• The slabside pearlymussel was once found in Alabama, Kentucky, Mississippi, Tennessee and Virginia. Now it has been lost from Kentucky and survives in no more than 11 streams in the Tennessee River watershed in the other four states. It is four inches long with a shiny, greenish-yellow, triangular shell that is white on the inside.
• The fluted kidneyshell was once found in the Cumberland and Tennessee river watersheds in Alabama, Kentucky, Tennessee and Virginia. It already is extinct from Alabama and now occurs in only 12 of 37 of the streams where it was once found. It is five inches long with a yellowish-brown oval shell with wide green rays outside. Its inside shell is bluish-white with a streak of salmon pink.
Source: Center for Biological Diversity
The U.S. Fish and Wildlife Service has proposed Endangered Species Act protection today for two species of freshwater mussels, and the agency wants to designate 1,380 miles of the Tennessee River and some of its tributaries as "critical habitat."
The designation would affect rivers in Alabama, Kentucky, Mississippi, Tennessee and Virginia.
Biologists say water pollution and dams have caused the steep decline of the once-plentiful Tennessee River native mussels -- the slabside pearlymussel and fluted kidneyshell.
The decisions to protect the slabside pearlymussel and fluted kidneyshell are a result of a 2011 settlement with the Center for Biological Diversity that requires the agency to speed protection decisions for 757 species around the country.
The proposal, announced Wednesday, offers specific plans to finalize that protection, according to Tierra Curry, a conservation biologist at the center.
Tennessee Valley Authority spokesman Bill Sitton said TVA does not expect the new additions to the Endangered Species List will affect the production of electricity on the region's rivers.
"The Tennessee Valley has an abundance of mussels, and some of those species are endangered and threatened. We recognize that, and we have a long history of trying to protect them," Sitton said. "So we don't expect adding a couple more to have a significant impact."
Mussels improve water quality by filtering small particles from the water when they eat. They also are important because they are indicators of high water quality in that they require clean, free-flowing rivers to survive and reproduce.
"Saving these mussels will take a shoulder-to-the-wheel effort," said Curry. "But with the Endangered Species Act being 99 percent effective at preventing the extinction of species under its care, we're hopeful these Tennessee River natives won't be erased."
The slabside pearlymussel "is no longer found in nearly 70 percent of its native streams. All remaining populations are in decline and several are on the verge of being lost," Curry said.
Once widely used to make buttons and jewelry, mussel shells, like trees, accumulate growth rings that can be used to determine their age. Freshwater mussels can live for centuries, making them among the longest-lived invertebrates.
Both mussels also are threatened by gravel mining, urban and agricultural runoff and pollution from coal mining and processing, according to Curry.