BEACHED WHALES
Beached sperm whale In the newspapers there are periodically stories of whale beachings involving dozens of individuals. In December 2009, 125 pilot whales died when they beached themselves on two beaches in New Zealand. Sixty-three whales died on a beach on the North Island of New Zealand and 43 were rescued by volunteers who were able to keep them wet until they could be picked and carried back to sea by the high tide. Scientists speculated that perhaps their leader was sick or they got lost in a shallow harbor and could not use their sonar to find a way out. Hundreds of kilometers away on a beach on the South island, 105 long-finned pilot whales died in a remote isolated area. Rescuers could not reach them in time.
In January 2009, 45 sperm whales got marooned on a sand bar off Tasmania. By the time they were spotted all but seven had died. An effort to save the remaining seveb was too little too late. They all died. The last one survived for three days but died because it was hemmed in by other whales that rescuers were unable to move. In March 2009, almost 90 long-finned pilot whales and bottlenose dolphins died at Hamelin bay in western Australia. A few weeks earlier almost 200 whales were stranded on Kings Island.
In January 2005, 33 pilot whales beached themselves in a beach near Oregon Inlet in North Carolina and a minke whale stranded itself 50 kilometers away in Corolla. The next day two dwarf sperm whales were stranded north of Cape Hatteras. Scientists tested the blood and urine and examined the ears and sensory organs for damage caused by radar but came up with little. Some were sick but other were healthy.
Websites and Resources: National Oceanic and Atmospheric Administration noaa.gov/ocean ; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Ocean World oceanworld.tamu.edu ; Woods Hole Oceanographic Institute whoi.edu ; Cousteau Society cousteau.org ; Montery Bay Aquarium montereybayaquarium.org
Websites and Resources on Fish and Marine Life: MarineBio marinebio.org/oceans/creatures ; Census of Marine Life coml.org/image-gallery ; Marine Life Images marinelifeimages.com/photostore/index ; Marine Species Gallery scuba-equipment-usa.com/marine
New Zealand Rescuers Use Trucks to Save 14 Whales from Stranded Pod
rescue effort at Farewell Split
South Island, New Zealand In September 2010 AP reported: “Rescuers who battled exhaustion and darkness succeeded in saving 14 pilot whales from a pod of 74 that stranded on a remote New Zealand beach. A total of 24 whales were trucked 30 miles (50 kilometers) from Spirits Bay, where they beached on to be refloated in more sheltered waters of Rarawa Beach, an hour's drive south. Two died en route, another on the beach and seven had to be euthanized after re-stranding. [Source: Associated Press, September 24, 2010]
Rescuers in boats and on shore worked strenuously to prevent those seven whales from beaching themselves again but were unsuccessful, Department of Conservation incident controller Jonathan Maxwell said. "By that stage it was dark, and all of us were pretty exhausted. We all agreed we had done everything we could for these animals. The most humane course of action was to end their suffering," Maxwell told the New Zealand Herald.
The whales were transported between beaches in six trucks packed with straw and sand, in the largest operation of its kind in New Zealand. Department of Conservation staff and volunteers used three boats and two jet skis to herd the whales out to sea, Doc community relations manager Carolyn Smith said. Twenty-one were eventually guided into the open sea but seven turned back to land.
"As far as I'm aware, this has not been tried before to this scale (in New Zealand)," Anton van Helen, a whale expert at New Zealand's national museum, told the Herald. "Its a huge undertaking and definitely contains risks for the whales, but is basically their only chance."
New Zealand has one of the world's highest rates of whale strandings, mainly during their migrations to and from Antarctic waters, one of which begins in September. Since 1840, the Department of Conservation has recorded more than 5,000 strandings of whales and dolphins around the New Zealand coast. Scientists have not been able to determine why whales become stranded.
Causes of Beached Whales
beached whale on a bay
on Kyle of Sutherland Most beached whale events involve toothed whales not baleen whales. Theories behind why they occur include high winds that throw off currents and storms that cloud up the water. Whales are often beached in gently sloping beaches or places with narrow continental shelves. Many of the beached whale events occur with highly social animals. It is possible their leader gets lost or that healthy ones follow sick ones or are escaping predators. Other theorize the beachings could be related to geomagnetic interference from elements such as iron or problems with the whale’s sonar and echolocation systems. Australian marine scientist Catherine Kemper told AFP the theories are almost endless but many may be caused by disruptions in the echolocation sonar of toothed whale making it difficult for them to find their way.
There is some evidence that mass whale groundings may linked with solar storms. A team from the University of Kiel compared records of sperm whale stranding in the North Sea between 1712 and 2003 and found that in many cases they coincided with period of high solar activity. In a report published in the Journal of Sea Research scientists theorized that geomagnetic storms associated with high solar activity disrupts the whale internal navigation system and caused them to run aground.
Australian scientists have found that mass beachings of whales and dolphins in the southern hemisphere come in 12-year cycles that coincide with cooler, nutrient-rich ocean currents moving from the south and swelling fish stocks, bring the marines mammals close to shore, where they can get trapped by tides and sand bars, as they pursue food close to shore. Some theorize that this phenomena could increase with global warming as this pattern increasess and bring more whales and dolphins close to shore.
Whales, Sonar and Human Noise
autopsy on stranded beaked whale Researchers believe that noise pollution from submarines, ships and communications may interfere with the ability of whales to locate food and communicate with one another and find mates. Beached whales in the Galapagos, Corsica, the Dutch Antilles, Greece, California and the Canary Islands have also been blamed on man- made noise.
Researchers have found that powerful sonar used to search for submarines — which environmentalists say reaches 215 decibels — may harm whales and dolphins. Low-frequency active sonar can produce vibrations equivalent to a jet fighter taking off while those in the midfrequency range produce sound equal to a rocket.
Research by the Smithsonian found “between 100 and 200 cases” over 40 years involving the beaching of beaked whales in areas where sonar was being used. It is believed that sonar can be particularly damaging in places where there are underwater canyons that channel, amplify or reflect sound.
Autopsies of marine animals suspected of being killed or injured by sonar have revealed holes in organs and bleeding around the brains and ears, conditions that are consistent with people who have the bends. Some scientist have theorized that the sonar scares them and causes them to ground themselves or rise too quickly, causing the nitrogen in their blood to transform into gas, causing the bends and bleeding in vital organs.
The oil and gas industries use of seismic air guns in their search for new oil and gas deposits under the sea bed. The noise is so loud that can be heard across entire oceans. In recent years these industries has also been called on to reduce the practice because of its threat to whales and other marine creatures.
Sonar Whale Beaching Incidents
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beached whale at Port Waikato The U.S. Navy has been fingered as primary suspect in whale beachings, deaths and injuries. In the spring of 2000, 16 beaked whales beached themselves, with six whales dying, on a beach on a northern Bahamas island, near where United States Navy ships were using powerful sonar (235 decibels) in anti-submarine exercises. Autopsies showed hemorrhaging around the brain and ear bones of the whales that may have caused them to beach themselves and may been caused by the impact of the sonar from the ships. Two minke whales and spotted dolphins also beached themselves in the same area. Afterwards the Navy acknowledged it played a role in the beachings and determined the whales may have gone ashore to try and escape the noise.
In 2002, ten of fourteen beaked whales that beached themselves on the Canary islands and died after military exercises there were found to have suffered from decompression sickness similar to the bends. Again navy ships in the area where using powerful sonar. Still a lot of questions remain. Among them are how a whale could get decompression sickness to begin with and how sonar could be connected to it.
In July 2004, 150 to 200 melon-headed whales were observed milling around Kauai Bay in Hawaii, confused and disoriented, after mid-frequency sonar was used during military exercises about 20 miles offshore from there. The whales are normally found in deep water but were swimming packed together within 100 meters of the shore, showing clear signs of stress. Action by local citizens prevent the whales from beaching themselves. The Navy acknowledged that it used the sonar periodically for 20 hours before the whales nearly beached themselves.
Strandings and injuries involving sea mammals and sonar have been reported all over the world and involved a number of species. In 2003. Harbor seals unexpectedly came ashore off the coast of Washington after the U.S. Navy conducted sonar tests there. In July 2004 the death of two Cuveir’s beaked whales that washed ashore in the Canary islands was blamed on sonar used in massive NATO exercises off Morocco. In April 2006 a Japanese hydrofoil collided into an object in the middle of the sea. Some speculated it had crashed into a whale that been disoriented by the use of sonar in the area to track Chinese submarines.
Researchers Find Beached Dolphins are Often Deaf
Dead Risso's dolphin
on Norwick Beach David A. Fahrenthold wrote in the Washington Post, “New research into the cause of dolphin "strandings" - incidents in which weakened or dead dolphins are found near shore - has shown that in some species, many stranded creatures share the same problem. They are nearly deaf, in a world where hearing can be as valuable as sight. That understanding - gained from a study of dolphins' brain activity - could help explain why such intelligent animals do something so seemingly dumb. Unable to use sound to find food or family members, dolphins can wind up weak and disoriented. [Source: David A. Fahrenthold, Washington Post, November 15, 2010]
Researchers are unsure what is causing the hearing loss: It might be old age, birth defects or a cacophony of man-made noise in the ocean, including Navy sonar, which has been associated with some marine mammal strandings in recent years. The study, published Nov. 3 in the journal PLoS One, examined several species of marine mammals - including dolphins and small whales - in the Gulf of Mexico, Atlantic Ocean and Caribbean Sea. The animals had been found stranded in the wild and taken in for medical treatment and feeding.
Each year, 1,200 to 1,600 whales and dolphins are found stranded off the U.S. coast, according to the National Oceanic and Atmospheric Administration. Most are dead: In 2007, the most recent year with data, 195 out of 1,263 animals were found alive. But many are euthanized on the scene or die later. Others survive but are too young or too debilitated to be returned to the wild. Of the 195 animals found alive that year, five were released.
Washed up dolphin at Eskmeal Trying to study what put these animals in distress, the researchers faced a puzzle. How do test a dolphin's hearing? "They can't raise their flipper" if they hear a tone, Mann said. Instead, researchers looked for reactions to the sound inside the animals' brains. The researchers affixed sensors to the creatures' heads with suction cups, which could detect electrical activity in the brain. They then played a series of tones: If the animals could hear them, the sensors would detect millions of neurons firing to process the sound.
In some of the species they studied, the tests showed that stranded animals could still hear normally. Three Risso's dolphins, two pygmy killer whales and a spinner dolphin showed no problems. But the researchers found severe to near-total hearing loss in two species. Among bottlenose dolphins, four out of seven stranded animals had hearing problems. Among rough-toothed dolphins, the total was five out of 14. That, they said, could be a serious problem for animals that live in often-murky waters. "These animals are living in an environment where vision can't play the same role it does on land," said Randall Wells, a senior conservation scientist at the Chicago Zoological Society who was another of the study's authors. "Sound is probably the most important sense that they have."
What Caused the Dolphins to Go Deaf
Dolphin head sound production David A. Fahrenthold wrote in the Washington Post, “Without the ability to hear these sounds, scientists said dolphins can be helpless. In some cases, the animals had lost more than 99 percent of their echo-locating capacity: If a normal animal could detect prey at 100 yards, these dolphins could do it only at a yard or less. [Source: David A. Fahrenthold, Washington Post, November 15, 2010]
The research did not indicate what might have caused the animals to lose their hearing. Mann said he thinks the problem is most likely a combination of old age, birth defects and disease. But other researchers have also identified a contentious and growing issue: too much noise in the ocean. Dolphins evolved when the only source of loud sounds underwater would have been thunderstorms or unusual events such as volcanic eruptions.
Now, however, there are the sounds of powerboats and huge oceangoing ships. Oil and gas exploration efforts use loud noises to conduct seismic tests of the seabed. Navy exercises fill the water with the sounds of explosions and sonar. In Sarasota Bay, Fla., home to about 160 dolphins, researchers have calculated that a powerboat passes within 100 yards of every dolphin every six minutes.
"These animals that are very finely tuned acoustic machines are now having . . . to deal with noises, with sounds that their ancestors never knew," Wells said. He said it's possible, but not certain, that chronic noise played a role in damaging some dolphins' hearing.
Action Taken by U.S. Navy Sonar Whale Beaching Incidents
Smelly whale As result of these and other incidents the U.S. navy has limited the use of sonar since 2003. In March 2007, California coast regulators and environmentalist with the Natural Resources Defense Council sued the U.S. Navy in separate law suits over the effect of sonar on whales. The navy was accused of refusing to comply with regulations aimed at protecting marine life from sonar. In August of the same year a federal judge barred the U.S. Nary from using a powerful sonar in war games off the California coast after a team of experts argued that sonar could harm whales and other marine life. In January 2008, a federal judge ordered the Navy to take measures to reduce the impact of sonar on whales and marine life by doing things like scanning an area to make sure it was clear of whales before conducting sonar tests.
In July 2008, the Navy and conservation groups reached a court-approved settlement that allows the Navy to conduct sonar test while taking into considerations marine life that might get in harms way. In November 2008, the U.S. Supreme Court ruled that the navy’s use of sonar in submarine hunting exercises ofd California had precedence over whales, giving the navy permission to restart its use of sonar. The court based it decisions on the fact that the consequence of sonars on whales was not clear and it wasn’t known how many sea creatures were affected while a lack of training exercises jeopardized the military preparedness of the United States against an attack.
Image Source: National Oceanic and Atmospheric Administration (NOAA); Wikimedia Commons
Text Sources: Mostly National Geographic articles. Also the New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
Last updated March 2011