Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1982 Spatial and Temporal Variations in Community Structure of the Demersal Macrofauna of a Subtropical Estuary (Louisiana). Thomas C. Shirley Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Shirley, Thomas C., "Spatial and Temporal Variations in Community Structure of the Demersal Macrofauna of a Subtropical Estuary (Louisiana)." (1982). LSU Historical Dissertations and Theses. 3821. https://digitalcommons.lsu.edu/gradschool_disstheses/3821 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. 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University Micrdnlms International 300 N. Zeeb Road Ann Arbor, Ml 48106 8312104 Shirley, Thomas C. SPATIAL AND TEMPORAL VARIATIONS IN COMMUNITY STRUCTURE OF THE DEMERSAL MACROFAUNA OF A SUBTROPICAL ESTUARY The Louisiana State University and Agricultural and Mechanical Ph.D. Col.1982 University Microfilms International 300 N. Zeeb Road, Ann Arbor, MI 48106 PLEASE NOTE: In all cases this material has been filmed in the best possible way from the available copy. Problems encountered with this document have been identified here with a check mark V . 1. Glossy photographs or pages______ 2. Colored illustrations, paper or print ______ 3. Photographs with dark background ______ 4. Illustrations are poor copy ______ 5. Pages with black marks, not original copy _____ 6. Print shows through as there is text on both sides of page ______ 7. Indistinct, broken or small print on several pages J 8. Print exceeds margin requirements ______ 9. Tightly bound copy with print lost in spine______ 10. Computer printout pages with indistinct print______ 11. Page(s)____________lacking when material received, and not available from school or author. 12. P age(s)____________seem to be missing in numbering only as text follows. 13. Two pages numbered _____________. Text follows. 14. Curling and wrinkled pages ______ 15. Other _________________________________________________________________________ University Microfilms International SPATIAL AND TEMPORAL VARIATIONS IN COMMUNITY STRUCTURE OF THE DEMERSAL MACROFAUNA OF A SUBTROPICAL ESTUARY A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Zoology and Physiology by Thomas C. Shirley B.S., Texas A&I University, 1969 M. S., Texas A&I University, 1974 December 1982 ACKNOWLEDGEMENTS This project has benefitted from the efforts, advice and criticism of a great many people. Foremost among those to be thanked is Dr. William B, Stickle, my committee chairman, for his advice, encouragement and patience. I thank my committee members, Drs. J. B. Woodring, W. J. Harman, Dr. J. W. Fleeger and the late N. B. Causey, Department of Zoology and Physiology, Dr. J. W. Day, Department of Marine Sciences, all from Louisiana State University, and Dr. H. D. Hoese, Department of Biology, University of Southwestern Louisiana, for their advice and constructive reviews of the manuscript. Gary Mayeaux, David Randall, Deborah French, Nancy Henderson, Jan Judice, Cay Villars and Karen Westphal were tireless "pickers" and sample sorters. Larry Racca, Louisiana Wildlife and Fisheries Commission, was the boat captain and an endless source of wildlife wisdom. Guy J. Denoux was a collaborator in the collection of hydrographic data and displayed indefatigable patience in the washing of myriads of bottom samples. Louis Kniepper helped in the processing of trawl samples and identified most of the fish speci­ mens. Drs. D. L. Felder and M. S. Loden aided in the identification of crustaceans and oligochaetes, respectively. Jerry Hader helped in pro­ gram formulation and debugging. The project was made possible by funding from PRECOL (Petroleum Refiners Environmental Council of Louisiana). The Louisiana Wildlife and Fisheries Commission generously provided a boat and numerous forms of assistance. Lastly, it is diffi­ cult for me to express sufficient gratitude to my wife, Susan, not only for editing the manuscript, but for her support and concern for my personal goals. ii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS .................................................... ii LIST OF TABLES ......................................................... iv LIST OF FIGURES...................................................... v GLOSSARY OF TERMS......................................................vii ABSTRACT............................................................... ix INTRODUCTION................................................ 1 MATERIALS AND METHODS ...................................... 3 The Study A r e a .......................................... 3 Hydrographic Data. ................................. 6 Biological Samples ..................................... 9 Sediments................................................ 9 Statistical Analyses ................................... 10 RESULTS .................................................... 14 Hydrographic Data........................................ 14 Sediments................................................ 33 Faunal Data.............................................. 38 Community Structure...................................... 43 Classification .......................................... 50 Normal Analysis (Q or Station) ......................... 50 Inverse Classification ...... .......... ..... 57 DISCUSSION.................................................. 67 LITERATURE CITED............................................ 76 APPENDICES........................................................... 85 VITA.................................................................. 133 iii LIST OF TABLES Table Page 1 Locations of sampling stations: longitudes and lattltudes, buoy numbers and distance from Calcasieu Pass................................. 7 2 Water temperature: means and ranges by station and temperature............................. 24 3 Dissolved oxygen data: means and ranges of mg ant* Percent saturation by station and position ...................... .... ............ 32 4 Rank, total number collected, frequency of occurrence and percentage of total collections for ten most abundant fish and invertebrates in trawl samples. 3? 5 Attributes of station groups............................ 56 6 Members of species groups ........................... 61 iv LIST OF FIGURES Figure Page 1 Map of the Calcasieu estuary with station locations............................................ 4 2 Means and ranges of salinity by station and position............................................ 15 3 Monthly surface salinities for stations 1, 3, 5 and 7.............................................. 17 4 Monthly bottom salinities for stations I, 3, 7 and 9 .............................................. 19 5 Means and ranges of water temperatures by sampling period................................. 22 6 Temperature-salinity polygons for surface and lake or channel bottom for stations 1, 4, 7, 9 and 10. 25 7 Means and ranges of dissolved oxygen content (mg 0^/l) by station and position................... 28 8 Means and ranges of percent oxygen saturation by station and position............................