|Scientific Name:||Etheostoma chienense|
|Species Authority:||Page & Ceas, 1992|
|Red List Category & Criteria:||Endangered B1ab(iii)+2ab(iii) ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
This species is listed as Endangered because its extent of occurrence and area of occupancy are less than 50 sq km, the species occurs in just a few locations, and its habitat is subject to ongoing degradation. Adult population size probably is not more than a few thousand.
|Range Description:||Range includes only the Bayou du Chien system, Graves and Hickman counties, western Kentucky (Page et al. 1992; Piller and Burr 1998, 1999; Page and Burr 2011). Surveys in the 1990s found the species in an area encompassing approximately 35 stream-kilometres (Piller and Burr 1998, 1999).|
|Range Map:||Click here to open the map viewer and explore range.|
Surveys in the 1990s found this species in 16 sites, with evidence of reproduction at 12 of these sites (six of the 12 sites yielded only 1–2 nests with eggs); these sites represent not more than a few distinct occurrences.
Total adult population size is unknown but apparently very small. The sites of greatest abundance support only about 80–100 individuals (Warren et al. 1994).
Area of occupancy, number of subpopulations, population size, and habitat quality have probably declined over the long term, but the degree of decline is unknown.
|Habitat and Ecology:||Habitat includes sandy pools of headwaters and creeks (Page and Burr 2011). Bayou du Chien is a typical sandy Coastal Plain stream system (Page et al. 1992). Individuals are concentrated in headwaters in slow-flowing pools, usually associated with gravel, sand, and leaf litter substrates near fallen tree branches, undercut banks, or overhanging streambank vegetation (USFWS 1992). The species appears to have a strong affinity for undercut banks and adjacent narrow, shallow (<25 cm), moderately flowing runs underlain with sandy gravel (Warren et al. 1994). Some individuals have been found within 1–2 meters of the stream bank under objects such as leaf litter, partially submerged logs and sticks, and human refuse (Piller and Burr 1999). Eggs are attached to the undersides of stones or similar artificial substrates (Piller and Burr 1999).|
|Use and Trade:||This species is not utilized.|
The single known spawning area is in an unprotected agricultural area (Page et al. 1992). Habitat has been and continues to be impacted by poor water quality and habitat deterioration resulting from stream channelization, siltation caused by poor land use practices, and by other water pollutants (USFWS 1992, 1993). This darter's limited distribution makes it vulnerable to toxic chemical spills (USFWS 1994).
Warren et al. (1994) reported that "probable historic reasons that may have restricted the spawning area, habitat, and distributional extent of the relict darter include: channelization of extensive reaches of the mainstem of Bayou du Chien with concomitant homogenization of instream habitat as well as dewatering of floodplain tributaries; ditching of tributaries and removal of shade-producing riparian vegetation and concomitant decrease in habitat and increase in maximum stream temperatures; increased siltation associated with poor agricultural practices; and deforestation and drainage of riparian wetlands with concomitant decreases in instream low flow, especially in potential spawning areas. All of these factors have continued potential to reduce or eliminate the species."
Jelks et al. (2008) categorized this species as Endangered due to (1) present or threatened destruction, modification, or reduction of a taxon's habitat or range and (2) restricted range.
Available habitat for restoration is very limited; recovery is not likely (USFWS 1994).
USFWS (1994) listed the following needed actions: determine threats and alleviate those that threaten the species' existence; solicit assistance of local landowners and initiate "Partners for Wildlife" projects to improve riparian habitat; develop and utilize an information/education program; through augmentation or reintroduction, protect and establish viable populations, with spawning occurring in five tributaries or main-stem stream reaches.
Potential nest productivity may be enhanced by adding artificial spawning substrates (half-cylindrical ceramic tiles) to shallow, low-flow reaches in headwaters (Pillar and Burr 1999).
Better information is needed on life history requirements (USFWS 1994). Sites suitable for reintroduction need to be identified (Warren et al. 1994).
The search for additional populations should be continued (USFWS 1994). However, Warren et al. (1994) concluded that it is extremely unlikely that additional populations will be found outside the immediately adjacent drainage area of Bayou du Chien. Long-term monitoring of darter populations and watershed conditions is needed (Warren et al. 1994).
Piller and Burr (1999) recommended that management focus on habitat protection and restoration rather than captive propagation and stocking of individuals. The most important needs are restoring riparian buffer zones to headwater tributaries, reducing channelization and ditching, and educating private landowners about the needs of this species.
|Citation:||NatureServe 2013. Etheostoma chienense. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 31 August 2015.|
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