How Is Navy Sonar Affecting Whales?

Powerful underwater sonar can harm sound-sensitive marine life. Paul Jones/flickr

Q. I’ve heard that whales are stranding themselves on beaches because of Navy sonar. How does sound affect marine life and what is the Navy doing to keep the whales safe?

– Janet, MN

A. You know the ringing you get in your ears after you hear your favorite death metal band play in concert? Well, that’s kind of what it’s like for marine animals when they’re exposed to sonar waves. Only, for them it’s much, much worse. According to the Natural Resources Defense Council, powerful underwater sounds produced by sonar can put out sounds of more than 200 decibels, a level that spreads sound across the ocean and severely harms sound sensitive marine life like whales.

“It’s like when workers in a high noise environment become deafened after a sudden high level of sound,” says Ken Balcomb, senior scientist at the Center for Whale Research, an organization that studies sonar’s effects on whales. Often, the sound is so loud that the mammals end up beaching themselves in an attempt to get away from the noise, an extreme tactic that usually results in death. According to the NRDC, sonar has caused several mass strandings in the Canary Islands, Greece, Madeira, the U.S. Virgin Islands, Hawaii and other sites around the globe.

Though environmental groups have successfully pushed for stricter control of military sonar, the Navy has pushed back. It appealed a decision to the Supreme Court, arguing that states have no right to limit naval operations and that training exercises using sonar “produced no evidence of sonar-related harm to any marine mammal.” Meanwhile, environmental groups say that environmental laws should apply to everybody, and that though the president can make an exception in a national emergency, naval operations and practices should be subject to the law, no questions asked. In 2012, a lower court ruled that military vessels were allowed to use a type of loud, low-frequency sonar, but a federal appeals court in San Francisco reversed that decision in July 2016, ruling that the Navy violated marine mammal protection laws, reports the Washington Post.

This is good news for marine animals. “It’s important to understand that the ocean is a world of sound, not sight,” Michael Jasny, director of the marine mammal program at the Natural Resources Defense Council, told Wired.

Although sonar can be a valuable resource to help the Navy pick up on any underwater threats, marine mammals can also perceive these sounds as threats and respond accordingly, Jasny said.

This story was originally written by Jessica A. Knoblauch for Plenty in October 2008, and was moved over to MNN in 2009. The story has been updated with more recent information. (Copyright Environ Press 2008)