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Title: Comparative Survival Study (CSS) of PIT-Tagged Spring/Summer Chinook and Summer Steelhead : 2008 Annual Report.

Technical Report ·
DOI:https://doi.org/10.2172/961815· OSTI ID:961815

The Comparative Survival Study (CSS; BPA Project 199602000) began in 1996 with the objective of establishing a long term dataset of the survival rate of annual generations of salmon from their outmigration as smolts to their return to freshwater as adults to spawn (smolt-to-adult return rate; SAR). The study was implemented with the express need to address the question whether collecting juvenile fish at dams and transporting them downstream in barges and trucks and releasing them downstream of Bonneville Dam was compensating for the effect of the Federal Columbia River Power System (FCRPS) on survival of Snake Basin spring/summer Chinook salmon migrating through the hydrosystem. The Completion of this annual report for the CSS signifies the 12th outmigration year of hatchery spring/summer Chinook salmon marked with Passive Integrated Transponder (PIT) tags as part of the CSS and the 9th complete brood year return as adults of those PIT-tagged fish (report covers adult returns from 1997-2006 hatchery Chinook juvenile migrations). In addition, the CSS has provided PIT-tags to on-going tagging operations for wild Chinook since 2002 (report covers adult returns from 1994-2006 wild Chinook juvenile migrations). The CSS tags wild steelhead on the lower Clearwater River and utilized wild and hatchery steelhead from other tagging operations in evaluations of transportation (report covers adult returns from 1997-2005 wild and hatchery steelhead migrations). The primary purpose of this report is to update the time series of smolt-to-adult survival rate data and related parameters with additional years of data since the completion of the CSS 10-yr retrospective analysis report (Schaller et al 2007). The 10-yr report provided a synthesis of the results from this ongoing study, the analytical approaches employed, and the evolving improvements incorporated into the study as reported in CSS annual progress reports. This current report specifically addresses the constructive comments of the most recent regional technical review conducted by the Independent Scientific Advisory Board and Independent Scientific Review Panel (ISAB and ISRP 2007). This report completes the 3-salt returns from migration years 2004 for wild and hatchery Chinook and steelhead (all returns are to Lower Granite Dam). For wild and hatchery Chinook, this report also provides 3-salt returns from migration year 2005 and 2-salt returns from migration year 2006 through a cutoff date of August 13, 2008. For wild and hatchery steelhead, it provides completed 2-salt returns for wild and hatchery steelhead that outmigrated in 2005 (any 3-salt returns of PIT-tagged steelhead are few, but will occur after July 1, 2008). All of the Chinook salmon evaluated in the CSS study exhibit a stream-type life history. All study fish used in this report were uniquely identifiable based on a PIT-tag implanted in the body cavity during (or before) the smolt life stage and retained through their return as adults. These tagged fish can then be detected as juveniles and adults at several locations of the Snake and Columbia rivers. Reductions in the number of individuals detected as the tagged fish grow older provide estimates of survival. This allows comparisons of survival over different life stages between fish with different experiences in the hydrosystem (e.g. transportation vs. in-river migrants and migration through various numbers of dams) as illustrated in Figure 1.1. The CSS is a long term study within the Northwest Power and Conservation Council's Columbia Basin Fish and Wildlife Program (NPCC FWP) and is funded by Bonneville Power Administration (BPA). Study design and analyses are conducted through a CSS Oversight Committee with representation from Columbia River Inter-Tribal Fish Commission (CRITFC), Idaho Department of Fish and Game (IDFG), Oregon Department of Fish and Wildlife (ODFW), U.S. Fish and Wildlife Service (USFWS), and Washington Department of Fish and Wildlife (WDFW). The Fish Passage Center (FPC) coordinates the PIT-tagging efforts, data management and preparation, and CSSOC work. The location of all tagging sites is identified in Figures 1.2 and 1.3. All draft and final written work products are subject to regional technical and public review and are available electronically on FPC and BPA websites: FPC: http://www.fpc.org/documents/CSS.html; and BPA: http://www.efw.bpa.gov/searchpublications/index.aspx?projid.

Research Organization:
Bonneville Power Administration (BPA), Portland, OR (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
35850
OSTI ID:
961815
Report Number(s):
P109205; R&D Project: 1994-033-00; TRN: US200915%%286
Country of Publication:
United States
Language:
English