Saving Stranded & Dying Marine Mammals from Navy Sonar Communications

According to The Verge, “The US Navy is now using a particular type of sonar in more than half of the world’s oceans under an illegal permit. That sonar harms marine mammals like whales, dolphins, seals, and walruses. On Friday, the Ninth US Circuit Court of Appeals in California found that a 2012 regulation that allowed the Navy to use a low-frequency active sonar for training and testing violates the Marine Mammal Protection Act.

The Navy uses LFA to detect quiet foreign submarines. The sonar involves the use of 18 speakers lowered hundreds of feet below the surface. It produces low-frequency sound pulses of about 215 decibels [dB], in sequences that last about 60 seconds. That can interfere over hundreds of miles with some marine mammals like whales, dolphins, and walruses that rely on underwater sound for navigating, catching prey, and communicating. LFA sonar can harm the animals by interrupting mating, stopping communication, causing them to separate from calves, and inflicting stress. Sounds above 180 dB can disrupt the animals’ hearing and cause physical injury. In 2005, 34 whales became stranded and died off in North Carolina because of nearby offshore Navy sonar training, according to Scientific American .

Some marine animals, such as whales and dolphins, use echolocation or "biosonar" systems to locate predators and prey. It is conjectured that active sonar transmitters could confuse these animals and interfere with basic biological functions such as feeding and mating.

Sonar sounds have been linked to hearing loss, deadly mass stranding’s and interference with dolphins and whales' communication with each other. One of the studies found that the distance the whales were from sonar sounds didn't matter — they generally fled whether they were close to or far from it.

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