Status of Wild Coho Salmon Passing Marmot Dam, Sandy River 1992

Identification Information

Citation

Originator: McGie, A. M.

Publish Date: 1992

Online Link: None

BPA Project #:

Contact Information

Agency: Oregon Department of Fish and Wildlife

Name: Cedric Cooney

Job Position: Natural Resources Data and Systems Manager

Telephone: 503-947-6094

E-Mail Address: Cedric.X.Cooney@odfw.oregon.gov

Description

Abstract: The number of wild coho salmon counted at Marmot Dam on the Sandy River has declined from an average annual return of 1,444 fish in 1960-66 to an average annual return of only 129 fish in 1987-91. In contrast, the total escapement of coho salmon has remained virtually unchanged, averaging 1,447 fish in 1987-91, reflecting an increase in hatchery fish returns. Wild fish currently compose 8.9% of the coho salmon counted at Marmot Dam. A shift in peak time of arrival in November in 1960-66 to a peak time of arrival in October in subsequent years is indicative of the increase in early-run hatchery fish and commensurate decline of late-run wild fish in the run. The loss in production of wild fish is likely the result of competition and introgression with.hatchery fish that have been extensively transplanted above Marmot Dam since 1964.

Purpose:

Time Period of Content:

Geographic Extent: Sandy River

Status: Final

Use Constraints:

Format: PDF file

Data Quality Information

Lineage-Source:

Data Information

No data information was supplied.

Entity and Attribute Information

Attributes Description:

Is a physical copy maintained for reference at Headquarters? No