Blue whales can now live in peace and relative quiet after the Ninth U.S. Circuit Court of San Francisco ruled out the U.S. Navy's request to use low-frequency sonar due to its potential harm to marine animals.

The U.S. Navy sought the approval from the National Marine Fisheries Service to use the said sonar under the Marine Mammal Protection Act. However, groups urged the Service to reassess, which led to their decision not to give the go signal to the Navy's request.

According to the NRDC, the SURTASS KFA sonar system technology of the U.S. Navy uses low-frequency signals, which could disrupt the animals' communication, breed and feeding habits. The basis of the ruling was the National Marine Protection Act, which states that U.S. citizens, organizations, agency, etc., are prohibited to do any harm to marine creatures, Wired reported.

The Surveillance Towed Array Sensor System Low Frequency Active, or simply SURTASS/LFA, is a long-range sonar that uses 18 source projectors. However, the main issue is on its emission of low-frequency sound, which in some cases caused death and beaching to whales and dolphins.

Michael Jasny, director of NRDC’s marine mammal protection project, said upon hearing the low-frequency sound from the sonar, the animals perceive it as a threat. The sonar could also be heard by animals over a hundred miles, which meant that the sonar could impact a wider range of marine animals.

“It’s important to understand that the ocean is a world of sound, not sight,” he added, noting that the low-frequency wave from the sonar would act as a barrier for whales and other mammals to interact and communicate with each other because the ocean is too noisy.

This leads not only to problems in communication but also in reproduction. Animals will be unable to socialize with their kind or breed due to the loud noise.

"It can mean the difference between feeding and not feeding, or breeding and not breeding," he added.