By Todd Shields and Paul W. Valentine
Washington Post Staff Writers
Sunday, September 21, 1997; Page B01
The Washington Post
The toxic microbe's first confirmed kill was in the Pocomoke River
-- about as far south as you can go on Maryland's Eastern Shore.
Then the microbe bloomed in a creek 15 miles north of the Pocomoke.
Last week, Pfiesteria piscicida apparently struck again, this
time in a Virginia waterway south of Washington.
And the questions grew louder: Was the microorganism spreading
and, if so, where?
Scientists cannot answer either question definitively.
It could be that the Pocomoke, the Chicamacomico River, the Kings
Creek tributary of the Manokin River and Virginia's Rappahannock
River are unusually ripe for pfiesteria.
Some surmise that the recent discoveries of pfiesteria attacks
could simply be a result of the intense search for them.
While scientists continue to grapple with the questions of where
and why, they feel fairly certain about one thing: If pfiesteria
outbreaks in North Carolina offer any insight to the microbe's
habits, the Chesapeake Bay area will likely see it subside for
the winter.
In coming months, scientists will compare data from pfiesteria-stricken
rivers, looking for similarities among factors such as salinity,
temperature, acidity and nutrient pollutants, said Carin Bisland,
associate director for ecosystem management for the Chesapeake
Bay Program, which coordinates research on the bay.
"This is a conundrum everyone is working on," Bisland
said.
Some scientists believe pfiesteria's growth is fostered by nutrients
such as nitrogen and phosphorus from air pollution, cities, suburbs,
sewage plants and farms.
Maryland scientists are just beginning to examine Kings Creek
and the Chicamacomico in hopes of finding similarities with the
Pocomoke, said Robert Magnien, director of Tidewater Ecosystem
Assessment for the Department of Natural Resources. Scientists
suspect or have confirmed that pfiesteria was at work in its toxic
stage in all three waterways where fish with sores were found.
Magnien earlier had theorized that the Pocomoke might be particularly
vulnerable to pfiesteria because the river's upper reaches, which
are swift, deep and cloudy, efficiently deliver nutrients to its
lower reaches. There, the microbe can thrive in a nutrient-rich
aquatic environment that is shallow, warm, slow-moving and filled
with algae and fish to eat. Pfiesteria erupted twice on the river
last month, killing 20,000 or more fish.
"There's no way they're going to be identical" to the
Pocomoke, Magnien said of the other waterways. But, he added,
"nothing in these events really changes our picture"
of how the Pocomoke might be an ideal place for pfiesteria.
But outside the Pocomoke, several scientists said, it is uncertain
whether pfiesteria was any more abundant or virulent than in years
past, when it may have existed relatively unnoticed.
Virginia authorities say they have long noticed sores like those
gaining attention on the Rappahannock last week, and officials
say some past fish kills may be attributable to the microbe.
In recent weeks, as telecasts and newspapers have been filled
with reports of pfiesteria, Virginia and Maryland have established
telephone hot lines for people to call to report fish with lesions.
Maryland's hot line is 888-584-3110; Virginia's is 888-238-6145.
"There's no question that at this moment, everyone is sensitized
to pfiesteria," said Michael F. Hirshfield, a vice president
of the Chesapeake Bay Foundation, a private advocacy group. "We
now have people looking for something specific, whereas before
you might have had a waterman saying, `Ahh, that's odd,' and neglecting
to pass it on."
In at least one case, the publicity served its purpose. Fisherman
Brian Parker, of Westover, noticed the pfiesteria eruption on
the Manokin River. He went home and turned on his television and
saw Maryland's new pfiesteria hot line number on the screen during
a newsbreak. He called, and officials arrived soon after to confirm
the outbreak.
More than 525 such calls have come into the 24-hour hot line since
Sept. 5, said Natural Resources spokesman John Surrick. Of those,
"several dozen" warranted dispatching a team of biologists
to take a closer look, he said. That sent state biologists to
13 rivers beyond the three already known to be infested.
They searched dozens of sites but found no new evidence of the
organism, Maryland officials said. Most of the 13 additional rivers
searched by biologists were on the Eastern Shore. On the western
shore, biologists inspected parts of the Potomac and Patuxent
rivers in the Washington area, the Patapsco in Baltimore and the
Bush and Susquehanna rivers farther north.
Despite such results, some remain apprehensive about what course
the microbe might take.
"That damn mess is coming right up," waterman Emerson
Travers said last week as he unloaded wicker baskets filled with
softly gurgling blue crabs in Cambridge, about 15 miles from the
Chicamacomico. Travers said he had spotted fish with lesions in
the Little Choptank River, one of those that state biologists
have checked.
"I've never seen anything like this," Travers said.
"It's a plague."
Staff writer Peter S. Goodman contributed to this report.
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Washington Post Company