Hearing Loss in Stranded Odontocete Dolphins and WhalesReport as inadecuate

Hearing Loss in Stranded Odontocete Dolphins and Whales - Download this document for free, or read online. Document in PDF available to download.

The causes of dolphin and whale stranding can often be difficult to determine. Because toothed whales rely on echolocation for orientation and feeding, hearing deficits could lead to stranding. We report on the results of auditory evoked potential measurements from eight species of odontocete cetaceans that were found stranded or severely entangled in fishing gear during the period 2004 through 2009. Approximately 57% of the bottlenose dolphins and 36% of the rough-toothed dolphins had significant hearing deficits with a reduction in sensitivity equivalent to severe 70–90 dB or profound >90 dB hearing loss in humans. The only stranded short-finned pilot whale examined had profound hearing loss. No impairments were detected in seven Risso-s dolphins from three different stranding events, two pygmy killer whales, one Atlantic spotted dolphin, one spinner dolphin, or a juvenile Gervais- beaked whale. Hearing impairment could play a significant role in some cetacean stranding events, and the hearing of all cetaceans in rehabilitation should be tested.

Author: David Mann , Mandy Hill-Cook, Charles Manire, Danielle Greenhow, Eric Montie, Jessica Powell, Randall Wells, Gordon Bauer, Petra

Source: http://plos.srce.hr/


Related documents