Charlotte Harbor Estuarine Studi!;S
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CHARLOTTE HARBOR ESTUARINE STUDI!;S • DISTRIBUTION AND FLUCTUATIONS IN THE FISH FAUNA OF THE CHARLOTTE HARBOR ESTUARY, FLORIDA BY Johnson C. S. Wang Mote Marine Laboratory Sa rasota, Florida Edwa rd C. Raney Corn ell University Ithaca, New York 950 I Blind Pass Road Sarasota, Florida 33581 DISTRIBUTION AND FLUCTUATIONS IN THE·fISH FAUNA OF THE CHARLOTTE HARBOR ESTUARY, FLORIDA Sponsored by: The Mote Marine Laboratory Sarasota and Placida, Florida and Cornell University Ithaca, New York Principal Investigators: Wang, Johnson C. S., Ph.D. Raney, Edward C., Ph.D. Editorial Assistance with manuscript: Moores, Donald D. June, 1971 ACKNOWLEDGEMENTS The authors would like to acknowledge the support glVen throughout this study by Dr. Perry W. Gilbert, the Director, and Mr. William R. Mote, the President of the Mote Marine Laboratory. Dr. Yoshie Dotsu, Mr. Martin Cole, Mr. John B. Heiser, Mr. Barry A. Smith, and Mr. Bruce A. Thompson assisted in the field collection. Dr. Charles M. Breder, Jr. made numerous helpful suggestions and assisted with some of the identifications during the course of the study. Miss Patricia Morrissey and Mrs. Katherine von Schmidt assisted in the preparation of this report. These studies were financed in part by grants to the Mote Marine Laboratory from the National Science Foundation for support of the R/V RHINCODON, the Theodore R. and Grayce W. Bartels Foundation and the Bauer Scientific Trust. II TABLE OF CONTENTS INTRODUCTION . .. 1 METHODS ................................. 1 WATER CONDITIONS .......................... 17 SYSTEMATIC ACCOUNT OF FISHES ................. 20 DISCUSSION ......................... ...... 49 SUMMARY ................................. 54 LITERATURE CITED .............. ............ 54 APPENDIX A (check list of fishes) .................. A-1 APPENDIX B (length-frequency distribution tables) .........B-1 III INTRODUCTION Charlotte Harbor is located on the Gulf coast of Florida. It is one of the largest and perhaps the least contaminated of the estuarine complexes in the state of Florida. In the present survey, emphasis has been placed on the small fish fauna of this estuary. Small estuarine fishes playa very important role in supplying a future stock of adults of their own species and as the food of other species. It can be safely predicted that conditions which adversely affect these small fishes will do considerable damage to Florida's commercial and sport-fishing industries. The fish fauna of Charlotte Harbor was studied by Storey and Gudger (1936) and Storey (1937) in th,e area of Sanibal Island, and by Dr. Charles M. Breder, Jr. during 1939-1942 when he was in charge of operations at the Palmetto Key Laboratory. Gunter and Hall (1965) made an ecological survey of the Caloosahatchee estuary. Springer (1960) made two collections of the fishes of the Caloosahatchee estuary in 1958 and 1959. Tampa Bay, 60 miles north of Charlotte Harbor, is another of the largest estuaries in Florida. Springer and Woodburn (1960) made a survey of the fishes of that estuary. The most recent reference available is the comparative study by Finucane (1965) between Charlotte Harbor-Pine Island Sound and Tampa Bay-Boca Ciega Bay. Methods Approximately 120,000 acres of Charlotte Harbor and contiguous waters were covered in this study. The total study includes 131 daytime collecting trips, 1169 trawl efforts, 32 seine hauls, 33 dipnet samples and 104 water samples. For the majority fo the samples, a 16-foot semi-balloon trawl with l/2-inch mesh and a 1/4-inch mesh liner for the codend was used. Two seines, a 4 x 50 foot bag seine and a 4 x 25 foot bag seine, both with 1/4-inch mesh, were occasionally used, primarily during the reconnaissance stage. The R/V RHINCOOON, a 33-foot diesel-powered vessel, was used in trawling operations. Water samples were taken at all stations and were returned to the laboratory for salinity determinations. Temperatures were measured at each station. All fishes collected were preserved initially in 10% formalin and subsequently transferred to 40% isopropyl alcohol. Measurements were made using both calipers and a measuring board. Standard length in millimeters was used except where noted in the text. Common names of fishes are those suggested by the American Fisheries Society (Bailey, et ai., 1970), and the order in which the species are listed also follows the arrangement suggested in that publication. The species discussed in the Systematic Account section are those collected during this study alone. The check list of fishes at the end of this report includes those taken from the Charlotte Harbor area by other investigators and those on deposit in the Mote Marine Laboratory fish collection which were taken from this area. Limitations Because of the mesh size of our collecting gear and the speed at which the trawl could be pulled by the boat, the size range sampled was primarily limited to small or young fishes. In addition, specimens smaller than 20 mm were rarely taken. As a result, only a portion of the life histories could be followed. Fishes inhabiting rocky areas or other habitats where nets could not be used were not sampled. Fast-swimming fishes such as mullets, and large fishes such as sharks occur in the estuary but were not collected. Reconnaissance Stage Before a regular sampling program was established, an extensive reconnaissance survey was made, beginning on February 12,1968. During that month, seine surveys were made at Devilfish Key in Gasparilla Sound, and at Bird Key in Placida Harbor. On February 26, trawl collections were made at Placida Harbor, Gasparilla Sound, lower Charlotte Harbor, upper Charlotte Harbor and the Peace River at Punta Gorda. In all, 54 trawling efforts were made, with an average catch of 61 specimens per trawl. In March, surveys were made at Placida Harbor, Gasparilla Sound, Charlotte Harbor, Pine Island Sound, San Carlos Bay, Matlacha Pass, Bull Bay, Turtle Bay, the junction of the Myakka and Peace Rivers, and the Gulf coast of Gasparilla Island. In all, 159 trawling effects were made. In excess of 19,000 specimens were taken, and over two-thirds of those were anchovies, primarily Anchoa mitchilli. During April, trawling continue~ at most of the above stations with the exception of Pine Island Sound. An extensive survey was made of Lemon Bay, and a one-day collecting trip was made at the Caloosahatchee River on April 10. Five trawl efforts were made in the river between Cattle Dock Point and Beautiful Island. The species compositions of Lemon Bay north of Englewood Bridge and the Caloosahatchee River are so similar to that of the Peace River that sampling in those two areas was discontinued. Gunter and Hall (1965) may be referred to for a detailed account of the fishes in the Caloosahatchee. In all, 178 trawling efforts were made during April, and of more than 27,339 specimens taken, more than 12,881 were anchovies. During May, uniform trawling efforts were made at the stations which were selected for the random sampling stage (which see), and in the Gulf of Mexico between Stump Pass and Gasparilla Pass. Samples from the Gulf were very small and trawling there was discontinued. In all, 94 trawling efforts were made during May. Over 5,972 anchovies and 5,263 others were caught. Random Sampling Stage From June, 1968 to May, 1969, uniform trawling efforts were made at each of the trawling stations described below. A total of 33 fish collecting stations and 5 water sampling stations were selected (Fig. 1.). Refer to U. S. Coast and Geodetic Survey charts no. 1255 and 857-SC for more detailed examinations of the station locations. Station No. 1. The Cutoff. Lat. 26°52'00'N. Long 82°18'35"W. (Figs. 1 & 2) This station lies in the Intracoastal Waterway, between Lemon Bay and Placida Harbor. The bottom is composed of silt-sand. The water is usually dark green. The average depth of trawling was 10 feet. Collections were always poor at this station. -2- CHARLOTTE HARBOR STATION LOCATIONS NAUTICAL MI LES -i &~~ .t!i~ ~ O~ ~. f) tf ".. ~ C.~tIY. Pa.. ,18 -.;...- ~C> ~ '"?C> Redtl,h Po.. 20 \\. Captiva Island 82'-20'W 8Z'OO'W Fig. I. Sampling stations in Charlotte Harbor and adja- cent waters. -3- N I Stump GULF OF MEXICO Gasparilla Sound F iQ. 2. Sampl inQ stations in Lemon Bay, Placida Harbor and Gasparilla Sound. -4- Station No.2. South Lemon Bay. Lat. 26°53' 50"N. Long 82°19'35"W. (Figs. 1 & 2) The main current from Stump Pass has a direct influence on this station. The bottom is vegetated with algae, the species varying seasonally. The water is usually blue to green. The average depth of trawling was 7 feet. A greater species diversity was encountered here than at any other station. Station No.3. Stump Pass. Lat. 26°53'55"N. Long. 82°20'30"W. (Figs. 1 & 2) Water samples only were taken at this station. Station No.4. Peterson Island Lat. 26°55'10"N. Long. 82°21'25"W. (Figs. 1 & 2) This station lies in Stump Pass Channel between Peterson Island and Englewood Beach at the extreme south end of Manasota Key. There is a residential area on the west side of the channel. Brackish water discharged from several large creeks into Lemon Bay meets higher salinity water from Stump Pass in this area. The bottom is vegetated by algae. The greatest number of fishes was collected from this station. Belted sandfish (Serranellus subligarius) and spotted scorpionfish (Scorpaena plumieri) occurred at this station but were rare elsewhere. Station No.5. Englewood Bridge. Lat. 26°56'00"N. Long. 82°21'05"W. (Figs. 1 & 2) Water samples only were taken at this station. The water was usually dark greenish or brownish.