Naval sonar drives whales from feeding grounds

13:07 25 March 2011 by John Cannon


The first detailed study of the effects of naval sonar on whales shows that whales flee from prime feeding sites when navy tests begin – leaving them famished when they finally return.

Blainville's beaked whales, Mesoplodon densirostris, use echolocation clicks to track down prey in the lightless depths they hunt in, a kilometre or more below the surface.

To find out whether the whales are disturbed by naval sonar operations, Peter Tyack of Woods Hole Oceanographic Institution, Massachusetts, and colleagues tracked the activity of Blainville's beaked whales during exercises at a US navy centre near Andros Island, Bahamas. The area encompasses an underwater canyon that is a prime hunting ground for these deep-diving whales.

By satellite tagging one whale and listening out for the echolocation clicks of others using underwater microphones, the team found that whales stopped echolocating and moved away from the area during the tests. Once the exercises stopped, a day and a half went by before the whales returned (PLoS One, DOI: 10.1371/journal.pone.0017009).

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http://www.newscientist.com/article/dn20288-naval-sonar-drives-whales-from-feeding-grounds.html