Whales, dolphins and other marine mammals swimming off the coasts of Hawaii and Southern California will be more protected from the Navy’s use of sonar thanks to a settlement Monday.

Two cases brought by environmental groups were resolved in federal court after a years-long battle to limit the military’s sonar training and testing as well as its use of explosives.

“If a whale or dolphin can’t hear, it can’t survive,” David Henkin, an attorney for Earthjustice, said in a press release. Earthjustice brought the initial challenge to the Navy’s latest round of training and testing on behalf of Conservation Council for Hawaii, the Animal Welfare Institute, the Center for Biological Diversity, and the Ocean Mammal Institute.

“We challenged the Navy’s plan because it would have unnecessarily harmed whales, dolphins, and endangered marine mammals, with the Navy itself estimating that more than 2,000 animals would be killed or permanently injured,” he said. “By agreeing to this settlement, the Navy acknowledges that it doesn’t need to train in every square inch of the ocean and that it can take reasonable steps to reduce the deadly toll of its activities.”

Certain restrictions were put in place for areas around Maui County and the Big Island as well as off the coast of Southern California.

The Navy is prohibited from using mid-frequency active sonar and explosives for training and testing activities on the eastern side of the Big Island and north of Molokai and Maui in an effort to protect endangered Hawaiian monk seals and certain types of whales.

The Navy is also not allowed under the settlement to exceed a set number of major training exercises in the channel between Maui and Big Island and on the western side of the Big Island, limiting the number of times local populations will be subjected to the massive use of sonar and explosives associated with major training exercises, the release says.

The Navy surface vessels are also required to use “extreme caution” and travel at safe speeds to minimize the risk of ship strikes in humpback whale habitat, the release says.

“We can protect our fleet and safeguard our whales,” said Rhea Suh, president of the Natural Resources Defense Council, whose lawyers challenged the Navy’s activities in Southern California and Hawaii on behalf of NRDC, Cetacean Society International, Animal Legal Defense Fund, Pacific Environment and Resources Center, and Michael Stocker.

“This settlement shows the way to do both, ensuring the security of U.S. Navy operations while reducing the mortal hazard to some of the most majestic creatures on Earth,” she said in the release.

Read the full release, complete with maps of the restricted areas, here.