Performance of Progeny From Steelhead and Rainbow Trout Crosses - Final Report 2009

Identification Information

Citation

Originator: Ruzycki, J. R., L. R. Clarke, M. W. Flesher, R. W. Carmichael, D. L .Eddy

Publish Date: 2009

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

BPA Project #:

Contact Information

Agency: Oregon Department of Fish and Wildlife

Name: Mike Flesher

Job Position: Assistant Project Leader

Telephone: 541-962-3764

E-Mail Address: Mike.Flesher@odfw.oregon.gov

Description

Abstract: Many salmonids exhibit partial migration: the phenomenon of populations partitioned into migratory and non-migratory individuals (Jonsson and Jonsson 1993). Oncorhynchus mykiss exhibit a complex of life-history strategies ranging from residency in small headwater streams to anadromy involving migrations of hundreds of kilometers. In the Grande Ronde River basin of northeast Oregon, both resident and anadromous life-history forms coexist, and thus populations found there likely exhibit partial migration. Partial migration may have important consequences for anadromous species listed under the Endangered Species Act (ESA). The recent decline of summer steelhead (Oncorhynchus mykiss) populations in the lower Snake River has prompted their listing under the ESA. Declines in steelhead are potentially due to elevated mortality rates associated with anadromous migrations. If resident and anadromous life-history characteristics result from a phenotypically plastic trait (i.e. a genetic trait that is highly variable due to influences from environmental factors), then elevated mortality associated with the anadromous type may be shifting the populations towards residency. Further, although the anadromous expression of the trait may be declining, the trait would not necessarily be lost. Identification of the plasticity of these traits would then be important for the management of these populations. We investigated life history traits of O. mykiss with studies in both the hatchery and natural environment. We anticipated that these complimentary approaches would allow us to evaluate the relationship between the two life-history forms. They should further allow us to explore the feasibility of using hatcheries to produce anadromous progeny from resident parents if the number of anadromous life-history forms becomes severely depressed. The overall goal of this study was to determine the plasticity of life history forms, specifically the ability of resident adults to produce anadromous progeny. Lower Snake River Compensation Plan (LSRCP) ODFW- Eastern Oregon Fish Research (EOFR)

Purpose: 1. Compare morphological (i.e., length, weight, and condition factor) and physiological attributes (i.e., a liver-somatic index and gill Na+ + K+ ATP-ase specific activity) of progeny from breeding crosses. 2. Use juvenile PIT tag detections at Columbia and Snake river dams to assess whether outmigration timing, the length of outmigrants, or the percent of detected outmigrants differs between the progeny of breeding crosses. 3. Use PIT tag detections at adult detection sites on Columbia and Snake river dams to assess whether the number of returning anadromous adults differs between the progeny of breeding crosses.

Time Period of Content: 1997-2009

Geographic Extent: Grande Ronde and Imnaha Rivers

Status: Final

Use Constraints:

Format: pdf

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Is a physical copy maintained for reference at Headquarters? Unknown