Three snails thought extinct discovered

[Melanie]

Three snails thought extinct discovered
The Associated Press
Last Updated 8:20 am PDT Friday, May 6, 2005
BIRMINGHAM, Ala. (AP) - Three snails listed as extinct have been rediscovered in the Coosa and Cahaba rivers, the Nature Conservancy announced Tuesday.
Jeff Garner, the Alabama Department of Conservation and Natural Resources' mollusk biologist, rediscovered the cobble elimia and the nodulose Coosa River snail on a dive in the Coosa River.


Stephanie Clark, a University of Alabama postdoctoral student from Australia, stumbled onto a Cahaba pebblesnail on a trip to the Cahaba River in Bibb County.
The findings, being announced by the Nature Conservancy, were reported Tuesday by The Birmingham News.

Alabama is known to be the nation's top spot for extinct and imperiled mollusks, the snails and mussels in river beds. Many were lost as dams were built along the Coosa River from 1917 to 1967, when it became a series of reservoirs.

In recent years, scientists have discovered some species hiding in the streams between reservoirs where the Coosa retains some of its original habitat.

Garner went diving below Lake Logan Martin and found two species that had not been spotted since the dams changed the river. Clark was accompanying a graduate student to the Cahaba River National Wildlife Refuge when she found the Cahaba pebblesnail that had not been spotted since 1965.

Garner, who has found several other species believed to be extinct, knew what he had immediately.

"One of these I found is pretty distinctive," Garner told the News. "I've always said it was my favorite snail - I hated it was extinct. It sort of has teardrops around the periphery."

Clark, who began postdoctoral research at the University of Alabama last year, didn't know what she had found at first.

"Behold, there was this oddball snail under a rock," Clark said. "I didn't know that I'd found an extinct one straightaway, but I knew I'd found something that I hadn't seen before."

The Cahaba pebblesnail - round, yellow, only about a quarter of an inch long - had not been spotted since 1965.

[Peter]

Alabama biologist, student find 3 snails thought to have been extinct

BIRMINGHAM, Ala. The Nature Conservancy say three snails listed as extinct have been rediscovered in the Coosa and Cahaba rivers.

Jeff Garner, a state mollusk biologist, rediscovered the cobble elimia and the nodulose Coosa River snail on the Coosa River.

Stephanie Clark, a University of Alabama postdoctoral student, found a Cahaba pebblesnail in the Cahaba River in Bibb County.

Alabama is known to be the nation's top spot for extinct and imperiled mollusks.

Of 174 species of aquatic snails to occur here, 39 are presumed to be extinct. The Coosa River is home to hundreds of aquatic animals, making it a global hot spot for snails and mussels. It is also the site of the largest extinction in the country's history.

In recent years, Garner is also credited with finding other species believed to have been extinct, including a snail in the Locust Fork, a mussel in the Alabama River and a mussel in the Tennessee River.

Last month Clark collected two snails she believes have never been recorded.

Copyright 2005 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Source: www.waff.com/global/story.asp?s=3293764&ClientType=Printable.

[Peter]

Scientific names:

Elimia vanuxemiana (Cobble Elimia)
Elimia Lachryma (Nodulose Coosa River Snail)
Clappia cahabaensis (Cahaba pebblesnail)

[Melanie]

Focus on Snails: 3 Snails—Rediscovery
Historically, the freshwater snail fauna of the Mobile River Basin (Basin) was the most diverse snail fauna in the world. It included nine families and about 118 species of snails. However, dam construction during the early twentieth century left the Basin fragmented, leaving surviving snail communities vulnerable to nonpoint runoff, acid mine drainage, siltation, de-stabilized river channels, and pollution from urban areas. These impacts have contributed to the extinction of nearly 40 species of snails, including all species of four endemic genera. This has had the unfortunate distinction of being the largest extinction event in the history of the continental United States.

However, late last year—2004—scientists saw a ray of hope when three of these presumed extinct species were rediscovered. Stephanie Clark, a post-doctoral researcher at the University of Alabama, discovered the Cahaba pebblesnail in a section of the Cahaba River in Bibb County, Alabama, and Jeff Garner, State Malacologist with Alabama’s Department of Conservation and Natural Resources, found two other snails—the teardrop elimia and the cobble elimia—in a stretch of the Coosa River between Lake Logan Martin and Neely Henry lake.

The pebblesnail genus Clappia is endemic to the Basin and includes two species of snails, both of which were presumed extinct. The Cahaba pebblesnail (Clappia cahabensis), one of those species, was formerly known from a single collection made in the Cahaba River in 1965. The site where Clark found the pebblesnails is near the original site but is currently a part of the recently dedicated Cahaba National Wildlife Refuge. Today, the shoals in the refuge support high numbers of native snails, including the endangered cylindrical lioplax, the threatened round rocksnail, and the recently reported endangered flat pebblesnail.

The teardrop elimia (Elimia lachryma) and the cobble elimia (Elimia vanuxemiana) were described during the mid-1800’s from a short reach of the middle Coosa River. Neither of the species had been seen in the Coosa for nearly 50 years, until Garner collected them late last year.

This section of the Coosa River, as well as the rest of the river, experienced extensive modifications during the early to mid 1900’s. The construction of large dams reduced the amount of riverine habitat available for snails and other aquatic species to short flowing reaches between the impoundments. Recent changes in dam operations and water quality improvements have likely contributed to the increase in snail diversity and numbers.

Since the rediscovery of these snails, things are hopefully looking up for the Basin. With the passage of two important pieces of legislation, the Clean Water Act and the Endangered Species Act, in the early 1970’s, water quality will hopefully continue to improve. Localized improvements in the way dams are operated, better water quality being discharged from industrial and urban sources, and increased understanding of the potential adverse affects certain land use practices have on water quality, have all been vital components to improving our rivers and streams.

Unfortunately, these three species have plenty of company on the Basin’s imperiled species list, including 39 other aquatic species listed as endangered or threatened under the Endangered Species Act, along with several candidates and a number of species of concern. These include mussels, fishes, snails, turtles and two aquatic plants. In order to maintain the positive momentum, we must continue to look for ways to improve water quality and protect riverine habitat, not only for the snails, but for everyone who relies upon its waters for consumption and recreation. In the old days, coal miners used canaries in the mines they were working to test the quality of the air before they entered. In a sense, snails are like those canaries. Every time a species goes extinct, it’s just another sign that something is not working properly in the ecosystem. Therefore, it’s up to the many citizens, researchers, and various interest groups in the Basin to continue working and searching for ways to improve both the quality and quantity of our water for the snails, as well as future human generations.

Photo of Cahaba pebblesnail



Photo of Teardrop elimia or Nodulose Coosa River Snail



Photo of Cobble elimia



Source of Information

www.mobileriverbasin.org/snails.htm