Research output: Contribution to journal › Article
Fishing for drifts : detecting buoyancy changes of a top marine predator using a step-wise filtering method. / Gordine, Samantha Alex; Fedak, Mike; Boehme, Lars.
In: Journal of Experimental Biology, Vol. 218, No. 23, 02.12.2015, p. 3816-3824.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Fishing for drifts
T2 - detecting buoyancy changes of a top marine predator using a step-wise filtering method
AU - Gordine, Samantha Alex
AU - Fedak, Mike
AU - Boehme, Lars
N1 - This research was partly funded by a Natural Environment Research Council grant [NE/E018289/1]. Further, a PhD studentship in Marine Biology partially funded by the Natural Environment Research Council [NE/L501852/1] and the University of St Andrews 600th Scholarship supported this work.
PY - 2015/12/2
Y1 - 2015/12/2
N2 - In southern elephant seals (Mirounga leonina), fasting and foraging related fluctuations in body composition are reflected by buoyancy changes which can be monitored by changes in drift rate. Here, we present an improved knowledge-based method for detecting buoyancy changes from compressed and abstracted dive profiles received through telemetry. We applied this step-wise filtering method to the dive records of 11 southern elephant seals, which identified 0.8% to 2.2% of all dives as drift dives. At the beginning of the migration, all individuals were strongly negatively buoyant. Over the following 75 to 150 days, the buoyancy reached a peak close to or at neutral buoyancy, indicative of a seal’s foraging success. Ground-truthing confirmed that this new knowledge-based method is capable to reliably detect buoyancy changes in the dive records of drift diving species using abstracted dive profiles. This affirms that the abstraction algorithm conveys sufficient detail of the geometric shape of drift dives for them to be identified. It also suggest that using this step-wise filtering method, buoyancy changes could be detected even in old datasets with compressed dive information, for which conventional drift dive classification previously failed.
AB - In southern elephant seals (Mirounga leonina), fasting and foraging related fluctuations in body composition are reflected by buoyancy changes which can be monitored by changes in drift rate. Here, we present an improved knowledge-based method for detecting buoyancy changes from compressed and abstracted dive profiles received through telemetry. We applied this step-wise filtering method to the dive records of 11 southern elephant seals, which identified 0.8% to 2.2% of all dives as drift dives. At the beginning of the migration, all individuals were strongly negatively buoyant. Over the following 75 to 150 days, the buoyancy reached a peak close to or at neutral buoyancy, indicative of a seal’s foraging success. Ground-truthing confirmed that this new knowledge-based method is capable to reliably detect buoyancy changes in the dive records of drift diving species using abstracted dive profiles. This affirms that the abstraction algorithm conveys sufficient detail of the geometric shape of drift dives for them to be identified. It also suggest that using this step-wise filtering method, buoyancy changes could be detected even in old datasets with compressed dive information, for which conventional drift dive classification previously failed.
KW - Buoyancy
KW - Marine mammal
KW - Elephant seal
KW - Body composition
KW - Drift diving
KW - Telemetry
KW - Foraging ecology
KW - Diving behaviour
UR - http://www.smru.st-andrews.ac.uk/Instrumentation/Overview/
U2 - 10.1242/jeb.118109
DO - 10.1242/jeb.118109
M3 - Article
VL - 218
SP - 3816
EP - 3824
JO - Journal of Experimental Biology
JF - Journal of Experimental Biology
SN - 0022-0949
IS - 23
ER -
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Research output: Contribution to journal › Article
ID: 173812742