Alternate Title

Seasonal Migration of Immature Kemp's Ridley Turtles (Lepidochelys kempii Garman) Along the West Coast of Florida


Six immature Kemp's ridley turtles (Lepidochelys hempii) were monitored via satellite telemetry to investigate their winter migration on the west coast of Florida. All turtles departed from Cedar Keys in late Nov., migrated southward in Dec., and overwintered in offshore waters from Anclote Keys to Captiva Island during Jan., 120 km and 296 km from Cedar Keys, respectively. Turtles migrated northward in Feb. and began returning to Cedar Keys in March. Five of the turtles occupied relatively small (3.8-48.0 km2) postmigration foraging ranges through Aug. The sixth turtle returned to Waccasassa Bay, east of Cedar Keys, but locational data were insufficient for postmigration analysis. Mean sea surface temperature (SST) used by turtles in Nov. decreased from 23.6 ± 1.9 C during the first 2 weeks to 17.1 ± 1.5 C during the latter 2 weeks, and corresponded to their departure from Cedar Keys. Mean SST used by turtles in Jan. increased from 14.0 ± 1.6 C during the first 2 weeks to 16.6 ± 1.4 C during the latter 2 weeks, and corresponded to the onset of their northward migration. Turtles traveled up to 13-56 km offshore to maximum depths of 15-31 m. Higher proportions of satellite location classes requiring four or more uplinks were obtained during winter months suggesting that turtles spent more time at the surface during their migrations. Further studies are needed to determine possible size-specific differences in depth use and migration patterns, to identify benthic habitats used by Kemp's ridleys during winter migrations, and to determine what anthropogenic impacts occur within their migratory routes along the Florida coast.