DATE: Thursday, September 25, 1997          TAG: 9709250376

SECTION: LOCAL                   PAGE: B1   EDITION: NORTH CAROLINA 

SOURCE: BY LANE DEGREGORY, STAFF WRITER 

DATELINE: COROLLA                           LENGTH:   64 lines

ONE PFIESTERIA CELL FOUND IN ATLANTIC SCIENTISTS WHO STUMBLED UPON IT AFTER CLAM KILL AREN'T WORRIED

Stirred-up sediment and unusually warm water killed thousands of clams that washed ashore between Corolla and Sandbridge, Va., last week, scientists said Wednesday.

But while researchers were testing the shellfish and nearby waters for signs of disease, they found a single cell of the microorganism pfiesteria in the Atlantic Ocean.

The organism, in its toxic form, has killed or sickened millions of fish in North Carolina, Virginia and Maryland and is suspected in health problems among watermen and researchers. But it is usually associated with inland waters.

Pfiesteria is a common organism, but it can take on a toxic form under certain environmental conditions. Scientists believe that pollution triggers the transformation.

The single cell of pfiesteria found about a mile south of the Corolla Lighthouse marks the first time in almost five years that the algae-like creature has been documented in the sea off North Carolina.

But scientists said that may be because they don't routinely test the water for the organism unless there has been a fish kill or other evidence of its presence. The organism can leave lesions on the skin of dead or dying fish, and sometimes on humans.

``I don't think there's any need to get alarmed by it at this time,'' Al Hodge, an engineer with the state Division of Water Quality, said. ``There's no indication the waters up there aren't fine. Pfiesteria's probably been around forever. And unless it gets into certain concentrations, it's not really anything to be concerned about.''

In December 1992, scientists discovered pfiesteria off Topsail Beach, a report in biologist JoAnn Burkholder's office says. Burkholder is the North Carolina State University professor who helped discover the microorganism in 1990. She was unavailable for comment Wednesday.

Hodge said the pfiesteria off the northern Outer Banks is a very small amount and should not stop people from fishing or swimming.

The single cell was the equivalent of 12 cells per milliliter of water, Hodge said Wednesday from his Washington, N.C., office. He said it would take 10 times that many to produce enough toxins to kill a fish.

``Our conclusion is that the passing of the hurricane off the barrier islands disturbed the sediment that got into the juvenile clams and brought unusually warm water into the area,'' Hodge said. ``The northern surf clams just couldn't survive. We did't see any lesions on any of the clams - although we looked at four gallon-bags filled with them.

``Our conclusion is that pfiesteria did not kill these clams.

``But I was surprised that there was any pfiesteria at all in the ocean around them.''

Hugh Porter, a researcher in North Carolina's Sea Grant program, also said that the Corolla clams had no lesions.

``Fish kill lesions from pfiesteria are pretty big, so we'd see them,'' Porter said. ``There was silt in these clams' tissues which leads me to believe that siltation was part of the problem.

``I don't think it was pfiesteria.''

State water monitors will keep in touch with watermen who work between Corolla and Virginia Beach to see if they notice any fish with strange sores or fish washing ashore.

But Hodge said the division of water quality doesn't plan to do any follow-up monitoring in the area - or find out if more pfiesteria is nearby. KEYWORDS: WATER POLLUTION

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