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Mapping the Sea with Air Guns Is Deafening Whales

Our technique for mapping the ocean floor involves blasting super loud soundwaves that can deafen and even kill whales and other sea life.
A humpback whale and its calf, via the NOAA

Whales are getting it from all sides these days. Between overfishing, ocean acidification, Japan's uncompromising stance in support of its proud whaling heritage, and getting bonked by cargo freighters in the trans-Pacific shipping lane, whales seem to catch the brunt of our commercial activity in the oceans. Now, we can officially add one more hazardous oversight to the pile these cuddly leviathans contend with: deafening by air gun.

new report from the conservation group Oceana claims that the government's plan to allow companies hunting for oil basins in the Atlantic to use seismic air guns will endanger more than 138,000 whales along the east coast and leave them deaf, distraught, dead or all of the above. Meanwhile, the humpbacks and gray whales that migrate along the west coast are at risk of suffering the same fate -- not so much from our quest for oil -- as PG&E ramps up its studies of an earthquake fault line beneath a nuclear power plant on the coast.

Via the USGS

State-of-the-art underwater mapping techniques rely on floating air guns that bounce high-powered acoustics off of the bottom of the ocean. The blasts penetrate through miles of seawater and illuminate underwater topography, as well as embedded pockets of oil and gas.

Typically arranged in arrays and towed by boats, the cannons fire every 10 seconds, 24 hours a day, for days on end, Oceana says. Wandering sea creatures are apt to get caught in the noisy crossfire and leave with hearing damage or worse.

Oceana calls the testing technique "an unnecessary insult" to whales, dolphins and other sea animals, and ultimately aims to use its new report to strike a blow against the fossil fuel industry. The group even launched a White House petition to halt the use of the air guns; so far, it has just under 20,000 signatures.

An oil industry trade group called the report "alarmist" but acknowledged that the use of air guns "does deserve our scientific review." However, crews operating the guns can spot approaching pods of whales or dolphins and shut down or adjust the frequency of the devices to avoid mishaps. "It's not like you just go into an area and start beeping the whales and the dolphins down," Florida Petroleum Council Executive Director David Mica told the Miami Herald.

On the West Coast, the air gun debate is more ambiguous than a what has been characterized as a clear-cut case of environmentalists versus oil interests. The 2011 Sendai earthquake off the coast of Japan, which caused seven meltdowns at three nuclear reactors stationed near the country's shoreline, has sparked concern in California that a similar calamity could befall the Golden State when the next big one hits.

West Coast utilities company PG&E has begun "low energy marine studies" of an underwater fault line discovered beneath the Diablo Canyon Nuclear Power Plant near San Luis Obispo. The company has said that "procedures have been implemented to monitor and protect marine mammals while the study is underway." But that's not good enough for some skeptics who say PG&E's study creates an excuse to delay moving the power plant, in addition to harming sea life.

As nasty as these air guns sound, perhaps the whales should be signing their thanks. After all, the preferred technique of seismic testing up until the 1950s involved detonating dynamite and chemical explosives implanted deep in the seafloor. Coincidentally, a similar technique was tested by the U.S. during World War II to create targeted tsunami bombs in the South Pacific.