A federal judge in California has sided with environmental groups in their lawsuit against the U.S. government over Navy training exercises off the West Coast involving sonar that they say harms endangered whales, dolphins and other protected marine mammals.

 

The ruling, the latest in a long-running dispute pitting whales against the military, requires the National Marine Fisheries Service to reconsider permits allowing the Navy to conduct its exercises in a vast stretch of open waters along the Pacific Northwest coast.

 

Environmental groups said similar mid-frequency sonar by the Navy has been linked to fatal mass strandings of marine mammals around the world, including Hawaii, the Bahamas, Greece, the Canary Islands and Spain.

 

Deafening underwater noise from sonar can also disrupt marine mammals' migration, nursing, breeding and feeding, the plaintiffs argued.

 

Under the ruling, the Marine Fisheries Service must reassess its permits based on new research from 2010 and 2011 showing that marine mammals are far more sensitive to sonar and other underwater noises than previously believed.

 

A spokeswoman for the marine service, is a branch of the National Oceanic and Atmospheric Administration, said the agency was reviewing the decision. There was no immediate comment from the Navy.

 

Environmentalists hailed the ruling as a key victory.