Hawaii – A Court of Appeals has ruled that the use of sonar by the US Navy has violated the Marine Mammal Protection Act, causing damage to various species of dolphins and whales.

For years, biologists have alerted about the dangers of the use of low-frequency sonar in the ocean. Sonar is used on some ships to assist navigation, and in the case of the US Navy, for detecting enemy submarines.

A Court of Appeals has ruled that the use of sonar by the US Navy has violated the Marine Mammal Protection Act, causing damage to various species of dolphins and whales. Photo credit: Lori Mazzuca / Science Burger
A Court of Appeals has ruled that the use of sonar by the US Navy has violated the Marine Mammal Protection Act, causing damage to various species of dolphins and whales. Photo credit: Lori Mazzuca / Science Burger

However, sonar is detrimental to the health of marine animals, especially dolphins and whales. The sonar transmitters confuse the animals’ echolocation system, interfering with their mating and feeding and can even cause mass strandings.

There have also been links between the use of sonar and decompression sickness, a condition suffered by whales in which sudden decompression forces nitrogen bubbles to form in the body’s tissues.

In 2012, the National Marine Fisheries Service permitted the US Navy to utilize low-frequency active sonar for peacetime training and testing in the in the Mediterranean Sea, as well as the Indian, Pacific, and Atlantic Oceans for five years. The Navy was supposed to delay or shut down its use when a whale or dolphin was detected near the ships.

However, environmental groups, led by the Natural Resources Defense Council immediately filed a suit, claiming the approval violated the Marine Mammal Protection Act.

Finally, on July 15, the Ninth Circuit Court of Appeals in San Francisco ruled 3-0 that the sonar indeed broke maritime laws. And also, that the Fisheries authorized incidental harm of marine mammal species, from failing to establish means of “effecting the least practicable adverse impact on [these] species, stock, and habitat,” as stated by the Marine Mammal Protection Act.

The Court went on, saying that Fisheries went against their own experts’ advice, which said particular areas of the world’s oceans as “biologically relevant”. The matter went back to district court for further proceedings. 

“We are aware the Ninth Circuit reversed the District Court’s grant of the government’s motion for summary judgment and the case has been sent back to the district court for a full trial” and avoided giving comment on the decision, arguing “the matter is still in litigation,” said Sheila Murray, Navy Region Northwest spokeswoman.

Why should marine mammals be protected?

Whales are at the top of the food chain in their respective ecosystems, which mean they have a crucial role in maintaining the well being of the marine environment.

However, after centuries of whaling for their meat, bones and oil, six of the thirteen great whale species face a significant risk of extinction. As few as 300, North Atlantic right whales remain, which makes them critically endangered; the blue whale is endangered, with around 10,000 to 25,000 specimens; and fin whales are also endangered, with a population of 100,000 to roughly 119,000.

Dolphins are also very vulnerable to human threats, with drive hunt, plastic, pesticides, nets and oil contamination purging their populations every year.

Sources: NBC News