Calibration of Methods to Survey for Fall Chinook Salmon in North Fork Nehalem and South Fork Coos Rivers, Annual Progress Report, September 1999

Identification Information

Citation

Originator: Riggers, B., S. Jacobs and J. White

Publish Date: September 1999

Online Link: None

BPA Project #:

Contact Information

Agency: Oregon Department of Fish and Wildlife

Name: Matt Weeber

Job Position: OASIS Program Analyst

Telephone: 541-757-5120

E-Mail Address: Matt.Weeber@oregonstate.edu

Description

Abstract: The Oregon Department of Fish and Wildlife (ODFW) has completed the first year of a multi-year study designed to develop methods that provide reliable estimates of fall chinook spawner escapements for Oregon coastal streams. Funding for this study was obtained through the US Letter of Agreement (LOA) and is administered by the Chinook Technical Committee (CTC) of the Pacific Salmon Commission. The CTC is responsible for evaluating the rebuilding process of naturally spawning chinook stocks covered by the Pacific Salmon Treaty and is comprised of scientists from all member states and countries. Three stock aggregates have been identified to originate from Oregon coastal basins. These aggregates are thought to represent populations within distinct genetic and behavioral characteristics and are managed separately. The North Oregon Coast (NOC) and Mid Oregon Coast (MOC) are the two stock aggregates that are north migrating, and are subjected to the CTC's abundance-based management program (USCTC 1997). Current monitoring programs for Oregon coastal fall chinook (Oncorhynchus tshawytscha) do not supply the CTC with information that is adequate for the management and rebuilding of an abundance-based fishery. ODFW has conducted standard surveys for more than 40 years to monitor the status of chinook stocks along coastal Oregon (Jacobs and Cooney 1997). A total of 56 standard index spawner surveys (45.8 miles) are monitored on an annual basis throughout 1,500 stream miles of spawning habitat to estimate peak escapement levels and track trends of north-migrating stocks. Although counts in these standard surveys may be sufficient to index long-term trends of spawner abundance, they are considered inadequate for deriving dependable annual estimates of spawner escapement. To provide estimates of escapements, index counts must be calibrated to known population levels. Without calibration, counts provide only trend information that may or may not follow actual population fluctuations.

Purpose: The purpose of this report is to describe the initial results obtained during the first year of the study (1998). Specific objectives are as follows: 1. Define the sampling methods. 2. Present adult chinook salmon population estimates and associated 95% confidence intervals derived from a Petersen mark-recapture experiment. 3. Present escapement estimates based on the survey design. 4. Discuss the adequacy of the methods and suggest refinements or changes in the survey design that will improve the accuracy and precision of the estimates.

Time Period of Content: 1998

Geographic Extent: North Fork Nehalem River and South Fork Coos River

Status: Final

Use Constraints:

Format: PDF File

Data Quality Information

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Data Information

No data information was supplied.

Entity and Attribute Information

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

Bibliography Information

Field Name	Value
Biblio ID	7346
Year	1999
Publisher
Request Type	Progress Report
Location	Salem HQ
Date Created	1999
Date Cataloged	6/15/05
Date Published	1999
Type	prog repo
Pages	23 pp
Volume
Status	2
Descriptor	Fall Chinook salmon; North Fork Nehalem River; South Fork Coos River;
Date Entered	2005-06-15 15:15:35
Location In Clackamas Library	S wall 1999 Prog Reports
Author	Brian Riggers; Steve Jacobs; Jody White
Duplicates	1
Number Remaining After Requests	6
Presumed All Distributed
Back Room Duplicates
Author
Risk
Species
Disposition Of Requests	StreamNet Library: Request filled

Is a physical copy maintained for reference at Headquarters? Yes