The diving behaviour of green turtles undertaking oceanic migration to and from Ascension Island: dive durations, dive profiles and depth distribution

Satellite telemetry was used to record the submergence duration of green turtles (Chelonia mydas) as they migrated from Ascension Island to Brazil (N=12 individuals) while time/depth recorders (TDRs) were used to examine the depth distribution and dive profiles of individuals returning to Ascension...

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Bibliographic Details
Main Authors: Graeme Hays, S Akesson, A Broderick, F Glen, B Godley, P Luschi, C Martin, J Metcalfe, F Papi
Format: Other Non-Article Part of Journal/Newspaper
Language:unknown
Published: 2001
Subjects:
Uncategorized
satellite telemetry
turtle
Chelonia mydas
diving
migration
Science & Technology
Life Sciences & Biomedicine
Biology
Life Sciences & Biomedicine - Other Topics
NORTHERN ELEPHANT SEALS
SATELLITE TRACKING
DERMOCHELYS-CORIACEA
LOGGERHEAD TURTLE
CARETTA-CARETTA
CHELONIA-MYDAS
ORIENTATION
BUOYANCY
ALBATROSSES
PREDATION
Elephant Seals
Online Access:http://hdl.handle.net/10536/DRO/DU:30058249
https://figshare.com/articles/journal_contribution/The_diving_behaviour_of_green_turtles_undertaking_oceanic_migration_to_and_from_Ascension_Island_dive_durations_dive_profiles_and_depth_distribution/20953807
Description
Summary:Satellite telemetry was used to record the submergence duration of green turtles (Chelonia mydas) as they migrated from Ascension Island to Brazil (N=12 individuals) while time/depth recorders (TDRs) were used to examine the depth distribution and dive profiles of individuals returning to Ascension Island to nest after experimental displacement (N=5 individuals). Satellite telemetry revealed that most submergences were short (<5 min) but that some submergences were longer (>20 min), particularly at night. TDRs revealed that much of the time was spent conducting short (2–4 min), shallow (approximately 0.9–1.5 m) dives, consistent with predictions for optimisation of near-surface travelling, while long (typically 20–30 min), deep (typically 10–20 m) dives had a distinctive profile found in other marine reptiles. These results suggest that green turtles crossing the Atlantic do not behave invariantly, but instead alternate between periods of travelling just beneath the surface and diving deeper. These deep dives may have evolved to reduce silhouetting against the surface, which would make turtles more susceptible to visual predators such as large sharks.

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