Contributed photo / The sickle darter, native to certain rivers and streams in Tennessee, North Carolina and Virginia, is the subject of a U.S. Fish and Wildlife Service proposal to list the species under the Endangered Species Act for certain protections that seek to stabilize sickle darter populations. There are only six known sickle darter populations, including a small number of the fish in the Sequatchie River.

The U.S. Fish and Wildlife Service is seeking comments on the proposed listing of a tiny fish that lives in the Sequatchie River and other bodies of water in East Tennessee as threatened under the Endangered Species Act.

The sickle darter — a small, slender-bodied fish native to the upper Tennessee River, also found in North Carolina and Virginia — exists in only six known populations, according to Fish and Wildlife officials, and it is primarily threatened by habitat loss and water quality degradation.

Those threats combined with negative effects of the sickle darter's reduced range have caused the disappearance of historically known populations. For threatened species, the agency has some flexibility to tailor prohibitions for their protection, according to agency officials.

"Species like the sickle darter, which are found nowhere else in the world, deserve our protection," agency regional director Leopoldo Miranda said in a statement. "Despite the challenges that the species is facing, much work has been set in motion to help stabilize populations and lay the foundation for its eventual recovery."

The six known populations of sickle darter are found in the Emory River, Little River and Sequatchie River in Tennessee and the Upper Clinch River, North Fork Holston River and Middle Fork Holston River in Virginia.

Before 2005, the sickle darter was known to be in the Emory, Clinch, Powell, Little, French Broad, North Fork Holston, Middle Fork Holston, South Fork Holston and Watauga rivers. Sickle darters were found in the Sequatchie River in 2014.

Because of habitat changes, sickle darter populations within the French Broad, South Fork Holston, Powell and Watauga rivers have been lost, officials said.

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Map contributed by the U.S. Fish and Wildlife Service / This U.S. Fish and Wildlife Services map shows the sickle darter's historic range and its current range, only a fraction of the former range across the Appalachians in Tennessee

A Knoxville, Tennessee-based nonprofit conservation group was able to produce 25 juvenile sickle darters from propagation efforts and released juvenile fish in 2017. The propagation effort provided valuable information on the species' reproduction and early life history and shows that there is potential for hatchery rearing and population restoration as a conservation tool in the future, agency officials said.

Conservation Fisheries Inc., a nonprofit organization, seeks to conserve aquatic species in the Southeast. The group is under contract with the federal agency and has been working with the sickle darter for the past several years.

Organization officials say propagation efforts with captive fish have been a struggle.

"We have been propagating it, and we actually have been reintroducing it into the Tellico River," Conservation Fisheries' Missy Petty said Wednesday.

"We've had limited success with that," Petty said. "They're a lot harder to breed in captivity than we anticipated."

Conservation Fisheries director J.R. Shute said trouble for the sickle darter probably started with dams built on the Tennessee River starting in the 1930s that dramatically limited movement of the tiny fish. When the river was dammed, that cut off established populations of sickle darters and ended any genetic exchange, he said.

In Tennessee, the sickle darter is most populous in the Little River in Blount County and in the Emory River in Morgan County, and "they found just a couple in the Sequatchie River, but not a whole lot," he said.

"The populations we see now are just remnants of what it must have been at one time," Shute said.

The goal of conservation work and the proposed listing is to stabilize the sickle darter's population, officials said.

"Our function was to try to determine if we could breed these animals in our hatchery and then release and establish populations where they once occurred and no longer do," Shute said of work with the agency.

"They've turned out to be really tough; I don't know why," he said. "We've spawned them, but we're not getting the kind of numbers that we'd like to be able to get."

Shute said the proposed listing "is really an effort to stave off extinction."

The agency will accept comments on the proposal postmarked by Jan. 11, 2021, or received electronically by noon that day.

The proposal, if ultimately approved, would not completely halt certain types of restoration work and transportation projects, but would limit those activities to certain times of the year to help protect the sickle darter's spawning period, officials said.

The proposed rule for the sickle darter under the act would provide exceptions to incidental take, or capture, of the fish resulting from restoration work by state wildlife agencies, channel restoration projects, stream bank stabilization projects and forest management activities that implement the highest standard of best management practices, according to the agency.

Under the proposal, federal officials said, transportation projects that include designs to provide for fish passage in waters inhabited by sickle darter also would be exceptions. Proposed provisions in the rule would mean those excepted activities can only occur between April 1 and Jan. 31 to help avoid the sickle darter's spawning period, which is generally from February to March.

For now, the agency is only proposing listing the sickle darter.

A "critical habitat" designation entails the protection of a species' habitat, according to the agency. That designation for the sickle darter will be proposed at a later date, officials said.

Contact Ben Benton at or 423-757-6569. Follow him on Twitter @BenBenton or at


The U.S. Fish and Wildlife Service will accept comments received or postmarked on or before Jan, 11, 2021. Comments submitted electronically using the Federal eRulemaking Portal must be received by 11:59 p.m. EST on Jan. 11, 2021.

You may submit comments by one of the following methods:

Electronically: Go to the Federal eRulemaking Portal: In the Search box, enter FWS–R4–ES–2020–0094, which is the docket number for this rulemaking. Then, click on the Search button. On the resulting page, in the Search panel on the left side of the screen, under the Document Type heading, check the Proposed Rule box to locate this document. You may submit a comment by clicking on “Comment Now!”

By hard copy: Submit by U.S. mail or hand-delivery to: Public Comments Processing, Attn: FWS–R4–ES–2020–0094, U.S. Fish and Wildlife Service, MS: JAO/1N, 5275 Leesburg Pike, Falls Church, VA 22041–3803.

The Fish and Wildlife Service requests that you send comments only by the methods described above. All comments will be posted on This generally means that the agency will post any personal information you provide.

The agency must receive requests for a public hearing, in writing, sent by Dec. 28, 2020, to:

Lee Andrews, Field Supervisor, U.S. Fish and Wildlife Service, Kentucky Ecological Services Field Office, 330 West Broadway, Suite 265, Frankfort, KY, 40601, or call 502-695-0468. Persons who use a telecommunications device for the deaf (TDD) may call the Federal Relay Service at 800-877-8339.

Source: U.S. Fish and Wildlife Service