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The Problem Rattlesnake Creek is a principal tributary to the White Salmon River, Washington. Before the construction of Condit Dam in 1913 on the main-stem White Salmon River (at river mile 3.2), Rattlesnake Creek was a productive stream for anadromous salmon, steelhead, and coastal cutthroat trout. Condit Dam blocked access of anadromous salmonids to Rattlesnake Creek, which enters the White Salmon River at river mile 8.5. With the proposed removal or laddering of Condit Dam scheduled for 2006, Rattlesnake Creek has high potential to support reintroduced or naturally colonizing populations of salmon and steelhead. Research on resident trout populations will serve as a surrogate for an initial evaluation of limiting factors to salmon and steelhead production in the watershed prior to major habitat restoration activities and probable reintroduction of salmon and steelhead. This project has been funded by Bonneville Power Administration since FY2001 (Project number: 2001-025-00). Objectives Our research will characterize current habitat conditions, fish populations, water quality, fish diseases, and levels of stable isotopes of carbon and nitrogen. This baseline information will provide the necessary background to track changes and evaluate management actions associated with habitat restoration and potential removal or provision of fish passage above Condit Dam (river mile 3.2 of the White Salmon River, WA). The two objectives of the project are: 1) Characterize stream and riparian habitat conditions in Rattlesnake Creek drainage, and 2) Determine the status of fish populations in the Rattlesnake Creek drainage. Methodology
We will conduct physical stream habitat surveys of Rattlesnake Creek and its tributaries. These habitat surveys will quantify key stream habitat components and indicators of aquatic health including: 1) large woody debris, 2) frequency and depth of pools, 3) substrate composition, 4) stream gradient, 5) floodplain connectivity, and 6) riparian vegetation characteristics (e.g., species composition, age structure, shading). Much of the stream lengths to be surveyed will be on state and federally-managed lands. Private lands will be surveyed when permission is secured from the landowners. Stream discharge measurements will be taken in major tributaries and several mainstem Rattlesnake Creek sites. These data will be used to characterize temporal and spatial patterns of flow during late spring through early fall (May--October) along the stream continuum. The population density and biomass of resident salmonids in selected portions of Rattlesnake Creek will be estimated, which will include streams on state and federal lands and on as much of the privately-owned lands as possible. These surveys will identify and measure dimensions (e.g., length, width, and depth) of stream habitat units (e.g., pools, glides, riffles, etc.). Soon after these habitat surveys, fish sampling will be conducted by snorkeling, electrofishing, or a combination of both.
To document the distribution and abundance of individual fish species within the watershed prior to restoration activities and the potential removal or laddering of Condit Dam, we will largely use the data collected during other aspects of the work. Where we are permitted access, we will conduct additional sampling above barriers to determine the distributional extent of resident fishes. In order to track movements, growth, and other life history attributes of resident salmonids, we will PIT tag most age-1 or older fish that we capture during our stream surveys. We will continue to use and adjust our remote PIT-tag detector that was established in 2001 with cooperation with Earl Prentice, National Marine Fisheries Service. The ISO FDX-B, 134.2 400 kHz (12 mm) PIT tags that we use will be detectable at Bonneville Dam in the event that these tagged fish migrate downstream and exhibit an anadromous life history. Because the possible removal or laddering of Condit Dam would allow adult anadromous salmonids and other species access to Rattlesnake Creek from the mainstem Columbia River, these fishes may introduce new pathogens or parasites into the watershed. Knowledge of current conditions will help managers anticipate and weigh possible risks or threats to existing resident fish populations. We will obtain fish for disease sampling using a longitudinal and tributary sampling strategy. This will facilitate the development of a fish-health baseline for areas that would be accessible and inaccessible (above barriers) to anadromous salmonids in the future. Fish will be analyzed by the U.S. Fish and Wildlife Service's Lower Columbia Fish Health Center, which will provide a thorough disease profile as part of the U. S. Fish and Wildlife Service's National Wild Fish Health Survey. A tissue sample (fin clip) from a subsample of salmonids captured during electrofishing will be preserved (95% ethanol) for future genetic analyses (an in-kind contribution will be sought to pay for this supplementary genetics work). These data will serve as a genetic reference point for rainbow trout and coastal cutthroat trout populations in the watershed prior to the reestablishment of congeneric anadromous salmonids. Highlights and Key Findings In FY2001, habitat and fish surveys were conducted in the mainstem Rattlesnake Creek and its tributary, Indian Creek. These study areas were sampled for salmonids and other fish species by backpack electroshocking and snorkeling within a stratified systematic sampling design. Both rainbow trout and cutthroat trout were found in these streams along with longnose dace, shorthead sculpin, and brook lamprey. Stream discharge measurements were taken at semi-weekly or bi-monthly intervals at four samplings sites from June through October. Habitat surveys were conducted to determine frequency of pools and woody debris pieces, as well as stream width, gradient, and riparian shade. Where Are We Headed In 2003 We will continue to characterize stream and riparian habitat conditions, and continue to determine the status of fish populations in the Rattlesnake Creek drainage. By partnering with the U.S. Forest Service and the Confederated Tribes and Bands of the Yakama Indian Nation, we will explore the importance of Rattlesnake Creek to the White Salmon River rainbow trout population. By a combination of PIT-tagging and radio tagging rainbow trout, we will let the fish tell us the degree of connectivity between Rattlesnake Creek and the mainstem White Salmon River. Project Contact Patrick J. Connolly Email: patrick_connolly@usgs.gov Publications |
