Effect of tidal and wind-induced surface currents on the offshore hatchlings dispersion. A comparative study among green and hawksbill turtles on Redang Island, Malaysia.
Abstract
Sea turtle hatchlings emerge from underground nests at night and rapidly crawl to the sea to swim offshore. Once in the water, hatchling might undergo high predation rates while in shallow water before reaching deeper water... [ view full abstract ]
Sea turtle hatchlings emerge from underground nests at night and rapidly crawl to the sea to swim offshore. Once in the water, hatchling might undergo high predation rates while in shallow water before reaching deeper water where both encounters with predators and mortality rates likely decline. Behavioural studies have described different swimming strategies performed by hatchlings to counter near-shore predation. Dispersal away from nearshore to open ocean is also likely to be influenced by coastal and oceanographic conditions. This study, to be carried out at Redang Island (Malaysia), seeks to compare predation rates of green turtle hatchlings (Chelonias mydas) and hawksbill turtle hatchlings (Eretmochelys imbricata) as they disperse from the same beach (Chagar Hutang Bay) under the same environmental conditions as well as how tidal and wind-induced surface currents influence the early phase of dispersal of these species. These two species show differences in their swimming activity, including a frenzy period, in green turtles, that lasts about 24 while hawksbill turtles remain relatively inactive once they enter the water. An Acoustic Doppler Current Profiler will be used to measure oceanic conditions and direct observations of hatchlings will be taken by kayaking and using GPS loggers to track hatchling swimming paths. The findings of this study will determine how both hatchlings species differ when they migrate offshore in natural conditions as well as whether hawksbill hatchlings in the field behave as they do in the tanks, according to previous studies.
Authors
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Javier OƱate Casado
(Universiti Malaysia Terengganu)
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Mohd Uzair Rusli
(Universiti Malaysia Terengganu)
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David Booth
(The University of Queensland)
Topic Areas
Topics: Conservation and management of tropical marine ecosystems , Topics: Other
Session
PS-1 » Poster Session (18:30 - Wednesday, 27th June, Ranyai Ballroom)