A ruling out of the 9th U.S. Circuit Court of Appeals says a lower court should not have dismissed a challenge of the Navy's use of sonar around dolphins.
Sonar uses pulses of sound under water to detect submarines. The noises can interfere with dolphins' hearing and behavior.
The Natural Resources Defense Council and other environmental groups sued the U.S. Navy and the National Marine Fisheries Service over its 2012 permit to use sonar. That permit allowed the Navy's use of sonar to harm or even kill some marine mammals, as long as it was a number small enough to be called an "incidental take" and would have a negligible effect on the species.
A three-judge appeals court panel ruling said the permit should have more fully considered the harm sonar could have done to the dolphins and provided steps to reduce the harm, action that is required under the federal Marine Mammal Protection Act.
The act doesn't ban all peacetime activities that could harm or kill dolphins and other sea mammals. But it requires that any harm be minimal.
The appeals court ruling revives the NRDC case against the government agencies and it goes back to the lower court for further litigation.