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NAVY EXERCISES RAISE NEW CONCERNS ABOUT SONAR USE
By Christopher Dunagan
Kitsap Sun
April 10, 2009
http://www.kitsapsun.com/news/2009/apr/10/navy-exercises-raise-new-concerns-about-sonar/
The Navy's use of sonar this week in the Strait of Juan de Fuca has again raised concerns about the appropriate balance between Navy operations and protection of marine mammals.
The USS San Francisco, a fast-attack submarine, left Bremerton on Tuesday and conducted "required training dives," including the use of sonar, according to Navy spokeswoman Sheila Murray. The sub and its escort ship took required steps to avoid marine mammals, she said.
Hydrophones (underwater microphones) operated by researchers in the San Juan Islands picked up loud sonar "pings" from about 7 p.m. Tuesday until after 3 a.m. Wednesday.
Val Veirs, a San Juan Island resident and retired professor of physics at Colorado College, reported that sound levels coming from the San Francisco could be heard underwater from Port Townsend to Whidbey Island to the San Juans and beyond.
"The received levels of the signals at Lime Kiln Lighthouse (on San Juan Island) were about the most intense sounds that the hydrophones there have recorded in the past several years of continuous operation," Veirs said in a written statement.
Based on an estimated distance of 10 nautical miles, sound levels were on a par with those from the USS Shoup during a 2003 incident that triggered an interagency investigation, he said.
In May 2003, the Shoup, a guided-missile destroyer, moved through Haro Strait in the San Juan Islands while transmitting "pings" from active midrange sonar. The piercing noise was so loud that boaters on the water said they could hear it resonating through the bottom of their boats.
J pod, a group of resident killer whales, uncharacteristically split into two groups and appeared disoriented, according to Ken Balcomb, a researcher who has studied the orcas since 1976. The animals moved one direction, then another, as if trying to decide how to escape the intense sounds reflecting off the walls of the underwater canyon in Haro Strait.
Other observers in the area saw a minke whale and several harbor porpoises moving away at high speeds. About that time, a dozen harbor porpoises were found dead, but an investigation revealed that some died of disease. Sonar possibly contributed to six of the deaths, but findings were inconclusive.
The Shoup incident led to a Navy policy requiring approval from the Navy's Pacific Fleet Command in Hawaii before using sonar in testing or training operations in Puget Sound. Little or no sonar has been used in that area since.
The San Francisco this week followed appropriate procedures, according to Murray. Trained Navy lookouts watched for marine mammals before beginning the exercise and during the tests. "Watch standers" aboard the submarine continuously listened for marine mammals with passive sonar. Navy commanders were prepared to cease the exercise if marine mammals were observed, she said.
But whale advocates contend that operating the San Francisco under conditions on Tuesday shows that the Navy learned little from the Shoup incident.
"This just underscores how inadequate their operation is now," Fred Felleman, Northwest consultant for Friends of the Earth, said during a Thursday night meeting in Port Townsend. "You shouldn't be doing this in the inland waters, where the echo chambers are, and you shouldn't be doing it at night, when you can't verify anything."
More than 100 people attended the meeting called by the Port Townsend Peace Movement to discuss the expansion of the Navy's testing ranges in Washington waters.
"They need to do a whole lot better before they even talk about expansion," Felleman told the group.
Howard Garrett of Orca Network, which keeps track of whales through an organization of professional and amateur observers, said he received reports of transient killer whales, a minke whale, and two gray whales on the day the San Francisco left. Conducting operations at night makes it difficult to see marine mammals, he said, and transient orcas are known for their stealthy hunting with little noise for passive sonar to pick up.
Active mid-frequency sonar, such as that from the San Francisco, can damage the hearing of whales, said Michael Jasny of the Natural Resources Defense Council. It can also disrupt normal behaviors, because many whales find each other and hunt for prey by using their own sonar, called echolocation. Loud sonar can even cause death, especially among the numerous species of beaked whales, he said.
During a Navy training exercise in the Bahamas in 2000, the deaths of at least seven deep-diving beaked whales were attributed to sonar after their tissues suffered injuries like "the bends." Other sonar incidents have been reported off the coasts of Greece, the Canary Islands and North Carolina.
In California, the NRDC filed a lawsuit against the Navy for failing to consider all the effects of sonar during routine training off the West Coast. A U.S. district judge noted that the Navy's own analysis revealed that there would be about 8,000 "exposures" of sonar powerful enough to affect marine mammals' sense of hearing plus another 466 instances of permanent injury to whales.
The judge imposed temporary measures pending a full environmental impact statement. Under the judge's order, the Navy was told not to conduct training exercises in sensitive environmental areas. The order also said sonar would have to be turned off when marine mammals were within a certain range -- a distance more protective than existing Navy guidelines. The ruling did not preclude nighttime operations, however.
Ultimately, the U.S. Supreme Court overturned the judge's conditions, saying that the Navy's judgment needed to be given extra weight. The need to train with sonar and protect against enemy submarines outweighs protections for marine mammals, at least until the environmental reviews are completed, the court said.
Murray, the Navy spokesman, said the Navy routinely tests submarines, such as the San Francisco, after repairs are made.
"Initial testing needs to be done in shallow water, under tightly controlled conditions, for the safety of the submarine and its crew," she said. "Once a submarine has passed its shallow-dive testing, the process is repeated in deeper water."
Jim Cortez, retired from the Navy as an assistant submarine navigator, pointed out that Friday was 46th anniversary of the USS Thresher incident. The Thresher, a fast-attack submarine, sank in deep water about 220 miles east of Boston while conducting diving exercises. Everyone on board --16 officers, 96 enlisted crew members and 21 civilians -- died.
As a result of the 1963 Thresher incident, the Navy created a certification procedure to ensure the safety of submarines and their crews. The lessons of the Thresher have never been forgotten, Cortez said.
Nobody denies the need for safety and readiness, Felleman said, "but minimizing collateral damage should be part of the training."
--For a discussion about water-related issues, check out the blog Watching Our Water Ways at kitsapsun.com.
2.
[Blog]
Watching our water ways
NAVY SONAR USE STIRS COMMOTION AMONG WHALE ADVOCATES
By Chris Dunagan
Kitsap Sun (Bremerton, WA)
April 9, 2009
Concerns about the Navy’s use of sonar Tuesday night in the Strait of Juan de Fuca are reverberating among environmental groups, whale advocates, and researchers.
Many are wondering whether killer whales and other marine mammals may have been injured by the intense sounds -- including human voices -- emanating from the recently repaired fast-attack submarine USS San Francisco.
From what I gather, there is talk about calling for an official investigation into the Navy’s activity, perhaps with input the National Marine Fisheries Service. More discussion is expected tonight at a public forum called by whale advocates concerned about an expansion of Navy training activities. The meeting is scheduled to begin at 7:30 p.m. at Port Townsend Community Center, 620 Tyler St.
Meanwhile, Val Veirs, professor emeritus of physics at Colorado College, has calculated that the highest levels of sound received at Lime Kiln Lighthouse on San Juan Island was about 140 decibels, according to a press release issued this afternoon by The Whale Museum. Veirs is president of the board for The Whale Museum.
“The received levels of the signals at Lime Kiln Lighthouse were about the most intense sounds that the hydrophones there have recorded in the past several years of continuous operation,” Veirs said a written statement.
The sonar pings were about as intense as those recorded in May 2003, when the Navy’s guided missile destroyer USS Shoup moved through Haro Strait, Veirs said.
Biologists observing killer whales at that time believe that the animals responded to the sound by moving away at a rapid pace. As a result of that incident, the Navy changed its protocols on the use of sonar.
I have requested additional information from the Navy about operations by the USS San Francisco, including general mitigation measures that the Navy takes when using sonar around marine mammals. Navy officials have indicated that the crew took the normal precautions to protect marine mammals.
For those still wondering about the strange human voice emanating through the water, you can start finding answers with this brief entry in Wikipedia: "The underwater telephone also known as UQC or Gertrude was developed by the U.S. Navy after World War II, the UQC underwater telephone is used on all manned submersibles in operation. Voices communicated through the UQC are heterodyned to a high pitch for acoustic transmission through water."
Based upon the Navy’s acknowledgment that crews were operating sonar in the Strait of Juan de Fuca but not Haro Strait, Veirs made additional calculations of the sound energy that must have emanated from the sub.
“We estimate that the distance between our hydrophone at Lime Kiln Lighthouse and the submarine was in the neighborhood of 10 nautical miles,” Veirs said. “For our hydrophones to pick up the strong signals that they did, the submarine was emitting sound with source level in the range of 174 to 226 dB re 1 microPa@1m.”
I’ll look to others to report on definitive studies and tell me whether these sound levels can cause injury under the circumstances we find in Puget Sound. But I seem to recall the levels reported by Veirs are worthy of concern. See “NOAA Technical Memorandum: Sound Exposure and Southern Resident Killer Whales (PDF 884 kb).”
While The Whale Museum has received no reports of stranded or injured marine mammals, the organization wants the public to be on alert and contact the San Juan County Marine Mammal Stranding Network, (800) 562-8832, if unusual behavior is seen.
Howard Garrett of Orca Network offered this response to a comment related to the previous entry about the sonar incident.
“The fact the sonar was taking place in the Strait of Juan de Fuca rather than Haro Strait is even more disturbing because 1) that is where the reports of Transients, a minke, & 2 gray whales were; & 2) if the sonar was happening in the Strait of Juan de Fuca, & it was being picked up so loudly at Lime Kiln & NW San Juan Island, then it must have been much louder closer to the source in the Strait…”
Obviously, this discussion will continue.
3.
News
Environment
MILITARY SONAR BLAMED FOR MASS DOLPHIN STRANDINGS
By Lewis Smith
Times of London
April 8, 2009
http://www.timesonline.co.uk/tol/news/environment/article6054843.ece
Mass strandings of dolphins and whales could be caused because the animals are rendered temporarily deaf by military sonar, experiments have shown.
Tests on a captive dolphin have demonstrated that hearing can be lost for up to 40 minutes on exposure to sonar. Hearing is the most important sense for dolphins and other cetaeceans, and losing it is likely to cause them to become disorientated and alarmed.
The finding by the Hawaii Institute of Marine Biology may explain several strandings of dolphins and whales in the past decade. Most strandings are still thought to be natural events, but the tests strengthen fears that exercises by naval vessels equipped with sonar are responsible for at least some of them.
The study also suggested, however, that dolphins and whales would usually be able to swim away fast enough and far enough to escape any ill effects from sonar.
To induce deafness in the Atlantic bottlenose dolphin, Tursiops truncatus, the sonar device would have to be loud, close and would need to last for at least two minutes.
This should give the animals plenty of time to escape but in some circumstances noises can be caught in “underwater sound traps,” Aran Mooney, of the University of Hawaii, said.
Sound can become trapped if a layer of warm water lies over cold water. When sound created in the warm zone reaches the cold water it can bounce back instead of travelling though it. This, Dr. Mooney said, would have the effect of trapping the sound in the warm layer, where it would bounce around “like a ping-pong ball”, giving whales and dolphins little chance of escaping it.
Similar effects could be experienced in parts of the sea with mountains and ravines, where the sound would bounce back and forth.
Dr. Mooney said that this could explain three of the best-known strandings that have been linked to military sonar -- in the Bahamas, the Canaries, and Hawaii -- because all three regions had a mountainous underwater topography.
In the Bahamas in March 2000, 16 Cuvier’s beaked whales and Blainville’s beaked whales and a spotted dolphin beached during a U.S. Navy exercise in which sonar was used intensively for 16 hours.
Sound traps might also go some way to explaining why there are only a few mass strandings compared with the frequency with which sonar is used by navy vessels.
“The big question is what causes them to strand,” Dr. Mooney said. “What we are looking at are animals whose primary sense is hearing, like ours is seeing. Their ears are the most sensitive organ they have.
“What we found was if you play sound you can cause temporary hearing loss. The sounds have to be surprisingly loud and they have to be repeated over an extended period of time -- two to three minutes.
“In that time you would expect them to swim away as fast as possible. They have to be within 40 meters of a ship, but when you have certain oceanographic conditions it’s hard for the animals to get out of the way.”
Observations by researchers while carrying out the tests, which are reported in the journal Biology Letters, showed that even though the dolphin involved was well accustomed to man-made noises and disturbances, it suffered subtle behavioral changes, which could cause further confusion.
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