The “cell from hell,” the mysterious killer-microbe pfiesteria that caused havoc in the Chesapeake Bay three years ago, has hardly been heard from since. But it’s still around.
It’s still something of a mystery, it’s still considered dangerous and it’s still a major environmental issue.
True, scientists now say that although the minute organism is “a concern,” it is not the menace it was blown up to be. Yet, says biologist David Goshorn, the public “overreaction” it created was “understandable” after the creature killed about 30,000 fish and poisoned humans.
Mr. Goshorn is a program chief in Maryland’s Department of Natural resources. He said the months-long blitz of media reports that appeared with increasing frequency about this time of year in 1997 was to be expected.
“Something was happening, and people were asking us for explanations. We had no answers. So naturally the anxiety grew. We know more now,” he said.
The fish kills and reported human casualties triggered a political spat because Virginia’s fishing grounds abut Maryland’s waters near the principal fish-kill area, and fallout from the adverse publicity affected and worried Virginia citizens and business interests.
That riled state leaders, who contended Maryland had rushed to a conclusion regarding the cause of the kills and then reacted hastily and rashly. Some scientists also got into the dispute.
Eventually the political sniping ended when the governors of Maryland and Virginia signed an agreement to share research findings. Representatives of North Carolina, Pennsylvania, Delaware and West Virginia also signed the pact.
A spokesman for the Virginia Department of Environmental Quality confirms the disagreements stirred by the microbe have ebbed. He said, “There’s no question that pfiesteria played a role in those kills although there still are a lot of unanswered questions.”
Quiet so far
Indeed, among the big questions is precisely why pfiesteria, which is mostly nontoxic but can turn poisonous, hasn’t attacked again in the past three years.
There has been just one pfiesteria-associated fish kill nearby since 1997. That occurred in New Jersey a year ago. However, officials there failed to report it for months, saying they couldn’t be sure pfiesteria was the culprit. Now, they are.
The Maryland Department of Natural Resources has this year located pfiesteria in the Middle and Transquaking rivers and at two sites in the Pocomoke. The discovered organisms weren’t in a poisonous stage.
Scientists understand in a general way that the weather, water temperature and amount of salt in the water help prod pfiesteria to become venomous. So do water currents and the presence of contaminating animal waste and phosphorus. But it’s now understood that the mix of conditions has to be exactly right.
All the right ingredients were present in summer of 1997, when the pfiesteria fright slowly began to build.
A scourge of fish
Early reports of sick fish came from the Pocomoke River area near Shelltown, about 20 miles from Salisbury and at the southern end of Maryland’s Eastern Shore. Commercial fishermen began complaining to wildlife officials and to the media that sores they found on fish weren’t normal.
Watermen reported thousands of dying and dead fish mostly menhaden floating on the Pocomoke River and sky-blanketing hordes of gulls gobbling the victims before fishermen could make accurate kill counts.
The fishermen contended they had been reporting abnormally high fish kills since the previous October, but their reports got little attention. Finally, a television reporter sent one of the diseased fish to JoAnn Burkholder, a North Carolina State University scientist running a laboratory specializing in the study of Pfiesteria piscicida.
That organism is a scourge of fish in some of North Carolina’s shallow, turbid, manure-laced waters. In the last decade, it is said to have killed a billion fish in the state.
Pfiesteria is a primitive, one-cell, microscopic animal. It’s quite similar to the creatures that constitute plankton, the water-dwelling organisms that at times flow in great hordes.
Although pfiesteria was not known to dwell in the Chesapeake Bay or its tributaries, Miss Burkholder identified it as the killer of the fish sent to her.
Meanwhile, fish-kill reports continued. Anglers increasingly reported their catches were ill with unusual sores, and people who were working, swimming or boating in the areas where ill and dead fish appeared began reporting they too were developing lesions and other symptoms.
Eventually pfiesteria was said to seriously poison at least 13 persons. The victims had experienced nausea, memory loss and confusion. There were shocking reports that tests showed some of the most affected victims experienced a reduced ability to learn. The symptoms lasted for months.
At length, state officials reacted, closing a seven-mile stretch of the Pocomoke River and two smaller tributaries for almost two months.
Activity on the Bay decreased. Tourism declined, and seafood sales dropped like an anchor, eventually causing a reported $43 million in damage to the industry.
Chicken farmers especially those in the $512 million chicken broiler industry protested they were being driven out of business by new laws passed in reaction to the pfiesteria attack. The legislation altered the way farmers could dispose of manure from their stock, and increased costs. But officials justified the regulations because runoff from farms was suspected of contaminating river water, heightening the water’s nutrient content and creating an environment in which pfiesteria flourishes.
Once pfiesteria was implicated in the fish kills, research on the organism increased dramatically. In Maryland, where the problem seemed most acute, the Department of Natural Resources increased its $1.5 million water monitoring program. Among other ventures, the National Institute of Environmental Health Science provided University of Maryland researchers with $6.3 million for a five-year study of the organism and its effects on human health.
A spokesman for the institute said results of the research efforts it is underwriting aren’t in yet. But Mr. Goshorn explains that Maryland is intensely monitoring waterways it paid relatively little attention to before. Crews on the state’s rivers are cataloging the fish, checking their health and sampling water quality.
Learning what’s normal
As a result of the monitoring system, researchers are learning what is normal, what kinds of abrasions and sores Bay-area fish can be expected to have and which afflictions are dangerous to the fish and to humans. They’re discovering where in the Bay system fish are most vulnerable to attack and disease.
Researchers now know that pfiesteria can metamorphose into 24 forms, at least three of which are toxic. Yet no one is sure exactly what causes the organism to turn poisonous. Scientists want to know that.
And there is still the question of how pfiesteria got to the Bay in the first place. Twenty years ago, no one in the area was aware of it.
Patricia Glibert, a University of Maryland researcher and professor, says, “There are many ways pfiesteria may have developed in the Bay. It could have been transported by currents or storms. It could have been present in a dormant stage in the sediment and grew when conditions became ripe for that.”
Until we find out, she concludes, “We certainly have to take pfiesteria very seriously.”