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Fish species, thought extinct, found hanging on by a thread

Officials work against time to save the robust redhorse

April 16, 1997
Web posted at: 7:06 p.m. EDT (2306 GMT)

An expanded Web version of segments seen on CNN
biologist battle to save fish

(CNN) -- Georgia officials have launched a dramatic rescue mission that could save a river-dwelling fish from extinction. But the efforts to reintroduce the robust redhorse to its native habitat have hit a snag, with the rare fish's offspring often dying.

Officials had hoped to release thousands of fingerlings in northeastern Georgia as part of an ongoing project. But when biologists drained hatchery ponds this spring, they found that all the young robust redhorse had perished. More common fish in the ponds were healthy.

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"Temperatures may have not been exactly right. The food source may not have been at its peak," explained Jimmy Evans, a biologist with the Georgia Department of Natural Resources.

fish in hand

The setback means there will be no robust redhorses to release in the fall, unlike last November, when about 15,000 fingerlings were released into northeast Georgia's Broad River. Each was tagged with a microwire that lets biologists track the fish's whereabouts.

It also means officials are frantically working against time to save the dying species.

"We just got a few years to learn what we can about these fish," Evans said.

A rare catch

The robust redhorse was thought extinct for more than 100 years until Evans discovered the fish in Georgia's Oconee River in 1991.

fish in bucket

"I had no idea at the time exactly what it was, except I knew it should not be there," Evans said. "There's no question it was discovered in the nick of time.

What he found was about 1,000 to 3,000 fish that were last seen 122 years ago. The fish is a species of redhorse sucker and has teeth in its throat used to grind up the shells of mussels, its primary food.

The robust redhorse population dwindled in the 19th century apparently due to deforestation and farm-clearing efforts that poured tons of silt into southern U.S. rivers, covering gravel river bottoms. The rocky bottoms were necessary for the fish to reproduce,because fertilized eggs were placed in the spaces of the gravel.

Unique union to save fish

fish with needle

After his discovery, Evans worked to find a way to save the fish, most of which were 15 years of age -- so old their reproduction systems were not functioning properly. He formed the Robust Redhorse Conservation Committee, a unique compilation of government agencies, power companies and conservation groups determined to save the fish.

The group decided not to put the fish on the federal endangered species list, because they believed red tape would slow down efforts to save the species.

As part of the reintroduction efforts, biologists inject the elderly fish with hormones to encourage them to produce eggs. Thousands of fish have been born and moved to protected ponds to ensure survival of the species.

Despite several setbacks, researchers remain determined. The breeding program is expected to continue for several years, and the fish in the protected ponds are doing well.

"We have a lot more questions than we have answers, and the answers are coming very slowly," said Jay Shelton of the University of Georgia.

From Medical Correspondent Al Hinman

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