Navy Sonar Challenge Is a Mixed Bag for Activists

     SAN FRANCISCO (CN) - The Navy must face claims that its proposed global sonar system may harm bottlenose dolphins and other creatures, a federal judge ruled.
     Surveillance Towed Array Sensor System Low Frequency Active Sonar, or SURTASS LFA, is a low-frequency sonar system the Navy uses to better detect enemy submarines during peacetime training.
     Though the Navy tested a variety of sonar technologies, it concluded that LFA was the only system that could meet its needs under various conditions.
     Since many species of marine mammals use sound to catch prey, navigate, and communicate with each other, however, artificial underwater sounds like shipping noise and sonar can interfere with their socialization, cause hearing loss and make them leave their habitats.
     The Navy counters that it has been using SURTASS LFA radar for almost 11 years without any obvious injury to or death of marine mammals.
     In August 2012, the National Marine Fisheries Service approved the Navy's five-year plan to deploy 18 loudspeakers deep underwater in the Atlantic, Pacific, Indian and Mediterranean Sea, covering 70 percent to 75 percent of the world's oceans.
     The plan allows the Navy up to four surveillance vessels but limits operations so that no more than 12 percent of any species marine mammal faces level B harassment, which covers many forms of behavioral disruption to activities like migration, breeding and feeding.
     The plan has many mitigation measures to reduce harm to marine mammals, including designating off-shore biologically important areas (OBIAs), keeping operations at least 12 nautical miles from coastal exclusion zones, and using mitigation zones around sources of LFA sonar, according to the ruling.
     After the Natural Resources Defense Council led a challenge to the plan that fall, the government countered that it followed all legal obligations and that LFA sonar is a matter of national security because the Navy can use it to achieve a higher level of "military readiness" and a faster response to potential threats.
     U.S. District Judge Elizabeth Laporte gave both side some relief Tuesday.
     In nixing claims that the OBIAs were set up arbitrarily and capriciously, Laporte noted that the government supported its methodology with plenty of scientific data.
     Laporte did express concern about the government's disregard of certain recommendations from a 2010 White Paper, but took heart in other mitigation measures, such as procedures to detect marine mammals within a 1 km mitigation zone and shut down the SURTASS LFA sonar if animals are present.
     The government also properly chose to limit OBIA protection to baleen whales and not to sperm whales because using seasonal OBIAs adequately protects them, the ruling states.
     In eliminating OBIA protection for harbor porpoises and beaked whales, moreover, the government relied on studies demonstrating that SURTASS LFA sonar is at a low-enough frequency that it will not disturb them.
     Claims that the government improperly relied on outdated research and did not consider recent studies showing the effects of underwater sound on marine mammals also fail, the court found.
     Among other things, the government used a 2012 study demonstrating that humpback whales exposed to LFA sonar resume singing within 10 minutes and that baleen whales exhibited "only minor, short-term behavioral responses" after exposure to LFA.
     Laporte found that other studies the plaintiffs cited are not superior to those that the government used.
     The plaintiffs found more success on claims that the final rule ignored a 2010 stock assessment study concerning bottlenose dolphin populations around Hawaii with small stock numbers. Relying on previous changes to these stocks, the Navy concluded that the impact of LFA sonar would be negligible, though the study suggested otherwise, the court found.
     "Defendants failed to use the best available data regarding the bottlenose dolphin stock, even though the 2012 stock assessment describing separate stock populations was released well before publication of the [environmental impact survey] and the final rule and within a few months of the finalization of the take estimates for them," Laporte wrote.
     Laporte was unconvinced, however, by claims that the Navy's environmental impact survey did not include enough alternatives to using SURTASS LFA sonar and did not "take a hard look at LFA's impacts on non-marine mammals."
     Here the Navy properly demonstrated that many of the potential alternatives identified in the survey were infeasible and that none could serve its purposes better than SURTASS LFA, according to the ruling.
     Laporte also shot down claims that the Navy ignored analysis of nonmarine mammals. Among many "inapposite" studies the plaintiffs cited, for example, was an analysis of hearing loss in fish caused by exposure to an hour's worth of high-intensity sound rather than short bursts of LFA sonar, the type of sound at issue, the court noted.
     Another study looked at the effects of long-term, high-intensity sound on goldfish for weeks at a time when LFA sonar bursts typically last 60 seconds and are punctuated by soundless intervals lasting between 6 and 15 minutes, according to the ruling.
     The Navy's decision not to create OBIAs for sea turtles meanwhile survived scrutiny because of evidence that sea turtle exposure to LFA sonar bursts would be infrequent in light of the Navy's distance from foraging and nesting grounds and sea turtle migration behavior, the court ruled.
     Joint case-management statements are due by April 7, and Laporte will hold a case-management conference on April 14.
     Co-plaintiffs with the National Resources Defense Council include the Humane Society; Jean-Michel Cousteau; Cetacean Society International; the League for Coastal Protection; the Ocean Futures Society; and Michael Stocker, a bioacousticican.