Re-Introduction of Lower Columbia River Chum Salmon into Duncan Creek, 2002-2003 Annual Report.
The National Marine Fisheries Service (NMFS) listed Lower Columbia River chum as threatened under the auspices of the Endangered Species Act (ESA) in March of 1999 (64 FR 14508, March 25, 1999). The listing was in response to reduction in abundance from historical levels of more than half a million returning adults to fewer than 10,000 present day spawners. Harvest, loss of habitat, changes in flow regimes, riverbed movement and heavy siltation have been largely responsible for the decline of Columbia River chum salmon. The timing of seasonal changes in river flow and water temperatures is perhaps the most critical factor in structuring the freshwater life history of this species. This is especially true of the population located directly below Bonneville Dam where hydropower operations can block access to spawning sites, dewater redds, strand fry, cause scour or fill of redds and increase sedimentation of spawning gravels. Currently, only two main populations are recognized as genetically distinct in the Columbia River, although spawning has been documented in most lower Columbia River tributaries. The first is located in the Grays River (RKm 34) (Grays population), a tributary of the Columbia, and the second is a group of spawners that utilize themore »
- Publication Date:
- OSTI Identifier:
- Report Number(s):
R&D Project: 200105300; TRN: US200713%%294
- DOE Contract Number:
- Resource Type:
- Technical Report
- Research Org:
- Washington Department of Fish and Wildlife
- Sponsoring Org:
- United States. Bonneville Power Administration.
- Country of Publication:
- United States
- 54 ENVIRONMENTAL SCIENCES; COLUMBIA RIVER; ENDANGERED SPECIES; FISHERIES; GENETICS; HABITAT; INCUBATION; MONITORING; PLANTS; REARING; RIVERS; SALMON; SAMPLING; SEDIMENTATION; SEDIMENTS; STREAMS Chum salmon - Spawning - Columbia River - Statistics
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