One of the most beautiful and haunting sounds on the planet, whale song is thought to have healing powers and is widely used for meditation and relaxation. Whales use sound to locate food and companions, and rely on their songs and hearing for navigation, orientation and communication. Marine mammal scientists from Vancouver Aquarium have therefore been concerned to note that killer whales who inhabit the coastal waters of British Columbia and Alaska have recently lost their collective voice.
The cetacean research team at the aquarium is headed by Dr. Lance Barrett-Lennard, who described how the normally loquacious creatures have been strangely quiet for the past two years, and how, consequently, they are now much more difficult to locate:
“They weren’t vocalizing, and that was quite a striking change after years and years of being very familiar with how noisy they are and how easy to find acoustically,” he said. "We were still blundering into them from time to time, finding them without the hydrophone and when we did, they were generally -- not always, but most of the time -- very quiet."
The team reported that, in every other way, whale behaviour appeared to be normal, aside from an unusually elevated mortality rate among pod matriarchs. Seven or eight deaths have occurred amongst the older females in the pod in the past two years, when the team would normally expect to see just one or two deaths per year. Despite this, the overall pod population does not seem to have declined and killer whale numbers have been increasing over the past couple of decades, but Barrett-Lennard says that the changes are significant and require extra research; is worried that irregularities in the ocean environment could be causing the anomalies.
The Natural Resources Defense Council (NRDC), one of the most effective environmental action groups in the US, suggests that the situation affecting marine life could in fact be very serious. Military sonar used by US navy has far-reaching and deadly effects on those forms of aquatic mammals using sound as a means of communication.
Joel Reynolds, the NRDC senior attorney states that "There is no question that sonar injures and kills whales and dolphins."
According to NRDC, sonar can cause bleeding around the brain, ears and other tissues and large bubbles in the organs of affected whales. The symptoms are similar to "the bends", a condition experienced by divers when they surface too quickly, and scientists believe that sonar blasts can alter dive patterns in whales causing debilitating and even fatal injuries. NRDC has been battling to have the use of sonar regulated in order to protect whales and similar species, and in 2008, a case filed by NRDC against the U.S. Navy was heard by the U.S. Supreme Court.
In the Pacific northwest, environmental groups from Washington and British Columbia have already been campaigning for a ban on sonar use in inland waters around Puget Sound, Georgia Strait and the Strait of Juan de Fuca due to the effect on whale behavior. There have been several unfortunate incidents already attributed to the effects of sonar, including the death of one three-year-old female Orca which died from unusual trauma and was washed ashore in Long Beach.
Recent scientific studies tests on blue whale groups in the area used low-level sonar to see how whales reacted, and the results indicated that the cetaceans avoided the sounds and shunned their usual feeding grounds. This seemed to confirm findings from earlier studies which illustrated that military-style sonar blips used in underwater navigation, object-detection and communication could distort whale songs, alter their feeding habits and could sometimes damage their hearing. The researchers issued the following statement from the study:
“Our results suggest that frequent exposures to mid-frequency anthropogenic sounds may pose significant risks to the recovery rates of endangered blue whale populations, which unlike other baleen whale populations (i.e. humpback, grey and fin whales), have not shown signs of recovery off the western coast of North America in the last 20 years.”
In its latest environmental impact statement, the Navy admits that the sonar exercises planned for 2014-2018 may unintentionally "harm marine mammals 2.8 million times over five years," but the only precautionary measures it has agreed to take is to post look-outs onboard ships to spot whales, a measure which has been deemed to be woefully inadequate.
Heather Trim, Director of Policy for People for Puget Sound said that the Navy should use listening devices to ensure that no cetaceans are in danger zones, and that whale sanctuaries, birthing nurseries, and whale migration paths should be off-limits to sonar testing.
"Visual detection can miss anywhere from 25 to 95 percent of the marine mammals in an area," she said.
In other areas, marine life is being similarly affected by seismic testing, a method of determining potential oil and gas reserves which employs airguns using compressed air to generate intense pulses of sound, 100,000 times more intense than jet engines. The blasts from the airguns, which go off every ten seconds, for 24 hours a day, for many weeks at a time, penetrate right down through the ocean floor then back to the surface, supplying information about the location of buried oil and gas deposits. Research has shown that the resulting damage to marine life is extensive.
If governments do not take action to preserve our sea life, there is a serious risk of some species dying out. Bruce Stedman, head of the Orca Relief Citizens' Alliance, is very worried about statistics issued by the Center for Whale Research and NOAA which illustrate that the number of reproductive-age males has dropped 26 percent since 2009, leaving just 14 surviving reproductive age male orcas.
"Slowly but surely, they would go extinct," Stedman said. "That's the worry."
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