Friday, April 22, 2011

Narwhals no fan of military, industrial noises

The news this week that the U.S. Navy is going to be allowed to “incidentally” harass marine mammals during tests of their sonar systems and unmanned submarines in the waters around Washington State is certainly worrisome in itself.  But it comes on the heels of an announcement that the Navy plans live fire tests in the Gulf of Alaska where the exercises could cause harm to whales and a report that training by the Navy off San Diego last month has been linked to at least three dolphin deaths.
                While most Americans will recognize the necessity of training by the Navy, there must be places it could be held where cetaceans are less likely to be affected.  A couple dozen species of marine mammals reportedly live in or pass through the area where the Washington State tests are to be conducted, and the Gulf of Alaska is famous for its marine mammal spectacle.
                It can be argued that military sonar has not been proven to negatively affect large baleen whales, but even the Navy admits that smaller toothed whales, especially beaked whales, are particularly sensitive to this type of sonar and are often killed or beach themselves. Although to my knowledge no military sonar tests have been conducted in the range of the narwhal, this species is a small toothed whale and is probably not immune. 
                Every narwhal biologist will agree, however, that narwhals are quite sensitive to even the slightest unnatural noise in their environment.  Inuit hunters told me that if they aren’t especially careful when paddling their kayaks and make a slight splashing noise, any nearby narwhals will dive and disappear.  The noise from the increased shipping and exploratory drilling for oil and minerals that is already resulting from the retreat of Arctic sea ice, while perhaps not killing the animals outright, is certain to cause them to abandon feeding, resting and breeding areas.  And during stressful times when the animals are competing for food and mates, these unnecessary and dangerous noises are the last thing they need. (Shipping noise is also known to be destructive to other marine life, including squid and octopus.)
                These man-made noises are also likely to affect communication by narwhals and their use of echolocation.  Little is known about narwhal vocalizations, though it is believed they have a sophisticated sound-based means of finding food and exploring their environment, much like many other cetaceans.  One scientist even believes that individual narwhals can be distinguished by their unique sounds, somewhat like a human accent or voice.  But those voices are of little use to them if they are being drowned out by military and industrial noises.

1 comment:

  1. For more on the issue of Navy sonar and its effect on marine mammals including Narwhals I invite you to check out the blog I recently started all about the issue. Check back every Friday for new posts and be sure to check back this Friday in particular when Narwhals might be front and center on the blog.