Year 2 Data Summary Report: Nekton of Sarasota Bay and a Comparison of Nekton Community Structure in Adjacent Southwest Florida Estuaries T.C. MacDonald; E. Weather; R.F. Jones; R.H. McMichael, Jr. Florida Fish and Wildlife Conservation Commission Fish and Wildlife Research Institute 100 Eighth Avenue Southeast St. Petersburg, Florida 33701-5095 Prepared for Sarasota Bay Estuary Program 111 S. Orange Avenue, Suite 200W Sarasota, Florida 34236 June 4, 2012 TABLE OF CONTENTS LIST OF FIGURES ........................................................................................................................................ iii LIST OF TABLES .......................................................................................................................................... v ACKNOWLEDGEMENTS ............................................................................................................................ vii SUMMARY .................................................................................................................................................... ix INTRODUCTION ........................................................................................................................................... 1 METHODS .................................................................................................................................................... 2 Study Area ................................................................................................................................................ 2 Sampling Design ....................................................................................................................................... 3 Gear Specifications and Deployment ....................................................................................................... 6 Sample Processing ................................................................................................................................... 7 Nekton Community Analysis ..................................................................................................................... 9 Bray-Curtis similarity calculation ........................................................................................................ 12 Non-metric multidimensional scaling (MDS) and Similarity Percentage Analysis (SIMPER) ............ 12 Mercury Content Analysis ....................................................................................................................... 13 RESULTS and DISCUSSION ..................................................................................................................... 15 Physiochemical conditions...................................................................................................................... 15 Composition of overall nekton community .............................................................................................. 18 Shallow water habitats sampled with 21.3-m seines .......................................................................... 19 Nearshore habitats sampled with 183-m seines ................................................................................ 22 Deeper-water habitats sampled with 6.1-m trawls ............................................................................. 26 Species Profiles ...................................................................................................................................... 29 Pink shrimp, Farfantepenaeus duorarum ........................................................................................... 30 Blue crab, Callinectes sapidus ........................................................................................................... 33 Ladyfish, Elops saurus ....................................................................................................................... 37 Bay anchovy, Anchoa mitchilli ............................................................................................................ 39 Common snook, Centropomus undecimalis....................................................................................... 41 Gray snapper, Lutjanus griseus ......................................................................................................... 43 Pinfish, Lagodon rhomboides ............................................................................................................. 46 Sheepshead, Archosargus probatocephalus ..................................................................................... 51 Spotted Seatrout, Cynoscion nebulosus ............................................................................................ 54 Striped mullet, Mugil cephalus ........................................................................................................... 56 Nekton Community Structure ................................................................................................................. 59 i Intrabay Comparison .......................................................................................................................... 59 Interbay Comparison .......................................................................................................................... 68 Mercury Content Analysis ....................................................................................................................... 77 Ladyfish, Elops saurus ....................................................................................................................... 79 Common Snook, Centropomus undecimalis ...................................................................................... 81 Sheepshead, Archosargus probatocephalus ..................................................................................... 83 Gray Snapper, Lutjanus griseus ......................................................................................................... 85 Gag, Mycteroperca microlepis ............................................................................................................ 87 Spotted Seatrout, Cynoscion nebulosus ............................................................................................ 89 Red Drum, Sciaenops ocellatus ......................................................................................................... 91 CONCLUSIONS .......................................................................................................................................... 93 Physiochemical conditions...................................................................................................................... 93 Composition of overall nekton community .............................................................................................. 93 Nekton Community Structure ................................................................................................................. 94 Mercury Content Analysis ....................................................................................................................... 95 LITERATURE CITED .................................................................................................................................. 97 APPENDICES ........................................................................................................................................... 105 Appendix A. Animals designated as Selected Taxa because of their commercial or recreational importance. ......................................................................................................................................... 107 Appendix B. Summary of species collected, by sampling event, during Sarasota Bay nekton sampling, June 2010 to April 2011 ..................................................................................................... 109 Appendix C. Summary of species collected, by gear and stratum, during Sarasota Bay nekton sampling, June 2010 to April 2011 ..................................................................................................... 113 Appendix D. Summary of species collected, by embayment, during Sarasota Bay nekton sampling, June 2010 to April 2011 ..................................................................................................... 117 Appendix E. Catch summary for taxa collected during both years, June 2009 to April 2011, of nekton sampling in Sarasota Bay with 21.3-m seines ........................................................................ 121 Appendix F. Catch summary for taxa collected during both years, June 2009 to April 2011, of nekton sampling in Sarasota Bay with 183-m seines ......................................................................... 125 Appendix G. Catch summary for taxa collected during both years, June 2009 to April 2011, of stratified-random sampling in Sarasota Bay with 6.1-m trawls .......................................................... 129 Appendix H. Species overview plots for dominant taxa collected in 21.3-m seines in Sarasota Bay, June 2009 to April 2011 ............................................................................................................. 133 Appendix I. Species overview plots for dominant taxa collected in 183-m haul seines in Sarasota Bay, June 2009 to April 2011 ............................................................................................................. 155 Appendix J. Species overview plots for dominant taxa collected