The genetic structure of juvenile green turtles (Chelonia mydas) foraging on the east coast of central Florida is not well understood, nor has it been examined over time. In the last three decades, the dramatic increase in the number of green sea turtle nests in Florida, in association with other population parameters, has led to this species being down-listed under the Endangered Species Act from “endangered” to “threatened” in the northwest Atlantic. However, it was unclear if the exponential growth in Florida nest numbers had any influence on the genetic structure of juveniles in nearby foraging aggregations. To understand this potential impact mixed-stock analysis was conducted using mitochondrial DNA fragments that were over 800 base pairs long on samples taken from juveniles captured from 2002-2005 and 2016-2018 in the central Indian River Lagoon and Trident Submarine Basin in Port Canaveral. Results indicate the sampled foraging sites are genetically distinct habitats. In both sites, recruitment from Florida nesting beaches remained low despite increases in nesting while contributions from rookeries in Costa Rica and Mexico dominated both foraging aggregations across time. Haplotype diversity and nucleotide diversity decreased at both foraging sites over time. The foraging sites shared the two most frequently occurring haplotypes, but also had haplotypes that were unique to the site or sample period. Our results highlight the need for broader sampling of rookeries and foraging aggregations to understand the impacts of nesting increases in one rookery on juvenile diversity. Future studies should include all life stages of green turtles to enhance understanding of both the census population and effective population to better inform conservation policies necessary for a continued recovery.
Bachelor of Science (B.S.)
College of Sciences
Ecology, Evolutionary, and Conservation Biology
Reusche, Monica R., "Genetic Structure of Green Sea Turtle (Chelonia mydas) Foraging Aggregations on the East Coast of Florida" (2020). Honors Undergraduate Theses. 750.