Dolphins are mysteriously dying around the world in Cape Cod, The Gulf of Mexico & Brazill. Since January, dead dolphins have washed ashore in Peru, the death toll reaching a staggering 877. Scientists are still trying to explain the bizarre deaths, and their best prediction at the moment is that its due to a virus outbreak or acoustic trauma.
Several mass deaths of dolphins have occurred over the past few years and while experts are worried about the die-off they say we are not witnessing a global population crash.
But what is behind the resent mass stranding and deaths is complicated and, inevitably, involves humans.
For example, the bottlenose in Gulf of Mexico started in early 2010, even before BP’s massive oil spill in April 2010. Disease was linked to some of the hundreds of Gulf dolphin deaths, but not all of them. The ultimate cause remains mysterious.
Nonetheless, the past two years have been rough for several species of dolphins, but not all of the nearly 40 species of dolphins are in hot water.
“There is not a large scale die-off of dolphins across the globe or throughout ocean basins,” said Connie Barclay, spokesperson for the National Oceanic and Atmospheric Administration (NOAA)’s National Marine Fisheries Service.
“What we do see are localized areas where stranding and deaths have increased,” Barcaly said. “Scientists have seen unusually high rates of illness and death in specific populations of bottlenose dolphins in the Gulf of Mexico, long-beaked common dolphins along the beaches of Peru and short-beaked common dolphins along the shores of Cape Cod.”
One population that suffered a serious dolphin disaster swam in the Pacific off the coast of Peru. Discovery News recently reported on the thousands of dolphin corpses washing up on the tropical beaches.
“The Peru mass stranding is the largest ever reported in the [Western Hemisphere] and the biggest since the mass stranding in Europe during the ’90s,” Carlos Yaipen-Llanos, president and science director for Organization for Research and Conservation of Aquatic Animals (ORCA).
The causes of the dolphin strandings and deaths seem to be varied as well. Unlike the fungus decimating multiple North American bat species, no single reason has been found for the dolphins’ dilemma.
When these mass deaths occur, whole family groups can be wiped out, said Yaipen-Llanos. The effect on the future of the species when whole generations of dolphins are wiped out is a serious concern to dolphin research and conservationists.
Other possible accomplices in the dolphins’ demise were abnormal weather, toxic algae blooms, parasites, pollution exposure, loss of prey leading to starvation, disorientation due to loud noises from ships and oil exploration and physical injury.
“In many cases, the cause of stranding is unknown and difficult to discern,” said Barclay.
What isn’t in doubt is that human impacts on the ocean are hurting dolphins around the world.
“People should recognize that the dolphins need the waters to survive — that we are visitors to their homes,” said Wells. “As visitors, we should be good stewards, and respect the needs of these animals as they try to make a living in the aquatic environment.”
Everyday choices can affect the fate of the dolphins. Dolphin experts have some suggestions for how to lead a dolphin-friendly life.
“No matter where you live, reducing pollution can help these animals, as chemicals such as PCBs can be transported by air for thousands of miles before being deposited into the marine environment,” said Wells.
Wells also warned against the illegal but popular practice of feeding wild dolphins. The practice brings dolphins closer to the dangers of being struck by boats or tangled in fishing lines and disrupts the animals’ social groups.
Since January, dead dolphins have washed ashore in Peru, the death toll reaching a staggering 877. Scientists are still trying to explain the bizarre deaths, and their best prediction at the moment is that its due to a virus outbreak or acoustic trauma.
Environmental authorities are investigating the deaths of more than 800 dolphins that have washed up on the northern coast of Peru this year.
The dolphins may have died from an outbreak of Morbillivirus or Brucella bacteria, said Peruvian Deputy Environment Minister Gabriel Quijandria, according to Peru’s state-run Andina news agency. Speaking to CNN, he said he expects test results to be ready within the week.
“Right now, the most probable hypothesis is that it’s a virus outbreak,” he said.
Quijandria said Thursday that 877 dolphins have washed up in a 220-kilometer (137-mile) area from Punta Aguja to Lambayeque, in the north of the country.
More than 80% of those dolphins were found in an advanced state of decomposition, making it difficult to study their deaths, according to Andina.
Earlier last week, the Peruvian government put together a panel from different ministries to analyze a report by the Peruvian Sea Institute (IMARPE). Officials have been able to conclude that the dolphins’ deaths were not due to lack of food, interaction with fisheries, poisoning with pesticides, biotoxin poisoning or contamination by heavy metals.
“When you have something this large, my gut would tell me that there’s something traumatic that happened,” Sue Rocca, a marine biologist with the Whale and Dolphin Conservation Society, told CNN. She floated a number of number of possibilities as to what could have killed the animals, including acoustic trauma, but concluded that investigators just don’t know yet. “More investigation needs to be done,” she said.
The dolphin deaths in Peru are mark the third set of high-profile strandings in about two months.
In February, 179 dolphins –108 of which were dead — washed ashore in Cape Cod, in eastern United States, according to the International Fund for Animal Welfare. Marine biologists are still trying to determine the cause of those deaths.
In early March, amateur video taken from a beach in Rio de Janeiro, Brazil, showed more than 30 dolphins on shore. In that instance, all dolphins were safely returned to the sea.
In less than a month, 129 common dolphins have stranded themselves on the shores of Cape Cod, more than three times the annual average, officials from an animal welfare group said today.
Katie Moore, manager of marine mammal rescue and research for the International Fund for Animal Welfare, said the strandings since Jan. 12 represent the largest single-species stranding on record in the northeastern United States, and more are expected.
“We are staging folks today, staff and volunteers, out on the outer Cape in anticipation of more dolphins coming in this afternoon,” Moore said in a telephone conference call with the media today.
Of the 129 dolphins that have stranded themselves on the 25-mile stretch of coast between Dennis and Wellfleet since mid-January, the group successfully released 37 dolphins into deeper water; 92 have died.
Moore said the common dolphins the group has released appear to be out of imminent danger. The group has attached satellite tracking tags to some of the dolphins and it also monitors reports of sightings from other agencies.
“We have had reports of up to three or four hundred animals in the bay at one time, though last week there were two hundred in the bay,” she said. “In some respects, I don’t know if I want to know how many [dolphins] are still out there.”
The number of stranding, and the lack of apparent cause, have bewildered rescuers.
Along with Australia and New Zealand, Cape Cod is one of the top three stranding locations in the world, according to IFAW. Moore said the Cape’s hook shape and gently sloping beaches, along with the social nature of dolphins, contribute to the danger for dolphins and other marine mammals.
An animal welfare group on Cape Cod has been busy for weeks in February trying to rescue dolphins that strand themselves in harbors and on beaches of the Cape. The group said they rescued nine more dolphins that were in danger of stranding themselves in Brewster.
The International Fund for Animal Welfare said the dolphins were “about to strand” in Brewster near Sea Pines Drive on February 1 at 11:15 a.m. Low tide, which occurred at 11:54 a.m., further threatened the marine mammals, said Kerry Branon, a spokesperson for the group.
“The team is bringing the animals to our rescue trailers and are doing health assessments to determine if the animals are healthy enough to be released,” Branon said in an e-mail.
Branon said the group released the dolphins into deeper water later that afternoon.
Since Jan. 12 to Feb 2nd at least 102 dolphins have stranded themselves on the shores of Cape Cod. The animal welfare group said 21 of the stranded dolphins were rescued, relocated, and appear to be doing well. The group says the cause of this year’s mass strandings remains a mystery.
Dolphins stranded on Cape Cod, Massachusetts
More then 200 Dolphins have beached themselves on Manila Bay, Philippians
Dolphins have beached themselves in New Zealand
Dolphins have beached themselves in Australia