Blue Shiner

Cyprinella caerulea

Description

The blue shiner, Cyprinella (=Notropis) caerulea, is a medium-sized minnow attaining a length of about 4 in (10 cm). Coloration is dusky blue with pale yellow fins. The species has a distinct lateral line and diamond-shaped scales outlined with melanophores.

Behavior

Isolation and fragmentation characterize present populations of the blue shiner. This species spawns from early May to late August.

Habitat

The blue shiner occurs in the east and central farming and forest region. The average annual precipitation is 40-50 in (101-127 cm) and the average annual temperature is 48.2-63°F (9-17°C). The topography of nearly one-half of this region consists of steeply sloping, mainly forest land, used for both recreation and timber production. Udults and Udalfs are the most extensive soils. Fluvents occur along streams and are cropped intensively throughout the region, but do not occur extensively.

Small farms are characteristic of this region and primarily grow corn, soybeans, small grains, and hay.

Specifically, the blue shiner occurs in clear, cool water over sand and gravel substrate among cobble.

Distribution

This species is historically known from the Cahaba and Coosa River systems. It is likely that the species once occupied most of the upper Coosa and Alabama Rivers. In 1971, the minnow was last collected from the Cahaba River system.

Currently, the species is found in Alabama in Weogufka and Choccolocco Creeks and the lower reaches of Little River. Also found in Tennessee, the species ranges in the Conasauga River and the tributary, Minnewauga Creek. In Georgia, the blue shiner is found in the Conasauga and Coosawattee Rivers, including various tributaries. The species no longer exists in Big Wills Creek, a tributary of the upper Coosa River.

Threats

The reason for the decline of the blue shiner is likely a result of water quality degradation due to urbanization, sewage pollution, and strip-mining activity in the upper Cahaba River basin.

Increases in blue-green algae and losses of vascular plants are indicators of the degradation of the water quality in the Cahaba River. Low oxygen levels coupled with high levels of total inorganic nitrogen and total phosphorous have also been documented on the river. These modifications in habitat have had adverse effects on the species.

Other factors that have reduced the species' range are reservoirs for flood control, hydropower, and impoundment. Such human alterations of the environment have caused the isolation of the blue shiner populations. Fragmented populations may be more vulnerable to environmental changes, and genetic diversity might be lowered as fewer mating pairs form.

As a result of all of these factors, the species is not nearly as pervasive as it once was. Rather, the species occurs in the Coosawattee River, the Turniptown Creek, and at seven sites on the Conasauga River, including three of its tributaries. Several of these populations do not come in contact with other populations, and it is speculated that distance, topography, and sites with poor water quality acting as barriers may isolate one population from another.

Conservation and Recovery

The blue shiner survives in only six populations occurring in headwater streams of the Coosa River drainage, where it requires water of high quality and not subject to excessive siltation or other kinds of pollution. The U. S. Fish and Wildlife Service published a Recovery Plan for the blue shiner in 1995. Actions to be taken under the plan include monitoring of the existing populations of the blue shiner, research to determine its habitat needs, the development and implementation of a plan to conserve its critical habitat, and efforts to reintroduce the species into suitable habitats from which it has been extirpated.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
http://southeast.fws.gov/

References

U. S. Fish and Wildlife Service. 1995. Blue Shiner Recovery Plan. Jackson, Mississippi. 20 pp.

U. S. Fish and Wildlife Service. 22 April 1992. "Endangered and Threatened Wildlife and Plants: Threatened Status for Two Fish, the Goldline Darter (Percina aurolineata ) and the Blue Shiner (Cyprinella (=Notropis) caerulea )." Federal Register 57 (78): 14786-14789.