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Massive Dolphin Die-Off Could Be From Measles-Like Virus

August 26, 2013
Image Credit: Thinkstock.com

Lawrence LeBlond for redOrbit.com – Your Universe Online

Researchers from the University of Pennsylvania’s School of Veterinary Medicine have turned a large laboratory designed to treat four-legged animals into a research facility to get to the bottom of one of this summer’s greatest tragic mysteries.

Some 70 miles away, dolphins are turning up dead along the Jersey shore and other coastal communities and, at this point, the cause still remains largely unknown. More than 200 dolphins have washed ashore since June and many have ended up on UPenn’s New Bolton Center research tables where veterinarians look to find an answer.

The UPenn lab was specifically called upon for this task due to close ties with the Marine Mammal Stranding Center (MMSC) in Brigantine, NJ, which handled many of the deceased creatures that turned up on nearby shorelines.

The Center, located in Kennett Square, PA, sits in the southeastern part of the state near the Delaware line. The board-certified veterinary specialists have performed detailed necropsies on each of the dolphins brought into the lab to hunt out and identify potential abnormalities. Hours upon hours are then spent examining tissues under microscopes and researchers conduct tests with antibodies, hoping to uncover the cause of death in these intelligent marine mammals.

After painstakingly long processes, some evidence has turned up.

“One of the saddest things to see on these creatures is some have horrible pneumonias and ulcers so you know that they are suffering. And the shark bites are kind of sobering to look at,” Dr. Perry Habecker, chief of large-animal pathology at the New Bolton Center, told USA Today’s Kristi Funderburk.

MORBILLIVIRUS

Habecker said morbillivirus, a measles-like disease that played a role in the massive die-off of 742 bottlenose dolphins along the East Coast in 1987, has been found in some of the dead dolphins washing up on beaches this summer. However, it is still too early to tell if this is the root cause of this year’s die-offs.

Through more extensive analyses, the researchers are looking at the virus more closely, as well as toxins, biotoxins, bacteria, pollutants and any other potential culprit, according to Maggie Mooney-Seus, a communications specialist with the NOAA’s Northeast Fisheries Science Center.

“We haven’t ruled anything out yet because we have had animals from a pretty wide area and we have to look at everything that could be behind this,” she said.

Some suggestions that have arisen are that last year’s superstorm Hurricane Sandy played a role or the Gulf of Mexico oil spill from 2010. But according to Robert Schoelkopf, director of the MMSC, neither Hurricane Sandy nor the oil spill has anything to do with this.

Schoelkopf said that he immediately knew these creatures were suffering from sort of lung infection when they began washing ashore earlier this summer. He noted, “My mind shot right back to 25 years ago when I did the same thing.”

During the 1987 dolphin die-off, Schoelkopf personally witnessed the death of 93 of the animals in NJ alone.

He said that what is very startling with what is being seen this go-around is that females are washing ashore and are visibly lactating. “That means there’s a baby out there swimming around without a mother. That baby is going to become shark bait.”

UNUSUAL MORTALITY EVENT

So far this summer, there have been at least 230 dolphin deaths along the East Coast, prompting the NOAA to declare it an unusual mortality event (UME). This clears the way for intense scientific research in order to find a cause of death.

There have been 60 recognized UMEs since 1991, but only 29 have been resolved with a cause.

Because the NOAA enacted so quickly, Habecker’s team have been able to get moving on finding a root cause. Cultures taken from the dolphins are being sent to labs in Florida and California. Habecker noted that these facilities have the expertise and technology to find out what may be at play here.

Habecker said tissue work will continue in his own lab to determine if morbillivirus is present in further specimens.

“We know it’s out there. It’s always been out there, but we don’t know why we’re seeing some more of it,” Habecker said of the virus.

Mooney-Seus said that knowing the cause of the illnesses and deaths seen in dolphins will give experts an idea of whether this is naturally-occurring in the dolphins or if this had started as a result of some human-based activity.

“You have to look at everything so you can look for opportunities at remedying it if we can,” she told USA Today. “It shows something is definitely going on in the ecosystem and that’s why we have to look at all those environmental factors as well.”

Habecker said that historically, the most common cause for premature dolphin mortality is pneumonia or a parasitic worm that attacks the brain. He and other colleagues are continuing to look for patterns before making any concrete estimates.

Kim Durham, a biologist with the NEFSC, said these dolphins are likely suffering from a bacterial or viral infection. This virus does resemble measles, she said.

“There’s a lot of skin contact among them,” Durham told CBS News. “They’re constantly rubbing each other, so yeah, the possibility that they’re spreading it among themselves is very large.”

LIFE CHANGING EVENT

Schoelkopf, who has been working with dolphins for decades, left a job at an aquarium to pursue a more important role. Once he found that dolphins were much smarter than they were given credit for, he launched the Stranding Center to save dolphins. He said this changed his life forever.

“I didn’t want to work with captive dolphins anymore,” he said. “It wasn’t right for them to do 13 shows a day and never see sunlight.”

After founding the MMSC, Schoelkopf went on to earn a national reputation for rescuing beached or distressed dolphins and other sea creatures.

This summer’s die-off is not the first such incident and won’t be the last. Schoelkopf said it looks to be a “naturally occurring” event and could occur again in another 25 years. “That’s the idea of doing the extensive tests like this, that they can possibly find somewhere or some way around the problem.”

Considering the massive dolphin die-off in 1987, Schoelkopf believes the deaths should start to taper off near the end of September. What is not known is how many more will turn up dead between now and then.

Schoelkopf told CBS News that when fewer dolphin carcasses are seen along the Jersey Shore, that won’t mean the problem is over. It is likely that more deaths will be seen along the southern states due to the animals’ annual migration routes south.

Mooney-Seus said that more dead dolphins are showing up in the south already. During July and most of August the farthest southerly extent of dolphin deaths was Virginia. Now, some dolphin carcasses are turning up in North Carolina.

Since the UME was declared by the NOAA’s NEFSC, the UPenn facility has taken in 33 dolphins, but Habecker noted that the lab had received some before that point, as well.

Schoelkopf is urging anyone who encounters a dolphin, whether it is in the water or on shore, to not approach it. Sharks have been known to attack the dolphins, most of which die before coming ashore, and pose a danger, he said.


Source: Lawrence LeBlond for redOrbit.com - Your Universe Online



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