by Brian Palmer // Natural Resources Defense Council
Scientists often say that whales and dolphins see with their ears, mapping out their vast, dark underwater environment with an exquisite sensitivity to sound. And for many years now, the growing amount of manmade noise in the ocean has been blinding them.
One particularly devastating source of that noise is used by naval vessels to detect submarines and other objects beneath the surface. The intense, high-volume, and far-ranging sound waves blasted by active sonar are traumatic for marine mammals, and evidence has been mounting for more than a decade that they pose an existential threat to many species.
Since the mid-1990s, NRDC (disclosure) and partner conservation groups have pushed the U.S. Navy to deploy its sonar systems and conduct training exercises in ways that will reduce their impact on whales and dolphins, winning a series of court battles stretching back to 2003 (and going all the way to Supreme Court).
Over the weekend, NRDC and the U.S. Navy finally reached a federal court agreement regarding one of those long-runng fights—in the whales’ favor. As a result of the settlement deal, the navy will silence its sonar in areas around Southern California and Hawaii during certain periods of the year when marine mammal populations are most vulnerable. The agreement, signed off on by the judge today, runs until the end of 2018, when the U.S. National Marine Fisheries Service is scheduled to issue new environmental impact statements and authorizations regarding military exercises in sensitive waters.
Advocates hope the win represents a turning point in the military's view that marine mammals are acceptable collateral damage in its training exercises.
Mass strandings are the most visible effect of active sonar on wildlife, and they often coincide with nearby naval deployments. In 2000, for example, 17 whales swam themselves aground in the Bahamas. A government investigation, published more than a year later, concluded that the most likely explanation was mid-frequency sonar emitted by the navy. The sonar caused “some sort of acoustic or impulse trauma” that drove the whales ashore, killing them.