Duncan Creek, a Washington tributary that enters the Columbia at River Mile 140 (approximately 6 miles downstream from Bonneville Dam) was an important spawning area for chum salmon.  In 1951, for example, over 500 chum salmon were observed in Duncan Creek. In 1963, a dam was placed near the mouth of the creek and a culvert was installed for fish passage.  However, chum returns rapidly declined after the dam was built and by 1969, no chum were found in the basin.

A three-pronged approach is being used to once again produce a self-sustaining chum salmon population in Duncan Creek. This approach included modifying the dam, enhancing spawning habitat, and using local brood stock to re-introduce chum back into the basin.

The first objective was accomplished in November 2000, when the dam was modified to allow fish passage.  The structure cost approximately $500,000 including a $131,106 self-assessment by the Skamania Landing Owners Association (SLOA).  Washington Department of Fish and Wildlife (WDFW) and SLOA obtained the balance from non-federal sources including the State of Washington Governor's Salmon Recovery Office, Salmon Recovery Funding Board, Washington Department of Natural Resources Aquatic Lands Enhancement Account, and the National Fish and Wildlife Foundation.  The second objective was accomplished in November 2001 when the spring/seep areas that chum historically spawned in Duncan Creek were cleaned of sediment, debris and reed canary grass and suitable spawning gravel was placed back into these areas.  The third objective began in November/December 2001 when adult chum were placed into the renovated channels to spawn naturally.  Concurrently, adult chum were taken to Washougal Hatchery to be artificially spawned.  Their progeny were then reared and released as fed fry at the mouth of Duncan Creek in the spring of 2002.

For FY 05, this project addresses the continued collection of brood stock and outlines a comprehensive plan for monitoring and evaluating the Duncan Creek chum re-introduction.  Adults will be collected from volunteers to Duncan Creek, adjacent chum salmon stocks, e.g. Hardy and Hamilton Creeks, and the mainstem of the lower Columbia River including individuals salvaged from higher water elevations in the Ives Island area (i.e. areas that may not be protected through 100% emergence by mainstem flows).  Adults meeting the criteria for broodstock will be placed in the rejuvenated channels to naturally spawn.  Naturally produced fry will be trapped as they outmigrate and will be marked by via immersion in a solution of strontium chloride hexahydrate.  Marking of naturally produced fry with strontium chloride hexahydrate is conducted under an Investigative New Animal Drug (INAD) permit issued by the FDA in 2003.  Otolith marks will be utilized to estimate fry-to-adult survival rates of both artificially and naturally produced fish.  Otolith marks and accurate population estimates will be used to estimate straying rates and percent contribution of Duncan Creek project origin adults to other Lower Gorge chum spawning locations.  The occurrence of non-marked adult chum recovered in Duncan Creek will be used to estimate how quickly wild fish are re-colonizing the stream.  Beginning fall of 2004, hatchery adult chum originating from this project will start returning to Duncan Creek.  The physical conditions in this part of the stream will be monitored and egg-to-fry survival rates will be determined.

The newly established habitat and the reintroduction effort will both provide clear survival benefits to Columbia River chum salmon returning to the Bonneville area and demonstrate the effectiveness of these kinds of reintroduction efforts.  Methods employed and associated results can be used as a template for future reintroduction efforts for Columbia River chum salmon.