LOS ANGELES, July 16 (UPI) -- The Navy has been given approval to launch further tests of a controversial sonar system, although the blessing by federal regulators comes with some limits aimed at protecting whales and other marine life that might be sensitive to the booming sounds produced by the system.
The National Marine Fisheries Service issued its approval late Monday for a 5-year testing program for the SURTASS LFA sonar, which the Navy is developing to help defeat the latest advances in stealth technology that could make enemy submarines virtually invisible to current sonar systems.
"Fisheries determined -- based on research, stringent monitoring requirements and strong mitigation measures outlined by the agency for the Navy -- that marine mammals are unlikely to be injured by the sonar activities and that the sonar will have no more than a negligible impact on marine mammal species and stocks," the agency said in its announcement.
The planned tests of Hawaii and California have yet to be scheduled, but they will restricted to 12 miles offshore and will be halted whenever a whale, sea turtle or member of any other potentially vulnerable species happens to swim within 1.1 nautical miles of the sonar array.
"The Navy will conduct visual monitoring and...sonar monitoring to ensure that marine mammals and sea turtles are detected before they enter the area where LFA sonar would be used," the Fisheries Service said. "The Navy will shut down the LFA sonar whenever marine mammals or sea turtles are detected."
The SURTASS LFA (Surveillance Towed Array Sensor System Low Frequency Active Sonar) system is supposed to be a major leap forward in the United States' defenses against prowling nuclear subs as it can scan large areas of the undersea world with sound waves measuring around 300 hertz (Hz), compared to current sonar system outputs of 3,500 Hz that don't travel as far underwater as the low-frequency sound waves.
The low-frequency sound waves, however, are said by some environmentalists to have been powerful enough during earlier developmental tests to actually damage the ears of whales, which rely on their own natural sonar to navigate.
"Imagine being told to drive down to the soccer field and pick up your kid, and to stop at the grocery store on your way back, all the while being blinded by a brilliant strobe light," Chris Clark of the International Marine Mammal Project said recently. "This is more or less the scenario that activists fear. The deafeningly loud sound pulse generated by SURTASS LFA will prevent marine mammals from feeding, navigating to calving grounds, and from finding members of their families."
The General Accounting Office issued a report last month at the request of Rep. Patsy Mink, D-Hawaii, which concluded that while the $375 billion SURTASS LFA system would likely work well in the open sea, its effectiveness in shallower coastal waters that are not so acoustically friendly remained a question mark. The agency called on the Navy to develop a plan for coastal waters before attempting to carry out such tests, but it nevertheless saw the entire program as something necessary to keep up with advances in sub design that make shipboard passive sonar -- which acts like a microphone that picks up engine noises -- virtually useless.
"Even though recent improvements to passive systems have extended their range, submarine quieting measures have lowered submarine noise levels to nearly the level of the ambient noise of natural sounds in the ocean," the GAO said. "As a result, the Navy is concerned that an enemy submarine could get within effective weapons' range of U.S. forces before passive systems could make contact with an enemy submarine."