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Single strandings, strandings of only one animal, can occur for a number of reasons. Dolphins, whales, porpoises, and seals may strand alone when the animal becomes lost or disoriented or is suffering from an illness, infection or injury. Newly weaned animals sometimes have a hard time thriving on their own and may strand as a result of their own inexperience. Older animals may also die of natural causes. Unfortunately, our actions as humans can often affect marine mammals. Some animals strand and/or die as a result of Human Interaction. The detrimental interactions include entanglement if fishing gear and marine debris, being struck by ships, being shot, and even being harassed by well-meaning beachgoers. The phenomenon of mass strandings affects only cetaceans (dolphins and whales, infrequently porpises). Mass strandings occur when two or more of these animals strand (excluding a mom/calf pair) within the same general geographic region and within the same tidal cycle. There are usually multiple factors that play a role in causing these events. The one constant thread among all mass strandings is that like humans, the species of whales and dolphins involved are highly social animals that depend upon the safety and resources of the group in order to survive. This group mentality that is so helpful to these animals at sea can unfortunately cause otherwise healthy animals to strand en masse when they are near shore. When one animal enters shallow water or strands, the entire group may follo. Other factors that may contribute to a mass stranding include predator evasion, complex topography, tidal fluxes, extreme weather, geomagnetic anomalies, and sonar or other acoustic disturbances. Mass strandings of whales and dolphins have occurred on Cape Cod for hundreds of years, thus it is unlikely that the events in this region are the result of modern human activities. In most stranding cases, the cause of stranding is unknown, but some identified causes include:
In addition, strandings often occur after unusual weather or oceanographic events. Social structure: Predators: Complex
topography: Extreme tidal
fluxes: Extreme weather: Sonar and other
acoustic disturbances:
Examples Of Strandings Around The World 16 November 2011 New
Zealand Department of Conservation
Department of Conservation Golden Bay Area Manager John Mason said 16 whales had died since yesterday morning and DOC staff had taken the difficult decision this morning to euthanize the remaining 18 whales to end their suffering. 'We had wanted to give the whales a chance to refloat and hopefully find their way out to sea in the high tides yesterday and overnight. But they re-stranded each time and more whales died. 'The whales seem to have come in a little further inshore in each re-stranding. The tides are reducing so it became very unlikely the remaining whales would get out to sea and that they would survive. "Rather than prolong the whales' suffering we decided to take the humane course of euthanizing the remaining 18 whales this morning.' The stranded pilot whales were reported to DOC staff on Monday evening by a Farewell Spit tour guide. DOC rangers who went to the area found 20 dead whales and one whale in a poor condition was euthanized. The next morning the rangers found another 44 whales stranded nearby, 2 - 3 kilometers from shore, 34 of which were alive and 10 dead. A rescue of the whales was too dangerous to undertake given the distance of the whales from shore in a remote location where tides come in rapidly over the shallow tidal flats. It would be arduous and unsafe for people to walk the 2 - 3 kilometers back to shore after refloating the whales in chest-deep water. DOC rangers remained at the Spit yesterday and overnight to monitor the whales. They found another 10 whales had died late yesterday afternoon when the high tide receded. A further six whales were found dead when rangers checked again at first light this morning. Whales die in stranding
Australia November 13, 2011-16 sperm whales died yesterday, leaving another four of the ocean giants struggling for survival overnight. The deaths occurred after 20 whales became stranded at Ocean Beach, near Strahan, on the West Coast, late in the morning. Only four survived despite the rescue efforts of West Coast Parks and Wildlife Service personnel. Late last night, another eight sperm whales were being monitored in nearby Macquarie Harbour. Four of them were stranded on sandbars.
Marine experts consider Ocean Beach and Macquarie Harbour to be among Australia's main hot spots for whale strandings. PWS West Coast parks and reserves manager Chris Arthur said it was not known why so many strandings occurred at the locations. "We don't know why, but there are several locations in the world where whale strandings occur frequently and Ocean Beach is one of them," Mr Arthur told the Sunday Tasmanian.
Mon 11
Nov 2010 Whale deaths in Donegal: pod stranded
on Rutland beach
SCIENTISTS HAVE taken skin and tissue samples from some of the 33 long-finned pilot whales which died after a mass stranding off Donegal. The carcasses of the 33 mammals were discovered early on Saturday on the back strand of Rutland Island between Burtonport and Arranmore island.
NOAA steps up probe of 146 New England seal deaths November 5 , 2011 NOAA At least 146 dead seals have been documented from September 1, 2011 to November 3, 2011, most of which were harbor seals (120), including 19 females, 28 males, and 99 animals of unknown sex. The majority of cases have involved young of the year and many have similar skin lesions (ulcerative dermatitis). Unlike historical young of the year harbor seal mortalities, which are often attributed to malnutrition, many of these animals are in good body condition. The highest number of strandings occurred during the week of September 25 (42 harbor seals). The 146 seals generally were less than a year old and had healthy appearances. They were found in Maine, New Hampshire and northern Massachusetts. Stranding records for the northeast region over the preceding four years show an average of 31 harbor seal strandings for the month of September and 24 harbor seal strandings for the month of October. Thus, the 2011 strandings that involved 61 seals in September and 46 seals from October 1-21 are above the expected average.
March 17, 2011-A POD of about 30 pilot whales has stranded on Tasmania's South Bruny Island. The whales are believed to be pilot whales and became stranded late this afternoon. Department of Parks and
Wildlife spokeswoman Liz Wren said about 12 of the whales were still alive
and Parks and Wildlife are on the beach trying to help the stranded
mammals. 28 whales die in New Zealand stranding
Feb 15, 2010 WELLINGTON New Zealand Twenty-eight pilot whales have died after they became stranded on a remote beach in the far south of New Zealand, conservation officials told local media . The whales came ashore at West Ruggedy Beach in the northeast of Stewart Island, Department of Conservation (DOC) manager Mark Townsend told the Southland Times. The whales were found by a hiker on Sunday morning. The DOC staff arrived about an hour later but were unable to save any of them. The conservation officials found nine whales already dead and there was no alternative to killing the remaining 19. Unprecedented mass whale stranding
New Zealand Sep 22, 2010 -Department of Conservation staff are calling a mass pilot whale stranding at Spirits Bay in Northland "unprecedented". Seventy-four whales are stranded across two kilometres on the remote beach north of Kaitaia. So far nine have been successfully refloated. There are up to 50 whales just off-shore.
Whales die after stranding on Senegal coast At least 38 died after dozens showed up on shore
DAKAR, Senegal — The bodies of at least 38 whales have washed up on a Dakar beach and wildlife officials say as many as 100 swam up close to the shore. Villagers living nearby said the whales were spotted late Tuesday night, veering closer and closer to the coast as the tide came in. By Wednesday morning many were beached. United States Marine Mammal Unusual Mortality Events
Nonactive UME's-Closure Pending
Closed UMEs
October 2011-Under the Marine Mammal Protection Act of 1972 (as amended), an Unusual Mortality Event (UME) has been declared for cetaceans (whales and dolphins) in the northern Gulf of Mexico (Texas/Louisiana border through Franklin County, FL) from February 2010 through the present. Note: These numbers are preliminary and may be subject to change. As of November 13, 2011, the UME involves 594 Cetacean "strandings" in the Northern Gulf of Mexico (5% stranded alive and 95% stranded dead). Of these:
An increased number of bottlenose dolphins (Tursiops truncatus) stranded along the Texas coastline in February and March of 2008. The February strandings were spread out along the entire Texas coast, although Brazoria, Galveston and Nueces counties saw the most increase. On March 3rd, 21 dolphins washed ashore in Galveston and Jefferson counties in late stages of decomposition. Most animals showed evidence of severe scavenging from shark bites with only a partial carcass present. The dolphin strandings continued to occur in high numbers throughout March 2008. The high numbers of strandings in March were limited to Matagorda, Brazoria, Galveston, and Jefferson counties with very few strandings (5 total) occurring along other areas of the Texas coastline. The total number of strandings recovered by the Texas Marine Mammal Stranding Network (TMMSN) in March was 78. In April, bottlenose dolphin strandings have decreased significantly with the total of 119 from February 1.
melon-headed whale Image Credit:FAO Fisheries Global Information System The appearance of as many as 200 of the normally deep-diving whales in Hanalei Bay in Kauai occurred while a major American-Japanese sonar training exercise was taking place at the nearby Pacific Missile Range Facility. The report is the latest in a series of scientific reviews linking traditional mid-frequency naval sonar to whale strandings. The sonar has been used for decades, but it was only recently the apparent connection to strandings was established. While the National Oceanic and Atmospheric Administration scientists said they could not definitely state that sonar caused the strandings, they said extensive study led them to the conclusion that there was no other likely cause. The Navy says it was virtually impossible for its sonar to have led to the Hanalei Bay stranding. The Navy is planning another major sonar testing maneuver in the same area in July and -- for the first time -- NOAA has formally asked the Navy to use expanded measures to protect whales from the possible effects of its sonar. The active sonar used by navies around the world sends out loud pings of sound that appear to frighten and disorient whales, especially deep-diving species like melon-headed whales. Dolphins stranded on day of sub mission BY JENNIFER BABSON The Miami Herald Tue, Mar. 08, 2005 KEY WEST - A nuclear-powered submarine used two different types of active sonar to navigate over several days as it trained off the Florida Keys last week, including the day of a massive dolphin stranding in Marathon, the U.S. Navy said late Monday. At the time, the submarine was approximately 39 nautical miles southwest of Marathon, where about 80 rough-toothed dolphins -- nearly 30 of which have since died -- beached suddenly late Wednesday. The submarine, the Connecticut-based USS Philadelphia, was in the Keys for about 10 days, the Navy said.
USS Philadelphia (SSN 690) A Navy spokeswoman said it was premature to speculate on the cause of the strandings and whether the incident had anything to do with sonar use. Necropsies and tests are underway on the dead animals by fisheries biologists from the National Oceanic and Atmospheric Administration. That process could take months to complete. ''The cause is not known and I cannot speculate, but every effort will be taken between federal agencies to determine what might have caused the stranding,'' said Lt. Cmdr. Jensin Sommer, spokeswoman for Naval Submarine Forces, based in Virginia. Some scientific reports say there is evidence that marine mammals may have a particular sensitivity to active sonar. The technology allows subs and ships to spot targets and other vessels by emitting sound waves that bounce off objects, revealing distance and location. Marine mammals rely on sound for just about everything, from feeding to finding a mate to communicating, which different animals do at different frequencies. Dolphin and whale strandings, however, are not unusual in Florida and can stem from a variety of circumstances, from a sick dolphin leading a pod onto shore to harmful algae blooms. SUB'S SONAR USE After it surfaced last Monday, the Philadelphia used mid-frequency active sonar on its bow in reduced visibility to ''provide for the submarine's ability to avoid potential contact with other vessels at sea'' for a period of 21 minutes, Sommer said. On three other days, Feb. 27, March 1 and March 2 -- the day the normally deep-water dolphins mysteriously beached on offshore flats -- the sub used high-frequency active sonar mounted on its sail while it was submerged to help it ''avoid other ships'' before it came to the surface, Sommer said. She did not know how long the high-frequency sonar was used, but said it was ''short duration'' and of low intensity. High-frequency sonar is considered to have a shorter range than medium frequency or low frequency. Factors like water temperature and salinity can also affect how far the sound travels. After a whale stranding in 2000 in the Bahamas, the Navy acknowledged in a report the existence of some marine mammal sensitivity to sonars, but has also argued at times that the extent of any cause-and-effect is scientifically vague. The Natural Resources Defense Council, an environmental group, successfully sued the military in 2002 to limit use of new, low-frequency sonar believed by some to be particularly damaging because of its ability to travel extremely long distances. Some types of sonar can be extremely loud -- as much as 235 decibels at close quarters, equivalent to the noise made by a Saturn V rocket on takeoff -- according to the council. ''It's too early to draw a conclusion, but the Navy's use of active sonar near the stranding site heightens our concern that sonar played a role in harming these animals. We already know that exposure to high-intensity sonar can kill marine mammals. A full transparent investigation is needed to get to the bottom of it,'' said Joel Reynolds, director of the council's Marine Mammal Protection Project. STRANDED WHALES Within the past two months, at least 35 whales of three species stranded off the Outer Banks of North Carolina. The stranding coincided with Navy sonar exercises in the area, though a final cause of death for the animals hasn't been determined. In recent years, military sonar use has also been alleged as a factor in the strandings of porpoises off the coast of Washington state, and of melon-headed whales off the coast of Hawaii, while other potentially sonar-related strandings have occurred in Greece and the Canary Islands. The International Whaling Commission last year issued a report supporting a link between active sonar use and whale deaths. Some researchers believe that sonars may disorient or scare marine mammals, causing them to surface too quickly and creating the equivalent of what divers know as the bends -- when nitrogen is formed in tissue by sudden decompression, leading to hemorrhaging. A POSSIBLE CLUE In South Florida, biologists are hoping that necropsies of the dolphins who died after the stranding may shed some light on what prompted the incident. One key clue may be the condition of the animals' acoustic tissue, a potential indicator of sonar damage. ''As with every marine mammal stranding, we are conducting a thorough investigation,'' said Laura Engleby, a biologist for NOAA Fisheries, which coordinated a massive response to the stranding last week and is now spearheading efforts to determine its cause. ``It's way too early for us to know what caused this, and our scientists are collecting as much data as possible.'' Eleven dead animals were examined and their tissue sampled over the weekend, with more scheduled for necropsy later this week. At least 20 of the dolphins managed to make it out to sea within a day of the incident. But at least 28 in poor condition or pain were subsequently euthanized or perished on their own. Researchers and volunteers are still trying to nurse back to health 26 rough-toothed dolphins that survived after being moved to several South Florida dolphin rehab centers.
Report: Sonar likely affected Puget Sound orcas Thursday, March 17, 2005 SEATTLE, Washington (AP) -- Sonar pulsing from a Navy guided-missile destroyer during training exercises near the San Juan Islands two years ago was likely loud enough to send killer whales fleeing, according to a government agency report. The National Marine Fisheries Service (NMFS) report backed up local experts who said sonar from the USS Shoup caused a group of orcas to behave abnormally, apparently trying to avoid the sound.
USS SHOUP (DDG 86) It contradicts the Navy's previous findings that orcas in Puget Sound's J Pod seemed unaffected by the sonar coming from the Shoup on May 5, 2003. The 10-page report, dated January 21 but not released publicly until March 10, said the Shoup's sonar was not loud enough to cause the whales any temporary or permanent hearing damage.
Orca Image Credit:FAO Fisheries Global Information System Cmdr. Karen Sellers, the Navy's spokeswoman for the Northwest, acknowledged the Shoup's sonar signals were the "dominant noise event" experienced by the orcas that day. She said the Navy maintains the "biological significance" was minimal, The (Bremerton) Sun newspaper reported Wednesday. Ken Balcomb of the Center for Whale Research in Friday Harbor said whether the whales suffered hearing loss is beside the point. "They are trying to get away, and they are stranding and dying. It is irrelevant whether they had hearing loss if they are dead," Balcomb said. Marine mammal researchers have also expressed concern about 15 harbor porpoises found dead in northern Puget Sound in the spring of 2003. Sellers said the Navy stands by its conclusions those deaths were not related to sonar. The NMFS report said scientists found no signs the porpoises' ears suffered any acoustical trauma, although decomposition hindered researchers' analysis. Puget Sound's orca population has been proposed for listing under the federal Endangered Species Act. NATO blamed for dead whales Ted
Harrison The Canary Islands authorities have asked Nato to halt a naval exercise in the area, fearing it may be responsible for the death of 17 whales washed up on the coast of Fuerteventura and Lanzarote this week. The heads of six Cuvier's beaked whales have been taken to the veterinary department of Las Palmas University for examination, in particular to discover if their inner ears were damaged by pressure from sonar devices.
Cuvier's beaked whale Image credit: Garth Mix, GMIX Designs The exercise Neo Tapon 2002, organised by the Spanish navy and involving about 30 Nato ships and submarines, is being held in the Atlantic between the Canaries and Gibraltar. They include the US frigate De Wert, which specialises in anti-submarine warfare.
USS DE WERT (FFG
45) Two months ago a new sonar system, Surtass LFA, was authorized for US naval use, despite fierce lobbying by conservationists who claimed that sonar had been responsible for the mass death of whales in the Mediterranean and off the Bahamas. The US government gave the navy a five-year exemption from the Marine Mammal Protection Act after tests led to the conclusion that the system was unlikely to injure marine mammals. One of the independent marine biologists conducting the tests, Dr Kurt Fristrup, said: "If the stranding is tightly correlated in time and space to the Nato exercise, this will be another clear indication of an environmental issue that must be studied." A Greenpeace spokesman in the Canaries said the link was clear, but a Nato spokesman said that by the time the whales were found dead the ships involved were 500 miles to the north-east. The Surtass LFA system can transmit signals as powerful as 215 decibels and the US navy says its use is vital in helping to detect super-quiet submarines. Some scientists believe that a whale's eardrums can explode at 180 decibels. Beaked whales which were
studied after the Bahamas incident in March 2000, when eight died, were found to
be bleeding from the ears, and there was evidence of damage consistent with an
intense pressure injury. Whales Die in Beaching Incident in The Bahamas
U.S. Navy Tests On Whales
LONDON, March 4 1998 -
NATO tests of an underwater sonar system could have caused a mass stranding of
whales off the coast of Greece, scientists said today.
SACLANTCEN
Press Release
The Director of NATO’s SACLANT Undersea Research Centre (SACLANTCEN) announced the public release of the findings of two panels, which convened in June 1998, relating to protection of the marine environment. A Bioacoustic Panel was formed to make assessments and provide advice and recommendations on an incident of whale strandings in Kyparissiakos Gulf (Greece) in May 1996. A second panel met to evaluate SACLANTCEN environmental policy and mitigation procedures and suggest improvements. Information was received in the fall of 1997 that a stranding of Cuvier’s Beaked Whales occurred (in May 1996) in the same general time and area in which NATO sonar research was being conducted. Based on that awareness, NATO scientists began to reexamine the acoustic data collected during that time. The issue received public attention in March 1998, when correspondence on this matter was published in the journal Nature. The NATO Supreme Allied Commander, Atlantic established guidelines for two panels to investigate the stranding incident and to review NATO procedures for protection of the marine environment. It was requested that the NATO Nations nominate national experts in various disciplines to sit on the two panels. The two panels were tasked to write reports to be reviewed for public release. The Bioacoustics panel met in mid-June 1998 to investigate circumstances surrounding the stranding of Cuvier's Beaked whales (Ziphius cavirostris) on the Greek Coast in Kyparissiakos Gulf in May of 1996. The NATO Research Vessel Alliance had been conducting sonar testing in Kyparissiakos Gulf at the time of the strandings. The following summary of findings regarding possible causes and panel recommendations are quoted from the panel report. Bioacoustics Panel Summary of Findings
Biacoustics Panel Recommendations
The Environmental Policy and Mitigation Procedures Panel met in June 1998 at the SACLANT Undersea Research Centre in La Spezia, Italy, to review and provide expert opinion on a draft policy by the Centre for protection of the marine environment. The panel reviewed procedures for the use of active sonar and methods of monitoring and mitigating procedures used during active sonar trials. The panel consisted of sonar, marine mammal and environmental policy experts nominated by NATO nations. Based on available knowledge and the results of the Bioacoustics panel, the Policy Panel gave valuable guidance to SACLANTCEN on the further development of its policy to conduct sonar research. The results of this review have resulted in the production of SACLANTCEN Human Diver and Marine Mammal Environmental Policy and SACLANTCEN Human Diver and Marine Mammal Risk Mitigation Rules. This policy and summary of the panel proceedings may be found at the SACLANT Undersea Research Centre's web site on the World Wide Web, at http://www.saclantc.nato.int/whales/, published in Adobe Acrobat format. For further information on the SACLANT Undersea Research Centre, see . For further information on the Supreme Allied Commander, Atlantic, see . Further inquiries should be directed to the Public Information Office at the Headquarters of the Supreme Allied Commander, Atlantic, in Norfolk, Virginia, USA .
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Data compiled from The British Antarctic Study, NASA, NASA Ozone Watch, Environment Canada, UNEP, EPA and other sources as stated and credited Updated Daily-Researched By Charles Welch- This Website is a project of the The Ozone Hole Inc. The Ozone Hole Inc. is a 501c3 nonprofit organization dedicated to protecting the ozone layer, the climate and Earth's environment by educating and motivating the public through its internationally respected websites, http://www.theozonehole.org and http://www.earthlyissues.com . Visit our other website
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