Monday, December 03, 2012

Fewer Dams = Better Fishing

While there is much to be said for dams in their role of flood control and reservoirs for drinking water, they also degrade the quality of fishing.

For years, the first thing Ranger Tom Charles has done on spring mornings at Cape Fear Lock and Dam No. 1 is let in the fish.

“There’s probably hundreds of them” waiting below the 11-foot dam 39 miles northwest of Wilmington, he says. “When they’re in there pretty thick, you’ll see them jump, but you can’t see how many there are.”

Most are American shad, waiting for Charles to open the lock to start them on the 90 miles or so to their ancestral spawning grounds in Harnett County. It’s the short leg of the journey for some of these fish important to the marine food chain; they started out in Nova Scotia.

The churning mass also includes striped bass, which migrate shorter distances, and there could also be an endangered sturgeon or two, says Charles, who works for the Army Corps of Engineers.

When spawning territories are blocked, “You lose the vast majority of the population,” says Mike Wicker, Raleigh-based biologist with the U.S. Fish and Wildlife Service.

When lifted by the locks, 35 percent of the shad make it past all three dams, according to a study by Dr. Joseph Hightower, U.S. Geological Survey biologist teaching at N.C. State.

Beginning next spring, North Carolina, the corps, and the fish will embark on a new venture. The lock will stay closed, and the fish will begin their journey on their own. They’ll jump up a natural-looking “rock arch rapids” or weir – a 200-foot slope of rock added to the downstream side of the dam.

It stretches up to the top, and “fish swim right over the dam,” Wicker says.

Although it’s a first for the Southeast, “That kind of rock arch weir has been done quite a bit in the Midwest,” Hightower says. “It’s been very successful there.”

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1 comment:

Old NFO said...

Then it truly WILL be only the strong surviving...