|Scientific Name:||Notropis topeka (Gilbert, 1884)|
Cliola topeka Gilbert, 1884
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
Listed as Least Concern because the species does not meet the criteria for any of the threatened categories: extent of occurrence exceeds 20,000 sq km, area of occupancy likely is more than 2,000 sq km, number of locations exceeds 10, and distribution is not severely fragmented. Distribution and abundance probably are declining but not at a rate of more than 30 percent over 10 years or three generations. However, the species has a restricted, shrinking range, and projected climate change and other factors could move the species closer to the Vulnerable category in the foreseeable future.
|Previously published Red List assessments:|
|Range Description:||This species formerly was widespread in western tributaries of the Mississippi River, from central Missouri through Iowa to southern Minnesota, west to eastern South Dakota, western Nebraska, and western Kansas (Phillips et al. 1982, Vandel 1982, USFWS 2009). It has been extirpated in many localities but still occurs in all six states in its historical range. Most of the remaining occupied habitat is in South Dakota-Minnesota and Kansas (USFWS 2009).|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Recent surveys have added many new occurrences and large expansions of known range in South Dakota and Minnesota (USFWS 2009).|
USFWS (2009) mapped eight patches of occupied habitat; the only large ones were in South Dakota-Minnesota and Kansas.
Total adult population size is unknown but probably exceeds 10,000. In the southern part of the range, this fish is generally uncommon even in suitable habitat (Page and Burr 1991, Lee et al. 1980). It is more numerous in the north (USFWS 2009).
Distribution and abundance have declined, but the extent of the decline is less than previously thought (USFWS 2009).
Trend over the past 10 years or three generations is uncertain, but distribution and abundance probably are slowly declining. Trend varies across range: relatively stable in the northern portion of the range, generally declining in the central and southern parts of the range (USFWS 2009).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This species typically inhabits quiet, open, permanent pools of small, clear, high-quality headwaters and creeks that drain upland prairie areas, including tiny spring-fed pools in headwater streams and larger streams (Gorman pers. comm.). |
Streams that have been channelized or impounded or that drain cultivated fields generally are not suitable habitat (Schrank et al. 2001, Gorman pers. comm., Prophet pers. comm.). Many occupied streams become intermittent in the summer but the pools are maintained by springs. Habitat includes off-channel sites in Minnesota and Iowa, (primarily cut-off channels and oxbows that are seasonally flooded (Hatch pers. comm. 1999, Menzel, Iowa State University pers. comm. 1999); these sites probably connect with the water table, which probably keep temperature and dissolved oxygen concentrations within tolerance levels during hot, dry periods and prevent total freeze-out of pools in winter. Streams may or may not be bordered by trees (Gorman pers. comm.). Riffles are occupied only if shiners are exceptionally abundant in a local area (Minckley and Cross 1959). Pool substrate is gravel, rubble, or sand, often with a slight silt layer (Kerns unpublished data); usually does not occur in pools with large amounts of silt on the bottom (Minckley and Cross 1959), but in the South Fork of the Cottonwood River, Kansas, the larger pools containing Topeka Shiners had several centimetres of silt (Kerns unpublished data). The pools usually do not have rooted aquatic vegetation but many have plankton blooms during the summer (Minckley and Cross 1959, Kerns, unpublished data). In Kansas streams, the Topeka shiner is pelagic, occupying the lower half of the water column (Kerns unpublished data), though Tabor (1993) stated that this fish occurs in mid-water and surface areas.
Temperatures of occupied waters vary from near freezing in winter to 90°F (32°C) in summer (Gorman pers. comm.).Oxygen levels are generally near saturation (Gorman pers. comm.). The water may range from clear to murky (from plankton blooms or suspended fine clay particles when the water is very warm) (Gorman pers. comm.). Occupied streams do not have a strong continuous flow; the flow is usually less than five cubic feet per second (Minckley and Cross 1959).
The male has a small territory around Green Sunfish (Lepomis cyanellus) or Orange-spotted Sunfish (L. humilis) nests. Spawning occurs over the sunfish nests. Juveniles remain in the shallow margins of pools in mixed-species groups during their first summer.
|Movement patterns:||Not a Migrant|
The major threats include land and water practices that alter the physical and biological characteristics of streams. This fish is fairly resistant to natural, short-term stresses but sensitive to permanent changes in habitat such as reduced water quality and increased water temperature.
Detrimental land practices, such as cultivation, clearcut logging, building projects, and intensive, continuous grazing, increase the amount of silt and sediment in streams (Platts 1979, Gorman pers. comm., Pflieger pers. comm.). Sedimentation in streams reduces instream cover, covers fish eggs, and covers food-producing gravel and rubble (Platts 1979).
Grazing livestock can directly damage a stream by eating stream-edge vegetation and trampling that causes erosion, and through defecation that pollutes water (Tabor pers. comm).
Several types of water projects can eliminate shiner populations. Channelization can alter the water temperature and flow rates and change the stream morphology. The lowering of the water table level is drying out some streams (Gorman pers. comm.). The building of impoundments stocked with predatory game fishes is a major threat in some areas (Schrank et al. 2001) because the shiners are eaten by the predators and because impoundment alter stream hydrology and act as barriers to fish dispersal (Cross pers. comm., Kerns pers. comm.). Construction of impoundments recently threatened the largest remaining populations in Kansas (Tabor 1993); threat of watershed dams persists but is now diminished since dams are not allowed to be constructed where Topeka Shiner populations are known.
Recent collections in Missouri revealed that some populations are afflicted with scoliosis, which causes deformities; the cause of the condition is not yet known.
Competition with the introduced blackstripe topminnow is a potential threat in some areas, but the significance of this is undocumented.
Predation by non-native fishes may be one of the factors that reduce Topeka Shiner abundance (Knight and Gido 2005).
USFWS (2009) summarized/updated threats information as follows:
In the northern portions of the range, the species continues to exist across nearly all of its historic range despite widespread land-cover and land-use changes. Ongoing and future threats to the habitat have been identified; however these threats are not believed to be meaningfully impacting the species' status in the northern portions of the range at this time. No threats in this portion of the range are thought to currently exceed a moderate overall threat level. While the species appears less vulnerable to known threats in this portion of the range, projected impacts to habitat may meaningfully impact water quantity and the suitability of stream habitat within the foreseeable future.
Long-term habitat degradations resulting from historical changes in landcover and land-use are still believed to be the major contributing factors in the long-term decline of Topeka Shiner across the southern portions of the range. Many of the threats from this long-term degradation are still current and have continued to impact the species and its habitat since listing. Within the southern portions of the range, threats to habitat are substantially more severe than in the northern portions of the range.
Overall, the threat of disease remains poorly understood, but is believed a minor issue except when habitat conditions are compromised. Predation by non-native fishes is considered a low level threat in South Dakota, Minnesota, and Iowa and a moderate to high level threat in Kansas and Missouri. Predation is poorly understood in Nebraska.
Current federal regulatory oversight has minimized many impacts across the range. However, current federal oversight has not been sufficient to prevent the species' continued decline and loss in some areas. Such continued losses have largely been limited to the southern portion of its range where threats appear more severe and habitat appears more susceptible to detrimental changes.
Much of the remaining range of the Topeka Shiner in Iowa, Kansas, Missouri, and Nebraska consists of highly fragmented, isolated populations with long distances of altered or unsuitable habitat between them, prohibiting redistribution. Many of these populations do not have the necessary downstream or off-channel refuges available to them to survive long-term drought conditions at this time. Increased periods of protracted drought, potentially resulting from climate change, would exacerbate the impacts of habitat fragmentation and isolation. Increased drought could also impact presently stable population complexes, forcing these populations to seek refuge downstream into larger streams with more predatory fishes and diminished habitat value. This threat is applicable to both the northern and southern portions of the Topeka Shiner's current range.
If climate change projections prove accurate, the long-term impacts to Topeka Shiner could be substantial. Impacts in summer are of particular concern. Increased air temperatures will lead to higher water temperatures, especially during low-flow periods. Reduced summer precipitation and increased evaporation is likely to reduce flows. Such conditions cause increased stress to fish. The timing and amount of precipitation will also impact groundwater recharge rates. Finally, substantially hotter summers would likely increase agricultural demand for surface-water and ground-water resources. Thus, the available information indicates climate change is a substantial long-term risk factor which could meaningfully impact water quantity and the suitability of stream habitat.
Maintain high quality pools in prairie streams. Monitor and control land and water use practices upstream and in preserve.
Research needs: document effects of impoundments; determine breeding habitat requirements and water quality tolerances; monitor populations.
Protection needs: improve farming practices to reduce siltation and dewatering; stop construction of tributary impoundments and channelization; promote permanent grass cover over tillage.
|Citation:||NatureServe. 2014. Notropis topeka. The IUCN Red List of Threatened Species 2014: e.T184092A19034321.Downloaded on 21 November 2017.|
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