Deakin University

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Informing the interpretation of dive profiles using animal-borne video: a marine turtle case study

journal contribution
posted on 2011-12-15, 00:00 authored by Jordan Thomson, M R Heithaus, L M Dill
It is often of interest to infer the behavior of air-breathing aquatic taxa (i.e., divers) based on the characteristics
of dive profiles, which are relatively affordable and easy to obtain. However, dives that appear similar in shape
or other attributes can reflect multiple activities, confounding their interpretation. Here, we used animal-borne
video and environmental data recorders (AVED) to examine correlations between the dive-surfacing patterns
and behavior of green (Chelonia mydas Linnaeus 1758) and loggerhead turtles (Caretta caretta Linnaeus 1758)
and evaluate our ability to make behavioral inferences from stand-alone dive data. Commonly performed
dive types, which have been previously defined, were behaviorally diverse but some generalizations about
their function could be made. Furthermore, within Type 1 dives (i.e., square-bottom, U-shaped dives), which
are often assumed to reflect benthic resting, dive features (maximum dive depth, duration and variation in
depth during the bottom phase) correlated with the proportion of bottom time spent resting versus engaged
in other activities. Statistical clustering of Type 1 dives based on these dive metrics identified groups of dives
differing in function (i.e., the degree of rest versus traveling or feeding) but some behavioral overlap occurred.
The probability of a dive reaching the sea floor varied by dive type, which has important implications if dive pro-
file data are used to infer habitat depth for benthic foragers in the absence of tracking data. Finally, the number
of breaths taken while at the surface between dives varied closely with surface interval duration, particularly for
loggerhead turtles, suggesting surface times in dive profiles may be useful for estimating oxygen loading prior to
a dive. This case study emphasizes the value of AVED technology for increasing the level of ecological insight
obtainable from stand-alone dive profiles.



Journal of experimental marine biology and ecology




12 - 20




Amsterdam, The Netherlands





Publication classification

C Journal article; C1.1 Refereed article in a scholarly journal

Copyright notice

2011, Elsevier B.V