More environmental groups are challenging the National Marine Fisheries Service's decision to allow the Navy to inadvertently harm whales and dolphins while conducting sonar and other training off Hawaii and Southern California.
Groups led by the Natural Resources Defense Council filed a lawsuit against the fisheries service and the Navy in federal court in San Francisco Monday.
The fisheries service last month issued the Navy a permit for the training.
Navy officials estimate its activities would have a negligible impact on marine mammal populations. But the NRDC argues sonar is responsible for population declines in marine mammal populations.
The lawsuit comes a several weeks after Earthjustice and other environmental groups filed a similar lawsuit in federal court in Honolulu.