Correction: This article originally stated that congresswoman Lois Capps represents the 35th district. In actuality, she represents the 23rd. The Nexus regrets this error.

The Supreme Court ruled 6-3 on Wednesday to allow the Navy to continue the use of sonar in submarine training operations off the Southern California Coast, despite the potential risks the practice poses to the marine mammal life there.

The ruling settles Winter v. Natural Resources Defense Council, the most recent suit in a decades-long effort by environmental groups to limit military sonar use off Santa Barbara and the rest of California. In this most recent decision, the courts came down heavily in favor of the Navy, ruling that national security interests outweighed the possible environmental consequences of the sonar operations.

“The most effective tool for identifying submerged diesel-electric submarines is active sonar, which emits pulses of sound underwater and then receives the acoustic waves that echo off the target,” the decision, authored by Chief Justice John G. Roberts and joined by four other justices, said. “The use of … sonar under realistic conditions during training exercises is clearly of the utmost importance to the Navy and the Nation.”

The decision reverses restrictions imposed by a federal judge in California, which stipulated that the Navy halt sonar operations when a marine mammal is spotted within 1.25 miles of a training vessel and reduce sonar power by 75 percent under certain thermal conditions.

Those advocating further sonar restrictions — including the Natural Resources Defense Council and International Fund for Animal Welfare — claim that the Navy’s use of active sonar disrupts the marine mammals’ feeding and other vital behavior and causes a wide range of species to panic and flee. Moreover, they cite studies that show that sonar used by the military — which is as loud as 2,000 jet engines — can cause marine mammals severe physical trauma.

However, the court decision ruled that the sonar training exercises are imperative to national security interests, and cannot be restricted based on limited evidence of detrimental effects.

“We do not discount the importance of plaintiffs’ ecological, scientific, and recreational interests in marine mammals,” the majority decision read. “Those interests, however, are plainly outweighed by the Navy’s need to conduct realistic training exercises to ensure that it is able to neutralize the threat posed by enemy submarines.”

Associate Justices Ruth Bader Ginsburg and David H. Souter, who cast dissenting votes, argued that the Navy should more effectively balance environmental concerns with military training needs.

“Sonar is linked to mass strandings of marine mammals, hemorrhaging around the brain and ears, acute spongiotic changes in the central nervous system, and lesions in vital organs,” the dissenting opinion read.

The ruling marks a decided setback for environmental advocates, among them local congresswoman Lois Capps of the 23rd district.

“It’s disappointing that the Supreme Court narrowly rejected common sense precautions for marine mammals during Navy training exercises.” Capps said. “Clearly, our military’s primary mission is ensuring the safety of our nation and comprehensive training exercises are critical to that effort. But that doesn’t mean we can’t find an appropriate balance between protecting our national security interests and protecting marine mammals, like whales and dolphins.”