Evidence from genetic and Lagrangian drifter data for transatlantic transport of small juvenile green turtles
C. Monzón-Argüello
Instituto Canario de Ciencias Marinas, Carretera de Taliarte s/n, 35200 Telde, Gran Canaria, Spain
Departamento de Biología, Universidad de Las Palmas de G.C. Campus de Tafira, 35017 Las Palmas de Gran Canaria, Gran Canaria, Spain
Estación Biológica de Doñana (CSIC), Américo Vespucio, s/n, 41092 Sevilla, Spain
Search for more papers by this authorL. F. López-Jurado
Departamento de Biología, Universidad de Las Palmas de G.C. Campus de Tafira, 35017 Las Palmas de Gran Canaria, Gran Canaria, Spain
Search for more papers by this authorC. Rico
Estación Biológica de Doñana (CSIC), Américo Vespucio, s/n, 41092 Sevilla, Spain
Search for more papers by this authorA. Marco
Estación Biológica de Doñana (CSIC), Américo Vespucio, s/n, 41092 Sevilla, Spain
Search for more papers by this authorP. López
Naturalia, Cape Verde Ltd., Sal-Rei, Boa Vista, Republic of Cape Verde
Search for more papers by this authorG. C. Hays
Department of Pure and Applied Ecology, Institute of Environmental Sustainability, Swansea University, Swansea SA2 8PP, UK
Search for more papers by this authorCorresponding Author
P. L. M. Lee
Department of Pure and Applied Ecology, Institute of Environmental Sustainability, Swansea University, Swansea SA2 8PP, UK
Correspondence: Patricia L. M. Lee, Department of Pure and Applied Ecology, Institute of Environmental Sustainability, Swansea University, Swansea SA2 8PP, UK.E-mail: [email protected]Search for more papers by this authorC. Monzón-Argüello
Instituto Canario de Ciencias Marinas, Carretera de Taliarte s/n, 35200 Telde, Gran Canaria, Spain
Departamento de Biología, Universidad de Las Palmas de G.C. Campus de Tafira, 35017 Las Palmas de Gran Canaria, Gran Canaria, Spain
Estación Biológica de Doñana (CSIC), Américo Vespucio, s/n, 41092 Sevilla, Spain
Search for more papers by this authorL. F. López-Jurado
Departamento de Biología, Universidad de Las Palmas de G.C. Campus de Tafira, 35017 Las Palmas de Gran Canaria, Gran Canaria, Spain
Search for more papers by this authorC. Rico
Estación Biológica de Doñana (CSIC), Américo Vespucio, s/n, 41092 Sevilla, Spain
Search for more papers by this authorA. Marco
Estación Biológica de Doñana (CSIC), Américo Vespucio, s/n, 41092 Sevilla, Spain
Search for more papers by this authorP. López
Naturalia, Cape Verde Ltd., Sal-Rei, Boa Vista, Republic of Cape Verde
Search for more papers by this authorG. C. Hays
Department of Pure and Applied Ecology, Institute of Environmental Sustainability, Swansea University, Swansea SA2 8PP, UK
Search for more papers by this authorCorresponding Author
P. L. M. Lee
Department of Pure and Applied Ecology, Institute of Environmental Sustainability, Swansea University, Swansea SA2 8PP, UK
Correspondence: Patricia L. M. Lee, Department of Pure and Applied Ecology, Institute of Environmental Sustainability, Swansea University, Swansea SA2 8PP, UK.E-mail: [email protected]Search for more papers by this authorAbstract
Aim A key life-history component for many animals is the need for movement between different geographical locations at particular times. Green turtle (Chelonia mydas) hatchlings disperse from their natal location to spend an early pelagic stage in the ocean, followed by a neritic stage where small juveniles settle in coastal areas. In this study, we combined genetic and Lagrangian drifter data to investigate the connectivity between natal and foraging locations. In particular we focus on the evidence for transatlantic transport.
Location Atlantic Ocean.
Methods We used mitochondrial DNA (mtDNA) sequences (n = 1567) from foraging groups (n = 8) and nesting populations (n = 12) on both sides of the Atlantic. Genetic data were obtained for Cape Verde juvenile turtles, a foraging group not previously sampled for genetic study. Various statistical methods were used to explore spatial genetics and population genetic structure (e.g. exact tests of differentiation, Geneland and analysis of molecular variance). Many-to-many mixed stock analysis estimated the connectivity between nesting and foraging groups.
Results Our key new finding is robust evidence for connectivity between a nesting population on the South American coast (25% of the Surinam nesting population are estimated to go to Cape Verde) and a foraging group off the coast of West Africa (38% of Cape Verde juveniles are estimated to originate from Surinam), thus extending the results of previous investigations by confirming that there is substantial transatlantic dispersal in both directions. Lagrangian drifter data demonstrated that transport by drift across the Atlantic within a few years is possible.
Main conclusions Small juvenile green turtles seem capable of dispersing extensively, and can drop out of the pelagic phase on a transatlantic scale (the average distance between natal and foraging locations was 3048 km). Nevertheless, we also find support for the ‘closest-to-home’ hypothesis in that the degree of contribution from a nesting population to a foraging group is correlated with proximity. Larger-sized turtles appear to feed closer to their natal breeding grounds (the average distance was 1133 km), indicating that those that have been initially transported to far-flung foraging grounds may still be able to move nearer to home as they grow larger.
Supporting Information
Appendix S1 Comparison of the trajectories of individual buoys with movements of juvenile green turtles inferred from genetic data.
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