Mixed‐stock analysis reveals the migrations of juvenile hawksbill turtles ( Eretmochelys imbricata ) in the Caribbean Sea

Abstract

Hawksbill turtles ( Eretmochelys imbricata ) migrate between nesting beaches and feeding habitats that are often associated with tropical reefs, but it is uncertain which nesting colonies supply which feeding habitats. To address this gap in hawksbill biology, we compile previously published and new mitochondrial DNA (mtDNA) haplotype data for 10 nesting colonies ( N = 347) in the western Atlantic and compare these profiles to four feeding populations and four previously published feeding samples ( N = 626). Nesting colonies differ significantly in mtDNA haplotype frequencies (Φ ST = 0.588, P ST = 0.089, P r = 0.378, P = 0.004), supporting the premise that larger rookeries contribute more juveniles to feeding areas. A significant correlation between the estimated contribution and geographical distance from nesting areas ( r = −0.394, P = 0.003) demonstrates the influence of proximity on recruitment to feeding areas. The influence of oceanic currents is illustrated by pelagic stage juveniles stranded in Texas, which are assigned primarily (93%) to the upstream rookery in Yucatan. One juvenile had a haplotype previously identified only in the eastern Atlantic, invoking rare trans ‐oceanic migrations. The mixed‐stock analysis demonstrates that harvests in feeding habitats will impact nesting colonies throughout the region, with the greatest detriment to nearby nesting populations.

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