Oregon North Coast Spring Chinook Stock Assessment – 2005-06; Information Reports 2008-01

Identification Information

Citation

Originator: Stewart, D. and Suring, E.

Publish Date: March 2008

Online Link: https://odfw.forestry.oregonstate.edu/spawn/reports.htm

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: Chinook salmon populations of the Oregon coast exhibit two general life history types, classified as either spring-run or fall-run depending on adult life-history traits. Fall chinook are present in most Oregon coastal basins, and the Oregon Department of Fish and Wildlife (ODFW) has identified 28 fall chinook populations in this area (ODFW 2005). Spring chinook salmon are found in larger river basins on the Oregon coast, and the upper portions of the Umpqua and Rogue rivers. This is a more limited distribution than coastal fall chinook and includes only 10 populations (ODFW 2005). Oregon coastal fall chinook stocks have been monitored through a set of 56 standard spawning ground surveys, many conducted since the 1950’s. There has not been a similar, consistent, coast-wide monitoring program for Oregon coastal spring chinook spawners. Abundance of these populations has been monitoring through a variety of methods including; freshwater harvest estimates, counts at dams and weirs, summer resting hole counts, and spawning ground surveys. In 1998, the National Marine Fisheries Service (NMFS) reviewed west coast chinook salmon populations in regards to status under the Federal Endangered Species Act (ESA). The NMFS identified a total of 15 Evolutionarily Significant Units (ESUs) of chinook salmon (Myers et al. 1998). Oregon coastal chinook are predominantly in the Oregon Coast ESU (Necanicum River to Elk River). This ESU includes both spring and fall chinook, and was determined to not warrant listing (Federal Register Notice 1998). In 2005, ODFW conducted a review of Oregon native fish status, in regards to the State’s Native Fish Conservation Policy. This review grouped populations by Species Management Unit (SMU), and examined coastal spring and fall chinook populations separately. The review determined the near-term sustainability of the Coastal Fall Chinook SMU was not at risk, but the Coastal Spring Chinook SMU was at risk (ODFW 2005). The Tillamook and Nestucca spring chinook populations were of particular concern because they failed to pass the interim criteria for abundance, productivity, and reproductive independence. Hatchery supplementation of spring chinook has occurred in the Tillamook and Nestucca basins since the early 1900’s. Currently, approximately 450,000 spring chinook smolts are released annually from Trask Hatchery, Cedar Creek Hatchery (Nestucca), and from a STEP program at Whiskey Creek. These hatchery smolts have been mass marked with an adipose fin clip since the 1998 brood year. Therefore, hatchery origin adult spring chinook may now be positively identified by the lack of an adipose fin. Declining trends in wild coastal spring chinook populations have resulted in management actions to target harvest on adipose fin clipped hatchery fish, and to restrict harvest of wild origin fish. Results of status reviews, and changes in management practices have required a more thorough evaluation of stock status for the Tillamook and Nestucca spring chinook populations (Keith Braun, personal communication). Therefore, ODFW developed a monitoring plan for spring chinook in these basins. The monitoring plan identified four project objectives; 1) Determine adult spring chinook abundance in the Trask, Wilson, and Nestucca Rivers, 2) Determine hatchery vs. wild ratios for these three basins, 3) Determine age structure and sex ratios for adult spawners, and 4) Determine distribution and abundance for spring chinook recycled from local ODFW hatcheries. This project began in 2004 with an exploratory season to determine distribution, survey methodology, and feasibility of the proposed protocol. In 2005 and 2006 a more intensive sampling effort was implemented, designed to cover the entire distribution of spring chinook spawning in the Nestucca, Trask, and Wilson rivers. Since 2004, project field work has been funded with Restoration and Enhancement Program (R&E) funds, administered by Oregon Department of Fish and Wildlife. Project administration is covered through existing funding for the ODFW Oregon Adult Salmonid Inventory and Sampling Project (OASIS). Funding from R&E is scheduled to continue through the 2008 spawning season. Further monitoring will require a new funding source for project field work. This report documents results for project Objectives 1 to 4, including the abundance and distribution of spring chinook spawners during 2005 and 2006 in Oregon’s Trask, Wilson, and Nestucca river basins.

Purpose:

Time Period of Content: 2005-2006

Geographic Extent: Wilson River, Trask River and Nestucca River

Status: Final

Use Constraints:

Format: PDF File

Data Quality Information

Lineage-Source: Final report for Grant 05-006, funded in part by the Restoration and Enhancement Program administered by the Oregon Department of Fish and Wildlife.

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? No