Yellow perch making surprise return

November 29, 1993|By Andrea F. Siegel | Andrea F. Siegel,Staff Writer

Yellow perch, an indigenous fish that all but vanished from many Chesapeake Bay waterways, made an inexplicable comeback this year, as yearlings turned up even in Sawmill Creek.

A Maryland Department of Natural Resources survey in October turned up 123 yellow perch in Sawmill Creek -- an area where none was found four years ago.

"We know that these urban streams could serve as spawning sites," said Stuart Lehman, a DNR biologist who electroshocked several areas of the creek last month. "We simply cannot write off urban streams." Electroshocking involves sending an electric current through the water, briefly stunning the fish and allowing them to be counted as they float to the surface.

The resurgence of young yellow perch is an encouraging sign, especially to area residents who worked over the past two decades to clean up the polluted Sawmill Creek Watershed. The watershed covers about 8.5 square miles in the Glen Burnie and North County vicinity.

"It's a good sign for the creeks in the area," said Rick MacDonald, president of the Sawmill Creek Watershed Association.

Yellow perch turned up at four stations along the main creek and in the tributary that runs behind the Glen Burnie Industrial Park, -- Mr. Lehman said.

One of the locations was above Wagner's Pond, a marshy pool near Crain Highway at Eighth Avenue, which indicated three possibilities: that water levels allowed the fish to get over a small dam to spawn, the fish were thrown into the upstream location by local fishermen, or they have been living undetected in the pond.

The high yellow perch count in the watershed is in keeping with this year's record reproduction around the bay of white and yellow perch, herring and striped bass, said Harley Speir, a DNR fisheries biologist.

Neither he nor others can explain the record spawning, nor why yellow perch apparently returned to spawn in Sawmill Creek, nor why the juveniles then survived the spring and summer in Sawmill. Sampling at 22 stations from the head of the bay south showed the yellow perch average had jumped dramatically.

"We know something has happened. We're not sure exactly what," Mr. Speir said.

Both he and Mr. Lehman suspect this year's weather has more to do with it than anything else.

Yellow perch swim upstream to shallow meandering streams to spawn in late February and early March. Crucial to a large spawning are mild winters -- so that eggs don't die -- and even temperatures. Stable and moderate water flows keep eggs and newly hatched fish from being rushed downstream and prevent adult fish from being trapped downstream at spawning time.

The past year's weather accommodated the fish, Mr. Speir said.

The water level in Sawmill Creek was slightly higher than in past years and showed less fluctuation, said Mr. MacDonald, who monitors the creek.

Water-quality analyses will be done this winter, Mr. Lehman said, but no one can imagine sudden, drastic water-quality improvement in Sawmill Creek and other waterways.

Nevertheless, biologists credit volunteers' cleanup efforts with removing blockages created by trash. Hauling away garbage and large items dumped near the creek beds creates an atmosphere that discourages further pollution, Mr. Lehman said.

Little by little, some man-made barriers, such as culverts, have been removed, giving the yellow perch the opportunity to spawn upstream.

Yearlings are only about 4 inches long now. Sawmill Creek empties into Furnace Creek, and the young fish can be expected to move into that warmer and deeper waterway next year, Mr. MacDonald said.

How many survive, as well as next spring's spawning run, will go a long way toward indicating whether this year's baby boom was an aberration, normal variation, or the start of a trend in the Sawmill area and elsewhere in the bay. Males mature at 2 to 3 years, and females at 3 to 5 years, so this year's young won't be parents soon.

A variety of factors caused the decline in the yellow perch population: pollution, acid deposits, barriers, overfishing and booming development that replaced trees and marshes with culverts and asphalt.

At the turn of the century, yellow perch were so plentiful in the bay that commercial fishermen harvested better than 1 million pounds a year. But by 1988, yellow perch were in such decline that the state closed several waterways to yellow perch fishing and began a stocking program.

But DNR has since reopened a somewhat recovered Choptank River for perch fishing after it had been stocked and is now considering reopening other rivers.

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