hays-behaviourandbuoyancy-2010.pdf (813.4 kB)
Behaviour and buoyancy regulation in the deepest-diving reptile : the leatherback turtle
journal contribution
posted on 2010-12-01, 00:00 authored by S Fossette, A Gleiss, A Myers, S Garner, N Liebsch, N Whitney, Graeme HaysGraeme Hays, R Wilson, M LutcavageIn the face of the physical and physiological challenges of performing breath-hold deep dives, marine vertebrates have evolved different strategies. Although behavioural strategies in marine mammals and seabirds have been investigated in detail, little is known about the deepest-diving reptile – the leatherback turtle (Dermochelys coriacea). Here, we deployed tri-axial accelerometers on female leatherbacks nesting on St Croix, US Virgin Islands, to explore their diving strategy. Our results show a consistent behavioural pattern within dives among individuals, with an initial period of active swimming at relatively steep descent angles (∼–40 deg), with a stroke frequency of 0.32 Hz, followed by a gliding phase. The depth at which the gliding phase began increased with the maximum depth of the dives. In addition, descent body angles and vertical velocities were higher during deeper dives. Leatherbacks might thus regulate their inspired air-volume according to the intended dive depth, similar to hard-shelled turtles and penguins. During the ascent, turtles actively swam with a stroke frequency of 0.30 Hz but with a low vertical velocity (∼0.40 ms–1) and a low pitch angle (∼+26 deg). Turtles might avoid succumbing to decompression sickness (‘the bends’) by ascending slowly to the surface. In addition, we suggest that the low body temperature of this marine ectotherm compared with that of endotherms might help reduce the risk of bubble formation by increasing the solubility of nitrogen in the blood. This physiological advantage, coupled with several behavioural and physical adaptations, might explain the particular ecological niche the leatherback turtle occupies among marine reptiles.
History
Journal
Journal of experimental biologyVolume
213Issue
23Pagination
4074 - 4083Publisher
Company of BiologistsLocation
Cambridge, EnglandPublisher DOI
Link to full text
ISSN
0022-0949eISSN
1477-9145Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
2010, Company of BiologistsUsage metrics
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gas solubilityendothermaccelerometerBoyle's lawcost of swimmingbody densityScience & TechnologyLife Sciences & BiomedicineBiologyLife Sciences & Biomedicine - Other TopicsFLIPPER BEAT FREQUENCYDERMOCHELYS-CORIACEAGREEN TURTLESSEA-TURTLESDIVE PROFILESMOVEMENT PATTERNSSTROKE PATTERNSELEPHANT SEALSCHELONIA-MYDASMETABOLIC-RATE
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