An assessment of the audibility of sound from human transport by
breeding Weddell seals (Leptonychotes weddellii)
Tamara D. van Polanen Petel, John M. Terhune, Mark A. Hindell and
Melissa A. Giese
Corresponding author. Email:
Abstract
Anthropogenic noise generated through travel in the Antarctic has the
potential to affect the region's wildlife. Weddell seals (Leptonychotes
weddellii) in particular can be exposed to anthropogenic noise because
they live under, and breed on, the fast ice on which humans travel. To
investigate the potential effects of anthropogenic noise on Weddell
seals we developed sound profiles for pedestrian travel, over-snow
vehicles, aircraft and watercraft operating at various distances and
altitudes from breeding seals. The received 1/3-octave noise levels were
then related to an assumed detection threshold for the Weddell seal. We
found that most noise levels generated by the pedestrian, quad
(4-wheeled, all-terrain vehicle) and Hagglunds (tracked, all-terrain
vehicle) were commonly categorised in the inaudible and barely audible
range of detection (both in-air and underwater), while noise levels
generated by the helicopter, Twin Otter aircraft and Zodiac boat were
categorised more commonly in the barely audible and clearly audible
range. Experimental underwater recordings of vocal behaviour of Weddell
seals exposed to continuous low-amplitude over-snow vehicle noise (i.e.
Hagglund operation) were also made. Weddell seals underwater did not
alter individual call types in response to low-level Hagglunds noise,
but they did decrease their calling rate.
Wildlife Research 33(4) 275-291
Submitted: 5 January 2005 Accepted: 3 February 2006 Published: 27
June 2006
Full text DOI: 10.1071/WR05001
(c) CSIRO 2006
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