Experts hope dolphin disease has nearly run its course

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A dolphin takes a breath while swimming off Ocean City Saturday with several others. Federal officials fear a deadly illness could be coming back north with the returning animals, although the hope is that the disease will peter out this spring. (photo by Bill Barlow) A dolphin takes a breath while swimming off Ocean City Saturday with several others. Federal officials fear a deadly illness could be coming back north with the returning animals, although the hope is that the disease will peter out this spring. (photo by Bill Barlow) With warming temperatures, the snowbirds are returning from Florida.

That goes for wildlife as well as human cold-averse residents. On platforms along the marshes and back bays, ospreys are choosing their nesting sites, and over the weekend, just past the wetsuited surfers in the 40-something degree water in Ocean City’s north end, a pod of dolphins made its way through the waves.

Now that the water is warming up some, the marine mammals are making their way back into local waters after migrating south for the winter.

Bob Schoelkopf, the founder and director of the Marine Mammal Stranding Center in Brigantine, said he expects to see fewer dolphins along the New Jersey coast after last year’s devastating die-off, but at the same time, the local population will likely be healthier.

Last year the center was swamped with calls as a massive number of bottlenose dolphins died. According to experts with the National Oceanic and Atmospheric Administration, the culprit was the morbillivirus.

Throughout the Northeast from July to November, 753 dolphins beached, more than 10 times the average for that period. Almost all of them were dead when they washed ashore, and none of those still alive survived.

In the fall, federal wildlife officials feared the animals migrating south would spread the disease to the dolphin populations that live in Florida year-round.

This is not the first time the disease has slammed the Atlantic Coast’s dolphin population. Last time, in 1987-88, dolphins were dying in huge numbers. In that instance, the returning dolphins brought the disease back north, according to Maggie Mooney-Seus, a spokeswoman for NOAA’s northeast region.

A generation later, both for human beings and the long-lived bottlenose dolphins, federal investigators blame the same virus. Morbillivirus is related to the virus that causes measles in humans, and there are related viruses in several species. Authorities say there is no reason to believe the illness can spread to people, but still cautioned against handling dead or ill animals because the disease suppresses the immune system, and there may be other illnesses present.

This time, there were more reported instances of dolphins beaching, but then there is also a larger dolphin population than there was in the 1980s.

Mooney-Seus said there is a possibility that the dolphins returning to local waters may still carry the sickness. In the instance 26 years ago, the course of the disease continued into the spring before it petered out, she said, suggesting that pattern may repeat this time.

“Not in New Jersey,” said Schoelkopf. He expects that most of the sick dolphins have not survived the trip south and the long swim back to New Jersey.

Schoelkopf said he well remembers the sickness of the 1980s. The epidemic 26 years ago played out in a similar way, he said, with few of the sick animals surviving the migration.

“We don’t expect to see the remnants of the morbillivirus. I think we’re going to see a normal cycle,” he said.

Still, he advises anyone who sees a beached dolphin or one that is floating to call the stranding center at 609-266-0538.

According to Mooney-Seus, the new generation of dolphins did not have immunity to the disease last year. The investigation into the deaths continue, but she said NOAA hopes the disease has almost run its course in the population.

Most of the infections were to bottlenose dolphins, although Mooney-Seus said indications of morbillivirus have been found in other species as well, including whales.

So far this spring, Schoelkopf said he had not heard of any dolphin sightings, although he expects the calls to start coming in soon.

“We’re still up to our ears in seals,” he said.

The New Jersey population of seals has greatly increased in recent years, and throughout the East Coast. He said he has 12 animals at the stranding center right now, including one that was injured by a dog that had been allowed to run free on the beach.


Related: 

Dolphin disease spreading south with migration

Feds confirm virus is cause of dolphin deaths


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