Dear Colleagues,
The following article was recently published in the Canadian Journal of Zoology: Mooney, TA, Pacini, AP, and Nachtigall, PE. 2009. False killer whale (Pseudorca crassidens) echolocation and acoustic disruption: Implications for long-line bycatch and depredation. 87: 726-733. Canadian Journal of Zoology. Abstract: False killer whales (Pseudorca crassidens (Owen, 1846)) depredate fish caught by the North Pacific pelagic longline fishery, resulting in loss of target species catch and the whales themselves becoming bycaught. This incidental take of false killer whales exceeds sustainable levels. In an effort to address a potential solution to reducing this depredation and bycatch, we tested an acoustic device designed to deter false killer whales from approaching longlines by reducing the whales echolocation performance capabilities. The device produced a series of complex, broadband signals (1 250 kHz) at high intensity levels (up to 182 dB). In the experiment, a trained false killer whale was asked to detect a target in the presence or absence of the acoustic device. Baseline performance capabilities were 95% correct responses. Initially, the device reduced the whales echolocation performance to chance levels. However, subsequent sessions demonstrated improvement in echolocation performance up to 85%. This improvement was likely a result of behaviorally adapting to the task and a decrease in the source level of the echolocation disruptor. The results underscore the challenges in using acoustic devices to reduce depredation and bycatch, and demonstrate the need for concern regarding anthropogenic noise levels and effects on odontocete echolocation capabilities. A pdf may be downloaded from http://pubs.nrc-cnrc.gc.ca/rp-ps/inDetail.jsp?jcode=cjz&vol=87&is=8&lang=eng pdf copies or further information are also available by emailing: amoo...@whoi.edu T. Aran Mooney Postdoctoral Scholar Woods Hole Oceanographic Institution (508)289-3714 (w) (518)339-1151 (c) ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. _______________________________________________ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
