LEXINGTON, Ky.— In response to a petition and lawsuit from the Center for Biological Diversity and allies, the U.S. Fish and Wildlife Service today proposed to protect the round hickorynut and longsolid freshwater mussels under the Endangered Species Act, with more than 2,000 river miles of proposed critical habitat from Pennsylvania to Mississippi.

“Freshwater mussels are at the leading edge of the U.S. extinction crisis, so it’s a relief that these two important river dwellers are finally on their way to gaining the protection they need to survive,” said Tierra Curry, a senior scientist at the Center. “Protecting these mussels helps people too by improving the water quality of our rivers.”

The Center and allies petitioned for protection of the mussels in 2010 and filed a lawsuit in 2019 to enforce a deadline for a decision on their protection.

The once-common longsolid has lost 63% of its populations, and only three out of 60 surviving populations are considered to have a high chance of survival. The round hickorynut has now lost 78% of its populations, and only four of 65 are ranked as having high resiliency.

The Service today denied listing for a third petitioned mussel, the purple lilliput, even though 47% of its populations have already been wiped out and 20% of its remaining populations aren’t expected to survive the next few decades.

Mussels improve water quality by filtering small particles from the water as they eat and breathe. They reproduce by making lures that looks like fish, crayfish or worms; when their host fishes attempt to prey upon the lures, the mussels release their fertilized eggs onto the fish’s gills. Juvenile mussels develop on the gills before dropping off to begin life on their own.

“Most people have never even heard of freshwater mussels, but their importance can’t be overstated,” said Curry. “They save cities money by filtering water, they stabilize streambanks, their shells provide homes for small fish and crawdads, and they provide food for turtles, otters, birds and sports fish. We really need to take better care of them and their river homes.”

Species Background

The longsolid is a five-inch long mussel with a light brown shell with darker brown stripes and a pronounced ridge. It lives in the Ohio, Cumberland and Tennessee River basins in Alabama, Kentucky, North Carolina, New York, Ohio, Pennsylvania, Tennessee, Virginia and West Virginia.

The round hickorynut is a 2.5-inch, almost perfectly round mussel with a greenish-olive shell with a yellow band. It lives in the Great Lakes and in the Ohio, Cumberland, Tennessee and Lower Mississippi River basins in Alabama, Indiana, Kentucky, Michigan, Mississippi, Ohio, Pennsylvania, Tennessee and West Virginia.

The mussels are threatened by water pollution from urbanization, agricultural, oil and gas drilling and pipelines, coal mining and coal-fired power plants, and by increasing stream temperatures and storm events caused by global climate change. The listing proposal states that threats to the species are expected to worsen.

The southeastern United States is the world center of freshwater mussel diversity, but the region has already lost 23 species to extinction. Nearly 70% of mussels are at risk of extinction due to historical collection to make buttons, dams and ongoing water pollution.