Strange noises have been costing Jay Murray sleep since August 25, 1994.
An experienced scuba diver, he was diving with some friends that day, not far from Carmel, Calif. The last man into the water, Murray was barely submerged when he sensed something wrong.
"I could hear and feel a deep, low hum," he recalls. "It was an immediate assault on my senses." His lungs vibrating from the force of the noise, Murray surfaced to look for an approaching ship, but saw none.
Thanks to the Natural Resources Defense Council (NRDC), we now know Murray had probably overheard the U.S. Navy secretly testing new technology called low frequency active sonar (LFAS).The system is designed to detect enemy submarines from great distances by filling the ocean with sonar signals, then listening for the distinctive echo created when the sound bounces off an enemy sub. This "active" sonar is designed to detect the new generation of super-quiet subs, which the Navy fears can slip by the current "passive" sonar detection systems. The British, the Dutch, and the North Atlantic Treaty Organization (NATO) are developing similar LFAS systems.
Some scientists, activists, and a large coalition of environmental groups lead by the NRDC are concerned that LFAS could injure or kill marine mammals, and even harm humans. Although the system only has been tested and not fully deployed, at least 12 whales have apparently died at the hands of LFAS; they beached themselves off the coast of Greece -- presumably due to acute disorientation, panic, or both -- after a secret NATO test of an LFAS system. Several people also claim they have been hurt and perhaps permanently disabled.
In 1997, the Marine Mammal Commission reported to Congress that exposure to LFAS may cause hearing loss in whales, dolphins, seals, sea lions and other marine mammals; may disrupt feeding, breeding, nursing, and communication (whales use a form of sonar to navigate); and even may cause death from lung hemorrhage. During Navy testing in Hawaii, independent observers from the Ocean Mammal Institute (OMI) came across three separate calves, two whales and one dolphin, near the test site which appeared to have been abandoned by their mothers. OMI researchers have never observed or heard of any incident comparable in nine years of research in the Hawaiian Islands. Although Navy researchers believe the OMI's claims were not documented sufficiently enough to verify them, this incident adds to concern that LFAS may disorient whales and disrupt vocal communication between mothers and calves.
Humans are vulnerable as well. According to a Navy document, after being exposed to 160 decibels of LFAS for 15 minutes, a Navy diver suffered dizziness, confusion, and tingling in the arms. Months later, the diver complained of ongoing memory loss, depression, and seizures. In 1998, eco-tour guide Chris Reid experienced similar symptoms, both short and long term, after being exposed to 125 decibels during LFAS testing in Hawaii. And Jay Murray has suffered from sleep disturbances and depression, maladies he believes are connected to LFAS exposure.