Abstract. Marine turtle tag- 

 ging records were collected off east- 

 central Florida by a shrimp trawler 

 from May 1986 to December 1991. 

 The data were analyzed to deter- 

 mine species composition, size dis- 

 tribution, seasonal occurrence, 

 movements, morphometries, and 

 growth of 928 incidentally captured 

 turtles. Loggerhead turtles, Ca- 

 retta caretta, were the most fre- 

 quently captured species (83% of 

 total catch), while Kemp's ridley, 

 Lepidochelys kempi, and green 

 turtles, Chelonia mydas, were 

 caught less frequently (12% and 

 4%, respectively). The loggerhead 

 turtle population consisted of a sea- 

 sonably variable aggregation of 

 subadult and adult turtles. The 

 Kemp's ridley and green turtle 

 populations were composed of sub- 

 adult turtles and were captured 

 primarily during winter months. 

 Kemp's ridley and loggerhead 

 turtles appeared to exhibit a sea- 

 sonal north-south migrational pat- 

 tern along the Atlantic coast. Re- 

 gression equations were developed 

 for the morphometric relationships 

 of each species. Average yearly 

 growth rates and estimates for the 

 von Bertalanffy growth interval 

 equation were calculated for logger- 

 head and Kemp's ridley turtles. 

 These results indicate that the 

 coastal waters of the Cape Cana- 

 veral area provide an important 

 developmental habitat for the three 

 species of marine turtle. 



Marine turtle populations on the 

 east-central coast of Florida: results 

 of tagging studies at Cape Canaveral, 

 Florida, 1986-1991* 



Jeffrey R. Schmid 



Southeast Fisheries Science Center, 



National Marine Fisheries Service, NOAA 



75 Virginia Beach Drive, Miami, Florida 33149 



Archie Carr Center for Sea Turtle Research 

 223 Bartram Hall, University of Florida 

 Gainesville, Florida 3261 I 



Manuscript accepted 29 August 1994. 

 Fishery Bulletin 93:139-151 (1995). 



The marine turtle life history is a dy- 

 namic progression of stages which 

 includes oceanic dispersal of the off- 

 spring and utilization of a series of 

 distinct developmental habitats 

 (Carr, 1980; Hendrickson, 1980). 

 The early in-water stages of marine 

 turtle development have not been 

 as extensively studied as the repro- 

 ductive stage of females. Informa- 

 tion concerning the early life histo- 

 ries of threatened and endangered 

 marine turtles is critical in formu- 

 lating conservation and recovery 

 strategies as mandated by the En- 

 dangered Species Act of 1973 and 

 subsequent amendments. 



Inaccessibility of immature tur- 

 tles in the open ocean is the major 

 factor contributing to the lack of 

 information on the early stages of 

 development. Other than possible 

 current-mediated dispersal sce- 

 narios (Carr, 1986; Collard and 

 Ogren, 1990), little is known about 

 the pelagic stage of marine turtle 

 development. However, information 

 concerning the populations of im- 

 mature turtles foraging in the 

 coastal waters of eastern Florida 

 has been accumulating as a result 

 of data collected through commer- 

 cial fisheries (fishery-dependent) 

 and fishery-independent activities. 



Fishery-independent capture and 

 tagging efforts have characterized 

 the populations of loggerhead 

 turtles, Caretta caretta, and green 

 turtles, Chelonia mydas, foraging in 

 the northern part of the Indian 

 River lagoon system (Ehrhart and 

 Yoder, 1978; Mendonca, 1981, 1983; 

 Mendonca and Ehrhart, 1982; 

 Ehrhart, 1983). All green turtles 

 collected in the lagoonal habitat 

 were immature, as were almost all 

 of the loggerhead turtles. Aggrega- 

 tions of marine turtles in the Port 

 Canaveral ship channel were first 

 reported in 1978, when two trawl- 

 ers caught unprecedented numbers 

 of loggerhead turtles while search- 

 ing for a concentration of shrimp 

 (Carr et al., 1980). This prompted 

 the National Marine Fisheries Ser- 

 vice (NMFS) to conduct trawl sur- 

 veys of the ship channel from 1978 

 to 1984 (Butler et al., 1987; Hen- 

 wood, 1987a; Henwood and Ogren, 

 1987). The surveys provided infor- 

 mation on the seasonal occurrence 

 and movement patterns of subadult 

 and adult loggerhead turtles 

 (Henwood, 1987a), as well as sub- 

 adult Kemp's ridley, Lepidochelys 



"Contribution MIA-92/93-94 of the Miami 

 Laboratory, Miami, Florida. 



139 



