Notes on Snail Darter (Percina tanasi)

Being a Tennessee native, I was interested when my recent study of darters led me to become familiar with the controversy of the snail darter and the TVA's construction of Tellico Dam in the late 1970's. For information about the snail darter controversy, google "TVA vs Hill (1978)". The lead counsel representing the farmers, Cherokee, anglers, and environmentalists who opposed the dam, Zygmunt Plater, wrote a book about the case and its implications titled "The Snail Darter and the Dam: How Pork-Barrel Politics Endangered a Little Fish and Killed a River".

"The snail darter is a federally protected species and is listed as threatened under the Endangered Species Act of 1973 as a result of habitat destruction from the completion of the Tellico Dam."

On the status of the species, from the USGS (
"The Snail Darter was intentionally introduced to create an additional population of this endangered fish when its only known habitat was threatened by construction of a dam. Seven hundred and ten Snail Darters were introduced into the Hiwassee River from June 1975 to February 1976 (U.S. Fish and Wildlife Service 1982a; Etnier and Starnes 1993). In October 1975, 61 were introduced into the Nolichucky River. Introductions into the Nolichucky River were halted when the sharphead darter Etheostoma acuticeps was discovered there, for fear the introduction would jeopardize this rare species (U.S. Fish and Wildlife Service 1982a; Etnier and Starnes 1993). The Holston River was stocked with 533 Snail Darters from the Hiwassee and Little Tennessee rivers during the period 1978 to 1979. The Elk River was stocked in July 1980 with 425 Snail Darters from the Little Tennessee River (U.S. Fish and Wildlife Service 1982a).
Status: Established in Hiwassee River and range expanding (U.S. Fish and Wildlife Service 1982a). One darter observed in Nolichucky River in 1980. Single individual possibly from small reproducing population or escapee from fish hatchery upstream; none found since. Elk River populations apparantly extirpated due to failed introduction (Etnier and Starnes 1993). Snail Darters found in lower French Broad and lower Holston rivers in 1988 and 1989 presumably represent progeny of Holston River transplants (Etnier and Starnes 1993). In 2005, Ashton and Layzer (2008) found robust populations in French Broad and Hiwassee Rivers, and low abundances in Holston, Little, and Sequatchie Rivers and Big Sewee and South Chichamauga Creeks. Ashton and Layzer (2008) suggested that these low population sizes may be due to a lack of reproducing populations in these streams, with individuals migrating into these streams from larger, reproducing populations in French Broad and Hiwassee Rivers."

Publicado el 22 de diciembre de 2017 21:26 por mattgeo1990 mattgeo1990


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