DATE: Thursday, September 4, 1997           TAG: 9709040471

SECTION: LOCAL                   PAGE: B5   EDITION: FINAL 

SOURCE: BY SCOTT HARPER, STAFF WRITER 

DATELINE: NORFOLK                           LENGTH:   91 lines

SCIENTISTS SEE MORE BAY FISH WITH LESIONS - BUT NOT PFIESTERIA MANY THINGS CAUSE SORES ON FISH, A MARINE SCIENCE OFFICIAL POINTS OUT.

A 45-pound black drum, caught Sunday near the Chesapeake Bay Bridge-Tunnel, had lesions covering 60 percent of its body, some the size of baseballs.

Was this the ugly work of Pfiesteria piscicida, the deadly microorganism that attacks fish and whose suspected presence has closed the lower Pocomoke River for five days now?

And worse, was this the first time that pfiesteria had reared its toxic head in the open waters of the Bay?

Almost definitely not, researchers at the Virginia Institute of Marine Science said Wednesday, after completing lab tests on tissues of the afflicted fish.

What the black drum illustrates, researchers and scientists say, is a significant rise this summer in the number and severity of cases of lesion-stressed fish found in the Chesapeake Bay and its tributaries.

While the rise in reports can partly be explained by a heightened public awareness of fish lesions, brought on by ``pfiesteria hysteria,'' researchers say something else - something still unexplained - may be at work, too.

``We see lesions every summer, but for some reason we're seeing a lot more this year,'' said Wolfgang Vogelbein, a fish pathologist and assistant professor at VIMS, a branch of the College of William and Mary.

``All I can tell you with certainty is that for about two months now, this is just about all we've done,'' he added, putting the number of fish autopsies that he and his colleagues have performed at ``an awful lot.''

Environmentalists charge that the pfiesteria scare, along with major fish kills in North Carolina, highlight poor government regulation of hog and chicken farms.

Hog and chicken manure is rich in phosphorus and nitrogen - two nutrients suspected of speeding pfiesteria's evolution from a quiet, bottom-dwelling microorganism to an aggressive fish predator.

Since state governments across the region mostly ask farmers to voluntarily comply with manure controls, environmentalists, led by the Chesapeake Bay Foundation, say the time has come to start considering tougher strategies for curbing this pollution source.

Late summer is probably the most stressful time for fish in the Bay. Water temperatures are high, dissolved oxygen is low, fishermen are out in strength, and pollutants washing off farms, back yards and city streets tend to spark algae blooms.

And parasites and microorganisms are most active. The black drum caught Sunday suffered from a bacterial infection of unknown origin, but Vogelbein said there was no evidence the cause was pfiesteria.

``Although it was a terrible-looking animal, it still was healthy enough to feed,'' he said.

One summer parasite, called a copepod, burrows into the tissue of a fish and rides around with its body parts flapping in the water.

``Quite a remarkable - but pretty disgusting - creature,'' Vogelbein said of the copepod.

It's this parasite that researchers found in two large, lesion-covered menhaden caught last week in Folly Creek, on the seaside of Virginia's Eastern Shore.

The fish were originally thought to be suffering from pfiesteria, and scientists combed Folly Creek last week in search of other, similarly stressed fish for testing.

They found one with abrasions caused by a fishing net, and another pocked by a still-unexplained lesion near its anal fin, according to the state Department of Environmental Quality, which led the Folly Creek hunt.

In May, just after reports first surfaced of lesion-covered fish on the Maryland side of the Pocomoke River, anglers near the Eastern Shore town of Cape Charles netted several striped bass with red sores on their bodies.

The Virginia Marine Resources Commission whisked the bass to VIMS, which quickly determined that the fish were suffering from a condition called lymphocystis, which does not harm the fish nor the humans who may eat one.

``What people need to know is that there's a hundred things that cause lesions and abrasions on fish,'' said Jack Travelstead, Virginia's director of saltwater fisheries.

``We encourage reporting (of troubled fish), but let's not panic; it's not automatically pfiesteria. We're not even sure if we have pfiesteria,'' Travelstead said.

Part of the fear over pfiesteria is that it can harm humans who come in contact with it. In closing about eight miles of the Pocomoke River to swimming, fishing and crabbing last Friday, the governors of Maryland and Virginia pointed to a medical report that linked pfiesteria to the illness of 13 Marylanders exposed to the river.

The victims, watermen and state workers, suffered slight memory loss, nausea and fatigue. They continue to be treated for their symptoms of pfiesteria exposure.

On Wednesday, Virginia officials continued to report widespread compliance with the Pocomoke's closure and said Virginia Marine Patrol officers will maintain a 24-hour surveillance of the lower parts of the river until scientists determine that the water is again safe.

More than 12,000 fish, mostly menhaden, have died in the lower Pocomoke during the outbreak, although none has been reported dead since Aug. 26, when about 2,000 perished on the Virginia side of the river.

Send Suggestions or Comments to webmaster@scholar.lib.vt.edu