURE 27. WIND DIRECTION AND SPEED, MARCH. Cy' 30, 20 10' 00 so, 40' 30' 2' 10' as. so,0 40' 30 ISS.IALA. ~~~~ MOBILE SAY 3 0 MISSISSIP~~~~~~~~IS.~L\ WIND DIRECTION (PERCENT OF TIME) A LPRI WIND SPEED (PERCENT OF' TIME) SFEE0 (11frS) 1-3 4-6 7-10 11-16 17-2.1 22-27 2&-33 3'I-4 41-47 40-55 �3 6 016,~~~~~a 0 .8 1.6 2.6 1.1 .2 .0 IN .9 1.6 2.7 .8 .2 .1 .0 NE .9 1,2 1.5 .3 .0 10 ETE~~~~~~~~~~~~~~~~~~~~~0 .6 1,2 1.3 .2 .0 E - .5 .9 1.2 .4 . ESE .3 1.0 3.0 2.3 .2 .0 .0 SE .4 1.4 4.4 2.9 .2 .0 SSE .7 2.1 6.3 3.1 .2 I 1 .0 30,~~ ~ ~~~~~~~~~~~~~~~~~~~~ s .5 I2.5 7.0 2,9 .1 .I Sb W .4 1,5 4.3 2.6 .2 .0 .0 SW .3 .7 2,2 1.1 .1 .0 658SI .2 .6 1.3 .6 .1 .0 Xy il~~~~~~~~~~~~~~~~~~~~~ .3 .7 1,0 .3 .0 WR8Ii .4 7 1.1 .5 .1 4I 11 .8 .9 .5 .0 . .4 1,0 1.8 .8 .1 . C.4r1I TOTALCOIOO7.7 I8.0 19,L4 42.5 102.1 1.9 .4 .0 40. 30, 20' 10 a s. s o, 40' 30, 20 10' 4 50' 40' 30' FIGURE 28. WIND DIRECTION AND SPEED, APRIL. 40' 20' 20 10, 090 40' 30' 200' 99088 50' 40' 30' 990,6 o ~~~~~~~~~f r .-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- ~ ~ ~ ~ ~ ~ 0 30, A~~~~~~~~~~~~~~~~~INO~A BILECTO SAEYEN OFcTME DIR,~~~~~~~~~~~~~~~~~~~~~~~~~~~~I 60 1.1IN DIRETO 1.E6EN 1,6 .3 ..I .6N SPED (PRCN .1TI~ 50, (0s) 1-3 4-6 7-10 U-16 3-7-21 22-27 28-33 34< 41-47E 4 8 I .6 .6 .3 0 I 5 ND i .2 I 1.6 . 1.7 . 6 II SiE 1 .1 1.6 3.4 2.1 .1 I.n DIE 1.217 1 . .2. 65 36 .3 1 40~~~~~~~~~~~~~~~~~~~~~~~~~ DE 7 6 2.9 7.7 2,6 4 . ssv .3 .69 5.9 23 .1 . BE I .2 I 6, 31. 1.23 .1I I SE1 I .4 1.0 1.4 2 .1: .D .0 30,~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~ II .67 2.9 7,0 2".2 .4D 0 . 40 *4 1D .9 5 ,0 2 .3 .6 .D SW .4 1 4 3 6 .1 .0 y I iN& .4 1.1 11. .,4 .1 .6 �914 I ToT7Lcluo, l I9.9 121.7 140~.9 1q.0 1.3 .0 .6 I9 40, 30, 20 19' 990 s o, 0' 30, 20' 10' 940 I 0 4' 9 FIGURE 29, WIND DIRECTION AND SPEED, MAY. 40' 30' 20' 10' 89. 50s 40' 300 20N 10' 8M0 50' 40' 30' UOBIV DIR, MISSISSIPPI SO~~UNE �~"o :"ih~~~~~~~~~~~I I . 2611 1. JO"U~~~~~~~~~~~~~~~~~~~~~~S .3a .7' 1. 6. 0. WISE .3 4. -0 11 721,2 27 28 3 3 4 - 41-4 4.05 so~~~~Sh' DIR 3l18 .6 2,2 59 1.4 . 2 .0 N .0 3.9 1.4 1.2 .1 .0 E9 .5 2.2 6.8 . . 2 .0 ESE 3 .7 1.8 ,8 1.9 .1 . E 1. 3 1.9 2.2 . . .0 SSE .5 2,2 5.6 1.7 .2 .0 30 10 1 6 707.1 .2 404 .7 1,3 1.8 .3 ,0 ,0 WS11 5 1.3 1.9 .5 .0 2 w 1.0 1.6~~ES . . 1.1 .2 6 .O . MY .701 31. .2 .0 .0 2 N14 19 1.1 .7 . 1 2 . 1I44 .7 1.1 .7 .1 .0 CAMO TOTAL CALM 12.5 0,2.2 25.7 38.2 10,5 .8 .1 .0 40. 30' 20' 10' 090 500 40' 30 20' 10' 880 so, 4 30 FIGURE 30. WIND DIRECTION AND SPEED, JUNE. 40' 30, 2' 10' 890 50' 40' 30' 20' 10' 990 500 40' 30' 00,0-e ~~~~~~~~~~~~~~~~~40' 30' MISIS.IALA. MOBILE BAY30 ~~~~~~~~~~~~~~~~~~~~~JLY WIN13 11EETIO (PERCENT OF TIME) SPEED (l,'S 1-3 14-6 7-10 11-16 17-21 22-27 28-33 314-4 141-147 140-55 560 N 1.9 I23 1.0 .1 .n I NINE II1.3 2.2 1.3 .2 .6 1E ;I 1.3 I118 .9 .1 .0I I 40' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~EDOE .8 I 1.3 .3 .1 .0 .0I E .69 11 6 . ESE .3 I .6 1.3 .14 .0 II SI ' .4 .9 1.6 .3 .0 0 II SSE II 'S 1.5 3.6 .7 .0 33 C.61 2.3 5.0 1.5 .1 . 1 50 -61 13 3.8 1.3 .1 .o1 VS0 11 .5 1 1.14 2,0 .7 .1 .0 20'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ VI 1.21I2.9 2,1 .3 .0 2DI 11H. 11 .7 11.8 1.7 .3 .0 I4 1.1 20' .9 .1 .0 ( I3 ., . .8 .1 , CALM TOTAI CAI M IN 3 10' ~~~~~~~~~~~~~~.1114.0 1 28.8 133.9 7.1 .8 .8 0 40. 30' 2 0 9 10' 090 s o, 40' 30' 20' i n, BOO 90' 40' 30' FIGURE 31. WIND DIRECTION AND SPEED, JULY. 40' 30' 20' 10' 9 so , 40' 30' 20' 10' as- 50' 40 30' 19~~ ]or0,03 WIND DIRECTION (PERCENT OF TIME) AUGUST WIND SPEED (PERCENT OF TIOE) (Iqffs) 1-3 '4-6 7-10 11-16 17-21 22-27 2&-33 34-40 '41-47 '40-55 2 56 50, DIR~~~~~~~~~~~~~~~~~~~~~~~~~1. 0 ff 2,5 3.0 1.7 .2 .0 NNE 1.7 2.7 1.8 .2 .6 .0 tE 1.7 2.7 1.0 .2 . 40 ENE~~~~~~~~~~~~~~~~~~~~~64 .7 1.7 1.6 .3 .0 .040 E .7 1.3 1.0 .2 .0 BE6 .3 .7 1.0 .2 .0 SE I .4 1.0 1I7 .5 .0 .0 SSE .4 1.7 3.0 .6 .2 .0 ,0 3w ~ ~ ~~~~~~~~~~~~~~~~~~~~~~S I1,0 3.1 4.7 1.0 .0 ZI .6 1.9 4.7 1.3 .2 .0 SW .5 I1.4 3.1 .9 .0 II~ '4 1.3 1. .3 .0 .0 20, w ~~~~~~~~~~~~~~~~~~~~~~~1.1 2.0 1.4 .2 .0 Ml.8 1.4 1.3 .3 .0 il 1.0 1.4 1.1 .1 . 612 1.0 1.4 1.0 .2 .0 .0 culM TOI TALC0101016;8 10, .1 ~~~ ~~~~~~~~~~~~~~~~~~14.08 128.8 32.5 1 6.6 .4 .0 .0 .0 .0IV 40 30? 20 10 89' 500 40' 30' 20' 10' s o 50' 40' 30' FIGURE 32. WIND DIRECTION AND SPEED, AUGUST. 49 30' 2 0' 10 53 0, 40- 30 2 00 10' 488 s o, 40' 30' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~MBL540' 30 MiSSO.ALA. MOBI LE BAY 30, 20'~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~sop ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~016 40' ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ O 1,1. .1 . i~ 30,~~~~~~~~~~~~~~~~~~~~64 1. . 45 15 . ~ 0 o ~~~~~~~~~~~~~~~~~~~~~~6 ls 45 1. . 2 l 0'. 8~~E I .712,2 3.5 1.1 .11.0 .6 .01~~~~~~~~~~2 WIN1 DRECIO (PECEN 2.6 T8 .0IME) lI~~~~~EPTEMBER 18 8 .1 .0 . 10'~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~S 312 23 . 1. 0 . SSE I .5 I 1.5 3.2 1.1 .1 .0 .0~~~~~~~~~~~~~~~~~~~~~~~~~10 50~ ~ ~~~~~~~~~~~~~~~~44 I 3 .R14 .1 . 2,1 37 .8 3.7 1.10 HE4 Iq 3611 419 .1. 1 21,.01, N E11122 471 4181.24 1.2 1,3.1 .0.6lo 40 E 3E 00 2 12 3 95 401 30 I 0 1040 .0 40 30 FIGURE~~~~~~~~~~~~~~~~~~~~~~~ 7 . 33. WIN DIRETO AND SPEETEBR 40' 30' 20 ' 10' 090 590 40' 30' 20' 1 ' 880 50' 40' 30' 40' MISS.IL0. i MOBILE BAY 30 O~~r*NBPRINOTOBE MISSISSIPPI s 2& ' 20' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~290' WIN)D SRECTIO (PERCENT OF TIME) 29-~ ~ ~ ~ ~ ~ ~~~~~- P.~~~~~~~~~~~~~~~~9 SPEED 10 (111~~~~~~~~~~~~~~~~~~~~RTS) 1-3 14-~6 7-10 11-15 17-21 22-27 28-33 314-W 0 1-147 4I0-55 � 56 DIR. 00* N 2.2 14.2 14.9 1.8 .3 .0 .0 NNE 1,6 4 .0 4 .,4 1.1 I . .1 .0 I6E 1.7 3.9 4 .2 .7 I . SEE .7 1.9 2.6 .8 .1 . 40 E .08 1,7 2.1 .0 . ESE .3 .08 2.0 1.1 .1 0I SE .1 1.0 2.0 . 7 I . .0 SSE I 6 1.14 2.5 1.1 .1 .0 S .0 2,0 2.5 .6 I 1 .0 .0I00' Old I .3 1.2 1 .7 .5 .0 .0I Sri - .3 . 8 1.0 .3 . t~q .2 ,L4 .5 .2 . 20 .3 .6 .6 .2 . 5087 II .3 .5 .9 .2 2 0 30' JRI : .5 1.3 1,2 14 .8 u10 8 1 ,04 1.0 .8 .2 .0 1010 'I TOTAL CALM % 1 .6 211.9 6.9 34,90 11.2 11, .2 1 I 40, 30' 2 0' 10' 400 s o, a u 30 20' 10' 880 50' 40'30 FIGURE 34. WIND DIRECTION AND SPEED, OCTOBER. 40' 30' 20' 10' , 50, 40' 30' 20' 1(B B e - 0' 0 3D' 40'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 40' 30' ~~~~~~~~~~ ~ ~~~~~~~mts&.A MOILE 8AY 30' LA - ~~~~~~~~~ISSIP S O U N D ' '86~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DIR ~~~~~~~~~~~~~~~~~~~~E ~1124 1.1 . 2(Y~~~~~~~~~~~~~~~~~~~~SE . ,2026 11 1 . 2~~~~~~~~~~~~~~~~~~~~~~~~~1 i 9 .8 .7 .2 . FIGURE 35. WIND DIRECTION A~~~~~WND SPEED, (ECNTOFVEMBER. 40' a u ' 2 0' 10, 89. 50' 40' 30, 200 10' 8' 00 40s. 30 30' ~ ~~~~~~~~~~~MISS.JALA. MOR LE S A 30 MISSISSIPPI SOUND WIN DIRECTION (PERCENT OF TIME)0 DECEMBER WIND SPEED (PERCENT OF TIME) SPEED 50, (111T~~~~~~~~~~~~~~~~~~~07S) 1-3 4-6 7-10 11-16 17-21 22-27 28-33 34-)40 41-47 48-55 �056 0 0 9 2.7 4.3 2,6 .7 .1 .0 ME I 1,4 2,6 3.9 1.9 .6 .0 IIE I 1.4 2.3 3.0 .8 .1 .0 4~~~~~~~~~~~~~~~~~~~~~~~0' 10 .9 1.5 2.5 .6 .040 E 1 .7 1,9 2.5 .7 .1 ESE I . 1,2 2,6 1.2 .1 SE .1 5 0.1 2.5 .9 .1 SS E - 5 1.4 2.3 .8 .1 30,~~~~~~~~~~~~~~~~~~~~~~~~' . 9 1.6 2.7 .7 I0 .0 0 .91 .5 10 1 2.0 .71 .1 SI Ij .4 .9 0.5 .3 .8 .0 WW.2 .6 .0 .3 .1 Wl0 ,4 .7 1,0 .4 .21 . flt .5 .8 1.3 .7 .2 .0 [1 .61 1.2 1.9 1.3 .3 .0 .0I CAMN TIT I 'ro 110=2. 8 111.0 223 35.7 14.4 2.8 .3 . 411 30- 20' 10, s o , 40' 021' 0 04 30, FIGURE 36. WIND DIRECTION AND SPEED, DECEMBER. 40' 30' 20' 10' 090 50' 40' 30' 20' 10, (80 50' 40' 30' 30, MISS.~AA MOBILE BAY 30 300 3~~~~~~~~~~~~~~~~~0 30' P�. P~~~~~~8 WIND DIRECTION (PERCENT OF TIME) ALL WINO SPEED (PERCENT OF TIME] SPED5 (6913) 1-3 4-6 7-10 U1-15 17-21 22-27 28-33 34-40 41-47 48-55 >56 DIR.s I .9 2.1 4.2 2.6 .5 .1 .6 ap .9 2.3 4.4 2.4 .5 .2 .0 60 E 1.0 2.1 3.0 1.2 .2 .1 .0 -EE .7 1.6 2.7 .9 .1 .0 .5 .0 4D- E .5 1.5 2,9 1,2 ,2 .0 .0 ESE .3 .9 3.5 2.6 .4 .1 .0 SE .4 2.0 3,3 2,2 .4 .0 SSE .4 1.3 3.9 2.6 .5 .1 .0 I .5 1.4 33 1.8 .3 .1 .0 553 .3 .8 2.0 1.4 ,2 .0 .5 .0 SW I .2 ,6 1 .3 ,6 I .1 .0 W0.I .1 .5 .9 .4 .1 4 VI 53 .7 1,0 .3 .1 .0 201 .2 .5 .8 .4 .2 .0 .5 SM .3 .5 .9 .7 .2 .0 SOs !11.4 .7 1,5 1.2 .4 .1 .0 .0 1057) 'I I I TOTAL CALM %6=. .1 7.2 18.6 39.7 122.5 4.4 .9 .2 .0 .0 40 30 30 10' 000 50' 40' 30' 20' 1i' 040 s 0o 40 30' FIGURE 37. WIND DIRECTION AND SPEED, YEAR. Surface Circulation as Inferred from Surface Drifters Surface drifters were employed during 1964 and 1965 over the northeast Gulf shelf area to provide supplemental data on the surface circulation. Results of the surface drifter study, when considered in conjunction with the previously discussed spatial distribution of density, add substantially to the understanding of the shelf hydrography. The surface drifters utilized were 4/5 pint, clear-glass bottles containing a numbered and prepaid postal card addressed to the investigating institution. A ballast of dry sand was added to the bottles to assure a vertical orientation of the bottles afloat and to minimize the amount of exposed-surface area thus reducing the direct influence of the wind. Reported recoveries from each surface-drifter release location were divided into quadrants according to the direction determined from the release to recovery point. Figures 38-45 illustrate the prevailing surface drift determined from the use of surface drifters. The length of the vectors corresponds to the speed in nautical miles per day. The speed is based on the first recovery for a particular quadrant of the release point. The number of surface drifters deployed and the percentage recovered are shown in parenthesis by each release point. The dot-dash pattern used in constructing the drift vectors has an associated key appearing in the legends of the illustrations which furnishes the percent recovered from each quadrant. Surface drifters recovered from the east coast of Florida, to 81 avoid confusion, were assigned a southeast orientation of the drift vector. As the path of the drifters often assumes a course other than straight, the conclusions concerning surface drift must be determined in view of the previously discussed density fields and prevailing winds. The surface circulation for January 1965, as determined from surface drifters is depicted in Figure 38. A counterclockwise circulation around a well-developed eddy over the shelf results in a surface transport to the southeast and west. While surface drifters were recovered west of the Mississippi River along the Louisiana coast, their speeds were much less than those transported to the southeast. If the April 1965 drift results (Figure 39) are studied jointly with the spatial distribution of surface density for the same period (Figure 16), it can be seen that there is good agree- ment between the two. The presence of the cyclonic eddy over the shelf is again substantiated by the pattern of drift vectors. The surface-drift data of April 1964 (Figure 40) suggest a flow from the south moving in a cyclonic manner over the shelf. From the vicinity of the 500-fathom isobath of the upper DleSoto Canyon, there is a westward flow along the shelf at speeds approaching two knots. The surface drift during May 1965 (Figure 41) was primarily to the north as indicated by the large number of recoveries from the coasts and barrier islands of Mississippi and Alabama. The density distribution (Figure 18) for the same period shows that 82 the cyclonic eddy was weakly developed during this time, but that the Loop Current had probably extended further north altering the shelf circulation. It should be remembered that the winds during May (Figure 29) are primarily from the south. The surface current south of the Mississippi River Delta was oriented to the northeast during May 1964 (Figure 42). There appears to be a bifurcation of this current south of Pensacola, Florida, at the apex end of DeSoto Canyon. The resulting branches flow to the southeast and to a more northerly course. The lighter water flowing out of Mobife Bay (Figure 19) appears to have sufficient momentum to prevent the occurrence of the usual near- shore surface flow to the southwest. In late June and early July 1964 (Figure 43) the surface drift was generally toward the southeast. The distribution of surface drifter recoveries reported from along the northwest coast of Florida suggests the presence of a current paralleling the edge of the shelf. The presence of this current (Figure 20) is probably due to the drag of the subsurface, heavier waters on the unusually large amount of lighter waters over the shelf. The surface currents of July 1965 (Figure 44) show a current flowing to the northeast along the shelf from south of the Mississippi Delta and dividing over the DeSoto Canyon south of Pensacola, Florida. One branch flows to the west generating a cyclonic circulation west of the Canyon south of Mississippi- Alabama. The other branch flows to the east producing an anti-cyclonic eddy east of the Canyon around the less dense waters. 83 The surface circulation implied by surface drift for September 1964 (Figure 45) is in good agreement with the distribution of sur- face densities for the same period (Figure 22). There existed a northeast flow south of the Delta and a cyclonic circulation over the shelf region. A portion of the surface drifters deployed south of the Mississippi Delta was recovered west of the Delta suggesting a westward transport immediately south of South Pass. The winds during September (Figure 33) are primarily from the northeast and likely influenced the resulting drift trajectories. 84 S9 9 p. 49' 29' 8 46' 2p' a 49'2 P' 40'ko 20, 40 2~~~~~~~0(0 X (6-25%) 4~~~~~~~~~............... 0 29-K .... *.... ..'~t12% -29 4(30-fl 41 40'-~~~~~~~~~~~ ... .............~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[0 2~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0' LEGEND20 TOTAL NUMBER, SPEED AND PERCENT OF SURFACE DRIFTERS R.ECOVERED PERCENT RECOVERED 116 %-~75% . n~~~~~~~~~~~~j ~~~~~~~~~~~~~~~~ ~~~~~10% -I /. 40'- 85%- 90/. . . 4......... .3000105'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 00 GRAPHIC SCALE......... eb- 40' 20' 89' 4'0 2,0, '6 '0 ,s 4 I 20, FIGURE 38. SURFACE DRIFT 11 - 14 JANUARY, 1965. 9PI~ * p�_ 40' Z~~�20 A P. ( -? 49' 29' p' 20' A 40 20' to 20' 30 K . .... ..... I- / . osl?~~~~~~~~~~~~~~~~~~ cr *. 4C~ ........ . -. i-3t... . ...... ST JOSEI!N PT. 40 AC,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4-31 1~ 4 ~~~~~o ��: rli C.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~..... .... ... [E Nq N, ~'W" . ...... C~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4 .. ........ ~~~~~~OALANUMER, SPEED AND PERCENT OF SURFACE DRIFTERS -REGOVERED (2sa~~~~~~~~~~wL�~~~~~~~��';~~~~~~~~~~ ��"+ 4f~~~~~~~~~~~~~~~~l~~~~-~~~~nO (ro-lawl i..~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ . . . . . . . . . . . . PERCENT RECOVERED bN%- 5% , Af, AO~~~~~~~~~~~~~~~~~~~% - 15% 4J~~~~~,cs-1 ~ ~ ~ ~ ~ 4%-5 4~~~~~~~~~~~~~~~oO~.0 A C' GRAPHIC SCALE ~ ' s,40' 2,0' *'. C'2 ad 40 20AV 20'V5 0 20' FIGURE 39. SURFACE DRIFT 31 MARCH - 9 APRIL, 1965. Sp 40 20, 413 21V f ar 40 ~ 2p 4P' 20 40 g 20,-2 LAKE a~~~~~~~~~~~~i. 'a~~~~~~~~~~~~~~~~~~~~~o ..........% 40'm . . . . . . . . . . . . . ~ ~ ~ ~~~~940) 40--~ ~~~~~~~~~~~~~~~... ...... .1....0~ 20 ~~~~~~~~~~~LEGEND 2 TOTAL NU;MBER SPEED AND3 PERCENT OF 28- ~~~~~~~~~~~~~~~~~~~SURFACE DRIFTERSRECOVERED -9 PERCENT RECOERED O%-5% F 00~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GRAPHIC SCALE .' SPEED nm,'doy 910-~~~~~a 402 20 40 26~ o~ 40' 20~ 866 0 20, FIGURE 40. SURFACE DRIFT 10 -12 APRIL, 1964 sp 4~~~~~~~' 20' ~~~~~~49 t o (~ 40' 29'a 4.0 20' 40' 20, 20' -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 ~~~~~~~~~~~~~~~~~~~J40' 40'- - ......*4 S~~~~~~~~= . . . . . .. So' - / "N~~~~~~~~~~~~ N / '----. -. L E G E N D 2 P~ERCENTRCVED % %'- URSPEANPECNOF / 40'- ~~~~~~~~~~~~~~~~~~~~~~~~~8%9%K -40 f '-3 ~~~~~~~~~~~~~~~~~~~~GRAPHIC SCALE ...... . .. SPEED -am/"day 40 2 4'0 40l td. a'r Sd4 O' 40 t o, FIGURE 41. SURFACE DRIFT 10 - 14 MAY, 1965. BP. lk'0o.9 4P' 2.0 ( 4P'p 8.7 4P' 20 4'20, W~~~~~~~~~~~~~~~I - o a~~~~~~~~~~~ IL 40'.~~ ~ ~ ~ 40' Y 20'.20 (7-71A ....... ....~~~~~~~~~ . . ............. 40'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (15-8%)~~~~~~~~~~~~~~~~~~~~~~~~~~0 2 ( ... ~~~~~~~~LEGEND 2 TOTAL- NL7MBER, SPEED AND PERCENT OF SURFAcia DRIFPTERS--RECOVERED 2 8 K .. .. 2 8~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~..... PERCENT RECOVERED 0z5/ r 10%- 15/ '.~~~~~~~~~~ooO ~~~~~~~~~~~~~~~ 0 0 ~~~~~~~~~~~~~~to GRAPHIC SCALE ..................I........... ... ... .... .. ... ......... .. SPEED n/a 40, s'r 40, 20y wo id 204'tis. 40 2 FIGURE 42. SURFACE DRIFT 24 -31 MAY, 1964. S0 z' 6 p . � r i p f 0S 02 ............~~~~~~~~~~~~~~~~0 go,0 LAKE~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~' 40~~~~~~~~~~~L4 All,~~~~ ve,~~~~ I I - .' ... . ..... ..... 40 -. (p-mv 71.~~~~~~~~~~SUF0EDITE---%VEE PERCENT DRFESRECOVERED %51 26~~~~~~~~ ~ ~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - / QZ.. N.-6 8 0%5%> I. ________ [~~~~~~~~~~~~""'>J ~~~GRAPHIC SCALE FIGURE 43. SURFACE DRIFT 19 JUNE - 3 JULY, 1964. Sp.9l' 2049' 20'7 0' 29 e 4flP_ 0'2 LME -Wy~~~~~~.... ........ e1 11OU 64%W 3 re~~~~~~~~~~~~~~~~~~~~...... 0-33% ~ ~ ~~~~~1-% (-% .. ... ...........~~~~~~~\ I 110~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 .~~~~~~~~~~~~~~~~~~f ..... *Jj~~~~~~~gW'~~~ ...... L E G E N D (224 A ~ ~~~~~~~~~..... .. . ... 404~~~~~~~~~~~~~~~~~~~~~~~~~~~5 -"Io% '-a'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~' 2 ~ ~ 4b' 2o' 4olUAL NMBE, asPEE 40D PERENO FIGURE 44. ~~~~~~~~~~~~~~~SURFACE DRIFTER 19-24OVLYERE65 40' 29' 4P' 29' r* 1 L IP' 29' s 4.0' 2'I 40 20, / j ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~N 20, 20' )~~~~~~~~~~~~(-% 40'. . .. - to 20 .-~~~~~~~~~~~~~~~~~~~~~~ / .... LEGEND~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.......... (1 fl-f~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.... . ......... F~~~~~~~~~~~~~~~~~~~......i~T~NUPR SPEED AN/D PECNTO FIGURE 45. SURFACE DRIFT 31 AUGUST -5 SEPTEMBERIFrERS--REC1964. Wind Rose Projections In addition to the geostropic surface flow transporting oil in the event of a spill, wind would also have a significant effect upon the path the spill would take. The assumptions were made that the spill would be transported at the rate of .037 of the wind speed and deflected 45 degrees to the right. The average monthly wind speed for each direction was used in computation of the projected paths. The probability that the spill would be carried in any one of the 16 directions considered is found just exterior to the projections (Figures 46-57). The probability, the larger numbers corresponding to the greater probability, was determined by the percentage of time the wind was oriented in a given direction. The shaded inner portion is the projected dis- tance that a spill would travel in 24 hours with the outer boundary representing the 48-hour projection. The configuration boundary does not represent the shape or areal extent of an oil spill. The period of greatest threat of a spill traveling toward the mainland is during the summer and fall. However, due to the reduced strength of summer winds, a spill would probably progress at a slower speed during this period. It should be realized that these projections are based on winds alone and therefore do not include the effect of the prevailing shelf circulation or river discharges on the trajectory. 93 40' 3' 20' l a 090 s o, 40' 30' 20' 10' a s. s o 40 30' 40' 40' an, ~~~~~~~~~~~~~~~~~~~~~~~~~~~MISS.IALA. MOBILE DAY 0 000~~~~~~~~~~1 A 0- WINO ROSE PROJECTION JANUARY ~~ 24 HOUR PROJECTION 30, ~ ~ ~ ~ ~ ~ IZZ 49 HOUR PROJECTION -XX PROBABILITY 49' 30' 20' 10' s o , 50 40' 30' 20' 10' 000 S W ' 40' 30' FIGURE 46. WIND ROSE PROJECTION, JANUARY. acy30' 2' 10' a90 so, 40' 39' 29' 19'80 9 49' so, 30, ~~~~~~~~~ ~ ~ ~ ~~~~~~~~~~~~MISS.IALA. MOBILE9 BAY ~~~~~~~~~~~049' WIN24 ROSE PROJECTION 39' ~~~~~~~48 HOUR PROJECTION -XX PROBABILITY 29'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 40. 30 20 in' e V 0 so, 40'39 29' 19' 6909 40' 39' FIGURE 47. WIND ROSE PROJECTION, FEBRUARY. 40 N Y ' 20' 10' 89. s o, 40' 34, N Y 10' 880 0' 40' 30' 40'40 30'9L MOBILE BAY 3 0 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 0 ~~~~WINO ROEDPOETO MARC FIGURE 48. ~~WIND ROSE PROJECTIONMRH 4V 30' 2D 10 B E ' S ol 40' 30' 2D0 10' , 0 30' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~40' 30, ~~~~~~~~~~ ~ ~~ ~ ~~~~~~~~~~~ ~~MISS.~ALA. MOBILE SAY 3 0 2V ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~O Al ~ API 40 3' 2'1' 9 0 0 3'2'1'99 0 0 3 FIGURE 49. WIND ROSE PROJECTION, APRIL.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 40' 30, 2' 10' a n- s o, 40' 30, 20' t o, a s- S W 40' 3 3D' 11SAL-MOBILE13AY30 10~~~~ 00 LI) \~~~~~~~~~~~~~~~~~2 WINO ROSE PROJECTION MAY ~~ 24 HOUR PROJECTION V ~~~~~~~~48 HOUR PROJECTION 0 *XX PROBABILITY 40. 30, 25 10' 5 50' 40' 3D' 20' 10' a5v*0 40'30 FIGURE 50. WI ND ROSE PROJECTION, MAY. 40' 30' 20' l a 890 s o, 40' 30, 20' 10' M- 55' 40'30 40' 20, 3'A MISSIS1A.MSIPPI S O U N D 0 300~~~~~~~~~ 40 2' 2 0 9 0 0 0 0 0 5 0 0 30' FIGURE 51. ~~WIND ROSE PROJECTION, UE 40' 30, 20' 10' 850 s o, 40' 3 0' 20' 10, 880 50' 4D' 30' 40' 40' MISSIALA. MBILE BAYN MISSISSIPPI SOUND ' I; o 0 40' 1,o "~~~~�p�"~~* J 20' 203- WINO ROSE PROJECTION JULY 24 HOUR PROJECTION Lr 148 HOUR PROJECTION *XX PROBABILITY 2D' 20'52, WIND ROSE PROJECTION, JULY2 40 30 20, 10' B O 0 S ol 40' 30' 20' 10' 50 50 40' 30' FIGURE 52. WIND ROSE PROJECTION, JULY. 40' 30, 20' 10' s o , 50 40' 30' 20' 10' , 0 0 30' 10~~~~~~~~~ .06 o~~~to 40 30 20' 0 0 0 0 ' 0 0000 0 FIGURE 53. ~~WIND ROSE PROJECTION, UUT 40' 39 20' 10' 890 50' 40' 00' 20' In, 880 00' 44 20' 40 001 40' 30' MISS.~ALA MOBILE BAY30 0 380 010 Os WINO ROSE PROJECTION SEPTEMBER ~' 24 HOUR PROJECTION 30, ~ ~ ~ ~ ~ ~ tZI 46 HOUR PROJECTION *XX PROBABILITY 40, 3 ' 20' 10' S a- 0' 40' 30' 20' 10' 880 500 40' 0 F IGURE 54. WIND ROSE PROJECTION, SEPTEMBER. 40' 30' 20' 10' 890 s o, 40' 20' 20' 10' 880 50' 401 -90' 30, ~ ~~~~~~~~ ~ ~ ~ ~~~~~~~~~~~MISS.IALA. MOBILEGAY 30' o 0 (o 0~~ ~~~~IV WIND ROSE PROJECTION OCTOBER 24 HOUR PROJECTION a~~~~~~~~I 48 HOUR PROJECTION *XX PROBABILITY 4a 30' 20' 10' s o, 50' s o, 2 0 0' 10' 0 50' 40'30 FIGURE 55. WIND ROSE PROJECTION, OCTOBER 40' 0 2D' 10,B' s o , 50 40' s o, 20' 10'y0 50' 40' 30' 40' 4 0' 30, ~~~~~~~~~~~~~~~~~~~~~~~~~~~MISSO)ALA. MOILE SAY D 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 20-~ 0~~~0 N ~~~~~~~~~~WINO] ROSE PROJECTION NOVEMBER 24 HOUR PROJECTION EZZ~~~~~ 48 HOUR PROJECTIONSi -XX PROBABILITY 4' 30 2 0 9 5'4 0 20' 10' 0000 40' 30' FIG;URE 56. WIND ROSE PROJECTION, NOVEM BER." 40' 30' 20' 50' 890 50' , 30' 20' I D ' 58' s o, 40 30' 40' 40' 30' MISS.IALA. MOBILES AY 0 7~~~~~~~~~0 0 0A ~~~~~~~~~~~~~~~~~~~~~~20' 4~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0'3 0 WIND ROSE PROJECTION QECEMBER 5 50'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 E~ 24 HOUR PROJECTION 30, ~ ~ ~ ~ ~ ~ iZ 48 HOUR PROJECTION -XX PROBABILITY 2 2V~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 40. 3'u 20' 10' E q 0 S ol 40' 30' 20' 10' 88055 40' 30' FIGURE 57. WIND ROSE PROJECTION, DECEMBER. -���~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ C:Z~:c �D � O: -*Bi: 9 PHOTO . NESING PLICANSON CHNDELER ISLADS. Dnald dward PHOTO 3. NESTING PELICANS ON CHANDELEUR ISLANDS. Donald Edwards Wave Height Statistics Water wave heights and frequency of occurrence are important considerations in the construction, installation, and operation of an offshore Superport monobuoy. Offshore construction or operation can be hampered or halted during periods when waves attain heights that make continued activity hazardous to men, equipment, and the marine environment. Judicious planning to assure meeting construction and operation schedules must include careful consideration of the wave climate. Knowledge of the existing sea state (wave heights) that can be expected during a given time is also essential to the development of a contingency plan for oil containment and cleanup in the event of a spill. The wave statistics discussed herein were determined for the rectangular area described by the following coordinates: 28�45'N, 87�30'W; 30�00'N, 87�30'W; 30�00'N, 89�30'W, 28�45'N, 89�30'W. This area encompasses the proposed site for the monobuoy located south of Pascagoula, Mississippi. The wave statistics were com- puted from an extensive analysis of meteorological information. Figures 58-69 are wave height histograms consisting of the seven most commonly used height divisions and depicting the frequency as a percentage of time. During the hurricane season, 1 June through 30 November, seas well in excess of 12 feet occur but because the frequency of hurricane occurrence is too small to substantially influence these data, waves associated with hurricanes are not included. 109 The mouth of January (Figure 58) shows the largest percentage of time, 13 percent, when waves are greater than 12 feet. However, 77 percent of the time the wave heights are less than 7 feet and 30 percent of the time the wave climate ranges from calm to 3 feet. While February (Figure 59) has a smaller frequency of waves in excess of 12 feet, there is a greater frequency, 30 percent, of waves higher than 7 feet. Even during this month of greatest "1roughness," a sea state where waves range from 0 feet (calm) to 3 feet accounts for 23 percent of the time. The wave climate during March (Figure 60) is considerably milder with waves smaller than 7 feet occurring 81 percent of the time. Thirty-one percent of the time waves of 3 feet or less prevailed. April (Figure 61) displays a frequency-shift to larger waves in the lower 0-5 foot range with the frequencies of the wave- height intervals above 5 feet remaining almost unchanged from the previous month. Waves greater than 7 feet account for 19 percent of the time while the frequency of waves greater than 12 feet amounts to only 3 percent. Figure 62 indicates a significant reduction in the height of waves occurring in May. The range of sea state from calm to waves of 5 feet prevails 80 percent of the time. June (Figure 63) shows a continuation of the trend to a calmer sea. Ninety-three percent of the time the waves are less than 7 feet. Seas in excess of 12 feet amounted to a frequency of less than 1 percent. 110 While the wave climate in July (Figure 64) is predominantly less than 5 feet, there is an increase in the frequency of occur- rence of waves greater than 7 feet. The sea is calmest during August (Figure 65) with waves of less than 5 feet occurring 86 percent of the time. Waves of I foot or less account for 25 percent of the time with waves greater than 12 feet amounting to a frequency of less than I percent. With the increase in winds associated with local fronts and tropical disturbances during September (Figure 66) there is a reversal in the trend to a calmer sea. However, the preponderance of waves, 83 percent, is still less than 7 feet. Fifty percent of the waves during October (Figure 67) are between 3 and 7 feet. The remaining portion of time is divided 34-16 with the sea state of calm to waves of 3 feet accounting for the former and those larger than 7 feet for the latter figure. In November (Figure 68) there is a definite increase in frequency of waves greater than 7 feet. The frequency of occur- rence of waves larger than 12 feet quadruples from the previous month to 4 percent. While the frequency of the upper-two classes comprising waves of heights 10-12 feet and greater than 12 feet remains at 4 percent, there is a definite shift to a milder wave climate during December (Figure 69). This trend is notable in the increase in frequency of the lowest two classes of wave heights. At the present state of technology, waves greater than 12 feet are considered the critical sea state for supertanker-off- loading operations. From the wave statistics presented for the proposed Superport site, waves in excess of 12 feet occur only slightly more than 3 percent of the time. Furthermore, if January, which experiences waves in excess of 12 feet 13 percent of the time, is excluded from the calculations, the frequency percentage for the remaining 11 months is then only 2.25 percent. Combined, the months of January, February, November, and December account for 65 percent of the waves greater than 12 feet. 112 36" 36' 34. 34. 32" 32 p 30" p 30 E 28 E 28" R R c 26 c 26* E 24' E 24~ NN 22'N 22" A 20 A 20' E . . .E 16 .16 rr 140 14 14 F 12F T 10T lo. N v M M E~~~~~~- . Ee 4~~~~~~~~~~v 4.* 2~~~~~~ 2C 0 0-1 1-3 3-5 5-7 7-9 10-12 >12 0-1 1-3 3-5 5-7 7-9 10-12 >12 WAVE HEIGHT (FEET) WAVE HEIGHT (FEET) JANUARY FEBRUARY 36" 36' 34. 34, 32" 32' P 30- p30. E 28E 28 R 28R C 26 C 26 E 24. 4 N N T 22 *.T22 A 20 ..A 20 G18 ..G 18---- E ..E 16 --16 14 "---- 14 F F 12 .. 12 T 10o. T I10 M 8NM 8 E 6 ..E 6---- 2 ..WNfff2 0-11-33-55-7 7-910-12 >12 0-1 1-3 3-5 5-7 7-910-12>12 WAVE HEIGHT (FEET) WAVE HEIGHT (FEET) MARCH APRIL FIGURES 58, 59, 60, 61. WAVE HEIGHT DISTRIBUTIONS. 36 36 34 . 34. 32 32 p 30 .. p 30 . : E 28 E /E 28 . R R c 26. c 26//.. C ..... ~~~~~~~////... E 24 .E 24 N N 22-... 22 7 .. T 22 ' . A 20 :;:;:;:;x. : A 20 ~~~-' I///I -Z-Z'::":.:.":: "/// ..... 14 0 14 ///--__ it,:,,- //!... F ....F -------it. 1 182 T 1 0 *N T 10 * /// .... -:::.; I ,,,,-- , 16- //// --.....:::.:-'.v _E 6 ..% -E 6 ,-i,4 -4 12 -.2//// :':. b: J.....;:.%//--- .::;.::':' 0 .. . :.:.,::-.,% �~~~~~~~~~8..� /s,/ ....:.'.::: //// ......~.::.;:~ /l,/ ..../~::': 8 /j// 8i-----C.'~.: .:.... :::,~: E 6 i,,, . � 0-1 1-3 3-5 5-7 7-9 10-12 >12 0-1 1-3 3-5 57 7-910-12>12 WAVE HEIGHT (FEET) WAVE HEIGHT (FEET) MAY JUNE 36 36 ,34/, ...3.. .4 32 32-- p 30 p 30----" ~~~~~~~~~~~~~~~~~~~~//// ..... : . : : -- E 28 ----- E 28 c 26 C 26 . . ..-----I - -----:~; �� ,,,, ---iri �::~ ~ ~ ~ ~ ~ ~~ '' ....::"' "' 0-1 1-3 3-5 5-7 7-9 10-12 ~12 0-1 1-3 3-5 5-7 7-9 10-12 >12 WAVE HEIGHT (FEET) WAVE HEIGHT (FEET) iV]AY JUNE 36 .. 36 34"~ 34 32 ' . 32 - p 30 .. p 30 .- ~�,%~ ::: E 24 E 24 6 IIII: R ~ ... ////... 26 " 11 26" ~~~~~ //// ..... E 24 '" //'/" -- E 24 ".-. .....=:=:II //I////... N //,, N ,,,, 22 22 T /,,. .T,,, A 20 " ";./"" ... A 20 ,,, ~G ////i 18 18 " 11111(1 ;;;;~~~~~1 E E //// .. //// ..... 16 //// 16 '- / 14.' . . . . . 14 1 *12 .... 12 " 2 // .. 1T //// ... T 10 - . ..4 , //-~~ ~ ~ ~ ~ ~ ~~~~~~ .....1"/,/ ..... E 6 .. F,// 6 2;:;... 12 - 2 . 1 -- 8 ~~//// -. it,,-I/ ..... 0-1 1-3 3-5 5-7 7-9 10-12 >12 0-1 1-3 3-5 5-7 7-9 io-12 >12 WAVE HEIGHT (FEET) WAVE HEIGHT (FEET) JULY AUGUST FIGURES 62,63,64,////65. WAVE HEIGHT DISTRIBUTIONS. E 6 ~~//// //// ...../ 10 ''/../T10"///'... 1111_III~~~~~~~~~~~~~//111 :..:: J //// J��� //// ._ :'... JVJ .. //" 8-- :"" 4 ///" --".':: I/ // M/ / / ....-: {{:-::::-~ 2 ~ ~~~~ / //, / /-- ...=.:.":': 4 ~~///////...:".-' I// ."/ //// . .... O rii ��� O,,,, ...// ..::~:; 0-1 1-3 3-5 5-7 7-9 10-12 :>12 0-1 1-3 3-5 5-7 7-9 10-'i2 :>12 WAVE HEIGHT (FEET) WAVE HEIGHT (FEET) JULY AUG UST FIGURES 62, 63, 64, 65. WAVE HEIGHT DISTRIBUTIONS. 36-- 36 34. 34. P 32" 32- E 30 p 30 R R P .�'' C 28- E 28 R E 26-- C 26 N 24 E 24-' T --- . N 2 A 22 T 22 ':'"'::�22----..'~~:; G 20 -- A 20 G ~~~//// E 18 G 18 " / ------- ..::::/ 16 - 16 ///'. . 0 / //......: ;�:t.;::;// .. 1...::""::O//// ..... 14 .. ////...-. //// . ..:;*:'::: ~ ////--- ..... ���� F~~~ 12 1 2: F T ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~...� 10 T lo~~~~~~12 i //// .....~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~;�::?:.?:/--: I 10 //// .-.... T1 .///"_ ///~~~~~~~~~~~~~~~~/ ..... . �:::'.'':.';//.. //// �....::':.:: . a----////----. T 4 .- //"" ::::: ::::': 2 .- //// ...... : : 0 1. 2.. 2~~� 2 ��' 2" ///, .....i:::-:.'2 0. //... 0-1 1-3 3-5 5-7 7-9 10-12 >12 0-1 1-3 3-5 5-7 7-9 10-12 >12 WAVE HEIGHT (FEET) WAVE HEIGHT (FEET) SEPTEMBER OCTOBER 36" 36" 34 " 34 P 32" 32 E 30" p 30 R C 28 E 28 R C ~~R ..... E 26 C 26.:: N 24 ' ". E 24 T :: N A 22" T 22 A ~~~~~~T G 20 . . ..A 20 '" E 18 G 18 ///.. . E / .. . 16 16" O //// ------ ~~~~~~~~~~~~~~F //// -----;~~�r F .... :/// F 14 "// 7�:: F 14 112 12 -,//- T" T 1//I~/0 - ,,-T 1/0 10 ~~//// " mM 8~~,- " ./.// M 8 / // / ////$$:::::s /I~~~~~~~~~~~~~~~///~-~::::� //// . �~ ~ ~ ~ ~ ~~~~// E E 6 ::- ---- ////Sooo% //"//// " 4.,,.,,, 4 //// 4~ ~ // ////---~~~r.4==---;:�� r� ..////--- :��� �� ///,'--:: ";'.;.::.\ � * // 2 //// ~ ~ ~ ~ ~ ~ ~ ~~///-- t~,'~'J�� 0 0" 0-1 1-3 3-5 5-7 7-9 10-12 >12 0-1 1-3 3-5 5-7 7-9 10-12 >12 WAVE HEIGHT (FEET) WAVE HEIGHT (FEET) NOVEMBER DECEMBER FIGURES 66, 67, 68, 69. WAVE HEIGHT DISTRIBUTIONS. Wave Refraction When a wave proceeds into progressively shallower water, it is affected in several ways. If the water depth becomes less than one-half the length of the wave (measured from crest-to-crest or trough-to-trough), the wave begins to "feel" bottom, i.e., friction becomes significant. As the wave enters shallow water, the front of the wave begins to feel bottom which results in its slowing down while the back of the wave is continuing at its original speed. The differential in speed thus produced over the length of the wave causes the wave height to decrease momentarily, followed by an increase continuing until the wave builds so steep that it becomes unstable and breaks. If a long-crested wave travels into shallow water at any angle other than perpendicular to the isobaths, one end of the wave will begin to "feel" bottom before the other. Because "bottom drag" along the wave is encountered at different times, a differential in speed results along the crest of the wave denoted by a "bending" of the wave. This action is referred to as wave refraction. While stable waves would probably have little effect on the transport of oil in deep water, the refraction of waves warrants attention. The bathmetry of the shelf area was digitized and represented by a uniform, equilateral grid with sides of 3.28 miles. A de- sign wave that would begin to feel bottom at a depth of 120 feet (the depth of the site for the proposed Superport monobuoy) was selected. A wave of this length (240 feet) corresponding to a 116 wave period of 17.0 seconds, although in itself occurring in- frequently, would depict generally what can be expected during refraction of shorter and longer waves. For this study three specific directions in which waves frequently travel were selected. From the refraction patterns of these three waves, the refraction pattern of waves with orientations intermediate to those used is easily deciphered. Waves traveling offshore were not considered for wave refraction studies simply because, with the increasing depth seaward, the waves would never feel bottom and thus would continue in a straight line. Figures 70-72 are computer generated refraction diagrams of three 17.0 second, long-crested, linear waves with orientations of 00 (north), 3150 (northwest), and 450 (northeast), respectively. The path of the wave crosses the proposed Superport site in each case. The wave rays, or wave orthogonals, shown in the figures are lines that are always perpendicular to the crest of the wave. There is an equal partitioning of energy between the wave orthogo- nals, i.e., there is a fixed amount of energy represented by the interval between any two orthogonals. A spreading or divergence of the orthogonals signifies a bend in the wave, a dispersal of energy along the wave crest, and a corresponding decrease in the height of the wave. The convergence of orthogonals, likewise, denotes a concentration of energy and an increase in wave height. Theoretically, a crossing of wave orthogonals signifies a wave of infinite height, but in actuality, usually indicates the presence of a caustic. A caustic is caused by waves from different 117 directions, and also possibly differing in height and period, intersecting. This area of intersection, depending on the difference in phases and heights, usually produces "choppy" or "confused" seas. The tick marks along the wave orthogonals denote the wave crest position every 357 seconds. The tick marks can also be interpreted as being the crest position of every twenty-first wave. The wave in Figure 70 is traveling due north and, in general, is perpendicular to the isobaths. There is little refraction or shoaling of the waves until they are much closer to shore. The refraction pattern of a wave oriented toward the north- West (Figure 71) shows the rapid bending as it approaches the barrier islands. A wave will break when it reaches a slope of 1:7, so the wave used in this study will become unsteady and break long before it reaches the islands. The northwest end of a wave traveling to the northeast (Figure 72) will "feel" bottom and begin to slow down causing a bending of the wave to a more northerly direction. Considerable dispersion along this northern portion of the wave results in a sizable decrease in wave height. 118 40' 3' 20' 10' 00' 50' 40' 300 20' 10, 8' 50B 40. 30 40' 4 30' MISS.IALA MOBILE BAY 20' 20' LA ~~~~~~~~~MISSISSIPPI SOUND h`� 'o,~~~~~~~~~~~i 101 30~~~~~~~ 0 30~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 20' 10, 100 50' 4~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 30,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 20' 20,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 10, 10,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 40. 30' 20' lo, 80' 50' 40' 30' 20' 10, 80 50' 40' 30' FIGURE 70. WAVE REFRACTION DIAGRAM FOR WAVE ORIENTED 0". 40' 30' 20' 10' eq. Sol 40' 30' 20' ICY 88000 40' 30' 40' b40' 30' MISSjALA. MOBILE SAY 0 50,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 30, 3V~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 20' 20'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 40 0 0 0 9 04 0 0 0 8 0' 40' , FIGURE 71. WAVE REFRACTION DIAGRAM FOR WAVE ORIENTED 3150. 40' 30' 20' 10' Be- 50' 40' 30' 20' ID' Es0 50' 4D` so, 40' b40' 30' ~ ~~~~~~~~~~~~~~~~~~~~~~~~MISS.JALA. MOBILE BAY 403' 20' 0 ' 04 0 20'1'905'4'3 ' FIUEL2 AV MISSISSIPP IAGA SOU AEOINTD 4 Water Characteristics of Gulf of Mexico Deep water entering the Caribbean basin through the Windward Passage between Cuba and Haiti is introduced into the Gulf of Mexico through the Yucatan Straits by the Loop Current. The relatively shallow sill depth of the Yucatan Straits governs, to a large degree, the types of waters passing into the Gulf by pre- venting the entry of heavier waters located below the sill. The presence of water originating in the Antarctic at the intermediate depths is identifiable by the salinity minimum at 500-1000 meters. Water from great depths of the North Atlantic, characterized by high levels of dissolved oxygen, is also present in waters entering the Gulf. The existence of high-salinity water at a depth of 100 to 200 meters substantiates the contribution of water with an origin at the surface in tropic regions. The significant distinction between the waters of the east and west Gulf is a direct reflection of the difference in degree of Loop Current influence on the hydrography of the two areas. The hydrography of the east Gulf is dominated by the Loop Current while the west Gulf, less influenced by the Loop Current, expresses a chemistry dictated primarily by river discharges. The chemistry of waters entering the Gulf via rivers is markedly different from the oceanic waters of the open Gulf. Fluctuations in levels of surface salinity are due to evaporation, precipitation, and mixing with run-off waters from contiguous land areas. Surface salinity, which varies seasonally across the Gulf, is complexed in the east Gulf by the presence of 122 the variable Loop Current and in the west Gulf by highly variable rates of run-off seasonally and annually. One major distinction between waters of the east and west Gulf lies in the vertical profile of dissolved oxygen. Figure 73 illustrates typical dissolved-oxygen profiles for the east and west Gulf and in the Yucatan and Florida Straits. As should be expected, there is a striking similarity in the oxygen profiles between waters of the east Gulf and the two straits. The east Gulf waters display a secondary oxygen minimum at about 200 meters which apparently is the low-oxygen water from the tropics. The oxygen minimum for west Gulf waters occurs at a greater depth and is broader in extent than waters of the east Gulf. It has been estimated that the difference in oxygen levels between the east and west Gulf is approximately that which is necessary to oxidize all the carbon produced in a three-year period in the euphotic zone. This is strong evidence that the renewal rate of east Gulf waters is three times faster than that of the west Gulf. The waters of the Gulf below 1,500 meters appear to be homogeneous with respect to the level of dissolved oxygen. In the vicinity of the Mississippi River Delta, surface waters have a dissolved organic carbon concentration of approximately 2.31 mg C/i. Open Gulf waters express a much lower level at 0.74 mg C/Z. Waters over the continental shelf remote to the influence of the Mississippi River discharge usually have a concentration near 1.0 mg C/k. 123 The surface distribution of particulate organic carbon in the Gulf of Mexico is similar to that of dissolved organic carbon with a maximum of 1.911 mng C/9? near the Mississippi River Delta decreasing to 0.05 mg C/Z in the open Gulf. Loop Current waters, characterized by salinities of 36.7 ppt at temperatures of 22.5C, are frequently detectable over the continental shelf south of Mississippi. The strong salinity and density gradients apparent in the upper layers of this shelf area during spring and summer are easily correlated with the freshwater discharge from Mississippi River's eastern passes. Considerable variation in the temperature structure of the. water column is apparently caused by advection, local climatic changes, and fluctuations in river discharge. In winter the waters of the outer shelf are isothermal to a depth of 100 meters where a well-developed thermocline exists. A seaward-oriented positive gradient is produced over the shelf during the winter months due to the waters from the rivers being colder and lighter. By early spring the thermnocline in outer-shelf waters rises to a depth of approximately 35 meters. The deeper waters, both on the shelf and further out, are considerably colder by mid-summer probably due to advection. Figure 74 depicts the average temperature, minimum and maxi- mum temperatures recorded at 28 stations located within a five-mile radius of the proposed monobuoy site. The stations were sampled almost monthly over a two-year period. A statistical investigation substantiates the skewness toward low values through the water 124 column as depicted in the illustration. For further clarification the median value was from 0.5 to 2.0 ppt higher than the mean value at every level through the water column. It should be noted that while there is a reduction in range with depth, it is still rather broad. On 13 January 1965 a temperature inversion to a depth of 31 meters was observed. The temperature at a depth of 31 meters was l.8C warmer than that recorded for the surface. The mean and extremes of salinity from the same 28 stations used for temperature are depicted in Figure 75. The reduction in range with depth begins quite rapidly below 5 meters. There is a negative skewness in the distribution of salinity to a depth of 15 meters below which the skewness becomes positive. This further implies that the Loop Current waters are at least peri- odically present over the shelf area. An inspection of the profile of the mean and extremes of density (at) (Figure 76) shoes there is relatively little variability below 15 meters. This depth appears to be the lower limit of influence by river discharges or run-off. 125 02 (ml/I) 02 (ml/l) 2.5 3.0 3.5 4.0 4.5 5.0 2.5 30 3.5 4.0 4.5 5.0 0 I 0 - 250 -250 - 50O n 0 500 VW u.I-- F YUCATAN FLORIDA , STRAITS STRAITS I- I- - 750 i -750 0 - 1000 - 1000 1250 1250 02 (ml/I) 02 (ml/I) 2.5 3.0 3.5 4.0 4.5 5.0 2.5 3.0 3.5 4.0 4.5 5.0 I I .o o -250 - 250 500 - 500 EAST WEST SU GULF Eu GULF - 750 LU - 750 Lu -- 1000 - 1000 1250 1250 FIGURE 73. DISSOLVED OXYGEN PROFILES, GULF OF MEXICO. TEMPERATURE �C 0 5 10 15 20 25 30 35 0 - 6- 8- 3- 19- 20- 21- 12- FU 13- w ", 216- 17- 19- 20- 29- EXT.' - 30- * r. fft � FIGURE 74. WATER TEMPERATURE PROFILE, AVERAGE AND EXTREMES. SALINITY (PARTS PER THOUSAND) 10 15 20 25 30 35 40 45 0- I I I I II 2- 3- 4- - 5-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i 6- 7- 10- 11- 12- .,. - c, MC 13- uj I- wu 14- Z 15- 16- W 17- 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 18- 19- 20- -i '' 21- 22- 23- 24- 25- 26- 27- 28- 29- 30- FIGURE 75. SALINITY PROFILE. AVERAGE AND EXTREMES. DENSITY (t"GRAMS PER LITER) 20 25 30 35 40 45 50 55 I I I III 0- 1- 2- 3- 4- 5- 6- 7- 8- 9- ~' -'"%../' ~. *",. ~.~,- . 10- 11- 12- 13- g.. i- 14- w 15- z 16- 17- w 0 18- 19- 20- 21- 22- 23- 24- 25- 26- 27- 28- 29- 30- FIGURE 76. DENSITY PROFILE, AVERAGE AND EXTREMES. 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FFFFF'FFkFFIF F' F .1tFFF4IFFFkFF&flFFFFJFFiFLA44iFIFFFF FFFFFF-FFFFFL F.IFFFFFFFFF -FIFtFS I 4FF'F.:'S< F-i FJF.F FFFi.F.4 Fr' F4FF.F FF F 'F F FIFF 4FFFF4FFF 2FF aF,FFFFF FFFF]FMTh4FFJFF-1F11 F&FI Mississippi Sound and Subsystem Circulation A chain of barrier islands serves to define the southern extent of Mississippi Sound for its entire length. Some of these islands: Dauphin, Petit Bois, Horn, and Ship now comprise a portion of the Gulf Islands National Seashore. The western boundary of the Sound is an indistinguishable region near Grand Island where the Sound merges with Lake Borgne. The shallow, discontinuous shell reefs that extend from Cedar Point, Alabama, to Dauphin Island define the east limit between Mobile Bay and Mississippi Sound. Mississippi Sound, a part of the "Fertile Fisheries Crescent,"t is a relatively shallow mixing basin for the fresh water discharged by the river systems and the sea water which enters the Sound through the island passes. Mississippi Sound, a highly productive estuarine system, has a wet surface area of 817 square miles within the boundaries defined. It has an average depth of 9.9 feet at mean low water with an elongated, basin-like configuration of isobaths. The deepest portions of the Sound occur at the western ends of the islands as a result of scouring. The profile of the few natural mainland beaches, in general, indicates a low energy coastline. However,, certain segments of the mainland, subject to strong currents and direct attack by waves, show considerable erosional activity. It has been estimated that the offshore chain of islands are migrating westward due to littoral drift at approxi- mately 50 feet per year. 133 Mississippi Sound is traversed by three major channels main- tained by the Corps of Engineers. The Pascagoula Ship Channel, with an authorized depth of 40 feet, extends from south of Petit Bois Island to a point within the Sound where it divides into two branches, one reaching to the mouth of Pascagoula River and the other providing access to Bayou Casotte Industrial Park. If approved, official requests from the Pascagoula Port Authority will authorize deepening the existing channel to a depth of 50 feet. The Biloxi East Approach Channel, with an authorized depth of 12 feet, begins south of the west end of Horn Island and proceeds on a northward course east of Deer Island into outer Biloxi Bay. In the outer Bay this channel is intersected by the West Biloxi Approach Channel which begins at the Sound's north 12-foot isobath, circumvents Deer Island to the west, and follows the mainland east- ward to the point of intersection with the East Biloxi Approach Channel. The resulting single channel continues up Back Bay of Biloxi Bay to Big Lake where it branches and provides access to the Harrison County Industrial Seaway and Biloxi River. The Gulfport Ship Channel, which begins south of the west tip of Ship Island and extends directly to the Port of Gulfport's Ship Harbor, has an authorized depth of 32 feet. The Intracoastal Waterway, which crosses Mississippi Sound in an east-west direction, requires dredging to 12 feet only at the east and west extremes. This waterway is used primarily by tug and barge traffic. 134 In the process of providing and maintaining the required channels and waterways, a problem of no small magnitude has de- veloped. It has been a common practice to place "dredge spoil," the material removed for channel construction, parallel to and some distance removed from the channel under construction. With subsequent dredging to maintain or deepen these channels, the parallel ridges of spoil attain a height which seriously alters the normal flow of water. These submerged unmarked weirs, fre- quently exposed at low tide, are also a hazard to navigation. While this matter has received some attention in recent years, the problem still remains and is growing. Lake Ponchartrain, which in part drains the highly industrial- ized and urbanized New Orleans and the rapidly urbanizing northern shoreline and interior by streams and small rivers, flows via the Rigolets and Chef Menteur Pass into Lake Borgne and on to Mississippi Sound. Pearl River, which drains much of the interior of Mississippi, discharges into Lake Borgne just east of Rigolets. The Pascagoula River, which with its tributaries drains much of the eastern and central portion of Mississippi, serves as the artery being developed as the Pat Harrison Waterway. Pascagoula River discharges into Mississippi Sound at Pascagoula, Mississippi. A portion of the discharge of Mobile Bay, which is the ter- mination of the major drainage systems of the State of Alabama, is forced apparently by density currents to flow into east Mississippi Sound through Grant's Pass. Other independent streams, draining rather large areas of south Mississippi, also empty into the Sound via St. Louis Bay and Biloxi Bay. 135 The approximately 817-square mile area of Mississippi Sound is the eventual recipient of the effluents via river discharges and direct run-off from 37,750 square miles of land of diversified usage. Since the estuary thus reflects the activities throughout the drainage basins, the water quality of Mississippi Sound is not determined wholly on a local basis. The general circulation over the shelf south of Mississippi, discussed earlier in this report, reveals a westward flow just south of the islands from southwest of Pensacola, Florida. The prevailing circulation over the shelf influences the circulation and general hydrography of Mississippi Sound. This westward flow, seaward of the islands, forces approximately one-fifth of the lighter Mobile Bay waters into Mississippi Sound through Grant's Pass. It seems reasonable that seasonal and annual changes in the pattern and intensity of the currents over the shelf must also affect the circulation within the Bound. The configuration of offshore islands and currents further suggest that they serve as a barrier that retards the dispersion of the brackish waters from the Sound. The predominantly diurnal tides of Mississippi Sound with an average range of 1.5 feet are those of the contiguous segment of the Gulf of Mexico that are modified by the barrier islands and the geometry of the Sound. Sustained winds and fluctuating rates of river discharges often further modify the local tides. North- westerlies that occur frequently during the winter months push the waters out of the Sound, exposing much of the bottom, especially 136 reefs and bars that are otherwise covered. Sustained winds from the south or southeast have the opposite effect of pushing water into the Sound and piling it up along the mainland shore. At times these wind-driven tides attain heights of 5 to 6 feet and cause flooding of low lying areas including the beach highway, U. S. 90, in Harrison County. There is usually a longer period between times of low and high water than between the times of high and low water. Records from tide gauge stations located along the Mississippi coast indicate that the tide wave progresses from east to west through the Sound. The combined effects of currents and waves from the southeast result in a net westward littoral drift through the Sound. This littoral drift is easily discernible from the longshore transport of sediment. The U. S. Highway 90 storm drains jutting into the Sound in Harrison County, Mississippi, act as groins trapping sand on the east side of the drain pipes and scouring the beach away on the west side. The process produces a scalloped coastline vividly displayed in aerial photographs. The presence of this natural phenomenon which occurs across the breadth of the Sound bears careful attention. Interruption of this "River of Sand" by channelization accompanied by poor disposition of the "dredge spoil" will cause an eventual depletion of sands suitable for beach refurbishment. Mississippi Sound is subject to rapid changes in both tem- perature and salinity due to sudden changes in air temperature, evaporation, river discharges, rainfall, and tides. The "wet 137 period" or period of high rates of river discharge occurs from November through June. Tables II-VII show the year and monthly average discharge in cubic feet per second for rivers emptying directly or via bays into the Sound. Fresh water from the rivers usually flows seaward as a thin surface layer mixing with the higher saline waters below. A re- cent three-year study found that only during periods of unusually high rates of discharge are the outflows from the rivers observed in an unmixed state seaward of the barrier islands. Two rivers, the Biloxi and Tchoutacabouffa, draining a total of 513 square miles, empty into Big Lake at the head of Biloxi Bay. A strong vertical discontinuity in salinity in Biloxi Bay detected during periods of high river flow would, by commonly-used guidelines, define the Biloxi Bay estuary as highly stratified. However, during the other periods, especially late spring and early summer, the water column becomes almost homogeneous with respect to salinity in the intermediate segment of this estuary. A one- year study showed this estuary to be predominantly of the partially-mixed type but an occasion it assumes other-type characteristics. A well-defined salinity wedge correlating with the flood stage of the tide was found proceeding up Biloxi Bay under the lighter bay water during several study cruises. Direct- current measurements further revealed the existence of a stratified flow structure on several occasions. Hydrographic sampling in St. Louis Bay has been too sparse to make any definite statements concerning the physical characteristics 138 of the water, water structure or current patterns. Two rivers, Jourdan and Wolf, with drainage areas of 340 and 380 square miles respectively, discharge into St. Louis Bay. Jourdan River is influenced by tides along its entire length making accurate gauging of its flow a difficult And costly task. It is presently not gauged. Flow records for Wolf and Jourdan Rivers are incomplete as shown in Tables V and VI. The two rivers discharging on opposite sides of the shallow bay complicate the circulation by their out- f lows varying in both rate and time relative to each other. Pearl River, with an average flow of 8,582 cubic feet per second and a record maximum of 88,200 CFS, discharges into the relatively shallow Lake Borgne, the west boundary of Mississippi Sound. Most of the Pearl River outflow continues seaward around Grand Island and through Cat Island Channel. Because of the maintenance of a regime of low salinity water in this area that deters immigration of predators requiring higher salinity, the area is considered desirable for establishment of oyster reefs. However, prolonged exposure of the reef's to extremely low salinity caused by continued high rates of river discharge results in ex- tensive oyster mortality. There is a definite negative salinity gradient from east to west through Mississippi Sound. There is, of course, a positive salinity gradient seaward from the mainland. Salinity levels observed through the water column taken from near the mainland to the island passes have ranged from fresh water to 35.5 ppt. 139 The temperature structure of the Sound and bays generally shows a positive gradient seaward during winter with the reverse being true for summer. Temperatures usually decline with depth through the water column with isothermal situations being common in the shallower areas. Cold fronts passing over the Sound cause pronounced temperature inversions. St rong thermoclines exist near river mouths during periods of high river flow. Mississippi Sound and bays receive an estimated total of 9,920,737 tons of sediment annually from only a portion of the streams contributing waters to the Sound. The fine silts, clays, and fine organic matter remaining in suspension largely account for the turbid conditions almost characteristic of Sound waters. The anions of the salts in sea water combine with the cations of the clay particles and flocculate out of suspension. The fine silts and clays of the relatively shallow Mississippi Sound are resuspended during stormy weather when waves attain heights that permit them to "feel" bottom. The surface isotherm and isohaline charts (Figures 77-82) of east Mississippi Sound in the vicinity of Pascagoula, Mississippi, were furnished by a presently on-going but yet incomplete study of Sound circulation. While these figures do not represent the final verified form of the data, any changes would be of a minor nature and thus will not significantly alter the patterns as depicted here. The warmer river water (Figure 77) is seen moving to the south- west around the southern extent of the dredge spoil ridges. The 140 discharge from west Pascagoula River moves westward along the mainland to where the coastline indicates an inflection point in the curvature. At this point, the flow turns south and on 23 May 1973, during a rising tide, shows a continued eastward deflection. The isohalines (Figure 78) constructed from data taken the same date clearly show a turn to the southwest. The pattern of isohalines extending from the west is in agreement with the pattern of isotherms. The relatively high salinities near the mouth of the river reflect a period of relatively low river flow. The surface temperature of 14 June 1973 (Figure 79) illustrates the seaward flow of lighter, fresher water from the west Pascagoula River. A negative temperature gradient is oriented seaward. A tongue of higher salinity water (Figure 80) is shown ex- tending into the Sound through Horn Island Pass during 26 June 1973. The close proximity of the 9.0 ppt isohaline to the river mouth again reflects a period of relatively small river outflow. Northwest of the tip of the "tongue" is a configuration of isohalines that indicates a westward deflection of the discharge from east Pascagoula River. The configuration of isotherms for 26 June 1973 (Figure 81) implies a flow first southward then eastward from the west mouth of the river. A sharp turn to the west by the east river outflow just south of the exposed ridge of dredge spoil is clearly shown. The surface temperature declines seaward. 141 The westward deflection of the lighter but mixed river outflow just south of the exposed line of dredge spoil is illustrated in the pattern of isohalines of Figure 82. An arm of higher salinity water is seen intruding into the Sound through Horn Island Pass. A cell of lower salinity water is located near the east end of Horn Island. A positive gradient exists from east to west across Petit Bois Pass, and is a semi-permanent feature caused by sea- ward outflow of a portion of the Mobile Bay water which enters Mississippi Sound through Grant's Pass. Figure 83 is a conceptual depiction of the tide-dominated currents of east Mississippi Sound. The currents in the passes between islands have been recorded at speeds in excess of 1.5 mph. It should be further noted that these currents have been observed to be strongest below mid-water depth on a rising tide and strongest at the surface on a falling tide. A strong interface characterized by strong gradients of salinity, temperature, pH, and dissolved oxygen has been fre- quently observed at a depth of 8 to 12 feet in the waters of the Pascagoula Ship Channel. Salinity increases markedly over a distance of 1 to 2 feet. The temperature gradient is less pro- nounced but coincides with that of salinity. Dissolved oxygen drops to very low levels and on several occasions to levels too low to measure in situ, i.e., less than .02 parts per million. This well-defined interface is restricted to the waters of the channel and those waters immediately adjacent. 142 Channel construction permits the intrusion of heavier, more saline waters into Mississippi Sound that would otherwise be restrained by the natural bottom bathymetry. The heavier water moves up the channel across the Sound as a bottom-oriented salinity wedge. This salt wedge continues up the Pascagoula River and its presence has been detected 20 miles upriver from the mouth. Figures 84 and 85, reconstructed from a recent three-year study, show the trends in levels of certain physical and chemical parameters with time. The charts were constructed from averages derived from pooling data from several stations in rather close proximity. The averages were computed for surface and near- bottom waters. River-discharge rates for the Pascagoula River during the study period are also illustrated as a frequency polygon. Temperature (Figure 84) of surface waters from the mainland to mid-Sound ranged from 8.3C in January to 30.9C in August. Maximum vertical difference in temperature between surface and bottom waters was 1.5G. Surface-temperature extremes recorded for the south half of the Sound (Figure 85) were 8.2C in December and 31.80 in July. Temperature extremes for the bottom waters were 9.5C and 30.10 recorded in January and August, respectively. Surface salinities for the cross section of the Sound ranged from 0.0 to 33.3 ppt. Salinity extremes for bottom waters were 6.0 and 35.5 ppt. The drop in salinity levels, as should be expected, correlates highly with the season and rate of river discharge. 143 Levels of dissolved oxygen decline rapidly with depth in the lower Pascagoula and Escatawpa Rivers to the point of anoxic conditions. This situation has been attributed to the heavy oxygen-demanding effluent discharging into the two rivers. Some steps intended to correct this undesirable situation have recently been taken. Dissolved-oxygen levels ranged from 5.88 to 13.05 ppm in the north half of Mississippi Sound. The latter figure was observed during an obvious phytoplankton bloom. The oxygen levels for the south half of the Sound were similar to those of the north half with the normal highs corresponding to saturation values at low temperatures. Peak nitrate values occurred during May in the north half of the Sound. The greatest nitrate levels are found near bottom. Nitrate levels diminish seaward. The trend line for inorganic phosphate is quite irregular attributed to the periodic activity of the various sources. Inorganic phosphate extremes for the transect of Mississippi Sound seaward from Pascagoula were 0.25 micro-gram atoms per liter to 5.06 jiga/Z. The peak levels of total phosphate occurred in May and were greater in the surface layer than in the bottom layer of water. Total-phosphorus concentrations throughout the Pascagoula River estuarine area reflect heavy pollution of the system. Of 315 samples, only 7 percent showed less than 2 paga/i of total phosphate. 144 As mentioned previously, some steps have been taken to correct this situation; however, the problem still exists and will re- quire additional effort. 145 TABLE II. Discharge, Pascagoula River at Merrill, Mississippi. Monthly Averages in Cubic Feet per Second. OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 1951 2245.0 2290.0 5945.0 8934.0 18830.0 16530.0 30430,0 3561,0 3457,0 2962.0 1811.0 2338.0 1952 1659,0 2066.0 6777�0 5446,0 11100,0 13180.0 9411,0 7264,0 3091.0 1872o0 1854.0 1601.0 1953 896,0 1338.0 3317.0 9014.0 15700.0 22160.0 14210.0 27540.0 3242.0 5618.0 3225.0 2193,0 1954 1137,0 1799.0 23120,0 8997.0 8527.0 7820.0 14060.0 5473.0 2109.0 2793.0 1177.0 885.0 1955 936.0 1082.0 1598.0 5965.0 10680,0 4671.0 19110.0 1083.0 2142,0 3320.0 6374,0 1428.0 1956 1111,0 1268.0 2961.0 2328.0 21340.0 22490.0 11210,0 2926.0 2876.0 4858,0 1995,0 1280,0 1957 1417o0 1128.0 3868.0 2659.0 4180.0 4971.0 13270,0 6147,0 2672.0' 3105.0 1606.0 11000.0 1958 10540,0 18340,0 12750.0 12660.0 16690�0 23510,0 11270.0 16040.0 5937�0 13760.0 6973,0 10230,0 1959 457?,0 2?84.0 3753.0 8067.0 16910.0 10790.0 13060.0 5800.0 18010.0 5944,0 4282.0 3798.0 1960 8314.0 10550,0 6743,0 10820.0 19320.0 17850.0 17430.0 13560.0 2262,0 2147.0 5355.0 3220.0 1961 2653,0 4058.0 3143.0 9929.0 44520,0 4?600,0 38540.0 4906.0 8517.0 11130.0 5341,0 5319,0 1962 2498,0 11990.0 45210,0 31900.0 16990.0 11850.0 20940,0 13260.0 5527,0 2568.0 2561.0 1654,0 1963 1887.0 2094,0 2250.0 8842.0 9265.0 10150,0 3049.0 1679,0 1517,0 1653.0 1318,0 1224.0 1964 ?63,0 914.0 2410.0 7414.0 ?876,0 27930.0 30140.0 13010.0 3268.0 4961.0 3332.0 1541.0 1965 6055,0 3657.0 17330.0 14850,0 24530,0 15730.0 7065.0 2625,0 2657,0 2651o0 3566.0 2627.0 1966 2385.0 1529.0 3910.0 11210.0 50030.0 24680,0 9554.0 14370.0 3484.0 2655.0 3723.0 2323.0 1967 2455.0 3344.0 4294.0 8836.0 9685.0 5068.0 4434.0 8480.0 2535.0 2780.0 2711,0 2100.0 1968 1371,0 2097.0 19770,0 14040,0 5496.0 9948.0 11300,0 6273.0 2147,0 1562,0 1801.0 1586,0 1969 1065.0 1601,0 10750,0 9707.0 9899.0 15710�0 32610,0 8558,0 2322.0 2699.0 3672.0 1906.0 1970 1421,0 1431.0 3938.0 7196.0 7509,0 14680.0 8452.0 5187.0 2356.0 2964,0 4446.0 2375.0 1971 6129.0 3746.0 6887.0 11970.0 17230.0 35140.0 13340.0 12690,0 3668,0 4021.0 5173.0 5541,0 1972 2504,0 2236.0 24640.0 27930,0 22650.0 16750.0 7845.0 9330.0 2421,0 2570.0 1674.0 1172.0 TABLE III. Discharge, Biloxi River at Wortham, Mississippi. Monthly Averages in Cubic Feet per Second. OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 1953 6.0 18.8 257.0 219.0 558.0 248.0 310.0 59.7 146.0 116.0 142.0 21.1 1954 4.3 109.0 498.0 128.0 69,6 96.7 81.0 12,7 9.8 100.0 7.0 5.3 1955 8.6 16.1 86.0 325.0 373.0 34.1 724.0 61.7 10.8 130.0 410.0 18.4 1956 11.1 16.7 53.2 60,6 201.0 246.0 55.8 7.9 311.0 97,5 29.6 237.0 1957 144.0 34.7 459.0 87.6 66.5 151.0 237.0 121.0 52.5 12.9 15.8 410.0 1958 107.0 346.0 181.0 356.0 189.0 470.0 197.0 407.0 232.0 430.0 171.0 223.0 1959 46.6 22.3 24,1 111.0 483.0 256.0 270,0 267.0 587.0 371.0 171.0 272,0 1960 352.0 119.0 92.2 298�0 417.0 194.0 323.0 206.0 7,8 93.1 279,0 231.0 1961 53.1 33.0 33,9 245,0 878.0 820,0 338.0 95.2 312.0 201.0 141.0 483.0 1962 50.7 379.0 652.0 372.0 222.0 191,0 122,0 13.4 38,0 21.9 29.5 26.0 1963 6.8 16.8 56.9 185.0 247.0 95.2 24.0 29.9 7.4 94.3 40.7 14.9 1964 1.9 10.1 92.7 400.0 166.0 274,0 534.0 98.9 67,3 84.5 190.0 52,4 1965 37.8 96,6 226.0 287.0 356,0 238.0 40.1 34.2 160.0 63,9 138.0 152.0 1966 89,8 94.6 156.0 509.0 870.0 547.0 211.0 199.0 23.8 34.2 96,1 16.0 1967 18.3 17.9 65,3 342.0 186,0 41.9 75,7 34,9 26.2 14,7 99.1 169.0 1968 114.0 89.0 431,0 155.0 63.6 68.3 46.3 18.1 33.2 14.9 43.6 62.2 1969 4.2 2?.0 220.0 286.0 204.0 453,0 307,0 ?0,9 7.4 13.6 235,0 32,3 1970 20.2 22.8 106.0 179.0 219.0 557.0 122.0 121.0 154.0 114.0 209.0 6Z.I 1971 229.0 60.5 292.0 202.0 386.0 254.0 55.0 71,0 25.8 132.0 150.0 300.0 1972 20.2 33.3 281.0 721.0 329.0 293.0 67.1 386.0 16.1 21,2 15,3 5.4 TABLE IV. Discharge, Tchoutacabouffa River at Tuxachanie Creek. Monthly Averages in Cubic Feet per Second. OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 1953 6.9 14.8 210.0 169.0 346.0 210.0 213.0 46.6 216.0 137.0 69.9 14.4 1954 5.0 46.8 372,0 72,8 31.8 64.9 31.9 9,1 5,5 25.4 4.5 5.3 1955 6,3 9.? 65.5 245,0 393.0 25,3 908.0 32.8 8.5 138,0 425.0 24.2 1956 35.0 14.8 60,3 91.4 211.0 282.0 54,? 8.7 153.0 102.0 25.1 246.0 1957 221.0 33.2 462,0 72.4 49.6 142,0 330.0 237.0 66.3 15.3 15.2 987.0 1958 126,0 347.0 165.0 304,0 177,0 574,0 190.0 612,0 197.0 660,0 264.0 186.0 1959 34.2 22.5 23,9 66.6 429.0 267,0 243.0 209.0 583.0 436.0 327.0 277.0 1960 478,0 108,0 64,3 357,0 341.0 220,0 300.0 246,0 10.2 56.9 398.0 266.0 1961 38.6 19.4 37.? 204.0 757,0 557.0 401.0 114.0 311,0 134.0 316,0 479.0 1962 71,5 355.0 487,0 354.0 270.0 139,0 85.6 11.0 184.0 52,2 32.3 48.? 1963 37.6 25,0 76,6 229.0 266,0 115.0 15.2 13,2 15,2 126.0 61,4 29.4 1964 5.0 13.4 127.0 465.0 173.0 214.0 709.0 81,1 13.0 94.0 301.0 197.0 1965 184.0 105.0 201.0 360.0 337.0 386.0 55.4 68.5 230.0 78.5 183.0 313.0 1966 123,0 36,4 127.0 453.0 732.0 466,0 199.0 157.0 36,6 34.9 116.0 56,8 1967 24.0 29.6 59,2 341.0 180.0 38.1 100.0 14.8 26.0 11.9 68.0 240.0 1968 195.0 120.0 277.0 113.0 53.4 52,7 50.2 24.1 9.6 12,3 15.6 40,0 1969 5.4 29.7 218.0 306,0 186,0 445.0 239.0 76,0 7.5 57.7 487.0 32.0 1970 19.4 21.8 107.0 185.0 244.0 381.0 109.0 73.6 139,0 266.0 288.0 99.9 1971 362.0 78.8' 333.0 193.0 379.0 244.0 58.8 32.0 56.7 112.0 125.0 472,0 1972 0.0 0.0 0,0 0.0 0.0 0,0 0.0 0,0 0.0 0.0 0.0 0.0 TABLE V. Discharge, Wolf River near Lyman, Mississippi. Monthly Averages in Cubic Feet per Second. OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 1965 332.0 307.0 828.0 854.0 1016.0 480.0 151.0 57.4 75.5 112.0 253.0 306.0 1966 185.0 232.0 384.0 1193.0 2356.0 1142.0 406.0 251.0 103.0 152.0 262.0 235.0 1967 160.0 135.0 277.0 716.0 560.0 211.0 352.0 306.0 107.0 67.4 166.0 116.0 1968 74.3 105.0 881.0 601.0 248.0 422.0 280.0 122.0 149.0 108.0 60.2 197.0 1969 66.2 150.0 503.0 522.0 352.0 841.0 917.0 252.0 66.1 273.0 634.0 219.0 1970 94.8 125.0 351.0 454.0 540.0 995.0 336.0 273.0 486.0 255.0 342.0 164.0 1971 453.0 212.0 654.0 532.0 838.0 699.0 235.0 244.0 91.6 332.0 458.0 736.0 TABLE VI. Discharge, Jourdon River at Santa Rosa, Mississippi. Monthly Averages in Cubic Feet per Second. OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 1964 10.7 21.0 193.0 719.0 236.0 425.0 963.0 141.0 64.7 118.0 162.0 146.0 1966 210.0 201.0 358.0 415.0 641.0 2.6 65.8 37.1 52.4 77.5 52.1 144.0 TABLE VII. Discharge, Pearl River near Bogalusa, Louisiana. Monthly Averages in Cubic Feet per Second. OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 1951 3215.0 2881.0 5287,0 10680,0 24870.0 15940.0 29690.0 6745.0 2946,0 2726.0 2049.0 1914.0 1952 1529.0 1710.0 5834,0 4300.0 7671.0 8912.0 7222.0 4519,0 2673.0 1773.0 1706,0 1440.0 1953 1188.0 1394.0 2240.0 7164.0 15150.0 27880.0 10380.0 36930.0 5618.0 3901.0 3574.0 2064.0 1954 1389.0 1690.0 8793.0 5636.0 7540,0 5274.0 9373.0 10090.0 2401.0 2424.0 1514.0 1246,0 1955 1408.0 1323.0 1713.0 6995.0 14960.0 10130,0 27200.0 6955.0 3374.0 3982.0 4201,0 1619.0 1956 1343.0 1424.0 2934.0 2174.0 26470.0 24230.0 21940.0 4412.0 3776.0 2046,0 1770.0 1423.0 1957 1343.0 1394.0 3463.0 3800.0 7272.0 8147.0 22800�0 5473.0 3700,0 5646.0 2252.0 3270,0 1958 5192.0 16150.0 16780,0 10550.0 12890.0 19220.0 11480.0 25650.0 7983.0 10390.0 6555.0 5004.0 1959 5352.0 2915.0 3808.0 8084,0 18860.0 10510.0 10860.0 7928.0 9046,0 3288.0 3006.0 2656.0 1960 3177.0 4437.0 6988,0 11500.0 20910,0 24480.0 9473,0 9945.0 2265,0 1852,0 4295,0 2388,0 1961 2059.0 2062.0 2390.0 7394,0 22830.0 38550.0 32270.0 4590,0 6145,0 10090.0 4514.0 3651.0 1962 2127.0 12560.0 35690.0 40220.0 21450.0 14390.0 24230.0 11480.0 4662.0 2795,0 2606.0 1996.0 1963 1991.0 1968.0 2151.0 6034.0 7641.0 8999.0 3214.0 1926.0 1651.0 2234.0 1917.0 1458.0 1964 1110.0 1233,0 2289.0 6009.0 5849.0 27820.0 25660.0 18590.0 2568.0 4684.0 3351.0 2147,0 1965 9023.0 3074,0 17820,0 8460.0 21110,0 18140.0 10300,0 2376.0 2028.0 2008.0 2454.0 3412.0 1966 3360.0 1923.0 2739,0 11310.0 34240,0 16860.0 8085.0 19960.0 4407.0 2471,0 2723,0 2532.0 1967 2197.0 2825,0 2972.0 4821.0 66740.0 4764,0 3927.0 10530.0 4891,0 3457,0 2197.0 2209.0 1968 1527.0 1702,0 12220,0 23850.0 6852,0 10960,0 15370.0 11380,0 3438,0 2309.0 2274�0 2071.0 1969 1402.0 1447,0 8578.0 77?8.0 8396.0 14370.0 26300~0 11340.0 1910,0 1564,0 2352,0 1766.0 1970 1391.0 1298.0 2390,0 7881.0 4346,0 13205.0 10292.0 9905,0 2850.0 2076�0 2657.0 1945.0 1971 5288.0 3858.0 4052.0 9044.0 11360.0 32450.0 11810,0 22610,0 4178.0 4084,0 6403,0 6400.0 1972 2885.0 2322.0 27860.0 30830,0 20120.0 14950.0 6409.0 9061.0 2562.0 2555,0 2331.0 1867,0 59' 45' 4s0' 35' $--.,25' FIGURE 77. SURFAC TEMPERATURE, MISSISSIPPISOUND,23MAY1973.3 LEGEND C _.. POLATEDAREAS , .. - 3 MARSH AREAS FIGURE 77. SURFACE TEMPERATURE, MISSISSIPPI SOUND, 23 MAY 1973. 'IA.O~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~. 1 MARSH. AREA Su' 45' 45* 88-3 25O35 FIGURE 78. SURFACE SALINITY, MISSISSIPPI SOUND, 23 MAY, 1973. 5D' 45' 49 351 88-au` 25, 25, 26 29. 29.0 3 6~~~~~~~~~~~~~~~~~~~2. MARSH AREAS 5'O 45 401. 53 FIGURE 79. SURFACE TEMPERATURE, MISSISSIPPI SOUND 14 JUNE 1973. 45'OS, 40 35' W a g 2 FIUE80 UFAESLIIY MISSISSIPP SON,4JUE193 ~~12.0~ 3. Vz.~ ~ ~ ~ ~ ~~~~~~~. ~~~~~~14 5. MARSH Aa~oREAS FIGURE 80. SURFACE SALINITY, MISSISSIPPI SOUND, 14 JUNE 1973. SLY 45� 40' a5' 8030 256 FIGURE MI8U ACLA 25' 28 7~~~~~~~~~~~~* 30.0 Jl , " 29.1 29.5 ,,, 29.0 .5~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~9. 2. 5 28.5 LEGEN. MARM AH IREAS 2222~4" - B B -Bo, 25' FIGURE 81. SURFACE TEMPERATURE, MISSISSIPPI SOUND, 26 JUNE 1973. 50' 45' 40* 354 883'y 255 FIGURE miss SURFAC SSS OiALA M2J 18.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~M~~sar 17.0~~~~~~~~~~~~~~~b4i 2~~~~~~~~~~~~~~~~~~~~~~~~~~~~TUPN LEGEND~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.UCLL I.L....E~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~a 45' 4 0 3 5 ' Wa l 25 FIUR 2.SUFCESAIIT, ISISIP SUN,26JUE193 15'~~~~~~~~~~~~~4,4 I-OUA2 AREA InMARSN AREAS- ZSZR 504 0'3 oO 5 FIGURE 83. CONCEPTUAL REPRESENTATION OF EAST MISSISSIPPI SOUND CURRENTS . 5 SURFACE BOTTOM SURFACE BOTTOM 20 TOTAL PHOSPHATE, UG-AT/L - 20 TOTAL PHOSPHATE, UG-AT/L o .:..:..---'~-: . . .-: 0~~~~~ 0 :..... 0 :; 10 PHOSPHATEUG-AT/LT T 101 PHOSPHATE, UG-AT!L T 0 : ; ; ; 1 ;: I .. �; 10 . 10; Ni;T , _AT- 10 PH 10 PH0 5 : ;:: :: :: ;::::: :;;": �: ;;~: ';: .:::::: 5 : :::: ::;: : :: ;;;::::::::: 20 TDISSOLVED OXYGEN, PPM1 -- 20 DISSOLVED OXYGEN, PPM - I~~~~~~~~~~~~~ ,oi =ss v- = O :::::: : ::::::: O ::::::: :::::: 0 o ~~~YPT354SALNITYPPT 5S 35 TEMPERATUREC 35 TEMPERATUREC 750 750 RIVER DISCHARGE.CF/1000 J71r VIR DISCHARGE. CF/lOOO J I 0 0 : :::::: :::. :::0. .. : t.\ ...... :l : :| : ::::::: A M J J AS O N D J FM AM M ASOND J F M A M J J A S O N D J FM 1968 1969 1968 1969 1968 1969 1968 1969 HYDROLOGICAL PARAMETERS IN HYDROLOGICAL PARAMETERS IN ESMISSIPSONEAST MISSISSIPPI SOUND ~~~~~~~~~~~~~~~~~~~EAST MISSISSIPPI SOUND FIGURE 84. PHYSICAL - CHEMICAL PARAMETERS OF FIGURE 85. PHYSICAL - CHEMICAL PARAMETERS OF ~~~~~~~~TOEAST MISSISSIPPI SOUND FROM MAID-SOND TO ESMISSIPSONFRMMILNTOEAST MISSISSIPPI SOUND FROM MAINLAID-SOUND IANTO MID-SOUND. ISLANDS. PHOTO 5. COMPACT GRASS ELLIPSOIDS CREATED BY HURRICANE BETSY, 1965. Charles K Eleuterius Climatology General Controlling Meteorological Conditions The subtropical anticyclonic Bermuda High exerts the greatest influence on the climate of the Gulf of Mexico and con- tiguous land areas. The Bermuda High intensifies during the spring extending its boundaries into the Gulf of Mexico region. This extension into the Gulf results in a shift in the source di- rection of the winds to the southeast and south. The wind speeds are much reduced from those of the winter and fall. In early fall the Bermuda High diminishes in strength and its boundary of influence retreats from the Gulf region. Simultaneously with this southeast emigration of the Bermuda High is a southward advance of the continental pressure systems over the Gulf. Accompany- ing this move, the predominant winds become northerlies. Graphical and tabular presentations of wind data appear in Figures 25-37. During winter, westerly systems influence the study area as cold fronts from the northwest move southward over the Gulf of Mexico. When these cold fronts, modified by the relatively warm Gulf waters, oppose strong maritime tropical air moving in the opposite direction, the front becomes almost stationary. Under these conditions the northern Gulf area becomes subject to cyclogenesis resulting in low cloud ceilings and precipitation. Because of the large heat-storage capacity of water and the size of the Gulf of Mexico, the Gulf greatly influences the 161 predominant year-around maritime tropical climate of the study area. Air Temperature Southerly winds from over Gulf waters during summer have an ameliorating effect on the heat of the immediate coastal area. Based on 30 years of records, there is an average of only 52 days per year when the temperature exceeds 90F. This figure is approximately half as often as areas only 80 miles inland. Although temperatures infrequently have exceeded 100F, the average summer high temperature is 88.9F. The summer southerly winds from over the relatively cooler Gulf waters effectively reduce the air temperature for a summer average of 81.5F. The winters are generally mild with an average of only 11 days per year when temperatures fall below 32F. There are no records of sub-zero temperatures ever having occurred. The average temperature for the winter months is 54.5F with an average minimum temperature of 46.3F. The dates of the first and last freezes, averaged from recorded data, are 12 December and 21 February, respectively. The average temperature for the year is 68.2F. Precipitation There is an average of 58.58 inches of rain per year on the Mississippi Gulf Coast. The wettest month is July with 7.33 inches of rain due primarily to the frequency of thundershowers. September and March are next in amounts of precipitation with 6.50 and 6.10 inches, respectively. The driest months are October and 162 November when the dry continental air masses push southward over the area causing clear skies and cool nights. Due to the close proximity of the cooler water surface of the Gulf, summer showers are less frequent and lighter than those 50-100 miles inland. Measurable snow has fallen on the Mississippi coast only 8 times in the past 78 years (February 1899; January 1935; March 1954; January 1955; February 1958; January 1964; January 1973; February 1973). Being of such rare occurrence, the appearance of snow on the Mississippi coast is considered by local residents to be an impressive phenomenon. Due to the relatively warm winter temperatures, the snow melts rapidly leaving only traces by late afternoon. Humidity and Fog Prevailing southerly winds during summer carry moist air over the northern Gulf coast. The combination of-high humidity and high temperature sometimes causes discomfort to those not acclimated to such conditions. Cold air masses moving out over the Gulf in winter lower the sea surface temperature. This, therefore, provides the mechanism for the formation of advection- radiation fogs along the coast from November to March. Dense sea fog forms offshore over the relatively cold water surface. Thunders torms, Thundershowers, Extratropical Cyclones, Waterspouts There is an average of 75 days when thunderstorms occur along the Mississippi coast. The moist air provided by the southerly winds results in more frequent showers during summer than in other 163 seasons. Thundershower activity increases during the day with 30 percent occurring between 6 a.m. and -noon and 60 percent between noon and 6 p.m. The frequency of thundershowers is highest in July. The Mississippi coast is far south of the usual path of winter cyclones, but on rare occasions one will traverse the area. While statistics on waterspouts do not exist for the Mississippi coast, waterspouts are observed but seldom come ashore. Tropical Storms and Hurricanes Tropical cyclones which derive their energy primarily from the latent heat of condensation of water vapor are generally from 60 to 600 miles in diameter at maturity and only rarely exceed 1,000 miles in diameter. The speed of the maximum winds is used as the criterion for classifying tropical cyclones. Circulations with maximum sustained winds up to 38 mph are tropical depressions. Tropical cyclones with sustained winds from 39 to 73 mph are categorized as tropical storms. When the maximum sustained winds exceed 73 mph, the tropical cyclones are called hurricanes. The term "hurricane" is used in the North Atlantic region, Caribbean Sea, Gulf of Mexico, eastern North Pacific, and the western South Pacific. In the western North Pacific, cyclones of comparable intensity are referred to as typhoons. In warm tropical ocean regions where evaporation rates are very high, large quantities of water vapor are transmitted to and stored in the atmosphere. When the vapor condenses and precipitates, latent heat is converted to sensible heat and kinetic energy in the form of winds. Warm ocean areas thus 164 serve as enormous reservoirs of energy used in the development and maintenance of tropical cyclones. The migration of the tropical cyclones into regions of cooler water or over land re- moves this source of energy. The awesome destructive power of a fully developed hurricane is in the form of extremely strong winds, torrential rainfall, and high tides and waves. A tremendous amount of property damage, totaling in the billions of dollars, has been attributed to hurricanes hitting the continental United States since 1900. More than 12,000 people have lost their lives in hurricanes in the United States during the same period. In 1900, 6,000 people were killed in Galveston, Texas, during a single storm surge. Since 1875 (Figure 86) only 17 tropical storms or hurricanes have crossed the Mississippi coastline. Of these 17, only 8 were of hurricane intensity. However, Mississippi has been affected by high winds, high tides or heavy rains from 70 tropical storms or hurricanes during this period. On 17 August 1969, the most powerful hurricane that has ever entered the North American Continent struck the Mississippi coast with winds of 200 mph and an accompanying surge that drove the water elevation to 22.6 feet above mean sea level. It continued inland through Mississippi, crossed Tennessee, Kentucky, and Virginia, and finally reentered the Atlantic. In the three Mississippi coastal counties it left in its wake: 3,861 destroyed homes; 39,744 homes damaged from near destruction to light; 322 businesses destroyed; and 1,668 businesses damaged. One hundred thirty-four people were killed and others were never accounted for. 165 Because of the counterclockwise winds of the hurricanes, the northeast quadrant of the cyclone is the most damaging to the northern Gulf coast. The winds of this quadrant pile water up against the coast and also drive large waves in a north or northwest direction. Due to the severity of the north- east quadrant, the direction of approach greatly determines the effect upon the Mississippi coast. Hurricanes that move northeastward from the general direction of the Mississippi River Delta and strike the coastline east of Mississippi are the least damaging as the winds encountered over Mississippi would be from the north or northeast and would thus drive the water away from the coast. Hurricanes that make landfall in southeast Louisiana usually have considerable effect on the Mississippi coast because of the effect of the northeast quad- rant. Hurricanes that might move westward offshore of Mississippi would also result in high tides, waves, and winds along the Mississippi coast. The reversed Z configuration of the coastline formed by the Mississippi River Delta and the Mississippi coast makes the Mississippi coast especially vulnerable when northeast quadrant hurricane winds prevail over the area. Enormous quantities of water are pushed into the Sound by these winds and move westward along shore through the Sound. The barrier formed by the Mississippi River Delta formation to the west, preventing any further westward transport, helps build even higher water levels inside the Sound. 166 While the hurricane season in Mississippi is from June through November, the preponderance of hurricanes occurs in August and September with September accounting for one-half of all occurrences. Hurricane statistics derived for 50-mile segments of the coastline show the probability of a hurricane occurring in any one year on the Mississippi coast (.13) is considerably less than 100-mile segments east and west of Mississippi (.21). Since hurricanes are such awesome powers and do invoke con- siderable damage, the problem of hurricane occurrence in the proposed site area will be addressed further. The object is to estimate the probability of a hurricane making landfall or passing close enough to the proposed Superport site to cause possible damage to the area. With the definition of "~significant"l including winds higher than 30 mph (statute miles), all tropical cyclones are considered. Tropical cyclones include hurricanes, tropical storms, and tropical depressions (storms with winds up to 38 mph). One should note the inclusion of tropical depressions in interpreting the tabulated probabilities since several of the tropical storms in the defined region were probably too weak to have a significant effect on the area in question. In developing probability distributions only data concerning North Atlantic tropical cyclones from 1901 to 1963 were con- sidered. Data prior to 1900 is not of a quality to be usable and there is no compilation of figures beyond 1963 available. Since 1900, 500 tropical cyclones were recorded, and 114 of these moved inland or passed close enough offshore to affect significantly 167 various sections of the coasts of Mississippi, Louisiana, and Alabama. Since published data pertained to the Mississippi, Louisiana, and Alabama coasts as a general area, probability dis- tributions were developed in terms of this three-state area. This should not greatly bias our probabilities as most storm centers affecting Louisiana or Alabama coastlines usually produce winds and tides of sufficient strength to affect the Mississippi coast. It is granted that storms moving inland in western Louisiana might have little effect on the area of interest, and the probability estimates could be a slight over-estimate. Papers by Cry and Thom established that the frequency of tropical cyclones and hurricanes reaching the United States coast was Poisson distributed, i.e., the probability law is defined by e_ X. Data published by Cry pertaining to the previously X! mentioned three-state area was tested against the assumption that it was Poisson distributed. The Chi-Square and Kolmogorov-Smirnov goodness of fit tests were used to test the Poisson assumption. Results of these tests appear in tables VIII and IX. The Kolmogorov-Smirnov cricital value (significance level .01) is 1.63/v6/- = .205361, and since our test statistic is less than .205361, we accept the hypothesis of a Poisson distribution with X = 1.81 (mean). Chi-Square = .92148 and this is less than the critical value of 13.3 (Chi-Square value for significance level .01 with 4 168 degrees of freedom). Again, the hypothesis of a Poisson dis- tribution with mean = 1.81 is accepted. The entries of the last two lines in Table IX were combined to form a single class. This was done because the expected number on the last line was too small. Such expected numbers lead to large Chi-Square values which do not reflect a departure of "observed from expected" but only the smallness of the "expected." The values in the Calculated Probability Function column (P) reflect the probability of X storms per year. There is a pro- bability of .296 that we will have one tropical cyclone within the three-state area. This storm could move inland or pass close enough to significantly affect the area. We could expect about three significant storms each decade. It is noted that both goodness of fit tests support the hypothesis of a Poisson distribution with mean = 1.81. The Kolmogorov-Smirnov test is a more powerful test than the Chi- Square test and is preferable. Also, t he calculated probabilities in table IX are in close agreement with those published by Cry. Whereas, the above analysis is for all tropical storms which either moved inland or remained offshore and moved inland in another area, table X and the resulting conclusions pertain to a storm moving inland in the three-state area being considered. Kolmogorov-Smirnov Statistic = .049 which is less than the critical value of .205361, and we accept the hypothesis of a Poisson distribution with mean =1.32. 169 The probability of one tropical cyclone moving inland in the three-state area would be .35283. Again, we should expect at least three tropical cyclones per decade in this three-state area. According to Cry, the regions of maximum tropical cyclone activity have been Florida, Texas, the middle Gulf Coast, and the Carolinas. The probabilities generated tend to reflect such an activity. 170 TABLE VIII POISSON DISTRIBUTION OF TROPICAL CYCLONES AFFECTING THE MISSISSIPPI, LOUISIANA, ALABAMA COAST, 1901-1963 Kolmogorov-Smirnov Test Observed Relative Expected Kolmogorov- No. Storms Observed Cumulative Cumulative Cumulative Smirnov Per Year Frequency Frequency Frequency Frequency Statistic 0 10 10 .15873 .16365 .00492 1 20 30 .47619 .45987 .01632 2 14 44 .69841 .72794 .02953 3 12 56 .88889 .88968 .00079 4 5 61 .96825 .96286 .00539 5 2 63 1.00000 .98936 .01064 X= 1.81, S2 = 1.74 Kolmogorov-Smirnov Statistic = .02953 TABLE IX POISSON DISTRIBUTION OF TROPICAL CYCLONES AFFECTING THE MISSISSIPPI, LOUISIANA, ALABAMA COAST, 1901-1963 Chi-Square Test Probability Calculated Annual No. Storms Observed Expected (Obs-ex)2/ex Probability Frequency Per Year (X) Frequency Frequency Function (P) >_X 0 10 10.31022 .00933 .163654 1.00000 1 20 18.66148 .09601 .296214 .83635 2 14 16.88857 .49405 .268072 .54013 3 12 10.18940 .32173 .161736 .27206 4 5 6.95033 .00035 .110323 .11032 5 2 TABLE X POISSON DISTRIBUTION OF TROPICAL CYCLONES REACHING THE MISSISSIPPI, LOUISIANA, ALABAMA COAST, 1901-1963 Probability Annual No. Storms Calculated Observed Calculated Frequency Per Year (X) Probability (P) Frequency Frequency (l-P) >X 0 .26781 17 16.872 1.00000 1 .35283 19 22.228 .73219 2 .23242 19 14.642 .38936 3 .10207 7 6.430 .14694 4 .03362 0 2.118 .04487 5 .00886 1 .558 .01125 X= 1.32, S2 = 1.19 ECENTER MOVED INLAND IN INDICATED AREA 0 CENTER REMAINED OFFSHORE OR MOVED INLAND IN ANOTHER AREA * HURRICANES (Winds74 m.p.h. or over) [ TROPICAL STORMS (Winds 39-73 m.p.h.) M 0 DEPRESSIONS ANNUAL NUMBER OF TROPICAL CYCLONE - CENTERS - PASSING -- INLAND 0 1901 1911 1921 1931 1941 1951 1961 FIGURE 86. HURRICANE, TROPICAL STORM AND DEPRESSION STATISTICS 1901 - 1961. S c ~~~~,]i 6' L TN, RSH~~i v vi B IOTA Marshes It is highly probable that marshes are the least understood, most underrated, and most abused pieces of land in the world. Historically, they have been the victims of avarice and ignorance, and due to the erroneous belief that marshes serve no useful purpose and being equated with deserts, they have been despoiled and destroyed. In actuality, very little land usage is as pro- ductive as are the salt marshes. Not only do marshes produce vast quantities of nutriently rich vegetation but they also pro- vide many beneficial services. Marshes are the vegetated, soft-land areas that border the estuaries and banks of the lower rivers. These areas, interfaces between the water and upland environment, are unique habitats that provide food and protection to many aquatic and terrestrial animals. The marsh substrate is the result of sediment deposition by river outflow. As a river widens near the mouth and the river out-- f low confronts the waters into which it is discharged, the velocity of the outflow is greatly reduced. This reduction in velocity re- duces correspondingly the ability of the river to keep the sediment in suspension and it thus settles to the bottom. The continued sedimentation process results in the construction of bars and banks on which marsh plants later appear. After such a lengthy develop- mental process, a marsh is established. 177 Dead plant material is attacked by bacteria that decompose the plant material found within the marsh. This decomposed com- position of plant material and bacteria is called detritus. Tidal action carries the detritus out of the marsh into open waters where it is consumed by an array of marine organisms including oysters, shrimp, and mullet. The young of many sport and commercial species enter the estuarine marsh areas where they find an abundant food supply and protection from predators. These young remain in the vicinity of the estuarine marshes until they have reached a certain stage of development at which time they depart. Due to this role served by the marshes of the estuaries, the word "estuary" has become synonymous with "nursery area." Some phase of the life-cycles of the major portion of the species found in the study area is estuarine related. With their thick root system, marsh grasses are a bulwark against bank and beach erosion. During storm conditions when the marsh is inundated, waves traveling through or over the marsh are greatly reduced or completely dissipated by friction with the grass surfaces. Where present, this frictional barrier decidedly reduces the damage that would otherwise be invoked by waves. The marsh slows the rapid water run-off from upland areas causing it to deposit its sediment load within the marsh region. In absence of marsh, this sediment would be discharged directly into the receiving waters thus increasing the turbidity of the water. 179 Increased siltation rates would then result in accelerated filling of navigation channels thus requiring more frequent and costly maintenance dredging. Marshes assimilate some chemical constituents that, occurring in abnormal levels as a result of domestic and industrial effluent loading, reflect polluted systems. Without marshes to help reduce excessive levels of these chemical components, the assimilative capacity of the estuary would diminish increasing the possibility of its attaining a state of pollution. The straight-line distance near the coast from East Pearl River, the west state boundary, to the Mississippi--Alabama line is approximately 68 miles. The actual coastline, however, is much longer due to the presence of rivers, bays, bayous, and the ir- regular shoreline. There are four major drainage systems along the coast: Pearl River, St. Louis Bay, Biloxi Bay, and Pascagoula River. The lowest portion of the rivers and the entire bays are estuarine subsystems of the larger estuary, Mississippi Sound. Each of these subsystems (Figure 87) contain sizable marsh areas. Mississippi marshes are divided into four regions: Saline, Brackish, Intermediate, and Fresh water. The saline marsh is comprised of two major species; Juncus roemerianus and Spartina alterniflora which usually form a common boundary. Interspersed with the J. roemerianus are some brackish water species S. cynosuroides, S. patens, and Scirpus olneyi. On the "salt flats" that appear throughout the saline-marsh area are found Salicornia bigelovii, Suaeda linearis, and Batis maritimus. 180 The brackish marsh is differentiated from the saline by the decline in the abundance of J. roemerianus and the decline and eventual disappearance of Spartina alterniflora. There is also an increase over that found in the saline marsh of both brackish and freshwater plant species. Interspersed among the J. roemerianus of the brackish marsh are the following plants: Spartina cynosuroides, Spartina patens, Limonium caroliniana, Boltonai asteroides, Ludwigia sphaerocarpa, Lythrum lineare, Ipomoea purpurea, Scirpus olneyi, Polygonum setaceum, and Sagittaria lancifolia. The'absence of S. alterniflora from this area is attributed both to low salinity and lack of suitable sub- stratum. The lower boundary of the intermediate marsh is defined by the complete disappearance of Juncus roemerianus. This transi- tional area between the brackish and freshwater marsh areas consists of plants found in both. Plants that are found in this area are: Phragmites communis, Scirpus validus, Cladium jamaicense, Eleocharis cellulosa, Scirpus americana, Sagittaria lancifolia, Pontederia cordata, Crinum americanum, and Iris virginica. The freshwater marsh consists, generally, of small discontinuous bands bordering the river banks. There is a greater diversity of plant species comprising the freshwater marsh than the other marsh regions. Plant species found in this area are: Eleocharis cellulosa, Eleocharis obtusa, Crinum americanum, Sausarus cernus, Sagittaria lancifolia, Iris virginica, Scirpus americana, Pontederia cordata, Rhynchospors macrostachya, Ptilimnium capillaceum, 181 Prosperpinaca pectinata, Pluchea purpurasens, Ploygonum setaceum, Scirpus validus, Ludwigia sphaerocarpa, Boltonia asteroides, Zizania aquatica, Eleocharis quadrangulata, Sium suave, Juncus megacephalus, and Osmunda regalis. There is a distinct lateral zonation between certain marsh species. While there have been a number of theories presented to explain this zonation, present evidence is still insufficient to be conclusive. There is also a difference between Pearl and Pascagoula Rivers with respect to the species composition of the fresh and intermediate marsh regions. Based on an analysis of fixed line transects, Mississippi's marsh composition is approximately 57.8 percent J. roemerianus; 9 percent Sagittaria lancifolia; 7 percent Spartina patens, 6.5 percent Spartina alterniflora; 6 percent Spartina cynosuroides. The following species comprise 2.5 percent or less of the marsh vegetation: Cladium jamaicense, Scirpus validus, Distichlis spicata, Fimbristylis spadicea, Osmunda regalis, Phragmites communis, and Boltonia asteroides. In 1968 of the 64,805 acres of mainland marsh, 61,398 acres was dominated by J. roemerianus and approximately 2,028 acres by Spartina alterniflora. Spartina patens and Scirpus olneyi dominate 460 and 96 acres, respectively. Of the 64,805 mainland marsh acreage, 823 acres is freshwater marsh and 63,982 acres is salt marsh. The barrier islands contain a total of 2,126 acres of salt marsh. The production of organic matter by Mississippi marshes is estimated in excess of 3 million tons annually. 182 Based on 1973 figures, since 1930, 8,170 acres of pro- ductive Mississippi marsh had been filled for industrial use. Another 85 acres have served as garbage dumps. Land developers, prevented from constructing Venecian-type canals in other states, moved into Mississippi and continued this building practice which destroyed additional marshlands. Due to the foresightedness of the Mississippi Legislature, a Wetlands Protection Act has been enacted to help prevent the misuse of one of Mississippi's most valuable resources. Figure 87 shows a portion of the marshes of east Mississippi Sound. Attention should be directed to the extensive marsh area east of Bayou Casotte. This marsh, associated with the abandoned Escatawpa Delta, has remained in an almost pristine condition due mainly to the absence of industrial or domestic land developments. The largest and one of the last relatively undisturbed marsh habitats in the States of Alabama and Mississippi, it provides a rich nursery area for many important marine species. 183 35' 30' 25' 20' 15' 10' -5 891O.0, -55 500' 45' _ 40' 35' 30' 25' 20' is, Z3SALINE MARSH 55 BRACKISH MARSH 5 0 rRESIH-WATER MARSH ImUNTYPED MARSH 60, so, 45' 45' 40' 25* 25' 20' n 15 15I' 35, 30' 25' 20' 15' l o '' S0 55' 50' 45' 40' 35' 30' 25' 20' is, FIGURE 87. MISSISSIPPI-WEST ALABAMA MARSHES. 40' 35, 88030, 25' 20' 15,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 ROUND~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~(N BSANY P.- DAUXP$i ~~~~~~~~~~~~~~~~~~~~~~~~~~UNTPE MARSHES 40'355532' 20'1 ' SAINUE 8.MARSHES O ATMSISPI-WS LBM Submerged Vegetation A recent survey revealed that approximately 20,000 acres (31.2 sq. mi.) of submerged vegetation exists within that part of Mississippi Sound in Mississippi. Most of the submerged vegetation is located just north of the barrier islands (Figure 89). Species identified were Thalassia testudinum, Cymodocea manatorum, Diplanthera wrightii, Halophila engelmanni, Ruppia maritima, and Vallisneria americana. Shoal grass (Diplantera wrightii) was found in Point aux Chenes Bay east of Bayou Casotte where a sandy substrate exists. It was also found forming a continuous b-lt north of Petit Bois Island associated again with a sandy bottom. Shoal grass was discovered in patches on the "Middle Ground," 'an area approximately midway and north of Horn Island. There the patches appeared separated from other grass species. The species also occurs as patches at Dog Keys, a shallow shoal area between Horn and Ship Islands. A strip of this vegetation is also found north of Ship Island. The lagoons of Cat Island and the area to the west and north, protected from the open Gulf, were heavily vegetated / with shoal grass. A small area of this species which is not indicated in the figure is located east of Bayou Caddy in Hancock County. In every instance, shoal grass occurred on sandy bottoms. Manatee grass (Cymodocea manatorum) was found in waters 4-6 feet deep north of the shoal-grass areas on the mainland side of Horn and Ship Islands. 186 Over thirty species of benthic algae including red, brown, and green were collected in Mississippi Sound. Widgeon grass (Ruppia maritima) and tape grass were collected in low salinity and freshwater areas in bays and near rivers. While information on these submerged grass beds is relatively sparse, they are considered to add substantially to the over-all productivity of Mississippi Sound. 187 35' 30' 25' 20' 15' 10' 5' 891.00, 55' 50' 45' 40' 30'5' 0 20' 1r,, I ~~ LEGEND SHOAL SHOAL-ALGAE I TTURTLE-MANATEE SHOA'L, ALGAE MANATEE-ALGAE 50' ~ALGAE .\~ 45~I~i TURTLE, MANATEE, ALGAE - K~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~5 40' 40' 35' 35' 30' 30' 25' 050' ~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~BAYOU LAB 5 30'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 15' 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~N 5 US-k IOU~~~~~~~~~~~~~~~~~~~......... 35' 30' 25' 30' - 5Ml ' 65~0 55 50' 45' 40' 35S' 1 30' 2 5 0' 15' 0 FIGURE 89. SUBMERGED VEGETATION OF MISSISSIPPI SOUND. Oyster Reefs Due to the scale of the chart, not all of the Mississippi oyster reefs are shown in Figure 90. Productive, commerically exploitable reefs exist in the following locations: Bangs Lake, Bayou Cumbest, Herron Bayou, West Pascagoula River Delta, Graveline Bayou, Biloxi Bay (four separate reefs), East End Deer Island, Pass Christian, Square Handkerchief, St. Louis Bay, Waveland, and Point St. Joe. Many smaller reefs are scattered throughout the Sound, but the ones mentioned here are the most productive. How- ever, of the estimated 2,030 acres of productive oyster reefs, only 1,035 acres are open to harvesting. Due to pollution, the remainder have been closed to shellfish harvesting by the State of Mississippi Health Department. The pollution criterion utilized in making de- cisions to close areas for oyster harvesting is an enterococci coli bacteria level above 70 MPN (most probable number) per 100 milli- liters of water. Some controversy exists concerning the appropriateness of the method and bacteria level used in declaring an area polluted. In any case, Mississippi is presently realizing approximately only half of the potential productivity of its oyster reefs because of pollution. In the near future, another notable shellfishing area, Graveline Bayou, will be closed - another casualty of pollution. Until a viable plan for waste treatment for the Mississippi Gulf Coast is devised and implemented, it appears that the present trend of pollution will force the State Health authorities to continue closing productive oyster reefs. 189 The Mississippi Marine Conservation Commission, in order to assure a continuing oyster supply for the Mississippi seafood industry and in the face of the encroaching pollution, has built new reefs in unpolluted waters. This practice of constructing new reefs is no small task. The environment in which a productive oyster reef can be established is restrictive. The immobility of oysters precludes their existence in areas with high siltation rates where they would soon become buried. Oysters are able to live only within a specified range of salinity. If the salinity level is too low due to high rates of river discharge, the oysters die. High salinities within the tolerance range of oysters per- mifts the predacious "oyster drill" (Thais haemastoma) to invade the reefs often annihilating the oyster populace. Bottoms where reefs can become established are also critical. The bottoms cannot be sandy as shifting sands would soon cover the oysters; the bottom cannot be soft mud because the oyster would eventually sink into it and "smother." There are many problems associated with the site selection, development, and maintenance of reefs as productive oystering areas. Improving the water quality and subsequently opening oyster reefs now closed due to pollution would double the present area available for shellfish harvesting. 190 35' 30' 25, 20' is, 10' 0' Bo.-oa' 55' 500 45' 40' 35' 30' 25' 20'15 55' 55' 50' 50'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 45' 7N45' 40' - l40' j ' ~LEGEND 2 Xj 35,I OYSTER REEFS 35 30' K)30' 25' ovu25' 20' 20' 35' 30' 25' 20' 0 0 5' 8 9'-00 55, 50' 45' 40' 35' 30' 25' 2'15' FIGURE go. MISSISSIPPI OYSTER REEFS. I t -- .+ - �- KY C - "C ##37 >"- -4 Vt -k <5 452< KY �s Vt Qt4; -4r --KY a, It PHOTO 7. MISSISSIPPI SHRIMP BOAT DWARFED BY MENHADEN BOAT Charles K. Eleuterius Commercial and Sport Fisheries Mississippi's coastal and offshore waters comprise a portion of the "Fertile Fisheries Crescent." Mississippi's long estab- lished fishery industry expresses a strength and intensity that probably would not be expected from its relatively short coast- line. The state ranked seventh in 1971 in fishery production and presently ranks second among the Gulf states in production volume. The fishery industry employs approximately 4,500 people directly and many others in the ancillary services such as ice and freezing plants, net manufacturers, ship yards, engine distributors, engine repair shops, and fuel suppliers. Mississippi's fishery production, including cat fish farming, for 1973 was evaluated by the National Marine Fisheries Service to have a dockside value of $18,432,000 and a manufactured value of $55,997,000. These figures do not include the contribution real- ized from support of the ancillary businesses. As do most other U.S. fishing industries, Mississippi's fishing industry contends with foreign, governmentally-subsidized fisheries. Generally, foreign fishing fleets and factories are better equipped and are not subject to the rigid inspections and laws as in the United States. Figures 91-97 illustrate the production volume and value of some of Mississippi's seafood industries since 1950. The dollar value is indicated at the top of each bar and refers to dockside value in all cases except for the Pet Food Industry (Figure 96). 195 Mississippi's oyster industry faces a dim future due primarily to encroaching pollution forcing the closing of productive oyster reefs. Since the remaining reefs cannot supply the demand of Mississippi's industry, oysters are -now being trucked into the state from Louisiana and Texas. The raw oyster production has increased steadily in the last 20 years (Figure 91). This does not reflect an increase in the resource, but a shift to marketing raw oysters rather than canned ones due to the unfair market advantage of foreign imports. Foreign imports have a cost advantage in that they are not subject to the strict regulations which, in the interest of public health, are imposed on U. S. shellfish industries. The canned-oyster industry has declined in the last decade (Figure 92) due to both the dwindling resource and unfair market competition with foreign products. The sudden decline in 1969 and 1970 reflects the loss of processing capability resulting from the destruction of facilities by Hurricane Camille. The shrimp fishery has been the mainstay of Mississippi's seafood industry. While the industry faces the uncertainties of an available resource which fluctuates with natural influences, the decline in Mississippi shrimp production (Figure 93) is due primarily to increasing competition from neighboring Alabama. It has been pointed out that Mississippi's shrimp-fishing vessels, generally, are obsolete and are at a disadvantage in competing with the larger horse-power vessels built for the open shelf waters. 196 The menhaden fishery began in Jackson County, Mississippi, in 1939, and produces three products: oil, solubles, and meal. The meal is used mainly as food for poultry and swine. The products are sold both in the U. S. and foreign markets. Each menhaden vessel costs in excess of $500,000. The catch data and corresponding pre-manufactured value are indicated in Figure 94. The red snapper industry is a relatively new fishery in Mississippi and its production has increased almost exponentially since its beginning (Figure 95). The production of pet food from bottom-oriented "industrial fish" has become a sizable industry since its establishment in Mississippi in 1956. The production has been relatively consistent (Figure 96). Two other important fisheries for which catch figures have not been included are the crab fishery and littoral fishery. Mississippi's seafood increased rapidly up through 1961; since then there has been a significant decline in volume (Figure 97). Identification of specific problem areas associated with Mississippi's seafood industry is addressed in a recent report (listed in the Literature Referenced section of this report) by fisheries expert Charles Lyles. Little information is available concerning Mississippi's sport fishery. While it is felt that the monetary contribution to the economy is considerable, the collection of essential statistics is extremely difficult. The gathering of pertinent information depends strictly on the cooperation of the sport 197 fishermen. Some investigative work in this area is now being conducted, but the financial support is at a level that severely restricts the scope of the study. Aerial surveys, while important, cannot furnish the required catch data, catch composition, and expenses necessary for determining the economic contribution. The Mississippi coastal area, coastal waters, and shelf waters abound with life. Tables XI-XIV have been prepared to illustrate the fertility and productivity of the study area. While considerable effort went into the preparation of these tables, it is realized that the lists are incomplete because not all the faunae of the area have been identified or reported. Table XI lists all of the mammals occurring in the study area that have been reported. The reptiles and herptiles found in the area are listed in Table XII. Birds, including migratory birds, that are found in the area comprise a substantial Table XIII. Table XIV incorporates many, but certainly not all, of the organisms that are found in the waters of the study area. Listed in these tables are a number of endangered species. Mississippi reaps a bountiful harvest from the sea that it will continue to enjoy with proper management and assistance. This renewable resource is a mainstay of the economy of the coast and the state as a whole, and adequate safeguards must be in- stituted in locating and operating a Superport in the area. 198 THOUSANDS OF MISSISSIPPI STANDARD CASES THOUSANDS OF GALLONS - - - - N) MM MM M C, C, -- M~0) 00 0 IQ .1h. 0)co0 M -ts a)0 co a K.,) .1h C) 0) -jcoto0) CO-CM CD). (110) 40) COO 0 )00 00 00 00 00 00 000 0000 0 0 0000000 -n ,........,..,...~~~~~~~~~~~~~I C 1950 1,179,746 C 1950 59,066 m 1951 888,542 m 1951 , 31952 2,079.152 1952 18,282 1953 1,713,525 1953 215,189 0w 1954 1,450,576 -0 1954 183,437 'a > 1955 1,518,892 1955 357,621 1956 1,317,861 < 1956 464,380 a < 196C >15 > r Z c c 1957 1,565,663 Cm 1957 457.155 mo 0 c 195 735,263 o 1958 293,442 o 0 0 1959 359,068 2 > 1959 265,283 -< c9Z 0 ci) > 0 - I -n 1960 27 9 m Z 1960 314,600 m o -- 0< rl >91 n1 i726.825 z 1961 r1 196 Oz m m mu 1962 5 1 1702,444 0 m m6 65,1 o 1963 1,646,583 19658,592 c 11963 1 9 1963 or -C -I m m 1964 4 1 890,355 o z Z co 1965 0 f 1965 833,560 ID 1966 - 9 1966 766,505 o~~~~~~~~~~~~~~~~~~~~~~ - 743,78 *1967 0 ~ 19677470 -I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~- 1968 ~~~~1968 1 1,009,685 1969 ? 1969 1,106,750 1970 ? 1970 1,568,325 1971 ? 1971 1,688,825 1972 ? MILLION OF POUNDS 3,713,000 C 1950 m 1951 2,906,000 1952 3,330,000 1953 3,746,000 1955 1954 2,596,000 co Co 3,076,000 - 1955 - , 1956 3,729,000 n1957 3,190,000 o r 0 1958 2,830,000 > 195 2,609,000 C) zr 1960 2,899,000 OZ G > : 1960 Z --I -- C ~ 1962 2,220,000 0 Li 1963 2,484,000 Io 1963 - 1964 1,805,000 1965 2,523,000 1966 51,000 1967 3,122,000 1968 3,677,000 1969 4011,000 1970 3,810,000 1971 4,362,000 MILLIONS OF POUNDS 00 0 C 0 0 0 0 00 0 M C D a 0 0 0 0 0 0 0 0 CD0 0)aD 00 a C 1950 828,000 m 1951 1,424,000 1952 1,252,000 1953 619,000 1954 890,000 1955 1,960,000 1956 2,589,000 Z D 1957 2,146.000 I < I> r g 1958 1,887,000 cm m > 1959 193000 z m 1960 2,198,000 Co Dz I o m- 1961 3,404,000 m >m -< o 1962 1 2,917,000 UD O 1963 3,276,000 O o , _ 1964 3,131,000 tD 1965 3,973,000 1966 3,465,000 1967 2,145,000 1968 1 2,038,000 1969 3,306,000 1970 3,888,000 1971 4,823,000 THOUSANDS OF POUNDS 0 0 0 0 0 0 0 0 0 C 1950 16,000 m 1951 1,000 1952 * 1953 7,000 1954 17,000 1955 '35,000 0 � 1956 62,000 M ? > >r 1957 143,000 > - 1958 274,000 a C m m O 1959 255,000 1960 367,000 Zn _ ml ~1961 537,000 I >-n m m F 1962 544,000 n 1963 471,000 g l 1964 461,000 ' - 1965 589,000 CD < 1966 771,000 1967 850,000 1968 11,118,000 1969 959,000 1970 930,000 1971 886,000 MILLIONS OF POUNDS In~~~~~- -. -. ~'iM M W C)~ Ci.~ ~~CiCtCiO ~ Q0'J -0 00 C O C 1956 w 1957 8,692,135 1958 12,590,291 cn Cl) 1959 rn 1959 8,974,517 ~El ~1 1960 1 114,425,922 - 0 r m 1961 13,558,875 co, >- -1 r, 1962 14,902,758 5; r- 0 q 1963 12,608,501 -n 0, >1 r 1964 8,478,585 m-n m DC/ v, o1o * m ZC/ 9686900 'C~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'0 CD 1966 9,176,003 1%j 1967 8,509,628 (7> m 1968 1966 6,D47 < 1967 1969 10,817,200 1971 9,431,311 MILLIONS OF POUNDS I~~n M M W E ~ ~ ~ ~ M 4.1 0) -0) (0 0- 0 04~ 3 ). C:) (0 -.4( a~ (30 - 0 0 0 MW .0 00 '-010 0 000000 000 000000000000000000 0000 C m w 1950 3,371,000 1951 3,133,000 r- 1952 3,165,00 0 1953 3,321.000 < -<M a >0 1954 3,267,000 1955 6 ,6850000 - Wz 1956 6, 6641,000 z m o 1957 6,318,000 M 1958 6,234,000 co 1959 6,246,000 m - 1960 7,606,000 z 1961 7,549,000 Co g~o m I 1962 7,983,000 rn" r r- 1963 00 > 1965 9,264,000 z - 1966 9,066,00 C) ( 1967 8,986,000 co)~ -1968 9,6,00 o 0 1969 10,528,000 1970 11,101,000 0 SUMMARY AND RECOMMENDATIONS The United States, in order to meet the growing energy requirements, will have to increase the importation of foreign crude to supplement its dwindling domestic resources. To deliver this large volume of crude to U. S. refineries expediently and at a reasonable cost will require the utilization of supertankers of 100,000 to 300,000 dead weight tons. At present, these large vessels cannot be accommodated by any port within the continental United States. This means that ports to accommodate such vessels must be developed or U. S. consumers must pay a higher price for energy. Failure of the United States to develop such ports that would supply foreign crude to U. S. refineries may necessitate the importation of higher cost refined petroleum products from foreign refineries. Monobuoys for off-loading crude from supertankers offer con- siderable monetary savings and are environmentally preferable to other superport designs. The employment of monobuoys in waters of sufficient natural depth precludes the necessity of costly and environmentally undesirable dredging. Locating monobuoys to ser- vice supertankers in the open sea is safer than congesting the on- shore ports with the increased small-tanker traffic required to sup- ply the same amount of crude. Furthermore, should a spill occur, an offshore location would allow time for an oil spill contingency plan to be initiated to clean up the oil, whereas, an oil spill 205 nearshore and in semi-confined waters would not allow much time for corrective action to be taken. Five major water routes are in close proximity to the proposed Superport location, 25 miles south of Pascagoula, Mississippi: Mississippi River, Pearl River, Pat Harrison Waterway, Tennessee- Tombigbee, and Intracoastal Waterway. Also, water in excess of 3,000 feet is less than 30 miles from the site which is an important factor during stormy weather. The proposed site, unlike areas near the Mississippi River Delta, possesses a stable bottom which is desirable for anchoring monobuoys and supporting pipelines. Areas around the Mississippi Delta, as a result of silt deposition, are unstable due to the con- tinued decay of organic matter in the substratum. This unconsoli- dated bottom is subject to slumping and turbidity currents. The Loop Current enters the Gulf of Mexico through the Yucatan Straits and periodically extends northward across the Gulf and over the continental shelf south of Mississippi. The current speed of the core, a relatively high 4.86 knots, would be a positive assist to maritime traffic, especially supertankers, trav- eling with the current. The Loop Current is also primarily respon- sible for the difference in the water characteristics of tli~ East and West Gulf. The vertical profiles of dissolved oxygen indicate that the waters of the East Gulf are renewed three times faster than those of the West Gulf. This renewal rate is, of course, environmentally desirable. A semi-permanent cyclonic eddy exists over the continental 206 shelf south of Mississippi and Alabama. In the event of an oil spill within this eddy structure, the eddy would detain the shoreward mi- gration while cleanup operations were expediently undertaken. Waves in the proposed site area exceed a height of 12 feet only slightly more than 3 percent of the time with the months of November, December, January, and February accounting for 65 percent of all waves exceeding 12 feet. The sea is relatively calm during the summer months. The winds are primarily northerly during the winter months and from the south and southeast during the summer. Should a spill occur during the winter when the sea state is usu- ally the greatest, the most probable prevailing winds, being from the north, would help keep the spill at sea. Should a spill occur during the summer months with prevailing southerly winds, the sea state is usually calmer allowing a cleanup operation to proceed successfully. There exists, of course, the probability that unf a- vorable seas and winds could prevail on the occasion of a spill and only an adequately equipped cleanup task force properly deployed could contain the spill. The pipeline route as proposed in this report is environmentally preferable for a number of reasons. The area east of Bayou Casotte is a fertile nursery area for the young of many important marine species and therefore should be protected from any unnecessary al- teration. The route of the pipeline discussed herein would parallel the existing ship channel from west of Petit Bois Island to just east of Bayou Casotte thus eliminating the necessity of extensive dredg- ing of a new access channel for use by a pipe-laying barge and tugs. 207 This minimizing of dredging likewise reduces the turbid conditions unhealthy for the young of the various species. The pipeline route is also preferable in that the pipe would come ashore where there exists only a narrow fringe of marsh along the shoreline thus mini- mnizing the effect on marsh productivity. In the event of an oil spill within Mississippi Sound along the proposed pipeline route, the combined actions of the discharge from Pascagoula River and tidal action would serve as a barrier retarding shoreward progression. If, however, an alternate route were selected allowing the pipe to enter and cross land further east of Bayou Casotte, considerable marshland would be affected. Additionally, extensive dredging to construct a channel for a pipe-laying barge and periodic maintenance would be required. Associated with this dredging activity would be the problem of "dredge spoil" placement. With the pipeline so located, an oil spill due to a ruptured pipe would endanger the productive marshland because of the prevailing current patterns. If such a spill should occur during summer months with the prevailing southeast winds, the spill would undoubtedly reach the marsh - the last remaining large productive marsh area in east Mississippi Sound. The southern boundary of the Citronelle Formation delineates a fault line. While earthquakes have not occurred in 'the area in a long time, geological investigations reveal that sudden movements cannot be ruled out. The hazard of crossing such a fault is avoided by the pipeline route as proposed within this report which would circumvent the fault to the west. 208 The proposed monobuoy system is located in the midst of the "Fertile Fisheries Crescent," a highly productive fisheries area. The area has historically produced vast quantities of fisheries products. Over 95 percent of the commercial species caught in the area are, at some phase in their lives, estuarine dependent. The marshes not only provide an abundant supply of food for the marine species but they also provide protection for the young of the species from predators and the more severe environment of the open waters. In the event an oil spill is not contained and reaches shore, the marshes being reached by the oil would show the most damage. The effect of the oil would be to kill the young of the many species directly, and indirectly by destroying the mechanism that converts the organic marsh material to the "detritus" food for the marine species. While the area south of Mississippi has a significant number of environmentally sound reasons conducive to locating a monobuoy, every precaution should be taken to insure the safety of Mississippi's renewable fisheries resource. Proper navigation, communication, meteorological, and oceanographic instrumentation should be located possibly on the pumping platform to direct tanker traffic and to provide vital information in the event of a spill. A contingency plan with adequate trained personnel and proper equipment to be de- ployed immediately in the event of a spill should be an integral part of the Superport operation. Placing responsibility for a spill should be secondary to the containment and cleanup operation and should be decided after the cleanup operation is completed. Only 209 in this manner can Mississippi insure the integrity of the marine environment, the esthetics of the coast, and the productivity of both the sport and commercial fisheries while acquiring and bene- fiting from yet another vital resource. 210 TABLE XI MAMMALS OF THE STUDY AREA Scientific Name Common Name Balaena glacialis Black right whale Balaenoptera acutorostrata Minke whale Balaenoptera borealis Sei whale Balaenoptera edeni Bryde whale Balaenoptera physalus Fin whale Blarina brevicauda Shorttail shrew Cryptotis parva Least shrew Dasypus novemcinctus Nine-banded armadillo Delphinus delphis Saddleback dolphin Didelphis marsupialis Opossum Eptesicus fuscus Big brown bat Feresa attenuata Pygmy killer whale Glaucomys volans Southern flying squirrel Globicephala macrorhyncha Blackfish Grampus griseus Gray grampus Kogia breviceps Pygmy sperm whale Kogia simus Dwarf sperm whale Lasiurus borealis Red bat Lasiurus seminolus Seminole bat Megaptera novaeangliae Humpback whale Mephitis mephitis Striped skunk Mesoplodon europaeus Antillean beaked whale Monachus tropicalis Caribbean monk seal Mus musculus House mouse Mustela frenata Longtail weasel Mustela vison Mink Myocastor coypus Nutria Neotoma floridana Eastern woodrat Nycticeius humeralis Evening bat Odocoileus virginiana White-tailed deer Ondatra zibethicus Muskrat Orcinus orca Killer whale Oryzomys palustris Rice rat Peromyscus gossypinus Cotton mouse Peromyscus leucopus White-footed mouse Peromyscus nuttalli Golden mouse Physeter catodon Sperm whale Procyon lotor Raccoon Pseudorca crassidens False killer whale Rattus norvegicus Norway rat Rattus rattus Black rat Reithrodontomys humulis Eastern harvest mouse Scalopus aquaticus Eastern mole 211 TABLE XI (Continued) MAMMALS OF THE STUDY AREA Scientific Name Common Name Sciurus carolinensis Gray squirrel Sciurus niger Fox squirrel Sigmodon hispidus Hispid cotton rat Spilogale putorius Eastern spotted skunk Stenella caeruleoalba Euphrosyne dolphin Stenella frontalis Bridled dolphin Stenella longirostris Long-snounted dolphin Stenella paliodon Spotted dolphin Steno bredanensis Rough-toothed dolphin Sylvilagus aquaticus Swamp rabbit Sylvilagus floridanus Eastern cottontail Tadarida brasiliensis Free-tailed bat Tursiops truncatus Atlantic bottlenose dolphin Urocyon cinereoargenteus Gray fox Vulpes fulva Red fox Zalophus californianus California sea lion Ziphius cavirostris Goose-beaked whale 212 TABLE XII REPTILES AND HERPTILES OF THE STUDY AREA Scientific Name Common Name Abastor erythrogrammus Rainbow snake Acris crepitans crepitans Northern cricket frog Acris gryllus gryllus Southern cricket frog Alligator mississipiensis Alligator Ambystoma maculatum Spotted salamander Ambystoma opacum Marbled salamander Ambystoma talpoideum Mole salamander Ambystoma texanum Small mouthed salamander Ambystoma tigrinum tigrinum Eastern tiger salamander Amphiuma means means Two toed amphiuma Ancistrodon contortrix contortrix Southern copperhead Ancistrodon piscivorous leucostoma Western cottonmouth moccasin Anolis carolinensis carolinensis Green anole Bufo quercicus Oak toad Bufo terrestris terrestris Southern toad Bufo valliceps Gulf coast toad Bufo woodhousei fowleri Fowler's toad Caretta caretta caretta Atlantic loggerhead turtle Carphophis amoenus helenae Midwest worm snake Cemophora coccinea Scarlet snake Chelonia mydas mydas Atlantic green turtle Chelydra serpentina serpentina Common snapping turtle Cnemidophorus sexlineatus sexlineatus Six lined race runner Coluber constrictor priapus Southern black racer Crotalus adamanteus Eastern diamond back rattlesnake Crotalus horridus atricaudatus Canebrake rattlesnake Deirochelys reticularia reticularia Eastern chicken turtle Dermochelys coriacea coriacea Atlantic leatherback turtle Desmognathus auriculatus Southern dusky salamander Desmognathus fuscus conanti Spotted dusky salamander Diadophis punctatus stictogenys Mississippi ringneck snake Drymarchon corais couperi Eastern indigo snake Elaphe guttata guttata Corn snake Elaphe obsoleta spiloides Gray rat snake Eretmochelys imbricata imbricata Atlantic hawksbill turtle Eumeces anthracinus pluvialis Southern coal skink Eumeces fasciatus Five lined skink Eumeces inexpectatus Southeastern five lined skink Eumeces laticeps Broad headed skink Eurycea bislineata cirrigera Southern two lined salamander Eurycea longicauda guttolineata Three lined salamander Farancia abacura reinwardti Western mud snake Gastrophryne carolinensis carolinensis Eastern narrow mouthed toad Gopherus polyphemus Gopher tortoise 213 TABLE XII (Continued) REPTILES AND HERPTILES OF THE STUDY AREA Scientific Name Common Name Graptemys flavimaculata Yellow bloched sawback Graptemys pulchra Alabama map turtle Haldea striatula Rough earth snake Haldea valeriae elegans Western earth snake Hemidactylium scutatum Four toed salamander Hemidactylus turcicus turcicus Mediterranean gecko Heterodon platyrhinos platyrhinos Eastern hognose snake Heterodon simus Southern hognose snake Hyla avivoca avivoca Western bird voiced treefrog Hyla cinerea cinerea Green treefrog Hyla crucifer crucifer Northern spring peeper Hyla femoralis Pine woods tree frog Hyla gratiosa Barking treefrog Hyla squirella Squirrel treefrog Hyla versicolor versicolor Eastern gray treefrog Kinosternon subrubrum hippocrepis Mississippi mud turtle Lampropeltis calligaster rhombomaculata Mole snake Lampropeltis doliata doliata Scarlet king snake Lampropeltis getulus getulus Eastern king snake Lampropeltis getulus holbrooki Speckled king snake Lepidochelys kempi Atlantic ridley Lygosoma laterale Ground skink Macrochelys temmincki Alligator snapping turtle Malaclemys terrapin pileata Mississippi diamondback terrapin Manculus quadridigitatus Drawf salamander Masticophis flagellum flagellum Eastern coachwhip Micrurus fulvius fulvius Eastern coral snake Natrix cyclopion cyclopion Green water snake Natrix erythrogaster flavigaster Yellow bellied water snake Natrix fasciata clarki Gulf salt marsh snake Natrix fasciata confluens Broad banded water snake Natrix fasciata fasciata Banded water snake Natrix rhombifera rhombifera Diamond backed water snake Natrix rigida sinicola Glossy water snake Natrix septemvittata septemvittata Queen snake Natrix taxispilota Brown water snake Necturus punctatus alabamensis Alabama waterdog Necturus punctatus beyeri Gulf coast waterdog Notophthalmus viridescens Louisianensis central newt Opheodrys aestivus Rough green snake Ophisaurus attenuatus longicaudus Eastern slender glass lizard Ophisaurus ventralis Eastern glass lizard Phrynosoma cornutum Texas horned lizard Pituophis melanoleucus lodingi Black pine snake 214 TABLE XII (Continued) REPTILES AND HERPTILES OF THE STUDY AREA Scientific Name Common Name Plethodon glutinosus glutinosus Slimy falamander Pseudacris nigrita nigrita Southern chorus frog Pseudacris ornata Ornate chorus frog Pseudemys alabamensis Alabama red bellied turtle Pseudemys concinna mobilensis Mobile cooter Pseudemys floridana hoyi Missouri slider Pseudemys scripta elegans Red eared turtle Pseudemys scripta scripta Yellow bellied turtle Pseudotriton montanus flavissimus Gulf coast mud salamander Pseudotriton ruber vioscai Southern red salamander Rana areolata sevosa Dusky gopher frog Rana catesbeiana Bullfrog Rana clamitans clamitans Bronze frog Rana grylio Pig frog Rana hecksheri River frog Rana pipiens sphenocephala Southern leopard frog Rhadinea flavilata Yellow lipped snake Scaphiopus holbrooki holbrooki Eastern spadefood toad Sceloporus undulatus undulatus Southern fence lizard Siren intermedia intermedia Eastern lesser siren Siren lacertina Greater siren Sistrurus miliarius barbouri Dusky pigmy rattlesnake Sistrurus miliarius streckeri Western pigmy rattlesnake Sphaerodactylus notatus Reef gecko Sternothaerus carinatus Razor backed musk turtle Sternothaerus minor peltifer Stripe necked musk turtle Sternothaerus odoratus Stinkpot Storeria dekayi wrightorum Midland brown snake Storeria occipitomaculata obscura Southern red bellied snake Tantilla coronata coronata Southeastern crowned snake Terrapene carolina major Gulf coast box turtle Thamnophis proximus orarius Costal ribbon snake Thamnophis sauritus sauritus Eastern ribbon snake Thamnophis sirtalis sirtalis Eastern garter snake Trionyx muticus calvatus Gulf coast smooth softshell Trionyx spinifer asper Gulf coast softshell turtle 215 TABLE XIII BIRDS OF THE STUDY AREA Scientific Name Common Name Accipiter cooperii Cooper's hawk Accipiter striatus Sharp-shinned hawk Actitis macularia Spotted sandpiper Agelaius phoeniceus Red winged blackbird Aimophila aestivalis Bachman's sparrow Aix sponsa Wood duck Ammodramus savannarum Grasshopper sparrow Ammospiza caudacuta Sharp-tailed sparrow Ammospiza maritima Seaside sparrow Anas acuta Pintail Anas carolinensis Green-winged teal Anas discors Blue-winged teal Anas fulvigula Mottled duck Anas platyrhynchos Mallard Anas rubripes Black duck Anas strepera Gadwall Anhinga anhinga Anhinga Anhinga anhinga leucogaster Water turkey Anous stolidus Noddy tern Anser albifrons White-fronted goose Anthus spinoletta Water pipit Anthus spragueii Sprague's pipit Aquila chrysaetos Golden eagle Archilochus colubris Ruby throated hummingbird Ardea herodias Great blue heron Arenaria interpres Ruddy turnstone Asio flammeus Short-eared owl Aythva affinis 'Lesser scaup duck Aythya americana Redhead Aythya collaris Ring-necked duck Aythya marila Greater scaup Aythya valisineria Canvasback Bartramia longicauda Upland sandpiper Bombycilla cedrorum Cedar waxwing Botaurus lenthginosus American bittern Branta canadensis canadensis Canada goose Bubo virginianus Great horned owl Bubuleus ibis Cattle egret Bucephala albeola Bufflehead Bucephala clangula Common goldeneye Buted harlani Harlan's hawk 216 TABLE XIII (Continued) BIRDS OF THE STUDY AREA Scientific Name Common Name Buted jamaicensis Red-tailed hawk Buted lineatus Red shouldered hawk Buted platypterus Broad-winged hawk Butorides virescens Green heron Calidris canutus . Red knot Capella gallinago Common snipe Caprimulgus carolinensis Chuck-Will's widow Caprimulgus vociferus Whip-poor-will Carpodacus purpureus Purple finch Casmerodius albus Common egret Cassidix mexicanus Boat'tailed grackle Cathartes aura Turkey vulture Catoptrophorus semipalmatus Willet Centurus carolinus Red-bellied woodpecker Certhia familiaris Brown creeper Chaetura pelagica Chimney swift Charadrius alexandrinus Snowy plover Charadrius melodus Piping plover Charadrius semipalmatus Semipalmated plover Charadrius vociferus vociferus Killdeer Charadrius wilsonia Wilson's plover Chen caerulescens Blue goose Chen hyperborea Snow goose Chlidonias niger Black tern Chondestes grammacus Lark sparrow Chordeiles minor Common night hawk Circus cyaneus hudsonius Marsh hawk Cistothorus platensis Short-billed marsh wren Clangula hyemalis Oldsquaw Coccyzus americanus americanus Yellow billed cuckoo Coccyzus erythropthalmus Black-billed cuckoo Colaptes auratus Yellow shafted flicker Colinus virginianus Bobwhite Columbigallina passerina Ground dove Contopus virens Eastern wood pewee Coragyps atratus Black vulture Corvus brachyrnynchos Common crow Corvus ossifragus Fish crow Coturnicops noveboracensis Yellow rail Crocethia alba Sanderling Crotophaga sulcirostris Groove-billed ani Cyanocitta cristata Blue jay 217 TABLE XIII (Continued) BIRDS OF THE STUDY AREA Scientific Name Common Name Dendrocopos borealis Red-cockaded woodpecker Dendrocopos pubescens Downy woodpecker Dendrocopos villosus Hairy woodpecker Dendroica caerulescens Black-throated blue warbler Dendroica castanea Bay-breasted warbler Dendroica cerulea Cerulean warbler Dendroica coronata Myrtle warbler Dendroica discolor Prairie warbler Dendroica dominica Yellow-throated warbler Dendroica fusca Blackburnian warbler Dendroica magnolia Magnolia warbler Dendroica nigrescens Black-throated gray warbler Dendroica palmarum Palm warbler Dendroica pensylvanica Chestnut-sided warbler Dendroica petechia Yellow warbler Dendroica pinus Pine warbler Dendroica striata Blackpoll warbler Dendroica tigrina Cape may warbler Dendroica townsendi Townsend's warbler Dendroica virens Black-throated green warbler Dichromanassa rufescens Reddish egret Dolichonyx orvzivorus Bobolink Dryocopus pileatus Pileated woodpecker Dumetella carolinensis Gray catbird Elanoides forficatus Swallow-tailed kite Empidonax flaviventris Yellow-bellied flycatcher Empidonax minimus Least flycatcher Empidonax traillii Traill's flycatcher Empidonax virescens Acadian flycatcher Ereuretes mauri Western sandpiper Ereunetes pusillus Semipalmated sandpiper Erolia alpina Dunlin Erolia bairdii Baird's sandpiper Erolia fuscicollis White-rumped sandpiper Erolia melanotos Pectoral sandpiper Erolia minutilla Least sandpiper Eudocimus albus White ibis Euphagus carolinus Rusty blackbird Euphagus cyanocephalus Brewer's blackbird Falco columbarius Merlin Falco peregrinus Peregrine falcon 218 TABLE XIII (Continued) BIRDS OF THE STUDY AREA Scientific Name Common Name Falco sparverius American kestrel Florida Caerulea Little blue heron Fregata magnificens Magnificent frigatebird Fulica amiercana American coot Gallinula chloropus Common gallinule Gavia immer Common loon Gavia stellata Red-throated loon Gelochelidon nilotica Gull-billed tern Geothlypis trichas Yellowthroat Grus canadensis Florida sandhill crane Guiraca caerulea Blue gosbeak Haematopus palliatus American oystercatcher Halioeetus leucocephalus Southern bald eagle Helmitheros vermivorus Worm-eating warbler Hesperiphona vespertina Evening grosbeak Himantopus mexicanus Black-necked stilt Hirundo rustica Barn swallow Hydranassa tricolor Louisiana heron Hydroprogne caspia Caspian tern Hylocichla fuscescens Veery Hylocichla guttata Hermit thrush Hylocichla minima Gray-cheeked thrush Hylocichla mustelina Wood thrust Hylocichla ustulata Swainson's thrush Icterus galbula Northern oriole Icterus spurius Orchard oriole Icteria virens Yellow-breasted chat Ictinia misisippiensis Mississippi kite Iridoprocne bicolor Tree swallow Ixobrychus exilis Least bittern Junco hyemalis Slate colored junco Lanius ludovicianus Loggerhead shrike Larus argentatus Herring gull Larus atricilla Laughing gull Larus delawarensis Ring-billed gull Larus hyperboreus Glaucous gull Larus philadelphis Bonaparte's gull Larus pipixcan Franklin's gull Laterallus jamaicensis Black rail Leucophoyx thula Snowy egret Limnodromus griseus Short-billed dowitcher Limnothlypis swainsonii Swainson's warbler 219 TABLE XIII (Continued) BIRDS OF THE STUDY AREA Scientific Name Common Name Limosa fedoa Marbled godwit Lophodytes cucullatus Hooded merganser Mareca americana American wigeon Megaceryle alcyon alcyon Belted kingfisher Melanerpes erythrocephalus Red headed woodpecker Melanitta deglandi White-winged scoter Melanitta perspicillata Surf scoter Meleagris gallopavo Wild turkey Melpspiza georgiana Swamp sparrow Melospiza lincolnii Lincoln's sparrow Melospize melodia Song sparrow Mergus merganser Common merganser Mergus serrator Red-breated merganser Micropalama himantopus Stilt sandpiper Mimus polyglottos Mockingbird Mniotilta varia Black-and-white warbler Molothrus ater Brown-headed cowbird Morus bassanus Gannet Muscivora forficata Scissor-tailed flycatcher Myiarchus crinitus Great crested flycatcher Numenius americanus Long-billed curlew Numenius phaeopus Whimbrel Nuttallornis borealis Olive-sided flycatcher Nyctanassa violacea Yellow crowned night heron Nycticorax nycticorax hoactli Black crowned night heron Oporornis formosus Kentucky warbler Oporornis philadelphia Mourning warbler Otus asio Screech owl Oxyura jamaicensis Ruddy duck Pandion halioetus carolinensis Osprey Parula americana Northern parula Parus bicolor Tufted titmouse Parus carolinensis Carolina chickadee Passer domesticus House sparrow Passerculus sandwichensis Savannah sparrow Passerella iliaca Fox sparrow Passerherbulus caudacutus Leconte's sparrow Passerherbulus henslowii Henslow's sparrow Passerina ciris Painted bunting Passerina cyanea Indigo bunting Pelecanus erythrorhynchos White pelican Pelacanus occidentalis Brown pelican Petrochelidon pyrrhonota Cliff swallow 220 TABLE XIII (Continued) BIRDS OF THE STUDY AREA Scientific Name Common Name Phalacrocorax auritus Double crested cormorant Pheucticus ludovicianus Rose-breated grosbeak Pheucticus melanocephalus Black-headed grosbeak Philohela minor American woodcock Pipilo erythrophthalmus Rufous sided towhee Piranga ludoviciana Western tanager Piranga olivacea Scarlet tanager Pirange rubra Summer tanager Plegadis chihi White-faced ibis Plegadis falcinellus Glossy ibis Pluvialis dominica American golden plover Podiceps auritus Horned grebe Podiceps caspicus Eared grebe Podilymbus podiceps Pied billed grege Polioptila caerulea Blue-gray gnatcatcher Pooecetes gramineus Vesper sparrow Porphyrula martinica Purple gallinule Porzana carolina Sora Progne subis Purple martin Protonotaria citrea Prothonotary warbler Pyrocephalus rubinus Vermilion flycatcher Quiscalus quiscula Common grackle Rallus elegans elegans King rail Rallus limicola Virginia rail Rallus longirostris Clapper rail Recurvirostra americana American avocet Regulus calendula Ruby-crowned kinglet Regulus satrapa Golden-crowned kinglet Richmondena cardinalis Cardinal Riparia riparia Bank swallow Rissa tridactyla Black-legged kittiwake Rynchops nigra Black skimmer S. hirundo hirundo Common tern Sayornis phoebe Eastern phoebe Sayornis saya Say's phoebe Seiurus aurocapillus Ovenbird Seiurus motacilla Louisiana waterthrush Seiurus noveboracensis Northern waterthrush Setophaga ruticilla tricolora American redstart Sialia sialis sialis Eastern bluebird Sitta canadensis Red-breasted nuthatch 221 TABLE XIII (Continued) BIRDS OF THE STUDY AREA Scientific Name Common Name Sitta carolinensis White-breasted nuthatch Sitta pusilla Brown-headed nuthatch Somateria spectabilis King eider Spatula clypeata Shoveler Speotyto cunicularia Burrowing owl Sphyrapicus varius Yellow-bellied sapsucker Spinus pinus Pine siskin Spinus tristis American goldfinch Spiza americana Dickcissel Spizella pallida Clay-colored sparrow Spizella passerina Chipping sparrow Spizella pusilla Field sparrow Squatarola squatarola Black-bellied plover Steganopus tricolor Wilson's phalarope Stelgidopteryx ruficollis Rough-winged swallow Stercorarius parasiticus Parasitic jaeger Sterna albifrons Least tern Sterna forsteri Foster's tern sterna hirundo Common tern Strix varia Barred owl Sturnella magna Eastern meadowlark Sturnella neglecta Western meadowlark Sturnus vulgaris vulgaris Starling Tachycineta bicolor Tree swallow Telmatodytes palustris Long-billed marsh wren Thalasseus maximus Royal tern Thalasseus sandvicensis Sandwich tern Thryomanes bewickii Bewick's wren Thryothorus ludovicianus Carolina wren Totanus flavipes Lesser yellowlegs Totanus melanoleucus Greater yellowlegs Toxostoma rufum Brown thrasher Tringa solitaria Solitary sandpiper Troglodytes aedon House wren Troglodytes troglodytes Winter wren Trynoites subruficollis Buff-breasted sandpiper Turdus migratorius Robin Tyrannus dominicensis Gray kingbird Tyrannus tyrannus Eastern kingbird Tyrannus verticalis Western kingbird Tyto alba Barn owl 222 TABLE XIII (Continued) BIRDS OF THE STUDY AREA Scientific Name Common Name Vermivora bachmanii Bachman's warbler Vermivora celata Orange-crowned warbler Vermivora chrysoptera Golden-winged warbler Vermivora peregrina Tennessee warbler Vermivora pinus Blue-winged warbler Vermivora ruficapilla Nashville warbler Vireo bellii Bell's vireo Vireo flavifrons Yellow-throated vireo Vireo griseus White-eyed vireo Vireo olivaceus Red-eyed vireo Vireo philadelphicus Philadelphia vireo Vireo solitarius Solitary vireo Wilsonia canadensis Canada warbler Wilsonia citrina Hooded warbler Wilsonia pusilla Wilson's warbler Xanthocephalus xanthocephalus Yellow-headed blackbird Zenaida asiatica White-winged dove Zenaidura macroura Mourning dove Zonotrichia albicollis White throated sparrow Zonotrichia leucophrys White-crowned sparrow Zonotrichia querula Harris' sparrow 223 TABLE XIV FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Ablennes hians Flat needlefish Abra aequalis Common Atlantic abra Abra lioca Dalls's little abra Abudefduf saxatilis Sergeant major Abyloposis eschscholtzi Abylopsis tetragona Acanthocybium solanderi Wahoo Acartia tonsa Common copepod Acetes americanus Sergistio shrimp Acetes carolinae Achirus lineatus Striped sole Acipenser oxyrhynchus Atlantic sturgeon Acteon punctostriatus Adinia xenica Diamond killifish Aegathoa oculata Aequipecten gibbus Calico scallop Aequipecten irradians concent Atlantic bay scallop Aetobatus narinari Soptted eagle ray Agalma okeni Aglaura hemistoma Ahlia egmontis Worm eel Aiptasia pallida Anemone Alabina cerithidioides Albunea sp. Mole crab Alectis crinitus Thread fish Alepisaurus ferox Longnose lancetfish Alpheus heterochaelis Alopias vulpinus Thresher shark Alosa alabamae Alabama shad Alosa chrysochloris Skipjack Alosa sapidissima American shad Aluterus hewdeloti Dotterel filefish Aluterus monoceros Unicorn filefish Aluterus schoepfi Orange filefish Aluterus scripta Longtail filefish Amia calva Bowfin Ampelisca abdita Ampelisca holmesii Amphicteis gunneri Polychaete Amphinema dinema Amphithoe longimanus Amphithoe validida Amphitrite ornata Polychaete 224 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Amygdalum papyria Anachis avara Greedy dove, shell gastropod Anachis obesa Fat dove shell, mud snail Anadara brasiliana Incongruous ark Anadara transversa Transverse ark Anasimus latus Anchoa cubana Cuban anchovy Anchoa hepsetus Striped anchovy Anchoa lamprotaenia Bigeye anchovy Anchoa lyolepis Dusky anchovy Anchoa mitchilli Common anchovy Anchoa nasuta Longnose anchovy Anchoviella perfasciata Flat anchovy Ancylopsetta dilecta Three eyed flounder Ancylopsetta quadrocellata Ocellated flounder Andara ovalis Blook ark Anguilla rostrata American eel Anomalocardia cuneimeris Wedge-shaped venus Anomia simplex Common jingle shell Antennarius ocellatus Ocellated frogfish Antennarius radiosus Singlespot frogfish Antennarius scaber Splitlure frogfish Aplodinotus grunniens Freshwater drum Aplysia willcoxi Willcox's sea-hare Apogonidae Cardinal fishes Aprionodon isodon Finetooth shark Arbacia punctulata Sea urchin Arca zebra Turkey wing Archosargus probatocephalus Sheepshead Arenaeus cribrarius Swimming crab Arenicola caroledna Polychaete Arenicola cristata Bloodworm Argentina atriata Argentine Argulus fuscus Ariomma regulus Spotted drift fish Arius felis Sea catfish Armina tigrina Tiger nudibranch Astrangia astreiformis Stony star coral Astrangia solitaria Stony coral Astropecten articulatus Starfish Astropecten duplicatus Astroscopus y-graecum Southern stargazer 225 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Atrina seminuda Half-spined pen shell Atrina serrata Saw--toothed pen shell Atylus minikai Aulostomus maculatus Trumpet fish Aurellia aurita Common white jelly fish Auxis thazard Frigate mackeral Axiothella muscosa Polychaete Bagre marinus Gafftopsail catfish Bairdiella chrysura Silver perch Balanus amphitrite Barnacles Balanus eburneus Ivory barnacle Balanus improvisus Barnacles Balanus tintinnabulum Acorn barnacle Balistes capriscus Gray triggerfish Bankia gouldi Barnea costata Barnea truncata Bascanichthys scuticaris Whip eel Bascanichthys teres Sooty eel Bassia bassensis Batea catherinensis Bathygobius sporator Frillfin goby Bellator militaris Horned sea robin Bembrops gobioides Clear head Benthodesmus tenuis Benthodesmus Benthopagurus cokeri Beroe ovata Oval comb jelly Bittium varium Variable bittium, snail Blennius marmoreus Seaweed blenny Bollmannia communis Ragged goby Bothus ocellatus Eyed flounder Bougainvillia carolinensis Bougainvillia frondosa Branchidontes exustus Bivalves Branchidontes recurvus Mussel Branchiostoma caribaeum Caribbean lancelet Branchipus sp. Fairy shrimp Bregmaceros atlanticus Antenna codlet Brevoortia gunteri Small-scaled menhaden Brevoortia patronus Gulf menhaden Brevoortia smithi Yellowfin menhaden Brotula barbata Brotula Bugula sp. Bryozoan 226 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Bugula neritina Treelike moss animal Bulla striata Bunodactis Bursatella leachi Ragged sea hare Busycon perversum Perverse whelk Busycon spiratum Prosobranch snail, pear whelk Caecum cooperi Caecum cf. glabrum Caecum nitidum Snail Caecum pulchellum Snail Calamus actifrons Grass porgy Calappa springeri Calliactis polypus Calliactris tricolor Common sea anemone Callianassa jamaicense Louisiana mud shrimp Callianassa major Mud shrimp Callinectes sapidus Common blue crab, blue edible cr Callinectes similis Callista eucymata Glory-of-the-seas venus Callocardia texasiana Cancellaria reticulata Common .nutmeg Cantharus cancellarius Cancellate cantharus Canthidermis maculatus Rough triggerfish Caprella carolinensis Caranx bartholomaei Yellow jack Caranx crysos Blue runner Caranx hippos Common jack Caranx latus Horse-eye jack Caranx ruber Bar jack Carcharhinus acronotus Blacknose shark Carcharhinus leucas Bull shark Carcharhinus limbatus Blacktip shark Carcharhinus longimanus White-tipped shark Carcharhinus milberti Sandbar shark Carcharhinus obscurus Dusky shark Cardita floridana Bivalves Carinogammarus mucronatus Amphipod Carpiodes carpio River carpsucker Carpiodes cyprinus Quillback Catharus tinctus Prosobranch snail Caulolatilus cyanops Blackline tilefish Cavolina longirostris Centropristis melana Southern sea bass 227 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Centropristis ocyurus Bank sea bass Centropristis philadelphica Rock sea bass Centropristis striata Black sea bass Ceratocymba leukartii Ceratocymba sagittata Cerebratulus lacteus Large ribbon worm Cerithiopsis greeni Cerithium variable Herbivorus snail Chaenobryttus gulosus Warmough Chaetodipterus faber Atlantic spadefish Chaetodon capistratus Four eye butterflyfish Chaetodon ocellatus Spotfin butterflyfish Chaetodon sedentarius Reef butterflyfish Chaetopterus variopedatus Polychaete Chama congregata Chasmocarcinus mississippiensis Chasmodes bosquianus Banded blenny Chasmodes saburrae Florida blenny Chaunax pictus Painted gaper Chelonibia patula Crab barnacle Chelophyes appendiculata Chilomycterus schoepfri Striped burrfish Chione cancellata Cross-barred venus, bivalves Chione grus Gray pygmy venus Chione intapurpurea Cribrara venus Chiropsalmus quadrumanus Chloropthalmus chalybeius Mottled greeneye Chloropthalmus truculentus Truculent greeneye Chloeroscombrus chrysurus Bumber, atlantic Chrysaora quinquecirrha Chthamulus fragilis Barnacles Cistenides gouldii Citharichthys macrops Spotted whiff Citharichthys spilopterus Bay whiff Cleantis sp. Isopod Clibanarius vittatus Striped hermit crab Cliona celata Sulphur sponge Clione vastifica Sponge Clypeaster Conchoderma virgatum Congrina flava Yellow conger eel Corambella baratarioe Corbicula contracta Bivalves 228 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Corbula sp. Cordagalma cordiformis Corophium acherusicum Corophium louisianum Coryphaena equisetis Pompano dolphin Coryphaena hippurus Dolphin Crassinella lunulata Lunate crassinella Crassostrea virginica Eastern oyster Crepidula convexa Convex slipper-shell Crepidula fornicata Common atlantic slipper-shell Crepidula maculosa Crepidula plana Eastern white slipper-shell Creseis acicula Straight needle pteropod Cryptotomus auropunctatus Parrotfish Cubiceps athenae Cigarfish Cumingia tellinoides Cuna dalli Moore's cuna Cunina octonaria Cunina peregrina Cyanea capillata Cyathura polita Isopod Cyclinella tenuis Burrowing bivalves Cyclopsetta chittendeni Chittenden's flounder Cyclopsetta fimbriata Spotfin flounder Cyclostremiscus trilix Cylichna bidentata Cylisticus convexus Convex sowbug Cymadusa compta Cymadusa filosa Cynoscion arenarius White weakfish Cynoscion nebulosus Speckled weakfish Cynoscion nothus Sand weakfish Cyprinodon variegatus Sheepshead minnow, killifish Cypselurus cyanopterus Bearded flying fish Cypselurus heterurus Four wing flying fish Cyrtopleura costata Burrowing bivalves Cytaeis tetrastyla Dactylometra quinquecirrha Sea nettle Dactylopterus volitans Flying gurnard Dactyloscopus tridigitatus Gill Dasyatis americana American sting ray Dasyatis centroura Roughtail sting ray Dasyatis sabina Atlantic stingray 229 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Dasyatis sayi Say's sting ray Dentalium eboreum Decapterus punctatus Round scad Dentalium texasianum Dibranchus atlanticus Two-gilled batfish Dinocardium robustum Giant atlantic cockle Diodon holocanthus Balloonfish Diodora cayenensis Little or cayenne keyhole limpe Diopatra cuprea Polychaete Diphyes bojani Diphyes dispar Diplectrum bivittatum Dwarf sand perch Diplectrum formosum Sand perch Diplodonta punctata Common atlantic diplodon Diplodus holbrooki Spottail pinfish Diplothyra smithii Dipurena ophiogaster Donax obesus Flat wedge clam Donax variabilis Coquina shell Doris verrucosa Dormitator maculatus Fat sleeper Dorosoma cepedianum Gizzard shad Dorosoma petenense Threadfin shad Doryteuthis plei Dosinia discus Disk dosinia Drilonereis sp. Polychaete Dromidia antillensis Crustaceans Echeneis naucrates Sharksucker Echinaster modestus Eirene pyramidalis Eirene viridula Elagatis bipinnulata Rainbow runner Eleotris pisonis Spinycheek sleeper Elops saurus Ladyfish, tenpounder Emerita portoricensis Puerto Rican mole crab Emerita talpoida Baitbug, sandbug Emerita talpoides Mole crab Encope michelini Sand dollar Engyophrys senta Spiny flounder Enneagonium hyalinum Ensis minor Miniature jack-knife clam Epinephelus drummondhayi Speckled hind Epinephelus itajara Jew fish 230 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Epinephilus morio Red grouper Epinephelus nigritus Warsaw grouper Episcynia multicarinata Epitonium angulatum Epitonium rupiculum Rock-inhabiting peg Equetus acuminatus High hat Equetus lanceolatus Jackknife fish Ericthonius brasilensis Erimyzon tenuis Sharpfin chubscuker Erotelis smaragdus Emerald sleeper Ervillia concentrica Esox americanus redfin pickerel Esox niger Chain pickerel Etropus crossotus Fringed flounder Etropus microstomus Smallmouth flounder Etropus rimosus Gray flounder Etrumeus teres Round herring Eubranchus sp. Eucalanus attenuatus Euceramus praelongus Sandbug Eucinostomus argenteus Spotfin mojarra Eucinostomus gula Silver jenny Eudoxoides mitra Eudoxoides spiralis Euglandina rosea Rosy euglandina Eulamia obscurus Dusky shark Euleptorhamphus velox Flying half beak Euphysora gracilis Eurycerus lamellatus Muller's waterflea Eurypanopeus depressus Crustaceans Euthynnus alletteratus Little tunny Euthynnus pelamis Skipjack tuna Eutima mira Eutima variabilis Evorthodus lyricus Lyre goby Fasciolaria hunteria Banded tulip Fasciolaria tulipa Snail Finella dubia Dubious finella Fistularia tabacaria Cornet fish Fundulus chrysotus Golden topminnow Fundulus confluentus Marsh killifish Fundulus grandis Gulf killifish Fundulus heteroclitus Gulf mummichog 231 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Fundulus jenkinsi Saltmarsh topminnow Fundulus notatus Blackstripe topminnow Fundulus notti Starhead topminnow Fundulus olivaceus Blackspotted topminnow Fundulus pulvereus Bayou killifish Fundulus similis Longnose killifish Galeocerdo cuvieri Tiger shark Gambusia affinis Mosquitofish Gammarus locusta Seaweed hopper Gastropteron rubrum Gastrosaccus dissimilis Gemma gemma Geryonia proboscidalis Ginglymostoma cirratum Nurse shark Glycera dibranchiata Proboscis bloodworm Gnathagnus egregius Freckled stargazer Gobiesox strumosus Skilletfish, cling fish Gobioides broussonneti Violet goby Gobionellus boleosoma Darter goby Gobionellus gracillimus Slim goby Gobionellus hastatus Sharptail goby Gobionellus oceanicus Highfin goby Gobionellus shufeldti Freshwater goby Gobionellus stigmaticus Spotted goby Gobiosoma bosci Naked goby Gobiosoma longipala Twoscale goby Gobiosoma robustum Code goby Graptemys flavimaculata Gunterichthys longipenis Gold brotula Gymnachirus melas Naked sole Gymnachirus texae Fringed sole Gymnothorax moringa Spotted moray Gymnothorax nigromarginatus Blackedge moray Gymnothorax ocellatus Ocellated moray eel Gymnura micrura Smooth butterfly ray Haemulon carbonarium Caesar grunt Haemulon plumieri White grunt Haemulon sciurus Bluestriped grunt Halichoeres radiatus Puddingwife Haliclona sp. Deadman fingers Halieutichthys aculeatus Deep-sea batfish Haminoea antillarum Globose paper bubble Haminoea succinea Snail 232 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Haploscoloplos fragilis Polychaete Harengula pensacolae Sardine Haustorius spp. Amphipods Haustorius mexicanus Hemanthias leptus Longtail bass Hemanthias vivanus Red barbier Hemiaegina minuta Hemicaranx amblyrhynchus Bluntnose jack Hemipteronotus novacula Pearly razorfish Hemiramphus balao Balao Hemiramphus brasiliensis Ballyhod Heterandria formosa Least killifish Hepatus epheliticus Box crab Hippocampus erectus Lined seahorse Hippocampus zosterae Dwarf seahorse Hippolyte pleuracantha Hippolyte zostericola Hippopodius hippopus Histrio histrio Sargassumfish Holocentrus ascenionis Squirrel fish Hoplunnis macrurus Silver conger Hybocodon forbesi Hybognathus hayi Cypress minnow Hybognathus nuchalis Silvery minnow Hybopsis aestivalis Speckeled chub Hybopsis amblops Big eye chub Hydractinia echinata Hydroid Hydroides hexagonus Polychaete Hyperoglyphe perciformis Barrel fish Hypleurochilus geminatus Crested blenny Hyporhamphus unifasciatus Halfbeak Hypsoblennius hentzi Feather blenny Hypsoblennius ionthas Freckled blenny Ichthyomyzon gagei Southern brook lamprey Ictalurus furcatus Blue catfish Ictalurus melas Black bullhead Ictalurus nebulosus Brown bullhead Ictalurus punctatus Channel catfish Ictiobus bubalus Smallmouth buffalo Ictiobus niger Black buffalo Ircinia fasciculata Sponge Istiophorus platypterus Sailfish Isurus oxyrinchus Short fin mako 233 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Kathetostoma albigutta Lancer stargazer Kellia suborbicularis Thomson's lepton Kurtziella cerinella Kyphosus sectatrix Bermuda chub Labidesthes sicculus Brook silverside Labidocera aestiva Labiosa plicatella Sailor's ear Lachnolaimus maximus Hogfish Lactophrys quadricornis Scrawled cowfish Lactophrys trigonus Trunkfish Laeonereis culveri Polychaete Laevicardium laevigatum Common egg cockle Laevicardium mortoni Morton's egg cockle Lagocephalus laevigatus Smooth puffer Lagodon rhomboides Pinfish Lamna nasus Porbeagle Lampetra gepyptera Least brook lamprey Laodicea undulata Larimus fasciatus Banded drum Latreutes fucorum Latreutes parvulus Leander tenuicornis Sargassum shrimp Lensia campanella Lensia subtilis Leiostomus xanthurus Spot Lepidactylus burbanki Lepisosteus oculatus Spotted gar Lepisosteus osseus Longnose gar Lepisosteus platostomus Shortnose gar Lepi~osteus spatula Alligator gar Lepomis cyanellus Green sunfish Lepomis gibbosus Pumpkin seed Lepomis gulosus Warmouth Lepomis macrochirus Bluegill or brim Lepomis marginatus Dollar sunfish Lepomis megalotis Longear sunfish Lepomis microlophus Redear sunfish Lepomis punctatus Spotted sunfish Lepophidium graellsi Blackedge cusk eel Lepophidium jeannae Mottled cusk eel Leptochelia rapax Leptogorgia virgulate Soft coral Leptosynapta sp. Holothuroidean 234 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Lernaeenicus radiatus Libinia dubia Long-beaked spider crab Libinia emarginata Spider crab Ligyda exotica Sea roach Ligyda olfersii Sea roach Limulus polyphemus Horseshoe crab Liriope tetraphylla Listriella clymonellae Lithophaga aristata Boring bivalves Lithophaga bisulcata Mahogany date mussel, bivalve Littoridina sp. Littoridina (undescribed) Littorina irrorata Gulf or marsh periwinkle Littorina ziczac Zigzag periwinkle Livoneca ovalis Lizzia gracilis Lobotes surinamensis Tripletail Loligo pealei Lolliguncula brevis Lophius sp. Goosefish Loxothylacus texanus Lucania parva Rainwater killifish Lucapinella limatula File fleshy limpet Lucifer faxoni Lucina amiantus Lovely miniature lucina Lucina floridana Florida lucina Lucina multilineata Many-lined lucina Luidia sp. Starfish Luidia clathrata Lutjanus analis Mutton snapper Lutjanus apodus School master Lutjanus campechanus Red snapper Lutjanus griseus Gray snapper Lutjanus jocu Dog snapper Lutjanus mahogoni Mahognny snapper Lutjanus synagris Lane snapper Lyonsia floridana Florida lyonsia Lytechinus varigatus Sea urchin Macoma brevifrons Short-snouted macoma Macoma constricta Burrowing bivalves Macoma mitchelli Bivalves Macoma tageliformis Bivalves Macoma tenta Macrobrachium acanthurus 235 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Macrobrachium ohione Macrocalliata nimbosa Macrorhamphosus scolopax Snipe fish Mactra fragilis Fragile Atlantic mactra, bivalve Makaira nigricans Blue marlin Malacocephalus occidentalis Soft head Malongena corona Gastropod Manta birostris Giant manta Marcrocallista nimbosa Sunray venus Martesia cuneiformis Piddock Martesia striata Piddock Megalops atlantica Tarpon Meioceras nitidum Eel grass vitrinellid Melampus bidentatus Salt marsh snail Melanella intermedia Mellita fresneli Mellita nitida Mellita quinquiesperforata Sand dollar Melongena corona Crown conch Membranipora sp. Bryozoan Membranipora membranacea Sea mat Membras martinica Rough silverside Menidia berryllina Tidewater silverside Menippe mercenaria Stone crab Menticirrhus americanus Southern kingfish Menticirrhus focaliger Minkfish Menticirrhus littoralis Gulf kingfish Mercenaria campechiensis Southern quahog Mercenaria mercenaria Merluccius bilinearis Silver hake Microciona prolifera Red sponge Microdesmus longipinnis Pink worm fish Microgobius gulosus Clown goby Microgobius thalassinus Green goby Micropanope xanthiformis Micropogon undulatus Croaker Microprotopus raneyi Micropterus dolomieui Small mouth bass Micropterus punctulatus Spotted bass Micropterus salmoides Largemouth bass Micrognathus crinigerus Fringed pipefish Micrura leidyi Leidy's ribbon worm Mitrella lunata Lunar columbella, gastropod 236 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Mnemiopsis mccradyi Sea walnut Modiolus demissus Ribbed mussel Modiolus modiolus Snail Moira atropos Heart urchin Mola mola Ocean sunfish Molpadia cubana Monacanthus ciliatus Fringed filefish Monacanthus hispidus Planehead filefish Monacanthus tuckeri Slender filefish Monoculoides edwardsi Monolene antillarum Antilles flounder Morone americana White perch Morone mississippiensis Yellow bass Morone saxatilis Striped bass Moxostoma poecilurum Blacktail redhorse Muggiaea kochi Mugil cephalus Striped mullet Mugil curema White mullet Mulinia lateralis Dwarf furf clam, bivalve Mullys auratus Red goatfish Odontaspis taurus Sand tiger Murex fulvescens Spine-ribbed murex, snail Musculus lateralis Mustelus canis Smooth dogfish Mya arenaria Softshell clam Myctophidae Lantern fish Mycotophum affine Lanternfish Mycteroperca bonaci Black grouper Mycteroperca microlepis Gag Myrophus punctatus Speckled worm eel Mysella cuneata Cuneate lepton Mysella planulata Atlantic flat lepton Mysidopsis sp. Crustaceans Mysidopsis almyra Mysis stenolepis Mysid Mystriophis intertinctus Spotted spoon-nose eel Mystriophis mordax Snapper eel Nannodiella melanitica Nanomia bijuga Narcine brasiliensis Lesser electric ray Nassarius acutus Pointed basket shell Nassarius vibex Common eastern nassa, snail Natica pusilla Miniature natica 237 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Naucrates ductor Pilot fish Nausithoe punctata Neanthes succinea Polychaete Negaprion brevirostris Lemon shark Nemopsis bachei Neomerinthe hemingwayi Spinycheek scorpion fish Neopanope texana Mud crab Nephtys sp. Polychaete Nereis pelagica Reddish clamworm Nerine agilis Clamworm Neritina reclivata Green nerite, snail Nerocila acuminata Noetia ponderosa Ponderous ark Nomeus gronovii Man of war fish Notemigonus crysoleucas Golden shiner Notropis atherinoides Emerald shiner Notropis baileyi Rough shiner Notropis emiliae Pugnose minnow Notropis petersoni Coastal shiner Notropis roseipinnis Cherry fin shiner Notropis texanus Weed shiner Notropis venustus Blacktail shiner Notropis welaka Blue-nose shiner Nuculana acuta Bivalves Nuculana concentrica Bivalves Obelia spp. Obelia oxydentata Double-branching hydroid Octolasmis mulleri Goose-neck barnacle Octopus vulgaris Octopus Ocypode albicans Ghost crab Ocypode quadrata Ghost crab Odontaspis taurus Sand tiger Odostomia sp. Odostomia impressa Gastropod Odostomia seminuda Half-smooth odostome Ogcocephalus nasutus Shortnose batfish Ogcocephalus parvus Batfish, roughback Ogcocephalus vespertilio Batfish, longnose Ogilbia sp. Ogilbia Ogyrides limicola Olencira praegustator Oligoplites saurus Leatherjacket Oliva sayana Lettered olive, snail 238 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Olivella sp. Olivella mutica Little olive Olivella pusilla Onuphis magna Polychaete Oostethus lineatus Opossum pipefish Ophichthus gomesi Shrimp eel Ophidion welshi Crested tusk-eel Ophiothrix angulata Brittle star Opisthonema oglinum Atlantic thread herring Opsanus beta Oyster fish, gulf toadfish Orchestia grillus Beach hoppers Orchestia platensis Common sandflea Orthopristis chrysoptera Pigfish Ostrea equestris Horse oyster Ovalipes guadalupensis Portunid crab Ovalipes ocellatus Lady crab Ovalipes quadulpensis Owenia fusiformis Oxyurostylis smithi Pagrus sedecim Pagurus annulipes Hermit crab Pagurus floridanus Hermit crab Pagurus longicarpus Hermit crab Pagurus pollicaris Large hermit crab Palaemonetes intermedius Palaemonetes kadiakensis Palaemonetes paludosus Palaemonetes pugio Grass shrimp Palaemonetes vulgaris Grass shrimp Pandora trilineata Burrowing bivalves Panopeus sp. Wharf crab Panopeus occidentalis Papyridea soleniformis Spiny paper cockle Paralichthys albigutta Gulf flounder Paralichthys lethostigma Southern flounder Paralichthys squamilentus Broad flounder Paraphyllina sp. Parastarte triquetra 3-sided parastarte Parexocoetus brachypterus Sailfin flying fish Pecten papyraceus Pelagia noctiluca Penaeus aztecus Brown shrimp, edible shrimp Penaeus duorarum Pink shrimp 239 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Penaeus fluviatilis White shrimp, common shrimp Penaeus setiferus Pennaria tiarella Hydroid Peprilus alepidotus Harvestfish Peprilus burti Gulf butterfish Periclimenes longicaudatus Periploma fragile Bivalves Peristedion gracile Slender searobin Peristedion miniatum Common deep-sea gurnard Persa incolorata Persephona crinita Persephona punctata Petricola pholadiformis Petrochirus bahamensis Large hermit crab Petrolisthes armatus Crustaceans Phacoides radians Radiate lucina Phalium granulatum Scotch bonnet, snail Phialidium languidum Phoronis architecta Phoronid Physalia physalis Physiculus fulvus Pilumnus dasypodus Pimephales promelas Fathead minnow Pinnixa chacei Chace's worm crab Pinnixa chaetopterana Parchment worm crab Pinnixa cristata Pleuroploca gigantea Horse conch Plicatula gibbosa Kitten's paw Poecilia latipinna Sailfin molly Pogonias cromis Sea or black drum Polinices duplicatus Shark eye sand-color snail Polycera hummi Polydactylus octonemus Atlantic threadfin Polydora sp. Polychaete Polymesoda carolinensis Marsh snail Polymesoda caroliniana Polyodon spathula Paddle fish Pomacentrus fuscus Demoiselle Pomacentrus leucostictus Beau gregory Pomacenthus paru French angle fish Pomatomus saltatrix Bluefish Pomoxis annularis White carppie Pomoxis nigromaculatus Black carppie 240 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Pontinus longispinis Longspine scorpionfish Porcellana sayana Porcellanid crab Porcellana sigsbeiana Porichthys porosissimus Atlantic midshipman Portunus gibbesii Swimming crab Portunus sayi Swimming crab Portunus spinicarpus Portunid crab Portunus spinimanus Swimming crab Predilus sp. Polychaete Priacanthus arenatus Bigeye Prionotus alatus Winged sea robin Prionotus carolinus Northern sea robin Prionotus evolans Striped searobin Prionotus ophyras Bandtail searobin Prionotus paralatus Mexican searobin Prionotus roseus Rosy sea robin Prionotus rubio Common sea robin Prionotus salmoicolor Black wing sea robin Prionotus scitulus Slender sea robin Prionotus stearnsi Stearn's sea robin Prionotus tribulus Bighead searobin Pristigenys alta Short bigeye Pristipomoides aquilonaris Wenchman Pristis pectinata Smalltooth sawfish Pristis perotteti Largetooth sawfish Proboscidactyla ornata Prognichthys gibbifrons Bluntnose flyingfish Prontogrammus vivarus Streamer Psenes cyanophrys Freckeled driftfish Rachycentron canadum Cobia, lemon fish Rainoides louisianensis Raja eglanteria Clearnose skate Raja lentiginosa Freckled skate Raja texana Texas clearnose skate Rangia cuneata Remora remora Remora Renilla mulleri Short-stemmed sea pansy Retusa canaliculata Rhinobatus lentiginosus Guitarfish Rhinoptera bonasus Cownose ray Rhithropanopeus harrisii Rhizophysa filiformis Rhizoprionodon terraenovae Atlantic sharpnose shark 241 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Rhomboplites aurorubens Vermilion snapper Rhopalonema velatum Rhopilema verilli Rissoina chesneli Chesnel's rissoina Rissola marginata Striped cusk eel Rithrapanopeus spp. Mud crab Rocellaria stimpsonii Rossia tenera Rubellatoma diomedea Rypticus saponaceus Greater soap fish Sabellaria floridensis Hartman's sabellaria Sagitta enflata Sagitta hispida Hispid arrow worm Sarda sarda Atlantic bonito Sardinella anchovia Spanish sardine Saurida brasiliensis Large scale lizzard fish Saurida normani Short jaw lizzard fish Scaphella junonia Junonia Sciaenops ocellata Red drum Scomber japonicus Chub mackerel Scomberomorus cavalla King mackerel Scomberomorus maculatus Spanish mackerel Scomberomorus regalis Cero Scorpaena agassizi Longfin scorpionfish Scorpaena brasiliensis Barbfish Scorpaena calcarata Smoothhead scorpionfish Scorpaena plumieri West Indian scorpionfish Scyllaea pelagica Scyllarides nodifer Seila adamsi Adams miniature cerith Selar crumenophthalmus Bigeye scad Selene vomer Lookdown Semele bellastriata Cancellate semele Semele nuculoides Nuculoid semele Semele proficua Burrowing bivalves Seriola dumerili Greater amberjack Seriola fasciata Lesser amberjack Seriola rivoliana Almaco jack Seriola zonata Banded rudder fish Serranellus subligarius Belted sand fish Serraniculus pumilio Least sea bass Serranus annularis Orange back bass 242 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Serranus atrobranchus Blackear bass Serranus phoebe Tattler Serranus sublingarius Belted sandfish Serranus tabacarius Tobacco fish Sesarma cinereum Square-backed fiddler crab Setarches parmatus Setarches Sicyonia brevirostris Rock shrimp Sicyonia dorsalis Sicyonia laevigata Siderastrea siderea Stony coral Sinum perspectivum Prosobranch snail Solariorbis blakei Solariorbis mooreana Moore's vitrinella Solenocera vioscai Solmundella bitentaculata Sphaeroma destructor Sphaeroma quadridentatum Sphoeroides dorsalis Marbled puffer Sphoeroides maculatus Northern puffer Sphoeroides nephelus Florida swellfish Sphoeroides parvus Least puffer Sphoeroides spengleri Banktail puffer Sphyraena barracuda Great barracuda Sphyraena guachancho Small barracuda Sphyraena picudilla Southern sennet Sphyrna diplana Hammerhead shark Sphyrna lewini Scalloped hammerhead Sphyrna mokarran Great hammerhead Sphyrna tiburo Bonnethead Sphyrna zygaena Smooth hammerhead Spisula solidissima Altantic surf clam Squalus acanthias Spiney dogfish Squatina dumerili Monkfish Squilla chydaea Squilla empusa King shrimp, mantis shrimp Steenstrupia nutans Steindachneria argentea Luminous hake Stellifer lanceolatus Star drum Stenocionpos spinimana Stenorynchus seticornis Stenotomus caprinus Longspine porgy Stomolophus meleagris Cabbagehead 243 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Strigilla mirabilis White strigilla Strombus alatus Strongylura marina Atlantic needlefish Strongylura notata Redfin needlefish Strongylura timucu Timucu Sulceolaria biloba Sulceolaria chuni Sulceolaria quadrivalis Syacium gunteri Gunter's flounder Syacium papillosum Dusky flounder Symphurus civitatus Deep-water tongue fish Symphurus diomenianus Spotted fin tongue fish Symphurus plagiusa Blackcheek tonguefish Syngnathus floridae Dusky pipefish Syngnathus louisianae Chain pipefish Syngnathus pelagicus Sargasum pipefish Syngnathus scovelli Gulf pipefish Syngnathus scovelli Bull pipefish Synodus foetens Inshore lizardfish Synodus intermedius Sand diver Tagelus divisus Burrowing bivalves Tagelus plebeius Talorchestia longicornis Long-horned sandflea Talorchestia mississippiensis Tamoya haplonema Tapuromysis sp. Mysid Tegula fasciata Snail Teinostoma biscaynense Tellidora cristata Tellina alternata Alternate tellin Tellina iris Tellina lintea Linen tellin Tellina texana Tellina versicolor Cousin tellin Terebra concava Terebra dislocata Dislocated augar shell Terebra salleana Salle's augur Teredo navalis Ship worm Tetrapturus albidus White marlin Tetrapturus pflueferi Longbill spear fish Thais haemastoma Oyster drill Thais haemastoma floridana Thunnus albacares Yellow fin tuna 244 TABLE XIV (Continued) FISH AND OTHER MACROFAUNA OF THE STUDY AREA Scientific Name Common Name Thunnus atlanticus Black fin tuna Thunnus thynnus Blue fin tuna Thyone mexicana Tozeuma carolinense Trachinocephalus myops Snake fish Trachinotus carolinus Common pompano Trachinotus falcatus Round pompano Trachurus lathami Rough scad Trachycardium muricatum Burrowing bivalves Trachypenaeus spp. Hardback shrimp Trachypenaeus similis Tricanthodes lineatus Triaconthodes Trichiuris lepturus Atlantic cutlassfish Trichocorixa verticalis Trichopsetta ventralis Deep-sea flounder Trinectes maculatus Hogchoaker Triphora nigrocincta Black-circled triphora Tubularia crocea Hydroid Turbonilla sp. Turbonilla conradi Tylosurus acus Agujon Tylosurus crocodilus Houndfish Uca minax Fiddler crab Uca pugilator Fiddler crab Uga pugnax Fiddler crab Upogebia affinis Urophycis floridanus Southern Hake, or ling Urophycis regius Spotted hake Velella velella Viviparus sp. Swamp snail Vogtia glabra Vomer setapinnis Atlantic moonfish Xanthichthys ringens Sargassum triggerfish Xiphias gladius Swordfish Xiphopeneus kroyeri Yarrella blackfordi Yarrella Zalieutes mcgintyi Tricorn batfish Zenopsis ocellata Ocellated dory Zoobotryon pellucidum Zoobotryon verticillatum 245 SOURCES REFERENCED Air Weather Service (MAC). Revised Uniform Summary of Surface Weather Observations -Biloxi, Mississippi, 1968. Asheville, North Carolina. Antoine, John W. Structure of the Gulf of Mexico. Contributions on the Geological and Geophysical Oceanography of the Gulf of Mexico. Texas A&M University Oceanographic Studies. Vol. 3:1-34. 1971. Atwell, B. H. Mississippi Sound Remote Sensing Study Report II. N.A.S.A. Report No. 091. 1973. Austin, G. B., Jr. Some Recent Oceanographic Surveys of the Gulf of Mexico. Trans. Amer. Geophys. Union, 36(5):855-892. 1955. Carter, Danny R. "Hurricane and Hydrographic Statistics". May 15, 1974. (Typewritten). Chew, Frank, K.L. Drennan and W.J. Demoran. "Some Results of Drift Bottle Studies off the Mississippi Delta". Limnol. & Oceanog. 7(2):252-257. 1962a. Chew, Frank, K.L. Drennan and W.J. Demoran. "On the Temperature Field East of the Mississippi Delta". J. Geophys. Res. 67(1): 271-279. 1962b. Christmas, J.Y. and Charles K. Eleuterius."Cooperative Gulf of Mexico Estuarine Inventory and Study, Mississippi. Phase II, Hydrology". Gulf Coast Research Laboratory. 1973. Christmas, J.Y. and Walter Langley. "Cooperative Gulf of Mexico Estuarine Inventory and Study, Mississippi. Phase IV, Estuarine Invertebrates, Mississippi". Gulf Coast Research Laboratory. 1973. Christmas, J.Y. and Richard S. Waller. "Cooperative Gulf of Mexico Estuarine Inventory and Study, Mississippi. Phase V, Estuarine Vertebrates, Mississippi". Gulf Coast Research Laboratory. 1973. Cliburn, J. William. "A Key to the Amphibians and Reptiles of Mississippi". State Wildlife Museum. pp. 63. 1965. Cochrane, John D. "Separation of an Anticyclone and Subsequent Developments in the Loop Current. Contributions on the Physical Oceanography of the Gulf of Mexico. Texas A&M University Oceanographic Studies. Vol. 2. 91-106. 1970. Cry, George W. "Tropical Cyclones of the North Atlantic Ocean". Technical Paper No. 55. U.S. Weather Bureau. Drennan, Kirby L. "Airborne Measurements of Infrared Sea Temperature in the Northern Gulf of Mexico". Technical Report No. 2. Oceanography Section, Gulf Coast Research Laboratory. Drennan, Kirby L. "Hydrographic Studies in the Northeast Gulf of Mexico". Project Report. Gulf South Research Institute, 1968. Eleuterius, Charles K. "Hydrography of Biloxi Bay". Project Report NAS9-12965. (Unpublished). 1973. Eleuterius, Charles K. "Tidal Current Regime of Mississippi Sound". Project Report, Mississippi-Alabama Sea Grant Consortium. In Preparation. 246 SOURCES REFERENCED (Continued) Eleuterius, Lionel N. "Cooperative Gulf of Mexico Estuarine Inventory and Study, Mississippi. Phase IV,Section 1. The Marshes of Mississippi". Gulf Coast Research Laboratory. 1973. Eleuterius, Lionel N. "Cooperative Gulf of Mexico Estuarine Inventory and Study, Mississippi. Phase IV, Section 2. The Distribution of Certain Submerged Plants in Mississippi Sound and Adjacent Waters". Gulf Coast Research Laboratory. 1973. Franks, James S. "An Investigation of the Fish Population within the Inland Waters of Horn Island, Mississippi. Gulf Research Reports, 3(1):3-104. 1970. Franks, J.S. J.Y. Christmas, W.L. Siler, R. Combs, R. Waller and C. Burns. "A Study of Nektonic and Benthic Faunas of Shallow Gulf of Mexico - Mississippi. Gulf Research Reports, 4(1):1-148. 1972. Gainer, Thomas H.,Jr. "ATheoretical Investigation of the M2 Consti- tuent of the Tide in the Gulf of Mexico". United States Naval Postgraduate School. 1966. Gunter, Gordon and J. Y. Christmas. "Stranding Records of a Finback Whale, Balaenoptera physalus, from Mississippi and the Goose Beaked Whale, Ziphius cavirostris, from Louisiana". 4(2):169-173. 1973. Ichiye, T., Han-Hsiung Kuo and Michael R. Carnes. "Assessment of Currents and Hydrography of the Eastern Gulf of Mexico". Contri- bution Number 601. Dept. of Oceanography, Texas A&M University. 1973. Leipper, D.F. " A Sequence of Current Patterns in the Gulf of Mexico". J. Geophys. Res., 75(3):637-657. 1970. Lyles, Charles H. " A Review of the Fisheries of Mississippi 1950 - 1971". Unpublished Manuscript. 1974. McLellan, H. J. and W. D. Nowlin. " Some Features of the Deep Water in the Gulf of Mexico". J. Mar. Res. 21(3):233-245. 1963. Moore, Donald R. " The Marine and Brackish Water Mollusca of the State of Mississippi". Gulf Research Reports, 1(1):1-58. 1961. Neumann, Gerhard and Willard J. Pierson, Jr. Principles of Physical Oceanography. Prentice-Hall, Inc. Englewood Cliffs, New Jersey. pp.545. 1966. Nowlin, W. D. and H. J. McLellan. "A Characterization of the Gulf of Mexico in Winter". J. Mar. Res., 25(1):25-59. 1967. Nowlin, W. D.,Jr. and J. M. Hubertz. "Contrasting Summer Circulation Patterns for the Eastern Gulf". Contributions on the Physical Oceanography of the Gulf of Mexico. Texas A&M University Studies. Vol. 2: 119-138. Nowlin, Worth D., Jr. "Winter Circulation Patterns and Property Distri- butions"t. Contributions on the Physical Oceanography of the Gulf of Mexico". Texas A&M University Oceanographic Studies. Vol. 2:3- 52. 1970. Nowlin, W. D., Jr. "Water Masses and General Circulation of the Gulf of Mexico". Oceanol. Intern., 6(2):28-33. 1971. 247 SOURCES REFERENCED (Continued) Ostle, B. Statistics in Research. Iowa State University Press, 2nd. Ed. pp. 585. 1963. Otvos, Ervin G. "Cooperative Gulf of Mexico Estuarine Inventory and Study, Mississippi. Phase III, Sedimentology". Gulf Coast Research Laboratory. 1973. Otvos, Ervin G. Geology of the Mississippi-Alabama Coastal Area and Nearshore Zone. The New Orleans Geological Society. 1973. Pequegnat, Willis E. "A Deep Bottom Current on the Mississippi Cone". Contributions on the Physical Oceanography of the Gulf of Mexico. Texas A&M University Oceanographic Studies. Vol 2:65-88. 1970. Phillips, D. T. "Applied Goodness of Fit Testing". American Institute of Industrial Engineers, Inc. Norcross, Georgia. pp. 80. 1972. Priddy, R.R., R. M. Crisler, Jr., C.P. Sebren, J. D. Powell and H. B. Burford. "Sediments of Mississippi Sound and Inshore Waters". Mississippi State Geological Survey, Bulletin 82. 1955. Richmond, E. Avery. "The Fauna and Flora of Horn Island, Mississippi. Gulf Research Reports, 1(2):59-106. 1962. Roberts, Nash C."Wave Height Statistics, Mississippi". Nash C. Roberts, Jr. Consultants, Inc. Typewritten Report. Sackett, William M. Lela M. Jeffrey and Alan D. Fredericks. "Chemistry of the Gulf of Mexico". Contribution Dept. of Oceanography, Texas A&M University. 1970. Teal, John and Mildred. Life and Death of the Salt Marsh. Little Brown and Company. Boston, Massachusetts. 1969. Thom, H.C.S. "The Distribution of Annual Tropical Cyclone Frequency". J. Geophys. Res. 65(l):213-222. 1960. United States Dept. of the Interior, Geological Survey, "Water Resources Data for Mississippi 1951-1972. Wiegel, Robert L. Oceanographic Engineering. Prentice-Hall, Inc. Englewood Cliffs, New Jersey. pp. 532. 1964. � Personal Communication with Richard S. Waller, Marine Biologist, Gulf Coast Research Laboratory. � Personal Communication with W. David Burke, Biologist, Gulf Coast Research Laboratory. � Personal Communication with Charles H. Lyles, Fisheries Statistician, Gulf Coast Research Laboratory. 248