Annual report 1999 Season: Dry Torgtugas National Park sea turtle monitoring program, Monroe County, Florida

Reardon, Russell

The 1999 Dry Tortugas Sea Turtle Monitoring Program recorded a total of 545 turtle crawls. Of these crawls, 536 (98.3%) were by loggerheads (Caretta caretta), and nine (1.7%) were by green turtles (Chelonia m)Ws). A total of 249 nests and 296 false crawls were documented within the park, with seven nests and two false crawls identified as green. The greatest amount of turtle activity was recorded on East Key (54.3%), followed by Loggerhead Key(35.4%). The average loggerhead incubation period was 54.6 days (SD = 3.5; r = 48-68; n = 184), with an average clutch size of 102.7 eggs (SD = 23.4; r = 30-162; n = 207). The average incubation period of green turtle nests was 52.2 days (SD = 2.1; r = 48-54; n = 6), with an average clutch size of 127.7 eggs (SD = 7.7; r = 121-140; n= 6). Severe weather, spring high tides and high water tables inundated 49 nests with seawater. Twenty-six of these nests were lost completely to tidal erosion: The average hatching success of inventoried nests was 78.7% (SD = 20.5%; r = 0.0-99.00/o; n = 213) with an average release rate of 77.2%(SD = 20.9%; r = 0.0-99.00/o; n = 213). The average loggerhead hatching success was 78.5% (SD = 20.7%; r = 0.0-99.00/o; n = 207), with a release rate of76.9% (SD = 21.1%; r = 0.0-99.00/o; n =207). The average green turtle hatching success was 87.4% (SD = 6.2%; r = 80.8-97.9%; n = 6), with a release rate of87.6% (SD = 6.2%; r = 80.8-97.9%; n = 6). The green turtle release rate was slightly greater than the hatching success due to live pipped eggs that were not classified as hatched. An estimated 22,022 eggs were examined this season, with an estimated 17,060 hatchlings entering the Gulf of Mexico. During the last five seasons of daily monitoring, the Dry Tortugas Sea Turtle Monitoring Program has recorded 2,881 turtle crawls, comprised of 1,245 nests and 1,636 false crawls. An estimated 100,064 eggs have been excavated, with 75,944 hatchlings estimated to have entered the Gulf of Mexico. Researchers have recorded 3,959 turtle crawls- 1,605 nests and 2,354 false crawls- within the park since 1982.