A Court of Appeal in California, has ruled regulations allowing the US Navy to use a low-frequency sonar for training violate the US Marine Mammal Protection Act.
The US Navy currently uses this particular type of sonar in more than half of the world’s ocean, which potentially harms whales, dolphins, and other marine mammals like seals and walruses.
In 2012, the US Navy had been authorized to use the high-intensity long-range sonar — called low-frequency active sonar, or LFA — for five years across more than 70 percent of the world’s oceans. LFA helps detect quiet foreign submarines and involves the use of 18 speakers lowered hundreds of feet below the surface.
Low-frequency sound pulses of about 215 decibels (dB) are pumped out over hundreds of miles of ocean, which can then disturb whales and dolphins as they rely on underwater sound to navigate, communicate, breed and for catching prey to eat.