Fish and Wildlife Management Studies - Field Projects
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Habitat and Population Assessment Studies
Juvenile Chinook Salmon in Lake Washington and the Ship Canal
The number of Chinook salmon in the Cedar River (the major tributary to Lake Washington) has declined to critically low numbers. This population is part of the federally-listed Puget Sound Chinook salmon ESU. Large numbers of juvenile Chinook salmon outmigrate to Puget Sound through Lake Washington and the Ship Canal in May through July. Because juvenile Chinook salmon rarely inhabit lakes across their natural range, little is known about their basic ecology in lake habitats. To address questions about Chinook salmon ecology in Lake Washington, we began a series of field studies using state-of-the-art technology to track juvenile Chinook salmon movement in relation to habitat features in the lake. Additionally, we have tracked Chinook salmon predators (smallmouth bass and northern pikeminnow) in the lake to collect information on their habitat use and how these species overlap with juvenile Chinook salmon. From 2003 to 2006, we implanted micro-acoustic transmitters in outmigrating juvenile Chinook salmon and predatory fishes, then recorded their movements with sensitive listening devices (hydrophones) placed on the lake bottom. Results to date have identified important areas of juvenile Chinook salmon use in Lake Washington, Lake Union, and the Ship Canal, including the Ballard Locks. The City of Seattle and the U.S. Army Corps of Engineers has funded this work. In 2007, work continued and expanded to address questions about re-locating the SR 520 Bridge in Lake Washington, with additional funding from the Washington State Department of Transportation. Results of this study will be used in design and placement of habitat restoration projects, shoreline management, and fish passage at the Ballard Locks. (Contact: Mark Celedonia or Roger Tabor)
In 2007, we began remotely uploading the data collected by the hydrophones to our server in Lacey, eliminating daily trips to Seattle to physically gather the information. Our ITM staff prepared a slide presentation explaining the background, process, and the equipment used. Click here to see the presentation.
The Influence of Streamflow on Chinook Salmon Habitat in the Cedar River
The Cedar River is a primary water source for the City of Seattle and surrounding areas and is also used to produce electrical power. A Habitat Conservation Plan (HCP) has been established with the City of Seattle for water management in this system. However, the HCP listed several information needs, one of which was determining how streamflow influences available habitat for juvenile Chinook salmon.
To address this information need, we collected salmon habitat use data in the Cedar River at several temporal and spatial scales from 2002 to 2004. The data are being used to model habitat use by juvenile Chinook salmon and to determine if habitat use changes among seasons, diel periods, channel sizes, and discharge. We are also developing a sampling strategy to determine how discharge influences juvenile Chinook salmon habitat in this system. This information will be incorporated into the HCP to improve streamflow management for Chinook salmon recovery. (Contact: Roger Peters)
Sculpin Distribution and Habitat in the Lake Washington System
From 1995 to 2004, we collected sculpins from a wide variety of habitat types throughout the Lake Washington system to determine their distribution and habitat use. Results of this project will appear in a book entitled “Status, Distribution, and Conservation of Native Freshwater Fishes of Western North America,” to be published later this year. (Contact: Roger Tabor)
Distribution of Fishes in Seattle's Streams
In 2005 and 2006, we conducted an extensive survey of all Seattle streams (including small ponds) to determine the distribution of native and introduced fish species. Information will serve as a baseline for future restoration projects and other recovery efforts. Surveys were conducted during both low-flow (summer) and high-flow (winter) time periods. All streams were typed to establish riparian zone protection. All rivers and streams are identified under five types. Type 1, 2, and 2 streams are fish-bearing. Type 4 and 5 streams are non-fish-bearing. Accurate stream typing is essential to protecting fish and their habitats. This project was funded by the City of Seattle and a final report of findings will be completed later this year. (Contact: Dan Lantz or Roger Tabor)
Predation on Juvenile Salmonids in the Lake Washington System
Because the Lake Washington system is highly altered and inhabited by exotic species, losses of juvenile salmon to predation may be abnormally high. The objective of this project was to estimate how many juvenile Chinook and sockeye salmon are lost to predation in this system. From 1995 to 2000, we collected a variety of salmon predators in the Lake Washington system from three main areas: Cedar River, south Lake Washington, and the Ship Canal.Besides annual reports of findings, we recently completed a manuscript on predation of juvenile salmon by smallmouth and largemouth bass that will be published in the North American Journal of Fisheries Management. Predation by Lake Washington cutthroat trout was published in the same journal in 2004 (see our Publications section on this website). A manuscript on salmon predation by prickly sculpin in the Lake Washington system is currently being peer reviewed.
Additionally, in 2006, we began working with the Washington Department of Fish and Wildlife and King County to determine what impact resident trout predation has on populations of salmon and steelhead in the Cedar River. Sampling was conducted in summer 2006 and a report detailing the summer diet of resident trout will be available in June 2007. Sampling will be repeated in spring 2007 and possibly summer 2007 and winter 2008. (Contact: Roger Tabor)
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