Fish kill bay's worst in decade

200,000 died in week on Magothy, Patapsco tributaries, state says

2-year drought blamed

Situation could get worse, but DNR sees `no lasting impact'

July 02, 1999|By Joel McCord | Joel McCord,SUN STAFF

The estimated 200,000 yellow perch, menhaden, mummichogs and silverside that died in the upper reaches of Magothy and Patapsco rivers' tributaries in the past week represent the worst such fish kill in 10 years, state officials said yesterday.

And unless the weather changes, the fish kills will only get worse, said Charles Poukish, environmental specialist for the state Department of Natural Resources.

The kill is another indication of a Chesapeake Bay ecosystem "living on the edge of severe problems," added Robert Magnien, DNR's chief of resource assessments.

The waters of the Chesapeake Bay and its tributaries are so loaded with nutrients that "whenever Mother Nature throws us a curve like this, we have a real problem," he said.

In this case, much of Maryland has been under a drought for two years, with rainfall 10 inches below normal so far this year.

"The driving force behind [the fish kills] has been the drought conditions, and the only thing that will stop it is if we get some rain to flush out the system or some colder temperatures," Magnien said.

Since June 25, DNR officials have confirmed fish kills in Cockey, Cattail, and Deep creeks and Little Magothy River, all off Magothy River; Baltimore's Inner Harbor; and Bear, Colgate, Marley, Furnace, Stony, Rock and Bodkin creeks, and Old Road Bay, all off Patapsco River.

Poukish said the department has received unconfirmed reports of fish kills on the Eastern Shore directly across the bay from the mouth of Patapsco River and in Weems Creek off Severn River.

The fish, most of them minnows, have died from a lack of oxygen, Poukish said. The hot, dry weather has allowed nutrients, mostly phosphorus and nitrogen, to concentrate in the water, creating algae blooms, which deplete the oxygen in the waters.

An oxygen level of 2.0 parts per million is lethal to fish, Poukish said, and the levels in the tributaries where the fish have died have ranged between 0.05 and 0.07 parts per million.

Poukish and Magnien said none of the dead fish had lesions or showed any signs of Pfiesteria piscicida, the toxic microorganism that killed fish and sickened people along three rivers on Maryland's lower Eastern Shore three years ago.

Although the fish kills might cause problems in some small areas, they are insignificant in terms of the overall population of fish in the Chesapeake Bay, said Eric Schwaab, director of DNR's fisheries service.

"There will be no lasting or major impact on the bay," he said.

Dr. Robert Venezia of the state Department of Health and Mental Hygiene warned residents not to swim in areas where they find large numbers of dead fish, not to touch the fish with their bare hands and not to eat them.

Because they are decaying, he explained, the fish are targets for microorganisms that could be harmful to humans. The state operates a fish health hot line to answer any questions.

Normally, the dry weather that bedevils farmers is good for water quality in the Chesapeake Bay because the lack of rain reduces the amount of runoff from fields, lawns, roads and other surfaces. But in this case, the "sustained stagnant conditions" have led to concentrations of nutrients in the upper reaches of the tributaries, Poukish said.

The National Weather Service is forecasting hazy, hot and humid days with a chance of thundershowers through the weekend.

The state's fish health hot line is 1-888-584-3110.

Pub Date: 7/02/99

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