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ashy darter
The ashy darter (''Etheostoma cinereum'') is a species of darter endemic to the eastern United States.
==Distribution==
Historically, the ashy darter occurred in varying preimpoundment reaches throughout the Cumberland and Tennessee River drainages. Many populations were likely eradicated by anthropogenic causes before discovery. Thus, remaining populations are sporadic and rare, including localities found within the Cumberland, Duck, and Tennessee River systems. As declines reshaped distributions, only five river systems contained remaining populations. It is considered extirpated from Virginia, Georgia, and Alabama. However, Conservation Fisheries of Knoxville, TN, reconfirmed its Virginia existence in 2004.〔Shephard, T. E., and B. M. Burr. 1984. Systematics, status, and life history aspects of the Ashy Darter, ''Etheostoma cinereum'' (Pisces, Percidae). Proceedings of The Biological Society of Washington. 97:693-715.〕〔〔Hammerson, G. J.M. Clayton, F. Dirrigl, Jr., and P.W. Shute. Ashy Darter, ''Etheostoma cinereum''. 2007. Natureserve Conservation Status. http://www.cumberlandhcp.org/files/natureserve/Fish_10.23.08/Ashy_Darter_10.13.08.pdf〕
Notable populations persist in the Buffalo and Duck Rivers in Tennessee, and the Rockcastle and Big South Fork of the Cumberland Rivers in Kentucky. Individuals have also been collected in the Clinch and Elk Rivers of Tennessee over the last 30 years. Specific declines have been observed in the Little River of Blount County, TN, where populations once flourished, but have significantly diminished over the past 30 years.〔Etnier, D.A. and W.C. Starnes. 1993. ''The Fishes of Tennessee''. Univ. Tenn. Press. Knoxville, TN. 480-482 pp. http://www.newfoundpress.utk.edu/pubs/fishes/〕〔Powers, S. L. and R. L. Mayden. 2002. Threatened fishes of the world: ''Etheostoma cinereum'' Storer, 1845 (Percidae). Environmental Biology of Fishes. 63:264.〕〔Powers, S. L., R. L. Mayden, and D. A. Etnier. 2004. Conservation genetics of the Ashy Darter, ''Etheostoma cinereum'' (Percidae: subgenus ''Allohistium''), in the Cumberland and Tennessee Rivers of the southeastern United States. Copeia. 3:632-637.〕
Declines and extirpations of ''E. cinereum'', like other aquatic species, are often hard to measure and emerge from compounding factors. Causes are generally human-induced, and include runoff from urbanization, agriculture, mining, and logging. These sources of pollution, among others, are commonly referred to as “nonpoint” sources of pollution, because they are often hard to trace and are difficult to resolve. All of these can lead to substantial siltation, which ultimately destroys their preferred habitat types. Another primary factor in declines are impoundments, such as dams, which have drastically reconfigured river and stream dynamics over the past century.〔〔〔〔''Etheostoma cinereum'', Ashy darter. 2012. Conservation Fisheries, Inc. 2012. http://conservationfisheries.org/index.php/species/current-species/etheostoma-cinereum-ashy-darter/〕
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