Species Fact Sheet Foskett speckled dace Rhinichthys osculus ssp.
STATUS: THREATENED CRITICAL HABITAT: NONE
Foskett speckled dace potentially occurs in these Oregon counties: Lake (Map may reflect historical as well as recent sightings)
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.
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
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.
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
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.
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.
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.
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
U.S. Fish and Wildlife Service. 1985. Special
take of Hutton tui chub and Foskett speckled dace.