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Foskett speckled dace

Photo of Foskett Speckled Dace (USFWS)

Scientific name: Rhinichthys osculus ssp.

Status: Threatened

Critical Habitat: None

Listing:  The Foskett speckled dace was listed as a threatened species in 1985. Critical habitat has not been designated. A recovery plan was published in 1998.

Potential Range Map

  • Description

    This form of speckled dace is related to the speckled dace of Twentymile Creek in the Warner Basin, but is distinguished by a shorter lateral line and larger eye. Distinguishing characteristics are as follows: lateral line much reduced, about 15 scales with pores; eyes large; dorsal fin set well behind pelvic insertion.

    Historic Status and Current Trends

    Foskett speckled dace were probably distributed throughout prehistoric Coleman Lake of the Warner Basin during times that it held substantial amounts of water. The Warner Basin includes portions of southeast Oregon, northern Nevada, and northern California. As the lake dried, the salt content of the lake water increased. Suitable habitat would have been reduced from a large lake to any spring systems that provided enough habitat for survival. There is currently only one known population of Foskett speckled dace which is found in Foskett Spring in the Coleman subbasin. Dace Spring, a short distance away, may have been occupied by Foskett speckled dace in the past, but there were none found in a 1970 survey. In 1979 and 1980, 100 dace from Foskett spring were transplanted into an excavated area at Dace Spring. Over time, the artificial habitat filled in and fish in Dace Spring were last seen in the spring outflow in 1997.

    Habitat

    Both Foskett and Dace springs are extremely small and shallow with limited habitat for fish. Foskett Spring originates in a pool about five meters (16.4 feet) across, then flows toward Coleman Lake in a narrow, shallow channel. The source pool has a loose, sandy bottom and is thick with aquatic plants. The spring outflow channel eventually turns into a marsh and finally dries up before reaching the dry lake bed of Coleman Lake. Dace Spring is about one kilometer (0.6 mile) south of Foskett Spring and is smaller and more choked with plants. The spring outflow terminates in a cattle trough.

    Fish at Foskett Spring live in the main spring pool, outflow channel, and tiny outflow rivulets that are at times only a few inches wide and deep. The fish find cover under overhanging bank edges, grass, exposed grass roots, and filamentous algae.

    Reasons for Decline

    The disappearance of dace from Dace Spring was likely due to the limited habitat and the shrinking of this habitat over time as sediment and vegetation filled in the excavated area near the spring outflow. Also, the outflow from Dace Spring terminates in a cattle trough in which a number of Foskett speckled dace lived following the 1979 and 1980 transplant. The dace were probably caught in the flow to the trough, but were unable to return to the spring. The overflow water from the trough spills on the ground and any dace flushed out would perish.

    Conservation Measures

    A recovery plan for the Foskett speckled dace was published in April 1998. Foskett and Dace Springs are on public land managed by the Lakeview District of the Bureau of Land Management. The habitat is fenced from cattle use and is in stable condition.

    References

    Armantrout, N., and C.E. Bond. 1981. Basin Report: Oregon Lakes. Pp. 14-15. In: E.P. Pister (ed.) Proceedings of the Desert Fishes Council Vol. XII. (12th Symp. 1980).

    Bond, C.E. 1974. Endangered plants and animals of Oregon: I. Fishes. OR Agricultural Experiment Station Special Report 205:1-9.

    Deacon, J.E., G. Kobetich, J.D. Williams, and S. Contreras. 1979. Fishes of North America endangered, threatened, or of special concern: 1979. Fish. 4(2):30-44.

    U.S. Fish and Wildlife Service. 1985. Determination of threatened status for Hutton tui chub and Foskett speckled dace. FR 50:12302-12306.

    U.S. Fish and Wildlife Service. 1985. Special rule regarding take of Hutton tui chub and Foskett speckled dace.

    U.S. Fish and Wildlife Service. 1998. Recovery plan for the native fishes of the Warner Basin and Alkali Subbasin. Portland, Oregon. 86pp.

     

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