Helping fish get around

Conservation: Harford County passage lets hickory shad and other migrating fish return to old spawning waters.

April 26, 2000|By Joel McCord | Joel McCord,SUN STAFF

WILSON MILL -- The cold waters of Deer Creek just below this old mill dam in Harford County are stirring with life being spawned by migrating fish.

Midstream, where water bubbles over and around the rocks at a furious rate, schools of alewife herring and hickory shad are holding themselves against the current, waiting for nature to tell them to move on. Every so often, the calmer pools and eddies explode with the splashes of spawning.

What these fish don't know -- and what state Department of Natural Resources officials hope they will soon figure out -- is there is a way around this dam, which has stood here for more than 200 years.

Last month, the state opened a $263,000 fish passage on the south bank of the creek, about five miles upstream from its confluence with the Susquehanna River.

Anglers have hooked shad in the creek from Darlington Road east to the river for years, but this passage, skirting the edge of the dam, opens 24 more miles of the creek, to Rocks State Park, to the fish.

Although this passage benefits all migrating fish, it is the first in the state built primarily for hickory shad, which are smaller than American shad.

The passage is part of a national movement to open the nation's rivers to migrating fish by tearing down obsolete dams or providing ways for fish to get around them to upstream spawning areas they haven't reached in centuries.

Some fish take advantage of the passage, but others might not at first, says Brian O'Roark, a DNR fisheries biologist.

"The dam has been here so long, that the fish spawn here. It could take a couple generations for them to realize they can go further upstream," he says.

But even if not all of them go on, there is more spawning habitat for those that do, says Eric Schwaab, head of the DNR's fisheries division.

Less competition for food

Fish born farther upstream, with less competition for food and more places to hide from predators, are bigger and stronger than their downstream cousins when they begin the annual migration back to the ocean, says Jackie Fary, the DNR biologist in charge of this project.

More than 29,000 alewife herring, hickory shad, fallfish, sea lamprey and white sucker have slipped into the narrow passageway, up over wooden baffles designed to dissipate the energy of the water and into a huge net pen above the dam where they are counted, weighed and sent on their way.

The biologists have found small yellow egg masses at Nobles Mill, about three miles upstream, indicating that the fish are spawning successfully, says Larry Leasner, head of special projects for DNR's fisheries service.

Populations decimated

Since Colonial days, Americans have built about 75,000 dams to harness the power of water and to provide drinking water. Those dams have kept migratory fish from their historic spawning grounds, decimating shad and other populations.

In Maryland, the shad harvest crashed from 7 million pounds annually a century ago to 20,000 pounds in 1980 when a moratorium on American shad went into effect. A moratorium on hickory shad went into effect a year later.

State and federal agencies have removed 121 dams from rivers across the country and built numerous fish passages in just more than a decade.

Workers punched a 60-foot hole in Maine's Edwards Dam in July, allowing spawning fish to reach the headwaters of the Kennebec River for the first time since Andrew Jackson was president.

In October, state and federal officials staged a ceremony to celebrate the start of work on a fish passage at Little Falls Dam on the Potomac that will allow American shad, striped bass, sturgeon and perch to reach prime upstream spawning waters for the first time in 40 years.

The draft Chesapeake Bay agreement that was unveiled in December calls for restoring passage for migratory fish to more than 1,350 miles of rivers by 2003 and setting goals for more by 2004.

`Repay farmers, cities'

"Bringing shad and herring back to our rivers is one of the best ways to repay the farmers, the cities, the industries and others upstream for their efforts to reduce the supply of nutrients washing into Chesapeake Bay," says Bill Matuszeski, director of the U.S. Environmental Protection Agency's Chesapeake Bay Program.

Susquehanna Electric opened its first fish lift in 1972 and another in 1991 to get migratory fish past its huge hydropower dam on the Susquehanna near Havre de Grace. Amergen, an energy company, is to open a fish ladder at its dam at York Haven near Harrisburg, Pa., in June, allowing American shad to reach Binghamton, N.Y., near the headwaters of the river.

Friday, federal and local officials announced a schedule to remove Embrey Dam and build a fish lift on the Rappahannock at Fredericksburg, Va., opening 121 miles of that river.

Maryland has built 21 fish passages since 1987 and torn down seven dams, reopening roughly 292 miles of spawning habitat.

Early Monday afternoon, the net pen at the Wilson Mill fish passage was empty. The hickory shad and alewife herring were just below the dam, along with 30 or more sea lamprey that had attached themselves to rocks, their small fins swaying with the rush of the current.

The water temperature was 50, too cold to continue a spawning run, Leasner says.

Within two hours, nine alewife had gone up the passage, but the hickory shad were hanging back. They would come later, he says. "We've had days we had to take [the net pen] out of the water because there were so many fish in there."

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