A Comparison of Run Timing, Spawn Timing and Spawning Distribution of Natural and Hatchery Spring Chinook Salmon Oncorhynchus tshawytscha in the Imnaha River, Oregon - Information Reports 2005-03

Identification Information

Citation

Originator: Hoffnagle, T. L., K. A. Frenyea, R. W. Carmichael, P. J. Keniry

Publish Date: 2005

Online Link: https://www.fws.gov/lsnakecomplan/Reports/ODFWreports.html

BPA Project #:

Contact Information

Agency: Oregon Department of Fish and Wildlife

Name: Joseph Feldhaus

Job Position: Assistant Project Leader

Telephone: 541-962-3724

E-Mail Address: Joseph.Feldhaus@odfw.oregon.gov

Description

Abstract: We compared fourteen years (1990-2003) of weir collection and spawning ground survey data to examine differences in run timing, spawning distribution and spawn timing between adult natural and hatchery-reared Chinook salmon Oncorhynchus tshawytscha in the Imnaha River, Oregon. We compared run timing using arrival time at the weir and found that natural salmon arrived earlier than hatchery salmon in 12 of 14 years. Natural carcasses, of either or both sexes, were recovered earlier than hatchery carcasses for all years combined and during 6 of 14 years, indicating earlier spawning by natural salmon. We compared spawning distribution using the percent of female carcasses recovered in each spawning ground survey reach. A greater percent of natural female carcasses were recovered in reaches above the weir and further upstream than carcasses of hatchery-reared females, which were more commonly found in reaches closer to and below the weir. Management strategies designed to maintain the genetic integrity and life history characteristics of the Imnaha River Chinook salmon should be considered, implemented and evaluated. Collected broodstock should mimic the wild run and spawn timing. Release strategies should be developed to promote a broader spatial spawning distribution of returning hatchery adults. Lower Snake River Compensation Plan (LSRCP) ODFW- Eastern Oregon Fish Research (EOFR)

Purpose:

Time Period of Content: 1990-2003

Geographic Extent: Imnaha River

Status: Final

Use Constraints:

Format: pdf

Data Quality Information

Lineage-Source:

Data Information

No data information was supplied.

Entity and Attribute Information

Attributes Description: Field attribute information is available in the attached file(s).

Is a physical copy maintained for reference at Headquarters? Unknown