Environmental groups sued the Obama administration ... for granting the Navy permits to test underwater sonar along the West Coast -- and potentially harass up to 650,000 porpoises, seals, dolphins and whales over a five-year period. The alliance said it wasn't seeking to stop the testing but to scale it back, especially at certain times and in waters important for feeding and giving birth. Several studies have found that marine mammals can hear low-frequency sonar, which is magnified under water, and periodically dolphins and even whales have been found with perforated ear drums. The National Marine Fisheries Service fell down on the job and failed to require the Navy to take reasonable and effective actions to protect" marine mammals, Steve Mashuda, an attorney for the law firm Earthjustice, said. The lawsuit ... claims that the Navy's sonar use might be strong enough to kill the animals outright. But even if it doesn't, it claims, the repeated use of sonar in certain critical habitats is unwarranted. In 2010, the fisheries service approved the Navy's five-year plan for operations in the Northwest Training Range Complex, an area roughly the size of California that stretches from Washington state to Northern California. Under the five-year plan, the service said it was acceptable for the Navy to incur up to 650,000 cases of harassment of marine mammals.