Movement patterns of juvenile hawksbill turtles Eretmochelys imbricata at a Caribbean coral atoll: Long-term tracking using passive acoustic telemetry

Abstract

Understanding the ecological interactions that underlie marine ecosystem functioningrequires sufficient data describing habitat use by mobile species. Hawksbill turtles Eretmo -chelys imbricata are considered a key species in coral reef-associated communities, owing totheir specific foraging preferences, yet new information is still revealing details of the spatialand temporal aspects of habitat use. We used passive acoustic telemetry to monitor the movementsof 18 juvenile hawksbills (minimum curved carapace length: 32.0-59.7 cm, mean ± SD =43.9 ± 6.7 cm) at a developmental foraging site in a Mesoamerican barrier reef, Lighthouse ReefAtoll in Belize (tracking duration 10-1414 d, mean ± SD = 570 ± 484 d). Although specific homeranges were difficult to quantify, several turtles showed high site fidelity over timescales ofmonths to years, with occasional wide-ranging use of the atoll. Diel variation in the number ofdetections received strongly suggest nocturnal resting. Long-term tracking data reveal 3 de -grees of site fidelity across the atoll, based on the number of detection days near individual stations:high residency (n = 4 turtles), sequential residency (n = 5), and transient behavior (n = 4).These variations in movement raise questions about the differentiation of foraging habitats anddegree of individual specialization within this population, as well as the influences of microhabitatsand human disturbance.