In a bid to prevent “a massive degradation of ocean ecosystems,” a coalition of environmental groups has filed a lawsuit to block the U.S. Navy and National Marine Fisheries Service from deploying a powerful new sonar system.

The groups, led by the Natural Resources Defense Council, said the Navy’s low-frequency sonar would maim or kill whales, dolphins and other sea creatures that rely on a delicate acoustic environment to find food and mates, communicate and travel migratory routes.

“If we flood the oceans with high-intensity, low-frequency sound carrying enormous energy – energy large enough to affect the bodies of these organisms mechanically – we’re killing them,” said George Woodwell, a member of the NRDC board and director of the Woods Hole Research Center in Massachusetts.

Last month, the National Marine Fisheries Service agreed to exempt the low-frequency sonar system from the Marine Mammal Protection Act after determining that it would have a “negligible impact” on any species. The result is that the Navy has permission to “harass” and potentially injure whales while conducting exercises with the system. Unlike passive sonar – which listens for ambient noise – the new, “active” sonar transmits powerful signals to detect objects in the water.

But environmentalists said the fisheries service’s ruling was backed by inadequate science and may kill members of protected species in U.S. waters. This, they said, violates several federal laws, including the Endangered Species Act.

Gordon Helm, a spokesman for the fisheries service, said he was disappointed that the lawsuit was challenging the agency’s scientific findings. “All told, we addressed 280 issues before we made our decision,” he said.

Navy officials have said the Surveillance Towed Array Sensor System is needed to protect aircraft carriers and other warships from new ultra-quiet submarines being built by several nations, including Russia.

Such submarines could allow a hostile country to send an attack sub within striking distance of a U.S. ship in international waters without being detected. The threat from the new submarines, the Navy said, is “real and increasing.”

“We are disappointed that some groups refuse to accept scientific, peer-reviewed findings (about the minimal harm to whales) and instead rely on misinformation and unrelated facts,” the Navy said in a statement released in response to the lawsuit.

The Navy and the fisheries service contend that the sonar’s impact will primarily be local and that strict precautions will be taken to protect whales or dolphins. The Navy has even vowed to shut down the system if any animals swim too close to the ships.

But the NRDC argues that the sonar’s impact will be global in scale.

At a news conference Wednesday, members of the group said sound waves from the sonar could travel hundreds or thousands of miles beneath the sea.

Both the frequency and volume of those signals could kill a whale by causing internal tissues to tear – in the same way an opera singer can shatter a glass with a high note, said Naomi Rose, a marine mammal scientist with the Humane Society.

Rose and other officials from the NRDC pointed to the beaching of 16 whales in the Bahamas in 2000. Some of the whales died. The Navy admitted that its use of sonar caused the beaching but said it was a different type of system that used higher frequencies than the new system would employ.

The NRDC believes that at least 10 other nations may be developing similar sonar systems. Such widespread development, they fear, would smother the global undersea environment with noise pollution.

“Sound is to marine mammals what sight is to human beings,” said Joel Reynolds, an NRDC attorney. “If we interfere with their ability to hear, and if we recklessly turn our oceans into an acoustic traffic jam, then we threaten a broad range of species who depend on their ability to hear and be heard.”

The lawsuit was filed in U.S. District Court in San Francisco. Joining the resources council in the suit are the Humane Society, League for Coastal Protection, Cetacean Society International and Ocean Futures Society.

Attorneys for the resources council said they may seek a temporary restraining order to prevent the Navy from deployment of the system, which could begin as soon as Sept. 17.