The California Coastal Commission unanimously rejected a plan by the U.S. Navy for explosives and sonar training last week, saying damage to whales and other sea life was badly underestimated.

But the Navy ignored similar opposition in 2007 and 2009, according to the Associated Press, and if they decide to go ahead with the plan the commission may have no recourse but to sue. That also hasn’t been totally successful in the past.

A 2008 U.S. Supreme Court decision supported the Navy’s contention that military considerations “strongly” outweighed environmental concerns, although it upheld some of the mitigation measures proposed by environmentalists. The Navy argues that the tests are necessary to maintain coastal defenses, particularly against submarine incursions.

The Navy wants to set off underwater explosions within a 120,000-square-mile area off the Southern California coast in war-training exercises, and estimated that the five-year-exercise would kill 130 animals and cause hearing loss in 1,600. Endangered blue and fin whales, beaked whales, and migrating gray whales are all at risk.

The Navy characterized the impact “negligible.” Testing is scheduled to begin next January.

The California testing is part of a larger Navy plan that includes activities on both coasts and by the Navy’s own count will affect 33 million marine animals, many of them endangered, in some fashion. The animals may just be disturbed, rather than injured or killed, but loud oceans blasts, which are magnified by the water, are known to have significant effects on an animal’s internal navigation system. Some estimates say as many as 5 million marine mammals may suffer from ruptured eardrums and temporary hearing loss.

–Ken Broder

To Learn More:   

California Commission Rejects Navy Sonar Project That Threatened Whales, Marine Mammals (Center for Biological Diversity)

Coastal Commission Rejects Navy Training that May Hurt Whales (by Julie Watson, Associated Press)

Calif. Panel Rebuffs Navy on More Test Blasts, Sonar (by Michael Winter, USA Today)

Coastal Panel Rejects Navy Plan to Increase Underwater Explosions (by Tony Perry, Los Angeles Times)

New Permit Would Allow Navy to Harm Millions of Marine Mammals (National Resources Defense Council)

Coastal Zone Management Act Consistency Determination for California (U.S. Department of the Navy) (pdf)