Dead dolphins washing up on our shores, scientists looking for reason

The Riverhead Foundation released rehabilitated bottlenose dolphin "Seabreeze" in 2007 | Courtesy The Riverhead Foundation
The Riverhead Foundation released rehabilitated bottlenose dolphin “Seabreeze” in 2007 near Shinnecock Inlet | Courtesy The Riverhead Foundation

UPDATE: AUG. 9, 2013

The National Oceanic and Atmospheric Administration has declared an “Unusual Mortality Event” is occurring in bottlenose dolphins along the East Coast, with dolphin deaths along the coast reportedly seven times higher than usual for the month of July. NOAA says “an infectious pathogen is at the top of the list of potential causes for this UME” and they are still trying to determine what is making the dolphins sick. More information on NOAA’s research is available here.


From Virginia to Jones Beach to Montauk, dead dolphins began washing up in large numbers along the Eastern Seaboard in July, and scientists are just beginning to put together the pieces of what is happening to them.

The Riverhead Foundation for Marine Reserch and Preservation responded to 20 calls for dead or distressed bottlenose dolphins along the South Shore of Long Island this July, said rescue program director Kim Durham on Monday. Ms. Durham said, in a typical July, the Riverhead Foundation responds to five to six cetacean cases — of whales, porpoises or dolphins. In a normal year, maybe one or two of them are bottlenose dolphins. This hasn’t been a normal year.

“2013 has been across the board higher numbers than we’ve seen in previous years for all species of cetaceans,” she said. “We do all the forensics and we’ve been quite busy trying to document these animals. We hope to get our samples out to the labs at NOAA fisheries this week.”

The Riverhead Foundation reports its monthly figures to the National Oceanic and Atmospheric Administration, which authorizes the foundation to rescue marine animals, and to the state Department of Environmental Conservation.

Ms. Durham said the Riverhead Foundation has ruled out human interaction as the cause of death, meaning the dolphins haven’t been injesting marine debris, been struck by boats or been damaged by fishing gear.  She said one dolphin in New Jersey has tested positive for morbillivirus, a contagious dolphin disease that can present itself as pneumonia, and several in Virginia have had skin lesions that are also considered a side effect of dolphin pneumonia. But, she said, it’s too early to conclude that all the dolphins are suffering from a virus. The potential causes that first must be eliminated range from bacterial infections to other viral infections to biotoxins in the water due to red tide.

Ms. Durham said she hopes to have results from the morbillivirus test by the end of the week.

“Morbillivirus has been implicated in mortality events with dolphins,” she said. “In 1987 almost a thousand dolphins between Virginia and New Jersey died.”

She said in late June and early July, many of the dolphins found on the beaches were alive, but by the end of the month, most had already died before the Riverhead Foundation responded.

Seabreeze is placed in the rehabilitation tank in 2007 | Courtesy Riverhead Foundation
Seabreeze is placed in the rehabilitation tank in 2007 | Courtesy Riverhead Foundation

Complicating matters further, The Riverhead Foundation has the only dolphin rehabilitation tank in the Northeast, and a Risso’s dolphin named Roxanne has been living in the tank since she was found off of Oak Beach in June. The Riverhead Foundation would like to release her soon, so they can have a free tank in case a live bottlenose dolphin comes in.

“Right now, they have to be humanely euthanized,” she said of live bottlenose dolphins found in distress on beaches. “There are no other options for them. No other organization has the resources to rehab dolphins. There are a lot of cutbacks the stranding community is dealing with and our tank is the only one.”

Ms. Durham said she’d heard a report of a live dolphin at Gilgo Beach Sunday night, and beachgoers in East Hampton Saturday night reported a live common dolphin stranding, but people kept pushing it off the beach until it disappeared.

“We want people to know if they come across a dolphin on beach or a lone dolphin swimming close to shore, it’s something we’d like to know,” she said. “They tend to hang out in large groups. If you see a single animal, it’s probably in distress. We really don’t recommend they push the animals off. It’s not there by accident. It’ hasn’t misread the tides. Something is going on. If you push it offshore, it will strand in another location. Also, the animal is going to fight you. Bottlenose dolphins are 200 to 300 pounds and there’s a potential for injury.”

While they work to find out the cause of the strandings, The Riverhead Foundation and other sea animal rescue agencies are fighting another battle, this time with the U.S. Congress.

Ms. Durham said several of her colleagues were in Washington to testify before Congress last week because the John J. Prescott Marine Mammal Assistant Grant program, which provides up to $100,000 per year to marine mammal rescue organizations, is slated to be cut from the federal budget for the next two years, and NOAA’s fisheries budget is also facing severe budget cuts.

“That means a lot of cutbacks in what we’re able to do,” she said. “It’s scary when kids are swimming in the water and dolphins are dying around them. Their parents are going to want answers.”

To report a sea mammal stranding to the Riverhead Foundation, call 631.369.9829.

Beth Young

Beth Young has been covering the East End since the 1990s. In her spare time, she runs around the block, tinkers with bicycles, tries not to drown in the Peconic Bay and hopes to grow the perfect tomato. You can send her a message at

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