High-use oceanic areas for Atlantic leatherback sea turtles (Dermochelys coriacea) as identified using satellite telemetered location and dive information

Abstract

The movements and behavior of nine female leatherback sea turtles, Dermochelys coriacea (L.) were monitored for up to 370 days from their nesting beaches on the Caribbean island of Trinidad between 1995 and 2004 using satellite-linked time and depth recorders. During the inter-nesting period (typically March–July) turtles ranged widely, but frequented the area around Galera Point on the NE corner of Trinidad. Diving depths were typically <51 m. Upon leaving Trinidad, the three longest tracked turtles moved to higher latitude foraging areas, NE of the Flemish Cap; along the continental shelf of the Iberian peninsula to the Bay of Biscay; and along the N. Atlantic subtropical front, where they remained until the end of November. Dives were initially deep (100–300 m) and long (>26 min) as the turtles left the Caribbean, but became very shallow (>50 m) and short at high latitudes. Between mid-October and mid-November, the turtles left high latitudes for a presumed foraging area in the Mauritania upwelling where they resided until their tracking records ended. Diving remained relatively shallow. It is proposed that movements of these turtles from one foraging area to another are driven by the opportunity to forage in areas of distinct oceanic structure which serve to concentrate their gelatinous prey (e.g., salps, Scyphomedusae, Siphonophora) either at or below the surface.