Jeanne Hyde couldn’t understand why she was hearing human voices from under water all through the night last Tuesday. Normally, Hyde, a photographer and naturalist who works at the Whale Museum of Friday Harbor, Washington, monitors a network of hydrophones to track the pods of orca whales that live in the waters off Washington’s San Juan Islands. But the distorted sounds of people counting and talking were not normal. Listen here to a sample of what she heard.

Hyde has devoted her life to protecting the marine mammals that live in the frigid waters off the coast of Seattle. If she’s not on the water photographing orca whales, then she is part of a network of citizen activists, staying up late listening on her computer to the sensitive hydrophone stations that pick up underwater sounds in the Straits of Juan de Fuca, a shipping channel that links Seattle to the Pacific Ocean.

Hyde monitors the water because intense sonar sounds are thought to interfere with the navigation systems of marine mammals, sometimes causing some of them to run aground, often with disastrous results.

Environmentalists have been battling the U.S. Navy to limit their use of sonar systems in areas where orca whales are known to live and breed. President Bush exempted the Navy from following Marine Mammal Protection laws that would have prohibited them from using sonar in areas where orcas have been recently spotted. Environmentalists are fighting to have those exemptions overturned.

That night, Hyde knew she had stumbled onto a potential problem. After frantic phone calls to the Coast Guard, she confirmed that an attack class submarine, the USS San Francisco, was in the Strait, and was probably responsible for the strange underwater voices and loud “pinging” sounds. But there was nothing she could do to stop them. Except make the episode public.

Hyde posted updates all night on her blog, called her environmentalist friends, and through them urged the media to cover the story. At a town meeting in Port Townsend, Washington, the Navy confirmed that its submarine had been testing sonar in the Straits of Juan de Fuca, but denied it ever entered the protected Haro Straits, where orca whales spend much of their time.

While the Navy continues to test their sonar, Hyde says she will sit patiently at her computer, monitoring them as best she can. “I get frustrated at all the talk from so many people and groups, yet years and years go by and the same topics are still being addressed and very little has been done,” Hyde says. “If I don’t take action, who will?”

Andrew Chapman is a television writer.

Dr. Scott Veirs contributed to this piece and made recordings of the underwater sounds; he teaches and studies bioacoustics through Beam Reach, a marine science and sustainability school. The front page photo of an orca in air is also from Beam Reach.

More information on Beam Reach, and more recordings, are available here.

More information on the Salish Sea hydrophone network and Val Veirs available here.