Title

Early Life History and Stock Discrimination of Kokanee Salmon (Oncorhynchus nerka) in an Alpine Lake

Document Type

Oral Presentation

Campus where you would like to present

Ellensburg

Event Website

https://digitalcommons.cwu.edu/source

Start Date

18-5-2020

Abstract

Kokanee salmon (Oncorhynchus nerka) are an ecologically and recreationally important species in many lakes in the Cascade Mountains. One such population that inhabits Lake Keechelus in the central Cascades of Washington state are considered a vital food base for a critically low population of bull trout in the lake. The kokanee spawn in large numbers in the lake’s main tributary, Gold Creek. However, other than spawning areas, not much is known about the early life history of this population, how they interact with unique features in their rearing environment, or their natal origins (hatchery vs. wild-born). With my research I created a descriptive early life history of Gold Creek kokanee and a framework to determine the natal origin of spawning adults. Monitoring in 2019 showed kokanee that spawned in Gold Creek produced viable eggs that survived the winter, and emerged in mid-April. The majority of adult kokanee avoided spawning in Gold Creek itself, preferring a man-made outlet channel from Gold Creek Pond that had significantly higher water temperatures and a prominent beaver dam. Significantly higher densities of larvae were recorded below the beaver dam compared to upstream, with larvae emergence being episodic throughout spring months. Stock discrimination (hatchery vs. wild-born) of spawning adults is being determined by comparing early life history stages using otolith microstructure analysis. With this research, the future restoration efforts of the region can integrate the life history data of kokanee as well as quantify the potential role hatchery fry contribute to the ecosystem. College of the Sciences Presentation Award Winner.

Faculty Mentor(s)

Paul James

Department/Program

Biological Sciences

Additional Mentoring Department

https://cwu.studentopportunitycenter.com/2020/04/early-life-history-and-stock-discrimination-of-kokanee-salmon-oncorhynchus-nerka-in-an-alpine-lake-environment/

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May 18th, 12:00 PM

Early Life History and Stock Discrimination of Kokanee Salmon (Oncorhynchus nerka) in an Alpine Lake

Ellensburg

Kokanee salmon (Oncorhynchus nerka) are an ecologically and recreationally important species in many lakes in the Cascade Mountains. One such population that inhabits Lake Keechelus in the central Cascades of Washington state are considered a vital food base for a critically low population of bull trout in the lake. The kokanee spawn in large numbers in the lake’s main tributary, Gold Creek. However, other than spawning areas, not much is known about the early life history of this population, how they interact with unique features in their rearing environment, or their natal origins (hatchery vs. wild-born). With my research I created a descriptive early life history of Gold Creek kokanee and a framework to determine the natal origin of spawning adults. Monitoring in 2019 showed kokanee that spawned in Gold Creek produced viable eggs that survived the winter, and emerged in mid-April. The majority of adult kokanee avoided spawning in Gold Creek itself, preferring a man-made outlet channel from Gold Creek Pond that had significantly higher water temperatures and a prominent beaver dam. Significantly higher densities of larvae were recorded below the beaver dam compared to upstream, with larvae emergence being episodic throughout spring months. Stock discrimination (hatchery vs. wild-born) of spawning adults is being determined by comparing early life history stages using otolith microstructure analysis. With this research, the future restoration efforts of the region can integrate the life history data of kokanee as well as quantify the potential role hatchery fry contribute to the ecosystem. College of the Sciences Presentation Award Winner.

https://digitalcommons.cwu.edu/source/2020/COTS/14