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Saving the Shell Game

Article from the Birmingham News, March 14, 2004, Front Page

Saving the shell game

03/14/04

KATHERINE BOUMA
News staff writer

Scientists hope they are making history on the Coosa River this year, restoring a snail that was believed to be extinct to a stretch of river thought to be dead.

It's a drama that's playing out around the state as scientists try to stop the nation's largest extinction cluster from expanding.

Alabama is recognized as the globe's most densely populated home of mollusks - the snails and mussels that dot the beds of rivers, the acres of white shells that gave Muscle Shoals its name.

It also is now known to be the nation's top spot for extinct and imperiled mollusks. But that recognition took a long time.

In other parts of the country, biologists began decades ago to take heroic measures to save rare animals. They have hatched whooping cranes in Maryland, taught them to survive in Florida, and used ultralight aircraft to guide them on annual migrations to Wisconsin. In the Pacific Northwest, billions of dollars have been spent studying, hatching and recreating habitat for salmon.

In Alabama, zoologists still are trying to figure out how some of their endangered species reproduce. Proposals for protection include gaps and guesses. Even so, in four spots biologists are placing mollusks in rivers where they once flourished.

"When you're looking at water, and you know there's mussels and snails down there but you can't see them - there's a little bit of a disconnect there," said Stan Cook, chief of fisheries for the Alabama Department of Conservation and Natural Resources. "We don't get to flip on the video and see the whooping cranes flying down to Florida."

Why they matter:

Although small, forgettable and often invisible, snails and mussels are animals whose necessity is well and truly understood.

Mollusks are food for a variety of larger creatures: fish, turtles, ducks and small mammals. Most important to humans, they are filter feeders. Mussels and some snails suck in water wholesale and pull out bacteria and waste material. Other snails clean the riverbed.

"That's the way that the ecosystem has of cleaning itself," Cook said.

Little else in the river cleans the water, although plenty else soils it.

Ultimately, if all the filter feeders in the rivers gave up their work, the state could be forced to stop issuing pollution permits to mills, factories and others that pour pollution into rivers, scientists say. "Industry that is looking ahead is starting to recognize this and get on board," Cook said.

However, no one knows exactly how many filter feeders a river needs. "You can't say, `The next species is the one that will not allow us to locate industry on the river because the system cannot cleanse itself anymore, or because people can't eat fish anymore, or eat shrimp in the Gulf anymore,'" Cook said.

Lost and found:

In 1990, the entire Coosa River had been dammed and was no more than a string of reservoirs with locks and dams for navigation and power generation. The famous Muscle Shoals of the Tennessee River were in a similar condition. So was every other major river in Alabama, the state with more river miles than any other.

Some mollusks that had survived the 20th century now lived only in isolated creeks or no longer reproduced.

The outlook was bleak for many river species. The state was in danger of losing 10 percent of its fish species, 65 percent of snails, 69 percent of mussels and 43 percent of turtles, according to the University of Alabama.

Then scientists found something that gave them a sliver of hope. North of Montgomery, an endangered snail was surviving more than 20 years after its stretch of river had been bypassed and abandoned. It was living, apparently, on the leakage from a nearby dam.

The discovery of the Tulotoma Magnifica suggested something stunning to aquatic zoologists - that one section remained of the Coosa River reefs that had spawned such an unparalleled multitude of animals. And it still could sustain life.

Because of the quirks of building a reservoir at that particular spot, Alabama Power Co. had dug a canal into the middle of a cornfield and built the Walter Bouldin Dam far from the actual riverbed, said Willard Bowers, the company's vice president for environmental affairs. As a result, a seven-mile relic of the river was not submerged in a reservoir.

Scientists approached Alabama Power, and the utility agreed to try to restore natural conditions. Mimicking nature for a snail, Bowers said, is a record-keeping nightmare.

The slow-moving creatures tolerate only gradual changes so they don't drown when the water rises or become stranded when it's low. One day the snail might need 4,000 cubic feet of water per second, the next 3,900 - no more, no less. "It's hard to measure 3,900 cubic feet per second," Bowers said.

But in the end the Tulotoma thrived.

Suddenly biologists had what they desperately needed: a waiting room for creatures teetering on the edge of extinction.

"This represents some of the best riverine habitat in the Southeast," said Paul Johnson, director of the Tennessee Aquarium Research Institute.

Not-so-extinct snail:

But it was not until this winter that the river fragment was used to save another animal.

Scientists had been grappling with the problem of the interrupted rocksnail since 1997, when a graduate student pulled one of the supposedly extinct creatures from a Georgia tributary of the Coosa.

Biologists now had a chance to save an animal believed to be lost - and they had a new species to add to the list of those that had more troubles than chances of survival.

The interrupted rocksnail was declining rapidly in its last holdout, which was on the Oostanaula River. Because it was officially extinct, it had no federal protection or hope for help from federal agencies. Furthermore, in 1997 no one had ever coaxed a river snail to reproduce in a laboratory. So scientists had no interrupted rocksnails to spare.

But Johnson and his staff already were working in their laboratory outside Chattanooga to propagate plicate rocksnails, an endangered species with only a toehold in the Locust Fork.

After four years of playing with water temperature and current, they produced the first lab-born river snails. They immediately tried the same ploy on their new snail, which turned out to be far less picky. By this winter, the aquarium had more than 3,200 interrupted rocksnails to put in the Coosa in the section north of Montgomery.

"The question is: Will these animals still be able to survive there?" Hartfield said. "The rocksnails have been gone two or three decades."

Conservation crisis:

The rocksnail and the Tulotoma are two animals that may have been found in time. A handful of animals around the state are being propagated by Johnson's team or moved by conservation scientists to spots where they will have their best shot at survival.

But for dozens more, little or nothing is known or being done.

"Basically, here we are with a conservation crisis on our hands, with no knowledge, no science, no facilities to deal with it," Hartfield said.

He recently proposed 11 mussels for federal protection. He doesn't even know how two of them reproduce.

"You don't know anything about these animals - you don't even know what they eat," Hartfield said. "You have to fake a lot of it."

Some mussels remain in such small numbers that their survival is doubtful without aggressive and accurate efforts.

At the newly restored stretch of river, there are worries it will become little more than a seven-mile natural zoo for animals that have no real-world chance of survival. Worse, if enough rare animals are planted on that spot, a single disaster could wipe out a significant portion of genetic database of the river basin.

State scientists hope to double their chances by getting a similar stretch of river restored near the Georgia state line, just below Weiss Lake. They are now in negotiations with Alabama Power to restore flows there.

"There's a lot of good habitat left, including the Coosa, but it's in bits and pieces," Hartfield said. "And every piece has a different problem."

But he said many scientists around the state are optimistic that the "extinct" snail that got a second chance is the beginning of an awakening.

"Nobody had been paying attention," Hartfield said. "It never really dawned on people what we had truly lost."


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