Articles from Studies on Effects of Navy Sonar Testing on Whales and Dolphins
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Articles from studies on effects of navy sonar testing on whales and dolphins. Every year, thousands of whales, dolphins and porpoises get into trouble on coastlines around the world. There are reports of cetacean stranding since records began and it is a potential issue for every country with a coastline. Stranding occurs for two reasons – natural processes including age and disease, or human-related issues including bycatch, vessel collisions, navy sonar testing/blasting, and environmental degradation. Natural and human-related factors can also interact to cause stranding. Animals may strand alive on the beach, or die at sea and be carried on to land by the currents. There is evidence that active sonar leads to beaching. On some occasions cetaceans have stranded shortly after military sonar was active in the area, suggesting a link.[10] Theories describing how sonar may cause whale deaths have also been advanced after necropsies found internal injuries in stranded cetaceans. In contrast, some who strand themselves due to seemingly natural causes are usually healthy prior to beaching: The low frequency active sonar (LFA sonar) used by the military to detect submarines is the loudest sound ever put into the seas. Yet the U.S. Navy is planning to deploy LFA sonar across 80 percent of the world ocean. At an amplitude of two hundred forty decibels, it is loud enough to kill whales and dolphins and has already caused mass strandings and deaths in areas where U.S. and/or NATO forces have conducted exercises. — Julia Whitty, The Fragile Edge[11] The large and rapid pressure changes made by loud sonar can cause hemorrhaging. Evidence emerged after 17 cetaceans hauled out in the Bahamas in March 2000 following a United States Navy sonar exercise. The Navy accepted blame agreeing that the dead whales experienced acoustically-induced hemorrhages around the ears.[12] The resulting disorientation probably led to the stranding. Ken Balcomb, a cetologist, specializes in the killer whale populations that inhabit the Strait of Juan de Fuca between Washington and Vancouver Island.[13] He investigated these beachings and argues that the powerful sonar pulses resonated with airspaces in the dolphins, tearing tissue around the ears and brain.[14] Apparently not all species are affected by sonar.[15] Another means by which sonar could be hurting cetaceans is a form of decompression sickness. This was first raised by necrological examinations of 14 beaked whales stranded in the Canary Islands. The stranding happened on 24 September 2002, close to the operating area of Neo Tapon (an international naval exercise) about four hours after the activation of mid-frequency sonar.[16] The team of scientists found acute tissue damage from gas-bubble lesions, which are indicative of decompression sickness.[16] The precise mechanism of how sonar causes bubble formation is not known. It could be due to cetaceans panicking and surfacing too rapidly in an attempt to escape the sonar pulses. There is also a theoretical basis by which sonar vibrations can cause supersaturated gas to nucleate, forming bubbles (cavitation).[17] The overwhelming majority of the cetaceans involved in sonar-associated beachings are Cuvier's beaked whales (Ziphius cavirostrus). This species strands frequently, but mass strandings are rare. They are so difficult to study in the wild that prior to the interest raised by the sonar controversy, most of the information about them came from stranded animals. The first to publish research linking beachings with naval activity were Simmonds and Lopez-Jurado in 1991. They noted that over the past decade there had been a number of mass strandings of beaked whales in the Canary Islands, and each time the Spanish Navy was conducting exercises. Conversely, there were no mass strandings at other times. They did not propose a theory for the strandings. A letter to Nature by Fernández et al. in 2013 reported that there had been no further mass strandings in that area following a 2004 ban by the Spanish government on military exercises in that region.[18] In May 1996, there was another mass stranding in West Peloponnese, Greece. At the time, it was noted as "atypical" both because mass strandings of beaked whales are rare, and also because the stranded whales were spread over such a long stretch of coast with each individual whale spatially separated from the next stranding. At the time of the incident, there was no connection made with active sonar; the marine biologist investigating the incident, Dr. Frantzis, made the connection to sonar because he discovered a notice to Mariners about the test. His scientific correspondence in "Nature" titled "Does acoustic testing strand whales?" was published in March 1998.[19] Dr. Peter Tyack, of Woods Hole Oceanographic Institute, has been researching noise's effects on marine mammals since the 1970s. He has led much of the recent research on beaked whales (Pilot Whales and Cuvier's beaked whales in particular). War of the Whales: A True Story Winner of the 2015 PEN/E.O. Wilson Literary Science Writing Award: “Horwitz’s dogged reporting…combined with crisp, cinematic writing, produces a powerful narrative…. He has written a book that is instructive and passionate and deserving a wide audience” (PEN Award Citation). Six years in the making, War of the Whales is the “gripping detective tale” (Publishers Weekly) of a crusading attorney, Joel Reynolds, who stumbles on one of the US Navy’s best-kept secrets: a submarine detection system that floods entire ocean basins with high-intensity sound—and drives whales onto beaches. As Joel Reynolds launches a legal fight to expose and challenge the Navy program, marine biologist Ken Balcomb witnesses a mysterious mass stranding of whales near his research station in the Bahamas. Investigating this calamity, Balcomb is forced to choose between his conscience and an oath of secrecy he swore to the Navy in his youth. “War of the Whales reads like the best investigative journalism, with cinematic scenes of strandings and dramatic David-and-Goliath courtroom dramas as activists diligently hold the Navy accountable” (The Huffington Post). When Balcomb and Reynolds team up to expose the truth behind an epidemic of mass strandings, the stage is set for an epic battle that pits admirals against activists, rogue submarines against weaponized dolphins, and national security against the need to safeguard the ocean environment. “Strong and valuable” (The Washington Post), “brilliantly told” (Bob Woodward), author Joshua Horwitz combines the best of legal drama, natural history, and military intrigue to “raise serious questions about the unchecked use of secrecy by the military to advance its institutional power” Whales flee from the loud military sonar used by navies to hunt submarines, new research has proven for the first time. The studies provide a missing link in the puzzle that has connected naval exercises around the world to unusual mass strandings of whales and dolphins. Beaked whales, the most common casualty of the strandings, were shown to be highly sensitive to sonar. But the research also revealed unexpectedly that blue whales, the largest animals on Earth and whose population has plummeted by 95% in the last century, also abandoned feeding and swam rapidly away from sonar noise. The strong response observed in the beaked whales occurred at noise levels well below those allowed for US navy exercises. "This result has to be taken into consideration by regulators and those planning naval exercises," said Stacy DeRuiter, at the University of St Andrews in Scotland, who led one of the teams. "For whales and dolphins, listening is as important as seeing is for humans – they communicate, locate food, and navigate using sound," said Sarah Dolman, at charity Whale and Dolphin Conservation. "Noise pollution threatens vulnerable populations, driving them away from areas important to their survival, and at worst injuring or even causing the deaths of some whales and dolphins." Dolman said there were no accepted international standards regarding noise pollution and there was an urgent need to re-evaluate the environmental impacts of military activities. The US Navy part-funded the new studies but said the findings only showed behavioural responses to sonar, not actual harm. Nonetheless, Kenneth Hess, a US Navy spokesman, said permit conditions for naval exercises were reviewed annually and added: "We will evaluate the effectiveness of our marine mammal protective measures in light of new research findings." Advertisement Unusual mass strandings, where multiple species of whale and dolphin beach at several locations at once, have soared since the introduction of military sonar in the 1950s and can be fatal. The strandings occur every year and major recent events saw up to 15 animals beached in the Canary Islands, the Bahamas and Greece. In May, the naval activity was found to be the most probable cause of the deaths of at least 26 short-beaked common dolphins in Falmouth Bay, Cornwall in June 2008. Beaked whales are the most common species affected by unusual mass strandings, perhaps because their shy nature makes them more easily scared by noises that they may interpret as killer whale sounds. Researchers used suction cups to attach digital devices to Cuvier's beaked whales off the coast of Southern California to measure the noise they were exposed to and their response. When a simulated military sonar signal was sounded at 200dB and between 3km and 10km away, the whales initially stopped feeding and swimming. They then swam rapidly away from the noise and some performed unusually deep and long dives. "The missing piece of the puzzle was how whales changed their behaviour and how that led to mass strandings," said DeRuiter. She added that they also stopped feeding for 6-7 hours, which is unusual. "If they miss out on food, they will be less healthy," she said, noting that where populations have been measured, numbers of Cuvier's beaked whales are declining.