It’s an invisible threat, but noise pollution is a major — and often deadly — menace to ocean wildlife. Just as there’s hardly a mountaintop free from the roar of airplanes overhead, there’s virtually no place in the world’s oceans where human sounds aren’t detectable. The loudest and most disruptive anthropogenic ocean sounds come from military sonar, oil exploration and industrial shipping, and the Center is working to protect our marine life from each of these threats.
Naval sonar systems work like acoustic floodlights, sending sound waves through ocean waters for tens or even hundreds of miles to disclose large objects in their path. But this activity entails deafening sound: Even one low-frequency active sonar loudspeaker can be as loud as a twin-engine fighter jet at takeoff.
This onslaught of noise, which far exceeds the Navy’s own safety limits for humans, can have a devastating effect on marine species — especially whales, who use their keen sense of hearing for almost everything they do. Sonar can displace whales from their preferred habitat and disrupts feeding, breeding, nursing, communication, navigation and other behaviors essential to their survival. Most appallingly, sonar can directly injure whales — very often killing them — by causing hearing loss, hemorrhages and other kinds of tissue trauma, or by driving them rapidly to the surface or to shore.
Use of military sonar has been associated with mass whale strandings and deaths in Hawaii, the Bahamas, Greece, Madeira, Vieques, the Canary Islands, Spain, Japan and the American Northwest. But while the U.S. Navy openly acknowledges that its active sonar harms marine mammals, it refuses to comply with laws that limit sonar’s use. In 2007, we joined with allies to file suit against the Navy over its plans to use high-intensity, mid-frequency active sonar in Hawaii waters, including within a humpback whale sanctuary and near the Papahānaumokuākea Marine National Monument. In February 2008, a federal district judge found the Navy in violation of the law and declared that it may not proceed with its plans in Hawaii unless it adheres to measures protecting marine mammals and prepares an environmental impact statement. Most recently, in early 2012 we filed suit with allies against the National Marine Fisheries Service for failing to protect thousands of whales, dolphins, porpoises, seals and sea lions from ocean noise brought by Navy warfare training exercises along the coasts of California, Oregon and Washington.
Other kinds of oceanic noise pollution, such as that caused by seismic surveys — which create the loudest noises detectable in the ocean — also have a significant effect on whales. In 2002, two dead beaked whales were found stranded in the Gulf of California following underwater airgun blasts fired by a National Science Foundation-owned research vessel. The Center filed suit and won an injunction shutting down the seismic surveys.
Similarly, seismic surveys are used by the oil industry to search for oil and gas deposits in the ocean waters off Alaska and elsewhere. The Center has actively opposed numerous such proposals and in August 2007 won an injunction blocking seismic surveys off the Arctic National Wildlife Refuge that threatened bowhead whales. In 2011, we filed a notice of intent to sue Interior Secretary Ken Salazar for ignoring marine-mammal protection laws when approving noisy offshore oil and gas exploration in the Gulf of Mexico; that same year, the federal agency that oversees offshore drilling asked the National Marine Fisheries Service to review the effects of that exploration’s seismic blasts on Gulf whales and dolphins. And in 2013, after a lawsuit by the Center and allies, the Bureau of Ocean Energy Management announced that it would evaluate the effects of seismic surveys used to detect oil under the seabed in an environmental impact statement.
The shipping industry is not only responsible for the direct killing of whales by ship strikes and the contribution of significant greenhouse gas emissions to the Earth’s atmosphere — it also remains the most poorly regulated source of ocean noise pollution. The Center is working to clean up every aspect of the shipping industry.
We’re determined to save imperiled whales and other marine mammals from acoustic disturbances and sonar-caused mortality — what prominent biologist Sylvia Earle has called “a death of a thousand cuts.”