Imagine being exposed to an acoustic wave so powerful that, even at substantial distances, it can destroy your hearing, cause your lungs or ears to hemorrhage, or even kill you. Such may be the plight of many marine mammals worldwide if the U.S. Navy gets its way and deploys the low frequency active sonar system, according to a recent warning by the Natural Resources Defense Council (NRDC).
The full name of this submarine detection system is the Surveillance Towed Array Sensor System Low Frequency Active Sonar (SURTASS LFAS), often referred to simply as LFA. It is a source of environmental concern because it can blast very loud (235 decibels), very low frequency (100 to 500 hertz) sound over thousands of square miles of ocean. The navy contemplates using this system in over 80 percent of the world's oceans.
The Ocean Mammal Institute reports that, beginning in the 1980s, the U.S. Navy developed and tested the LFA without preparing an environmental impact statement (EIS) or obtaining the necessary permits--in the process spending millions of dollars in violation of environmental law. It wasn't until the NRDC called attention to these violations in a 1995 letter to the Secretary of the Navy that the navy took steps to come into compliance. It committed to the preparation of an EIS and obtained the necessary permits. The permits required suspension of testing if whales behaved in unusual ways, such as repeated breaching or pectoral fin or tail slapping.
In 1998, the navy conducted tests of the LFA system on whales off the coast of Hawaii. Observers from the Ocean Mammal Institute reported changes in whale distribution and behavior. Institute officials observed a humpback whale calf and a dolphin calf without mothers. The humpback calf breached 230 times and its pectoral fin slapped 671 times in four hours. Yet testing wasn't suspended.
Also during the Hawaii test, a snorkler was exposed to a 125 decibel LFA broadcast over a period of thirty to forty-five minutes. She emerged from the water with symptoms a doctor diagnosed as similar to acute trauma: "She could barely talk, had difficulties in expressing and finding words, expressed dizziness and confusion.... There was tremor in reaching for things and difficulties in walking straight forward with open eyes."
Noise pollution is now widespread throughout the world's oceans, and deployment of the LFA would further insult an already injured population of marine life for which hearing is a matter...