A Study of Nektonic and Benthic Faunas of the Shallow Gulf of Mexico Off the State of Mississippi As Related to Some Physical, Chemical, and Geological Factors
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Gulf and Caribbean Research Volume 4 Issue 1 January 1972 A Study of Nektonic and Benthic Faunas of the Shallow Gulf of Mexico Off the State of Mississippi As Related to Some Physical, Chemical, and Geological Factors James S. Franks Gulf Coast Research Laboratory J.Y. Christmas Gulf Coast Research Laboratory Walter L. Siler Gulf Coast Research Laboratory Ralph Combs Gulf Coast Research Laboratory See next page for additional authors Follow this and additional works at: https://aquila.usm.edu/gcr Part of the Marine Biology Commons Recommended Citation Franks, J. S., J. Christmas, W. L. Siler, R. Combs, R. Waller and C. Burns. 1972. A Study of Nektonic and Benthic Faunas of the Shallow Gulf of Mexico Off the State of Mississippi As Related to Some Physical, Chemical, and Geological Factors. Gulf Research Reports 4 (1): 1-148. Retrieved from https://aquila.usm.edu/gcr/vol4/iss1/1 DOI: https://doi.org/10.18785/grr.0401.01 This Article is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Gulf and Caribbean Research by an authorized editor of The Aquila Digital Community. For more information, please contact [email protected]. A Study of Nektonic and Benthic Faunas of the Shallow Gulf of Mexico Off the State of Mississippi As Related to Some Physical, Chemical, and Geological Factors Authors James S. Franks, Gulf Coast Research Laboratory; J.Y. Christmas, Gulf Coast Research Laboratory; Walter L. Siler, Gulf Coast Research Laboratory; Ralph Combs, Gulf Coast Research Laboratory; Richard Waller, Gulf Coast Research Laboratory; and Charles Burns, Gulf Coast Research Laboratory This article is available in Gulf and Caribbean Research: https://aquila.usm.edu/gcr/vol4/iss1/1 A STUDY OF NEKTOMC AND BENTHIC FAUNAS OF THE SHALLOW GULF OF MEXICO OFF THE STATE OF MISSISSIPPI AS RELATED TO SOME PHYSICAL, CHEMICAL AND GEOLOGICAL FACTORS James S. Franks, J.Y. Christmas, Walter L. Siler, Ralph Combs, Richard Waller and Charles Burns GULF COAST RESEARCH LABORATORY Ocean Springs, Mississippi 1972 This study was conducted in cooperation with the Department of Commerce, National Marine Fisheries Service, under Public Law 88-309, Project 2-42-R. Table of Contents Page ... I . List of Tables and Figures ................ 111 I1. Abstract ......................... 1 I11 . Introduction ....................... 2 IV . Station Location and Identification ........... 5 V . Bathymetry ....................... 8 VI . Materials and Methods .................. 8 VI1 . Hydrology ........................ 10 Temperature ...................... 10 Salinity ......................... 13 Chemical Determinations ............... 15 Transparency ...................... 15 VI11 . Sedimentology ...................... 17 Background ...................... 17 Technique ....................... 18 Findings ........................ 18 Sediment Composition ................. 20 Size .......................... 20 IX . Plankton Sampling .................... 24 Common Plankters ................... 27 Phytoplankton .................... 27 Zooplankton ..................... 27 X . Dredge Sampling ..................... 37 Species Account .................... 38 XI . Nekton Sampling ..................... 40 XI1. Trawl Sampling ..................... 42 Laboratory Work on Samples ............. 43 Systematic Account .Invertebrates ......... 44 Systematic Account .Fishes ............. 66 XI11 . Relative Abundance ................... 129 Seasonal Bathymetric Distribution ........... 132 Length-Frequency Distribution ............ 134 XIV . Estuarine Relationships ................. 134 xv . Summary ......................... 136 XVI . Literature Cited ..................... 139 XVII . Index ........................... 144 11.. List of Tables and Figures TABLES Page- 1. Number of Monthly Hauls . 7 2. Monthly Mean Temperature and Salinity . 11 3. Minimum, Maximum, Range and Mean of Monthly Average Temperature . 14 4. Minimum, Maximum, Range and Mean of Monthly Average Salinity . 14 5. Monthly Mean Nitrate, Nitrite, Total Phosphate and Ortho-phosphate . 16 6. Monthly Transparency Observations (May 1968 - May 1969) . 19 7. Sediment Properties of Offshore Stations . 21 8. Number of Offshore Plankton Samples Examined . 26 9. Settled Volumes, Salinity, Temperature and Relative Abundance of Common Plankters . 28 10. Total Dredge Catch from Six Offshore Stations . 39 11. Surface and Benthic Nekton Hauls . 41 12. Species Most Commonly Encountered in Nekton Hauls . 43 13. Distribution of Lolliguncula breuis by Bottom Salinity and Temperature Intervals . 48 14. Distribution of Penaeus aztecus by Bottom Salinity and Temperature Intervals . 52 15. Distribution of Penaeus fluuiatilis by Bottom Salinity and Temperature Intervals . 55 16. Distribution of Callinectes sapidus by Bottom Salinity and Temperature Intervals . 60 17. Distribution of Cdlinectes similis by Bottom Salinity and Temperature Intervals . 62 18. Contribution of Each Family to Total Catch of Fishes . 67 19. Percentage Distribution of Commercially Important Families . 67 20. Distribution of Anchoa hepsetus by Bottom Salinity and Temperature Intervals . 75 21. Distribution of Galeichthys felis by Bottom Salinity and Temperature Intervals . 80 22. Distribution of Centropristes ocyurus by Bottom Salinity and Temperature Intervals . 85 23. Distribution of Cynoscion arenarius by Bottom Salinity and Temperature Intervals . 92 24. Distribution of Leiostomus xanthurus by Bottom Salinity and Temperature Intervals . 95 25. Distribution of Micropogon undulatus by Bottom Salinity and Temperature Intervals . 98 26. Distribution of Lagodon rhomboides by Bottom Salinity and Temperature Intervals . .lo1 27. Distribution of Stenotomus caprinus by Bottom Salinity and Temperature Intervals . .lo4 ... 111 28. Distribution of Peprilus burti Fowler by Bottom Salinity and Temperature Intervals .................114 29. Distribution of Cyclopsetta chittendeni by Bottom Salinity and Temperature Intervals ............118 30. Distribution of Syacium gunteri by Bottom Salinity and Temperature Intervals ................ .123 31. Relative Numbers of the Most Abundant Fishes .... -130 32. Relative Numbers of the 12 Most Abundant Invertebrate Species ................... .130 FIGURES 1. The “Big House” ...................... 4 2. Location of Work ..................... 6 3. Bottom Profile ....................... 9 4. Nitrate Concentrations (May 1968 through May 1969) . 17 5. Total Phosphate Concentrations (May 1968 through May 1969) ......................... 18 6. Nomenclature for Bottom Sediments Based on Grain Size ............................. 22 7. Average Grain Size of Bottoms of Offshore Stations . 23 8. Qpe of Closing Plankton Net Used in Sampling ....25 9. Relative Abundance of Number Caught and Weight of Twenty-one Species of Trawl Caught Fishes (1967-1969) ........................ .131 10. Offshore Seasonal Bathymetric Distribution of Micropogon undulatus and Stenotomus caprinus .... -132 11. Offshore Seasonal Bathymetric Distribution of Cynoscion arenarius, Peprilus burti, Leiostomus xanthurus and Penaeus aztecus .............-133 Acknowledge ment s Mr. C. E. Dawson originally served as principal investigator for this project. We sincerely acknowledge his contributions to this study. Mr. Felix Jackson worked as project staff member through- out the program. We hereby acknowledge their contribution and the work of many others who, from time to time, gave assistance. iv NEKTONIC AND BENTHIC FAUNAS 1 Abstract A seasonal study of the nektonic and benthic faunas of the shallow Gulf of Mexico off Mississippi was conducted from January 1967 through May 1969. It was planned to sample monthly six fixed offshore stations at depths ranging from 5 to 50 fathoms in the open Gulf. In general this was carried out fairly well, as shown by Table 1. Water samples were taken from surface, midwater, and bottom levels each time a station was occupied, and temperatures and salinities were recorded for each of these. Samples were tested for the presence of nitrates, nitrites, ortho-phosphates and total phosphates. Secchi disc extinction points were recorded. Grab samples were taken for the determination of bottom composition. Plankton samples were taken from surface, midwater and bottom levels. Copepods, brachyuran zoea and megalops, stomatopod larvae, Lucifer faxoni, Acetes a. carolinae, Penilia avirostris, Doliolum sp. and fish eggs and larvae were present in greatest abundance. Surface and benthic nekton samples were obtained. Dredge samples were made quarterly and twelve invertebrate species and three species of fishes were collected. Renilla mulleri was the most abundant species taken, and the fish catch consisted of Centropristes ocyurus, Citharichthys spilopterus and Etropus crossotus. Accounts of 50 invertebrate species (24,679 specimens) and 129 fishes (93,563 specimens) taken in trawl hauls is presented. Tem- perature and salinity data are given for all species. Relative abundance, seasonal bathymetric distributions and movements, apparent growth patterns, catch per unit of effort and various biological data are noted for the most abundant species. Station 5 (40 fathoms) produced the largest percentage of trawl catches (22.7).Renilh mulleri was the most abundant invertebrate taken in trawling. The brown shrimp, Penaeus aztecus, was second in abundance (10.92%). The five most abundant species comprising 80.57% numerically of the catch were croaker, longspine porgy, butterfish, spot, and seatrout. The species comprising