A California federal judge yesterday blocked the use of high-power, midfrequency sonar during Rimpac 2006 exercises off Hawai'i, saying the court had received "convincing scientific evidence" that the undersea noise could harm marine life.

The ruling immediately affects the naval war games involving eight nations, which had been scheduled to begin using its sonar for submarine-hunting training as early as Thursday and to continue through July 28.

In a high-stakes game of legal and bureaucratic maneuvering, the court order appears to override the Navy's own wild card —an order Friday in which the Department of Defense declared that national security exempts the Navy from needing Marine Mammal Protection Act permits for its sonar exercises, which environmental groups say are hazardous to marine life.

"This type of sonar has been directly associated with repeated occurrences of mass strandings and deaths of whales, dolphins, and other marine species in U.S. waters and around the world," the Natural Resources Defense Council said in a news release.

The Navy, NOAA Fisheries, environmental groups and the courts have been fighting the sonar battle aggressively since early last week, when NOAA granted the Navy a permit to conduct its sonar tests with certain conditions. Convinced those conditions were inadequate to protect marine life, a court challenge was filed at mid-week by the NRDC, International Fund for Animal Welfare, Cetacean Society International, Ocean Futures Society, and Jean-Michel Cousteau.

The Navy responded with Friday's Department of Defense exemption from Marine Mammal Protection Act provisions, but conceded it still needed to comply with other federal environmental regulations.

"Last Friday the Navy did an end run around the law protecting marine mammals, but fortunately this country has more than one law against the needless infliction of harm to endangered whales and the environment," said Joel Reynolds, attorney and director of NRDC's marine mammal protection project.

In her temporary restraining order yesterday, District Judge Florence-Marie Cooper, in Los Angeles, cited both the mammal protection act and the National Environmental Policy Act.

Cooper noted that the National Environmental Policy Act requires "that federal agencies infuse in project planning a thorough consideration of environmental values" and must "study, develop and describe" alternatives as part of the environmental decision-making process.

She said the plaintiffs "have submitted considerable convincing scientific evidence demonstrating that the Navy's use of MFA sonar can kill, injure and disturb many marine species, including marine mammals."

Cooper ordered the Navy and the environmental groups to meet "to determine if an agreement can be reached on mitigation measures." The sides have until July 12 to inform the court about the success of such discussions. The injunction remains in effect until July 18.

Jon Yoshishige, media director for the U.S. Pacific Fleet, said the service is reviewing the judge's decision.

Reynolds said the plaintiffs are ready to meet with the Navy as early as tomorrow. In past cases, once a court ordered consultation, the Navy and environmental groups have been able to work out agreements, he said.

"If we can convene those discussions soon, I think there is a very good chance they could salvage virtually all of their training program," Reynolds said.

He said the environmental groups are not trying to block the use of midfrequency sonar — but they are insisting that extensive precautions are in place to protect whales and other marine life.

Among his proposed conditions: move training areas away from the individual islands, where marine mammals may congregate; that ships have more than just one person on deck with binoculars, looking for whales; avoid sonar training at night, when it would be difficult to spot whales or dolphins swimming within the hazard zone.

Reynolds said the groups oppose any high-intensity, midfrequency sonar training either within the Hawaiian Islands Humpback Whale National Marine Sanctuary or the new Northwestern Hawaiian Islands Marine National Monument. The Navy has told the court that Rimpac 2006 will not venture into monument waters.

The Maui-based Pacific Whale Foundation said that while NOAA had required the Navy to use sonar only in water deeper than 600 feet, that is where deep-diving whales are found, animals that may be particularly difficult to detect.

The organization noted that during July 2004, a pod of 200 melon-headed whales swam into the shallows of Hanalei Bay during Navy sonar activities, and one infant whale was later found washed ashore, dead. NOAA Fisheries concluded that the Rimpac 2004 sonar was the "plausible, if not likely" cause of the event.

"When presented with the facts about how dangerous this sonar is around whales and dolphins, Judge Cooper did the right thing—she took a stand on behalf of these animals, even when it meant standing up to the Navy," said Greg Kaufman, Pacific Whale Foundation president.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.