Environmentalists won reinstatement Friday of a legal challenge to the U.S. Navy’s use of sonar, which the groups say harms whales, walruses, seals and dolphins.
The 9th U.S. Circuit Court of Appeals reversed a lower court’s dismissal of the Natural Resources Defense Council challenge to a rule allowing some harm to marine mammals by use of low frequency active sonar (LFA) in the Navy’s military readiness training.
The NRDC alleged violation of the Marine Mammal Protection Act by the National Marine Fisheries Service, NMFS, which sought in 2012 to approve “incidental take” of whales and other marine mammals during the sonar use.
The NMFS “did not give adequate protection to areas of the world’s oceans flagged by its own experts as biologically important,” wrote Judge Ronald Gould for the panel.
Whales, dolphins, walruses, and other sea mammals rely on underwater sound for vital biological functions such as catching prey, navigating and communicating, according to Gould.
The Navy uses LFA along the U.S. coasts and around the world to detect hostile submarines. The LFA sonar projects pulses underwater and can detect submarines over much larger distances and is considered vital to national defense, the opinion said.
But LFA sonar also harms marine mammals. It disrupts hearing, can cause physical injury, make the animals flee the area, cease foraging for food, separate from their calves, avoid communicating with each other, disrupt migration and delay reproduction, the court said.
A 2012 rule intended to provide mitigation measures for the allowable injuries to animals from the LFA sonar during training. (Sonar use is not limited during active military engagement or war, the court notes.)
But the final rule “does not require that any specific mitigation measure be taken as a result of adaptive management activities,” the panel said.
Proposed mitigation could include requiring the Navy to shut down or delay LFA sonar use if it detects marine mammals near ships. The rule could also limited the intensity of sonar pulses and excluded sonar use near coastal zones.
The lower court said the rule should require mitigation that has the least adverse impact on the whales and other mammals. The question on appeal was whether the NMFS must allow “incidental takes” (injury to sea mammal) once it finds negligible impact, and is limited only to deciding which form of mitigation the Navy must use.
“We conclude the NMFS is required to prescribe regulations to achieve the ‘least practicable adverse impact’ before it can authorize incidental take,” Gould states. That standard was not satisfied, he said.
The dismissal favoring the NMFS and Navy was reversed and the case reinstated and returned to the trial judge in San Francisco.
Judges John Noonan and Michelle Friedland joined Gould.
Case: NRDC v. Pritzker, No. 14-16375