Fall Chinook Salmon in the Siuslaw River: Spawner Escapements, Run Reconstruction and Survey Calibration 2001-2002

Identification Information

Citation

Originator: Weeks, Hal, Brian Riggers, and Jody White

Publish Date: 2003

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: Using mark-recapture methods, we estimated there were 8600 adult fall Chinook spawners (95% relative precision of 22.6%) in the mainstem Siuslaw River in 2001 and 22,500 (95% relative precision 13.9%) in 2002. We expanded our efforts to include the North Fork Siuslaw in 2002, and we estimate 1550 adult fall Chinook spawners there (95% relative precision of 50%). Calibration of spawning survey indices is very preliminary at this point as we have only 2 years of data and no clear patterns are emerging yet. Radio telemetry tracking of fall Chinook in the mainstem Siuslaw in 2002 suggests that 75 – 80% of the fall Chinook spawn in what is classified as ‘mainstem’ habitats. This is consistent with similar studies in other basins such as the Nehalem and Coos. In 2002, we also performed an experimental study to coded-wire tag downstream migrating juvenile Chinook in the Siuslaw. The impetus for this study was the then-expected closure of Salmon River hatchery which serves as the exploitation rate indicator stock for the North Oregon coast fall Chinook aggregate. We successfully tagged nearly 42,000 fall Chinook presmolts with a mortality rate of just over 1.1%. It is generally agreed that using a wild stock as an exploitation rate indicator is preferable to using a hatchery stock that may not have the same ocean movement patterns as the wild counterparts. While our feasibility study can be viewed as a success, it must also be noted that a wild stock juvenile tagging project would be much more expensive to conduct than a comparable hatchery tagging project. With Salmon River hatchery presently expected to remain open, we do not have the funding from the Pacific Salmon Commission or the Department to continue this work.

Purpose:

Time Period of Content: 2001-2002

Geographic Extent: Siuslaw River, Oregon

Status: Final

Use Constraints:

Format: PDF

Data Quality Information

Lineage-Source: Cumulative Progress Report for work conducted pursuant to National Oceanic and Atmospheric Administration Award Numbers: 2001-2002: NA17FP1280 and 2002-2003: NA17FP2458, and U.S. Section Chinook Technical Committee Project Numbers: N01-20, C02-12A, C02-12B and C02-12D

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