It's a device the Navy has been developing since the late 1980s, which would allow it to detect newly quiet enemy submarines over great distances. Speakers send out pulses of low frequency sonar that creates a powerful sound and pressure wave through the water. A similar LFAS system already has caused havoc underwater. The Navy wants to deploy four LFAS-equipped ships around the world. Currently it is drafting an environmental impact statement for the National Marine Fisheries Service.
Sound travels very efficiently in water, and the lives of fish and whales revolve around sound.
They use sound to feed, mate, navigate, detect predators, and communicate with one another. Use of LFAS could well alter hearing ability in whales and other marine animals over a 15-mile radius, and could cause profound behavioral disturbance over an area bigger than Texas. The Navy says it has proven through its own studies that LFAS has no significant impact on any marine animal. But its studies were carried out over a matter of weeks on only four species. Its study did not include the deep divers such as the Cuvier's beaked whale, which are thought to be most at risk because the sound is loudest down deep.