KNOXVILLE, Tenn. (WJHL) — More than 50 miles of river habitat in Southwest Virginia has been proposed to be protected as “critical habitat” for a small fish once found in rivers across Southern Appalachia – the sickle darter.

The U.S. Fish and Wildlife Service (USFWS) has announced a final rule to protect the fish, which once was found throughout nine river systems in Tennessee and Virginia but is now confined to smaller portions of six rivers. Those include the North and Middle forks of the Holston River as well as Copper Creek, a main tributary of the Clinch River.

“Critical habitat is essential for this beautiful bronze fish and the rivers it calls home,” said Will Harlan, a scientist at the nonprofit Center for Biological Diversity in a release from the center. “Protecting these 104 miles is an important step toward restoring not only the sickle darter but the health of Appalachian rivers.”

A sickle darter. The species is proposed to get critical habitat protection along 104 miles of rivers, including 53 miles of the North and Middle forks of the Holston and Copper Creek of the Clinch River in Southwest Virginia. (Conservation Fisheries Inc)

Roughly half the stretches of river are in Smyth, Scott and Washington counties in Southwest Virginia. They include 25 miles of the North Fork of the Holston, 14 miles of the Middle Fork and 14 miles of Copper Creek.

Siltation from logging and development is a main threat to the fish as it fills space between river bottom rocks that sickle darters use to lay eggs and find prey. The release said animal waste, sewage, pesticides and metals from mining have also polluted the small fish’s habitat.

Dams have separated populations and limited movement of the fish, which grow to nearly five inches in length, can live up to four years and feature a prominent black side stripe.

Sickle darters once lived throughout the French Broad, South Fork Holston, Powell and Watauga river systems but have disappeared there, according to a USFWA frequently asked questions page. The species was listed as threatened under the Endangered Species Act in late 2020.

According to the Center for Biological Diversity, critical habitat is key to an endangered species’ survival. Species with designated critical habitats are twice as likely to recover as species without them.

USFSW biologists consider occupied areas of a species and their “physical or biological features needed for life processes,” according to the federal FAQ. It also says the stretches of river include 23 other listed aquatic species and that nine of them have already designated critical habitat overlapping with the proposed sickle darter habitat.

Most of those are shellfish, but they also include the fish spotfin chub and yellow madtom.

“When we protect the sickle darter’s future, we’re also safeguarding our own,” Harlan said. “People need healthy water and healthy rivers, just like the animals who live in them.”