Snail darter controversy

The snail darter controversy relates to the discovery in 1973 of an endangered species during the construction of the Tellico Dam on the Little Tennessee River. The dam project had been authorized in 1959 and construction begun in 1967 ("Tellico Dam") before passage of protective environmental legislation (e.g., Endangered Species Act). On August 12, 1973, University of Tennessee biologist and professor David Etnier discovered the snail darter in the Little Tennessee River while doing a reconnaissance snorkel survey in an effort to document the fish community that existed prior to the impending destruction of the pristine riverine habitat (Etnier 1976. ).

Shortly thereafter, Congress passed the Endangered Species Act (ESA, 28 December, 1973).

Believing the snail darter to be uniquely different from any closely-related species, Etnier began the process of publishing a formal scientific description that explicitly compared/contrasted physical features of the fish against the most likely closely related taxon, the Stargazing Darter (Percina uranidea) (Etnier, 1976). Even before the formal description was published, USFWS was petitioned to list the snail darter as endangered, and that was put into effect in November 1975. ()

Environmental Defense Fund lawyers were litigating a case against TVA on behalf of land owners and the Eastern Band Cherokee Tribe whose land was being taken under the principles of eminent domain (“Tellico Dam”). This lawsuit was brought under the National Environmental Policy Act (NEPA), and was based on the lack of a suitable Environmental Impact Statement for the Tellico project (as required by NEPA). The EDF lawyers declined to include any arguments related to the snail darter in their case. The NEPA lawsuit was ultimately dismissed when TVA presented an EIS prior to going to trial.

Once the ESA was passed, faculty and students in the University of Tennessee Law School filed a lawsuit against TVA (Tennessee Valley Authority v. Hill). The lawsuit said that the Tellico Reservoir, to be created by Tellico Dam, would alter the habitat of the river to the point of killing off the endangered snail darter.

The NEPA and ESA lawsuits slowed the construction of the Tellico Dam but did not stop it. The Supreme Court upheld protection for the snail darter under ESA, but Congress passed legislation specifically exempting the Tellico Dam Project from the ESA (“Tellico Dam”). The dam project and inundation of the reservoir were completed in 1979. Despite this setback, populations of the Tellico snail darters were translocated into other rivers, and new populations of the snail darter were discovered in other parts of the Tennessee River. The species status was upgraded from “endangered” to “threatened” in 1984 (USFWS 2013 ) and was eventually taken off the Endangered Species list in 2022 following significant recovery (USFWS ).

Subsequent research suggests that the snail darter may actually represent an eastern population of the stargazing darter, which is not considered endangered. But the recent research does not address whether that designation would have afforded the Little Tennessee River population of snail darters protections against the Tellico Project under provisions of the ESA, as either a unique sub-species or as a “distinct population segment” (see below).