DNA and dispersal models highlight constrained connectivity in a migratory marine megavertebrate

Ecography
By: , and 

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Abstract

Population structure and spatial distribution are fundamentally important fields within ecology, evolution, and conservation biology. To investigate pan-Atlantic connectivity of globally endangered green turtles (Chelonia mydas) from two National Parks in Florida, USA, we applied a multidisciplinary approach comparing genetic analysis and ocean circulation modeling. The Everglades (EP) is a juvenile feeding ground, whereas the Dry Tortugas (DT) is used for courtship, breeding, and feeding by adults and juveniles. We sequenced two mitochondrial segments from 138 turtles sampled there from 2006-2015, and simulated oceanic transport to estimate their origins. Genetic and ocean connectivity data revealed northwestern Atlantic rookeries as the major natal sources, while southern and eastern Atlantic contributions were negligible. However, specific rookery estimates differed between genetic and ocean transport models. The combined analyses suggest that post-hatchling drift via ocean currents poorly explains the distribution of neritic juveniles and adults, but juvenile natal homing and population history likely play important roles. DT and EP were genetically similar to feeding grounds along the southern US coast, but highly differentiated from most other Atlantic groups. Despite expanded mitogenomic analysis and correspondingly increased ability to detect genetic variation, no significant differentiation between DT and EP, or among years, sexes or stages was observed. This first genetic analysis of a North Atlantic green turtle courtship area provides rare data supporting local movements and male philopatry. The study highlights the applications of multidisciplinary approaches for ecological research and conservation.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title DNA and dispersal models highlight constrained connectivity in a migratory marine megavertebrate
Series title Ecography
DOI 10.1111/ecog.02056
Volume 40
Issue 5
Year Published 2016
Language English
Publisher Wiley
Contributing office(s) Wetland and Aquatic Research Center
Description 12 p.
First page 586
Last page 597
Country United States
State Florida
Other Geospatial Dry Tortugas Park, Everglades Park
Online Only (Y/N) N
Additional Online Files (Y/N) N