PS 22-94 - Tracking endangered marine turtles through the seascape: International movements of hawksbill and green turtles through numerous exclusive economic zones

Wednesday, August 10, 2016
ESA Exhibit Hall, Ft Lauderdale Convention Center
Allison M. Benscoter1, Kristen M. Hart2, Autumn R. Iverson3, Michael S. Cherkiss3, Ian Lundgren4, Clayton Pollock5 and Zandy Hillis-Starr4, (1)Cherokee Nation Technologies, Davie, FL, (2)Wetland and Aquatic Research Center, U.S. Geological Survey, Davie, FL, (3)U.S. Geological Survey, Davie, FL, (4)National Park Service, (5)U.S. Virgin Islands, National Park Service

Documenting the movements and habitat-use patterns of marine species is essential for conservation planning, especially for imperiled species. We satellite-tracked endangered hawksbill (Eretmochelys imbricata) and green turtles (Chelonia mydas) nesting at Buck Island Reef National Monument (BIRNM), U.S. Virgin Islands, and determined their migration paths and foraging areas. We quantified the number of exclusive economic zones (EEZs) through which each turtle passed during migration, on their way to sometimes distant foraging areas. This study represents the first substantial satellite-tracking investigation of marine turtles from BIRNM, a key nesting and foraging ground for these at-risk species.


Across both species, we tracked 41 turtles (n=31 hawksbill and n=10 green turtles) for a total of 10,409 tracking days from 2011 to 2014. Hawksbills showed higher levels of migration (30/31 turtles migrated a mean distance of 666.9 km) compared to green turtles (3/10 turtles migrated a mean distance of 405.7 km). Overall, the turtles were satellite-tracked throughout 20 total EEZs and foraged in 14 distinct geographic areas (e.g., country, state, or territory). The use of multiple EEZ zones and foraging areas exposes both of these endangered sea turtles to numerous threats and opportunities for conservation. In an age where human impacts threaten many imperiled species, understanding the movements and habitat use of marine species is vital for managers responsible for protecting vulnerable populations.