Alabama snail first to make comeback from endangered list

Reuters News
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Posted: Jul 26, 2011 3:33 PM
Alabama snail first to make comeback from endangered list

By Verna Gates

BIRMINGHAM, Ala (Reuters) - A snail in Alabama has become the first in U.S. history to make the move from an endangered to threatened species, a comeback from the brink of extinction befitting the "magnifica" in its scientific name.

In 1991, the Tulotoma snail was barely clinging to one small spot, extinct in 99 percent of its historic range. The snail now has expanded to ten percent of its range.

"The Clean Water Act and improved land use conditions have allowed the snail population to start growing again," said Jeff Powell, senior biologist with the U.S. Fish and Wildlife Service.

Under the Clean Water Act, the federal government has implemented pollution control programs and set water quality standards for contaminants in surface waters.

At the bottom of the food chain, snails consume algae and provide food for other species. More snails indicate better water quality.

"What is good for the critters is good for the people," said Allison Jenkins, statewide coordinator for the Alabama Clean Water Partnership, which helped craft a plan for the recovery of the snails' ecosystem.

The orangish, two-inch long Tulotoma snail with elegant swirls was once prized by Native Americans for its beauty and crafted into jewelry. Its historic range was destroyed in the early 1900s, when dams emerged on Alabama's 70,000 miles of flowing rivers.

Snails and mussels thrive on flowing water, which has higher oxygen content. Powell described impounded lakes created by the dams as "bathtubs" where oxygen goes down and temperatures go up.

The Tulotoma snail's recovery resulted in part from an agreement with the Alabama Power Company to release a steady flow of water from its dam on the Coosa River.

"We changed to pulsing flows and installed aeration systems to raise the oxygen. It has had a dramatic impact on the river species," said Brandon Glover, spokesman for the power company.

U.S. Fish and Wildlife biologists and others also embarked on a diligent search for the Tulotoma and other species. New populations have been found in three more tributaries, bringing the numbers from 10,000 to hundreds of thousands.

Dispersed populations ease the vulnerability of a single event wiping out the species, as was the case when pollution of a small creek wiped out one of four populations of the snail.

Alabama leads the lower 48 states in extinctions, with 29 snails, 28 mussels and two species of fish already extinct, according to Michael Buntin, biologist with the Alabama Aquatic Biodiversity Center.

The state also holds the record for a single mass extinction, when a dam opened and wiped out 40 species.

One reason for the high numbers is Alabama's freshwater biodiversity, which includes 310 species of fish, 150 snails and 181 mussels, Powell said.

"There are more species of fish in the Cahaba River than in all of Europe," he said.

The diversity dates back to the Ice Age, when glaciers stopped in Kentucky. Species took refuge in the southern states, especially in Alabama, where the land slopes from mountain to sea, Powell said.

The current crop of snail babies signals a solid future for the Tulotoma, Powell said.

"We hope it is the first of many species to recover," Jenkins said.

(Editing by Colleen Jenkins and Greg McCune)