Fig 1.
Map of the sea turtle nesting beaches on Bioko Island, Equatorial Guinea.
Gran Caldera Southern Highlands Scientific Reserve is shown in dark green covering the southern third of the island. Insert shows the five nesting beaches (A-E) in relation to the nearest village, Ureca. Satellite transmitters were attached to green turtles nesting on Beach C, at the end of the nesting season in January-February 2018. Service Layer Credits: National Geographic, Esri, Garmin, HERE, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, increment P Corp.
Fig 2.
Post-nesting movements of six green turtles (Chelonia mydas) tracked from Bioko Island, after the 2017–18 nesting season.
Individuals traveled an average of >1,000km using a combination of oceanic and coastal migratory routes. Two turtles exhibited oceanic migration routes (blue and dark green tracks); the remaining four turtles remained closer to the continental shelf, migrating more directly across the Bight of Benin, to the coastal waters near Lagos, Nigeria, and then maintained a coastal route. Dotted lines represent the Exclusive Economic Zones (EEZs) of each country. Service layer credits: Esri, Garmin, GEBCO, NOAA NGDC, and other contributors Esri, HERE, Garmin, OpenStreetMap contributors, and the GIS user community.
Fig 3.
Daily locations (circles) of six turtles tracked from Bioko Island after the 2017–18 nesting season.
Blue circles indicate transiting behavior and red circles indicate foraging behavior, as identified by the state space model. Three turtles exhibited migrations interspersed with short (<6 days) periods of foraging, while two exhibit direct migrations, followed by an extended period of foraging. Service Layer Credits: Esri, HERE, Garmin, GEBCO, NOAA NGDC, and other contributors OpenStreetMap contributors, and the GIS user community.
Fig 4.
Ocean currents and daily locations (circles) of two green turtles tracked by satellite from Bioko Island across the Bight of Benin.
One coastal and one oceanic migration route are overlaid onto averaged ocean surface current data for the 10 day period from 10–20 Feb 2018. White circles represent migrating behavior and red circles represent foraging behavior, as identified by the state-space model. Arrows represent current direction.