Dailypress.com: Big hike in dolphin strandings has experts baffled

http://www.dailypress.com/news/science/dp-nws-dead-dolphins-20130803,0,7140056.story

Dead and dying dolphins are washing up on Virginia beaches in numbers that are baffling marine stranding experts, who are hustling to determine the extent and pinpoint the cause. Dolphin beachings aren’t unusual in the summer months, and in a typical July the state might get six such reports. But by Thursday the number for this July had soared to 49 – and Mark Swingle with theVirginia Aquarium & Marine Science Center in Virginia Beach said they have no idea why.

“We really don’t know – I wish we did,” said Swingle. The aquarium’s Stranding Response Team has been gathering dolphin remains from throughout the Virginia coast – including two from Buckroe Beach in Hampton on Tuesday and one from Gwynn’s Island in Mathews County on July 26 – for necropsy and tissue testing. He said it could take two to three weeks to get results.

View/Submit Comments for this story

“In some ways, we’re trying to rush these tests to try and get a handle on what’s happening,” Swingle said. “We know there’s some sort of disease process going on. There’s no evidence on these animals of any sort of any human interactions.”
The number of reported dolphin strandings in Virginia for a typical year is about 64, he said. So far, the state has already seen 88. The unusual hikes were reported to the National Oceanic and Atmospheric Administration, or NOAA, which runs a network of stranding teams throughout the country.

So far, the only other state reporting an unusual uptick for July is New Jersey, said Maggie Mooney-Seus, spokeswoman for NOAA Fisheries. Their most recent number for New Jersey strandings is 20, but she said that figure might not reflect new strandings over the last couple of days. The state logged four strandings for July in 2012, and seven in 2011.

So far, she said, New York reported 15 dolphin strandings in July, Maryland seven and Delaware one. New York reported only one stranding July of last year, while Maryland and Delaware reported none. If enough unusually high numbers of strandings come in, she said, NOAA will assemble a team of experts to examine the data and necropsy results and determine if it qualifies as an “unusual mortality event.” The last such event in Hampton Roads occurred in 1987-1988, she said, and involved about 740 animals.

While that number was unusual, she said, dolphin beachings in general are not. “Keep in mind we do have strandings,” Mooney-Seus said. “They do occur regularly along our coasts and are caused by a number of reasons. If it’s a large population and living in close proximity, they’re not unlike deer populations or human populations where they can pass things to each other.”

Dolphin strandings can also be caused by entangling in fishing gear, ingesting plastics, toxic algal blooms or red tides, changes in water temperature and the rare vessel strike, as well as diseases like the distemper-like morbillivirus, which can also affect other marine animals such as seals, said Swingle. The stranding team hasn’t seen an uptick in stranding reports of other animals.

Determining the cause of death in a stranding can be hard, he said, especially if it’s not reported right away.
“The main thing is to call as soon as possible, because the sooner we get to the animals, the better the information we can get from them,” Swingle said. “It’s like the whole ‘CSI’ thing – if you have a fresh body, you can get a tremendous amount of information from it. If it sits in the sun for a day, it gets less valuable in terms of figuring out what’s happening.”
Seismic airguns. Meanwhile, environmentalists worry that even more such strandings could occur if geophysical survey companies are allowed to use seismic airguns to search for deposits of oil and gas buried deep beneath the sea floor, including off the coast of Virginia.

Airguns are typically towed behind ships and emit pulses of compressed air in a shock wave described as 100,000 times more intense than a jet engine. The airguns would boom every 10 seconds, day and night for days or weeks at a time.
To protest the plan, Oceana and the Sierra Club plan to make a big noise outside the Waterside Festival Marketplace in downtown Norfolk beginning at noon Saturday. Demonstrators are expected to use horns, vuvuzelas and the like to draw attention to the damage airguns can inflict on marine life and sensitive habitats.

An environmental impact statement released last year by the U.S. Department of the Interior estimated 138,500 whales and dolphins could be injured, deafened or possibly killed by the blasts over an eight-year period. “It’s loud, booming, and it disrupts their activity,” said Eileen Levandoski, assistant director of the Virginia chapter of the Sierra Club. “They depend on hearing to find their food. They can’t communicate with each other and they get lost. When you have a compromised animal with a bacteria or virus, they’re already weakened. You’re adding insult to injury.”

Swingle said seismic airguns have been used in other parts of the world, and “what those impacts may or may not be is open for question.” “Certainly anything that’s dangerous for marine mammals would be concerning,” he added.

President Barack Obama announced in March he was reversing a ban he’d placed on oil lease sales off most of the country’s coasts after the 2010 BP Deepwater Horizon drill rig exploded in the Gulf of Mexico, killing 11 workers and spilling nearly 5 million barrels of oil. Obama’s reversal re-opened the door to potential oil and natural gas exploration and drilling along the Atlantic coast, the eastern portion of the Gulf and part of Alaska.

Oceana and the Sierra Club want the Administration to reject proposals that include airgun use, and phase them out of U.S. waters. But if seismic testing is to occur, it should be done using the least harmful technology, with defined “no activity zones” to protect vulnerable marine habitats and species.

To report a stranding
If you see a beached dolphin or other marine animal, call the Stranding Response Program hotline 24/7 at 757-385-7575.

Leave a Reply

Your email address will not be published. Required fields are marked *