Virus or Poisoned Environment? : Scientists Race the Clock to Solve Dolphin Deaths
When the badly scarred bodies of two dolphins washed up on the New Jersey shore last month, Robert Schoelkopf, a marine mammal researcher, was not alarmed. About 30 of the carcasses drift onto mid-Atlantic beaches every year, usually for natural causes, he said, and the dolphins that tumbled out of the surf here seemed to fit that pattern.
But then the toll began rising dramatically, not only in New Jersey but also on the beaches of Delaware, Maryland and Virginia. By last weekend, the bloodied, ulcer-ridden bodies of more than 150 bottlenose dolphins had swept ashore and biologists said an equal number were floating at sea, most of them dying slow, painful deaths.
If the epidemic does not end soon, a herd of more than 1,500 dolphins that roams the Atlantic coast--and whose frisky, playful brethren have won the hearts of fans at marine shows around the world--could soon be fighting for its very survival.
Just as important, scientists say, the sudden and inexplicable deaths of so many intelligent marine mammals may pose disturbing questions about the long-range health and safety of the world’s oceans.
“I’ve never seen anything remotely like this, not of this magnitude,” said Schoelkopf, who directs the state’s Marine Mammal Stranding Center on a beach two miles east of Atlantic City. “Right now, we are looking at an environmental catastrophe.”
How the baffling disease began is anybody’s guess.
In recent weeks, scientists have conducted autopsies of the beached mammals, sent tissue samples to laboratories for analysis and run a multitude of tests to identify the baffling disease. But they still do not know why dolphins are dying in such record numbers. They cannot explain the ulcerous lesions covering the animals when they wash ashore. Most important, they do not know why a larger herd of nearly 14,000 Atlantic dolphins farther offshore has not been affected.
There is no shortage of theories, however. Some scientists believe the disease is a highly contagious virus that the dolphins have spread to each other. But others suggest that pollution is the culprit, especially on the New Jersey coast, where most of the dolphins have come ashore.
This weekend, state officials closed more than 30 miles of New Jersey beaches as an offshore mass of raw garbage, sewage and hospital waste products--including syringes and bandages--spilled onto beaches that are normally jammed with bathers. Environmental officials said the garbage either fell off barges headed for a landfill to the north, or was dumped illegally at sea and floated down to the New Jersey coast.
‘Haven’t Got a Clue’
“I don’t think anyone has proven conclusively that this (pollution) is the source of the dolphin problem,” said James Staples, a spokesman for the New Jersey Department of Environmental Protection. “But scientists can’t rule it out. At this point, they haven’t got a clue.”
Soon after the epidemic broke out, officials with the National Oceanic and Atmospheric Administration put together a team of marine biologists to investigate the mysterious disease. The group, headed by Dr. Joseph Geraci of the University of Guelph in Ontario, Canada, set up shop in a motel on the Virginia coast and has been painstakingly examining the dolphin bodies as they wash ashore.
Researchers report that most of the live animals that come ashore die minutes later. The mammals’ tongues and mouths have rotted away, and their normally gray, glistening bodies are overrun with sores that peel off and expose lower skin layers to salt water infections. Most of the beached dolphins show signs of not having eaten for two weeks.
“We’re stumped . . . there is nothing in the medical literature to explain this,” said Brian Gorman, a spokesman for the research team. “It is an enigma, pure and simple.”
Netted Dying Dolphins
Off the coast of Virginia Sunday, about 25 NOAA scientists, Navy divers and volunteers used three boats and a 400-foot-long net to capture and examine three dying bottlenose dolphins.
“They all had evidence of the problem,” said NOAA spokesman Jack LaCovey. “They probably will be dead in a day or two.”
Before researchers released the dolphins back into the ocean, they drew blood samples and examined each animal’s body. All had skin lesions, mouth lesions and blood that appeared abnormal, and one showed evidence of bloody fluid in its stomach cavity, LaCovey said.
“It’s quite helpful to get this information, because it tells us about the progression of the disease, which we haven’t had before,” he said.
LaCovey said the blood samples drawn Sunday would be analyzed at Virginia Beach General Hospital and Eastern Virginia Medical School. Preliminary results on the blood tests should be available today, as should results from dead dolphin tissue samples sent late last week to the National Animal Disease Laboratory in Ames, Iowa.
Preliminary Results
“Now whether or not we’re going to be able to comment on them, we don’t know,” LaCovey said. “After all, preliminary results are only preliminary results. I’m not sure the experts here expect the tests to come back with the answer.”
Although they have no conclusive proof, some scientists are skeptical that ocean pollution is killing the dolphins. For example, Dr. Andrew Robertson, a biologist who works for NOAA in Rockville, Md., said random tests do not show high levels of toxic contamination in the waters where most dolphins swim, nor is there any proof that garbage dumping has permanently fouled the Atlantic Ocean.
The epidemic is probably caused by an organism within the dolphins themselves, a rare virus, perhaps, that is causing “natural” deaths but on a larger scale than seen before, he added. Still, scientists should refrain from any speculation until autopsies yield conclusive results, Robertson cautioned.
Others find it hard to believe that pollution is not a factor.
As he stared intently at the surf, looking for traces of a dying dolphin that had been spotted several minutes before, Schoelkopf gestured with disgust at a sign closing off one of the beaches near Brigantine.
The beaches were reopened to bathers Sunday after an aerial survey found that the 50-mile-long garbage slick had disappeared and water tests found no dangerous levels of bacteria.
“In recent days, they’ve found every conceivable kind of hospital junk floating onto these beaches,” Schoelkopf said. “They even found a human skull, which had apparently been part of an autopsy, bobbing in the waves. How can you just ignore that?”
More important, he said, state officials were ignoring the actions of a sludge dumping operation, 100 miles off the New Jersey shore, which is licensed by the Environmental Protection Agency. The facility dumps acid residues from a paint-making business into the ocean, an activity that EPA officials have said is safe.
The treated chemicals are normally caught up by strong currents and pulled in an easterly direction far out to sea. But this year, Schoelkopf noted, a freakish “westerly finger” of the current has been carrying waters from the dump site toward the shore, along the path similar to that taken by dolphins on their summer migration.
Can Humans Be Far Behind?
“If this condition is killing off dolphins, can humans be far beyond?” he said. “We just can’t afford to let our oceans become permanently polluted.”
State environmentalist Staples said the metallic, acid residues being dumped off the New Jersey coast are not threatening marine life. Still, officials acknowledged that the state has been trying without success to put an end to offshore dumping.
“Everybody thinks the oceans are so limitless, but one day all of this may come back to haunt us,” Staples said.
