What's All the Noise About?
A Call for Lowering Underwater Noise from Ships
By Andrew Wright
One of the greatest things about being at sea is that, every once in a while, you get to see one of the largest animals on the planet swim by. It's quite an experience, especially when you consider that a full-grown blue whale has a heart the size of a classic Volkswagen Beetle. Most merchant mariners have no idea that noise produced by the ships they are standing on are affecting these gentle giants. We are not talking front-page impacts, like strandings of beaked whales that have been publicly associated with the use of military sonar. Instead, the impacts of noise from
commercial shipping are, for the most part, more subtle and not easily seen. However, many scientists believe that these subtle effects are much more widespread and on the increase. To really understand what's going on, we need to know a little bit more about the whales. Whales, like almost all marine animals, are acoustic specialists and depend on sound for survival. They use sound for communicating, navigating, finding food and mates, detecting predators, and other life functions. The great whales use lower frequency sounds (i.e., bass) to do this, which can travel large distance because of the properties
A blue whale near the shipping lanes in the Santa Barbara Channel in 2007.
(Photo courtesy of John Calambokidis)
22 MTR
June 2008
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