[MARMAM] New publication, Using gliders to explore fin whale habitat in coastal and offshore waters

burnhamr burnhamr at uvic.ca
Tue Jan 26 07:55:18 PST 2021


My co-authors and I are pleased to share our latest publication from our
use of gliders to explore whale habitat: _Remote sensing and mapping
habitat features pertinent to fin whale life histories in coastal and
offshore waters of Vancouver Island, British Columbia_  

Journal of Experimental Marine Biology and Ecology 537, 151511 

Abstract: Current knowledge of the population size and movement of fin
whales in the northeast Pacific is lacking, but is critical in
implementing effective management actions. Here we used ocean gliders to
survey the deep-coastal and offshore waters of Vancouver Island to add
to what is known about fin whale habitat use in the Canadian Pacific.
Passive acoustic recordings were made continuously, from which fin whale
vocalizations were used as a proxy to presence. Oceanographic and
preyscape variables were also taken to better delineate habitat units in
horizontal and vertical space. Comparisons were made between on-shelf
and shelf-break zones, and measures taken in- and out-side submarine
canyons. Temporal comparisons between winter and spring were also
possible. An on-shelf and shelf-break divide was seen, with cooler,
fresher waters present closer to the coast for both deployments. The
spring deployment showed fin whale acoustic presence focused around
topographical features, including the shelf-break and canyons. The most
prevalent cue was their 40-Hz call, which suggests foraging. Echosounder
readings suggested denser aggregations of larger bodied zooplankton prey
were present at canyon heads and along the shelf break. During the
winter, calls in the acoustic record were more numerous than in the
spring, and dominated by the 20-Hz call. A proportion of the recordings
also showed 'song' patterning, which suggests breeding activity.
Interpolated surfaces were used to examine the spatiotemporal
relationships between the high-resolution habitat point data and
presence of far-propagating fin whale calls. The predicted use of
habitat by fin whales, as represented by their calls, was examined
through Random Forest machine learning models using oceanographic and
preyscape measures as input variables from these interpolations.
Distance from the shelf break and preyscape variables were determined
important in predicting whale habitat use in the spring, with model
accuracy exceeding 80%. Call presence showed a much weaker relationship
to environmental var-iables for the winter recordings with reduced
accuracy of model predictions (13%). An understanding of habitat
selection by fin whales may also aid in determining the importance of
habitat units and areas that may critical to life history functions.  

The paper is free to read/download from JEMBE online at
https://authors.elsevier.com/a/1cThA51aUfmHA [1] until March 16, 2021 

Please feel free to contact me if you have questions, or for a PDF after
that time 

Best, 

Rianna Burnham, PhD 

 

Links:
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[1] https://authors.elsevier.com/a/1cThA51aUfmHA
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