Use of a towed camera system to investigate benthic habitat use by inter-nesting female hawksbill sea turtles

Walcott, J.; Eckert, Scott A.; Oxenford, H. A.; Horrocks, Julia A.

doi:10.3354/esr00597

Cited by 12 publications

(8 citation statements)

References 47 publications

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“…This could be accomplished by means of telemetry and towed cameras, similar to the methods described by Walcott et al (2014). Glover's Reef Atoll, despite its distance from the mainland and relatively high level of protection, has not entirely escaped the impacts of over-fishing that are evident throughout the Caribbean and that make systems less resilient to other impacts (Loh et al 2015).…”

Section: Discussionmentioning

confidence: 99%

In-water assessments of sea turtles at Glover’s Reef Atoll, Belize

Strindberg¹,

Coleman²,

Perez³

et al. 2016

Endang. Species. Res.

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The decline of sea turtle populations in the Caribbean has led to intensive recovery efforts. In Belizean waters, hawksbill turtles are seemingly making a comeback. At Glover's Reef Atoll particularly, juvenile hawksbill turtles are found in the fore-reef habitat. The population status and dynamics of this foraging aggregation were assessed to inform conservation management and to ascertain the national and regional importance of this site. During 12 sampling periods from 2007 to 2013, turtles of all species were counted, captured, and tagged. For hawksbill turtles, the capture-recapture histories were combined with the counts using a mark-resight analysis under a robust design. This provided estimates of abundance as well as survival and transition rates. From 2009 onward, distance sampling was also used to estimate density and abundance of hawksbill turtles and the less frequently encountered green and loggerhead turtles. Distance sampling provided a more cost-effective estimation method for multiple species and another more precise source of abundance estimates for hawksbills. This is the first study known to use either markresight or distance sampling methods during snorkel surveys of sea turtles. It produced reasonably congruent abundance estimates of >1000 juvenile hawksbills and an order of magnitude less of green and loggerhead turtles. The mark-resight analysis estimated an apparent juvenile hawksbill survival probability of 0.975 (95% CI: 0.936−0.99), indicating that mortality factors are low. The Atoll provides important developmental habitat for juvenile hawksbills, contributing to the recovery of the species on the national and regional scale.

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Section: Discussionmentioning

confidence: 99%

In-water assessments of sea turtles at Glover’s Reef Atoll, Belize

Strindberg¹,

Coleman²,

Perez³

et al. 2016

Endang. Species. Res.

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“…These have ranged from engaging recreational divers and photo-identification (Dunbar et al 2014) to using towed underwater video (Walcott et al 2014). Tracking technologies have included radio tele metry (Berube et al 2012), active acoustic telemetry (van Dam & Diez 1998, Scales et al 2011, and passive acoustic telemetry (Blumenthal et al 2009b, Okuyama et al 2010, Hart et al 2012.…”

Section: Introductionmentioning

confidence: 99%

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

Chevis¹,

Godley²,

Lewis³

et al. 2017

Endang. Species. Res.

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Understanding the ecological interactions that underlie marine ecosystem functioning requires sufficient data describing habitat use by mobile species. Hawksbill turtles Eretmochelys imbricata are considered a key species in coral reef-associated communities, owing to their specific foraging preferences, yet new information is still revealing details of the spatial and temporal aspects of habitat use. We used passive acoustic telemetry to monitor the movements of 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 Reef Atoll in Belize (tracking duration 10−1414 d, mean ± SD = 570 ± 484 d). Although specific home ranges were difficult to quantify, several turtles showed high site fidelity over timescales of months to years, with occasional wide-ranging use of the atoll. Diel variation in the number of detections received strongly suggest nocturnal resting. Long-term tracking data reveal 3 degrees 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 and degree of individual specialization within this population, as well as the influences of microhabitats and human disturbance.

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“…Hawksbills have been shown to use structurally complex benthic habitats as they can provide protection from predators (Walcott et al 2014). Management efforts should therefore include protection of these important benthic habitats.…”

Section: Conservation Implicationsmentioning

confidence: 99%

Diving behavior and thermal habitats of gravid hawksbill turtles at St. Croix, USA

et al. 2016

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29.06 ± SD 0.43 °C). Two turtles attained the deepest recorded dives for gravid hawksbills (95.1 and 84.4 m) and sometimes remained at depths greater than 60 m for up to 30 min. Although we recorded instances of relatively deep diving for the species, the overall pattern of seafloor resting and infrequent diving was consistent with hawksbills in other ocean basins with different offshore habitats. We propose that benthic resting is common behavior for gravid hawksbills globally, and protection of benthic habitats near the nesting beach should be a management priority.

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Use of a towed camera system to investigate benthic habitat use by inter-nesting female hawksbill sea turtles

Cited by 12 publications

References 47 publications

In-water assessments of sea turtles at Glover’s Reef Atoll, Belize

In-water assessments of sea turtles at Glover’s Reef Atoll, Belize

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

Diving behavior and thermal habitats of gravid hawksbill turtles at St. Croix, USA

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