Post-nesting movement of wild and head-started Kemp's ridley sea turtles Lepidochelys kempii in the Gulf of Mexico

Abstract

Nesting by the endangered Kemp's ridley sea turtle Lepidochelys kempii has increased on the Texas coast during recent years. Movements of 28 individual adult females that nested on North Padre Island or Mustang Island, Texas, USA, were monitored using satellite telemetry. Platform transmitter terminals (PTTs; n = 36) were deployed on the 28 turtles between 1991 and 2006, with 1 individual receiving 3 PTTs during different years, 6 receiving 2, and 21 receiving 1. Of the 28 individuals, 17 were from the wild stock, 9 were head-started turtles (reared in captivity for the first months of life) that had been experimentally imprinted to Padre Island as hatchlings, and 2 were head-started turtles that had been obtained directly from Mexico as hatchlings. Locations were obtained from 9 to 841 d (mean = 277 d) following deployment. After they completed nesting for the season, most of the tracked turtles left south Texas and traveled northward, parallel to the coastline, with their last identified location in the northern or eastern Gulf of Mexico. Inter-nesting residency was documented off south Texas and post-nesting residency in USA Gulf of Mexico waters from south Texas to the tip of Florida. Movements and habitat utilization by wild and head-started turtles and by individuals during different tracking events were generally similar. However, all of the 5 turtles that briefly traveled southward to waters off the coast of Mexico were wild. Tracking data were used to aid with nest detection and protection, and development of a regulation by Texas Parks and Wildlife Department that closed near-shore south Texas waters to shrimp trawling. Findings from this study demonstrate the importance of near-shore Gulf of Mexico waters, particularly offshore from south Texas, to post-nesting Kemp's ridley turtles. © Inter-Research 2008.