Pfiesteria-like lesions on fish in Middle River

Water samples show microbe is present

August 25, 1999|By Joel McCord | Joel McCord,SUN STAFF

State biologists have found live menhaden with lesions usually associated with Pfiesteria piscicida in three creeks off Baltimore County's Middle River, and water samples from five places in the river have tested positive for the microbe.

The water sample tests, performed by David Oldach at the University of Maryland, Baltimore, cannot determine whether the microbe, which can take 24 different forms during its lifetime, is in its toxic state.

There have been no reports of fish kills or of fish acting erratically and no indications of human health problems, which suggests "this is not an active outbreak" of Pfiesteria, said Robert Magnien, director of tidewater assessment for the state Department of Natural Resources.

In addition, the lesions are "to all appearances, old," Magnien said, suggesting the fish may have picked them up "at an earlier time in another place."

This is the farthest north scientists have found fish with lesions like those caused by Pfiesteria since they began extensive monitoring after the microbe killed fish and sickened watermen in 1997 in the Pocomoke River on the lower Eastern Shore.

Scientists have found Pfiesteria in one Western Shore river -- the Rhode, about 20 miles south of Annapolis -- but not in its toxic form. No fish with lesions and no fish kills have been reported there.

This is the second Pfiesteria-related incident in as many weeks.

Three people reported symptoms of Pfiesteria-related illnesses last week after coming in contact with water from Back Creek, a tributary of the Manokin River in Somerset County. Tests on two of them have been negative, and tests on the third have not been concluded, Dr. Robert Venezia, of the state Department of Health and Mental Hygiene, said yesterday.

Gov. Parris N. Glendening, who last week expressed concern about a repeat of the 1997 Pfiesteria outbreak, said yesterday there is "no reason to be concerned" about the findings.

"There is no evidence of toxic Pfiesteria in these early reports and no reports of Pfiesteria-related health problems," he said in a statement. "Lesions on fish can be caused by a variety of factors normally present in Maryland waters, so the Department of Natural Resources will continues to assess the fish caught in the Middle River area and to test additional water samples."

DNR biologists, who make a regular circuit of waterways in Wicomico, Somerset and Dorchester counties testing for Pfiesteria, came to Baltimore County after a caller to DNR's Fish Health Hotline reported catching menhaden Saturday with lesions.

Sunday, the biologists cast nets in Hopkins, Norman and Dark Head creeks and came up with 48 menhaden, 42 of which had lesions. Monday they got 84 menhaden, 75 of them with lesions, and by mid-day yesterday they had netted 48 menhaden, 14 of them with lesions.

The lesion on one of the fish caught yesterday probably is about a week old, said biologist Harry Rickabaugh. Unlike active Pfiesteria lesions, this one was dry and the skin was starting to grow back, he said.

Pub Date: 8/25/99

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