Post-breeding migration routes of marine turtles from Bonaire and Klein Bonaire, Caribbean Netherlands

Abstract

The management of small rookeries is key to conserving the regional genetic diversity of marine turtle populations and requires knowledge on population connectivity between breeding and foraging areas. To elucidate the geographic scope of the populations of marine turtles breeding at Bonaire and Klein Bonaire (Caribbean Netherlands) we examined the post-breeding migratory behavior of 5 female loggerheads Caretta caretta, 4 female green turtles Chelonia mydas, and 2 male and 13 female hawksbill turtles Eretmochelys imbricata during the years 2004-2013. After leaving Bonaire, the 24 tracked turtles frequented foraging grounds in 10 countries. The distances swum from Bonaire to the foraging areas ranged from 608 to 1766 km for loggerhead turtles, 198 to 3135 km for green turtles, and 197 to 3135 km for hawksbill turtles, together crossing the waters of 19 countries. Males represented the minority in this study, but we made 2 key observations that require further research: males remained in the vicinity of the breeding area for 3-5 mo, which is 2-5 times longer than females, and males migrated greater distances than previously recorded. Although the turtles dispersed widely across the Caribbean, there appeared to be 2 benthic foraging areas of particular importance to all 3 species of marine turtles breeding at Bonaire, namely the shallow banks east of Nicaragua and Honduras (n = 8 tracked turtles) and Los Roques, Venezuela (n = 3). Marine turtles breeding at Bonaire face threats from legal turtle harvesting, illegal take, and bycatch in the waters that they traverse across the Caribbean.