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by E Jo (writer), January 20, 2007

Last week in Long Beach the CA Coastal Commission, by a vote of 8 to 1, agreed to approve two years of proposed U.S. Naval exercises off of Southern California only if the U.S. Navy implements mitigation measures to protect marine mammals from the potentially lethal effects of mid-frequency sonar. Gray whales, humpbacks, blue whales, dolphins, porpoises and other sensitive species off the coast of California are at risk. According to the NRDC, “In 2004, the world’s leading whale biologists examined the link between navy sonar and whale strandings and concluded that the evidence of sonar causation is ‘very convincing’ and ‘overwhelming.’” Whales from all over the world have been found dead or dying following exposure to mid-frequency sonar.

Evidence of sonar effects on marine mammals began to emerge in 2000 when whales of four different species stranded themselves in the Bahamas after a U.S. Naval battle group used active sonar in the surrounding area. “Investigators found that the whales were bleeding internally around their brains and ears.” (NRDC). The Navy denied responsibility but government investigators established with certainty that the strandings were caused by active sonar. Since then, the area’s population of Cuvier’s beaked whales has disappeared.

Upon investigation, sonar stranded marine mammals had developed large emboli in their organ tissues. According to Nature, the animals suffered something akin to the “bends,” an illness that kills divers who surface too quickly. Whales stranded on shore are only the visible symptom of a much larger problem affecting huge numbers of marine life. Active sonar can also impact marine mammals and fish that use sonar to follow migration paths, locate individuals, find food, and care for their young. Naval sonar has been shown to alter the singing of humpback whales, which is essential for reproduction of this endangered species, disrupt feeding habits of orcas, and cause porpoises to panic (NRDC).

The U. S. Navy uses three types of active sonar: high, mid, and low frequencies. Mid-frequency has been used since WW II for locating submarines and has a range up to 11.5 miles generating 215 decibels, equivalent to the sound of a twin-engine fighter jet at takeoff. While low-frequency (SURTASS LFA) is used for long range searches up to 115 miles and produces 235 decibels, as loud as Saturn V rocket at launch. By Navy estimates, even 300 miles from the source LFA sonic waves can retain an intensity of 140 decibels, one hundred times more intense than the noise aversion threshold for gray whales. These sound waves are blasting everything in their path for hundreds of miles. In 2003, NRDC won a huge victory when a federal court ruled illegal the Navy’s plan to use LFA sonar in 75% of the world’s oceans. Soon after, the Bush Administration pushed legislation through Congress that exempts the U.S. Military from provisions of the Marine Mammal Protection Act.

Last July, a federal judge in Los Angeles halted the use of mid-frequency sonar in Hawaii during one of the Navy’s largest international training exercises. The Navy was allowed to proceed only if it agreed to take common sense measures to protect whales and marine species, such as staying away from underwater National Monuments in Hawaii. Similarly, the protective measures presented last week by the CA Coastal Commission were avoidance of key marine mammal habitat such as the Channel Islands National Marine Sanctuary and the gray whale migration path, to power down in low visibility conditions, and to expand safety zones around ships to keep from blasting nearby marine animals. Executing these simple measures will not negatively affect the Navy’s defense practices and is in accordance with CA Coastal Commission’s mandate to protect California’s waters. Although the Navy has acknowledged the lethal impact of sonar, it gave the Commission no assurances it would take these steps to protect marine life while conducting national security anti-submarine warfare training.

For more information on these practices or to help protect CA marine mammals:
http://www.youtube.com/watch?v=j8rZxmCejD0
http://www.nrdcaction.org/join.html
http://www.ifaw.org/ifaw/general/default.aspx?oid=153956
http://news.nationalgeographic.com/news/2003/10/1008_031008_whalebends_2.html
http://www.noaa.gov/

photo credit: Sandy Dubpernel

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E Jo is a writer for BrooWaha. For more information, visit the writer's website.