Oregon-Northern California Area Report / Case Study: Response of Foskett Spring Speckled Dace, Rhinichthys osculus ssp., to Habitat Restoration and Introduction into a Novel Habitat

Authors: Paul Scheerer, Jimmy Leal

Year: 2013 (xlv)

Abstract

The Foskett speckled dace is represented by a single population that inhabits Foskett Spring on the west side of Coleman Lake in Lake County, Oregon and was listed as threatened under the federal Endangered Species Act in 1985. Foskett Spring is a natural spring that rises from a springhead pool, flows through a narrow spring brook into a series of shallow marshes, and then disappears into the soil of the normally dry Coleman Lake. Oregon Department of Fish and Wildlife (ODFW) conducted population monitoring since 2007 and noted a substantial reduction in dace abundance, likely resulting from the conversion of open water vegetated habitat to emergent vegetated habitat, which is largely unsuitable for dace. The Bureau of Land Management (BLM), in cooperation with the US Fish and Wildlife Service, developed and implemented plans to restore open water habitats. BLM conducted a prescribed burn and hand-excavated pool habitat in 2012-13. The Foskett dace population abundance increased dramatically in 2013. At Dace Spring, located approximately 0.8 kilometers south of Foskett Spring, a second population was established from an introduction of 100 fish from Foskett Spring in 1979-1980, however surveys failed to document their continued existence at this location due to an apparent loss of open water habitat. In 2009, two new ponds were created at Dace spring. In 2010 and 2011, Foskett speckled dace were moved from Foskett Spring to the new habitat at Dace Spring. Survival of these fish has been low, presumably due to low dissolved oxygen levels (algal blooms and low turnover rate). BLM improved the water flow through the ponds in 2013 to remedy this situation. In 2013, the ponds were stocked with 200 Foskett speckled dace.