Comparative Survival Study (CSS) of Hatchery PIT-tagged Spring/Summer Chinook; Migration Years 1997-2002 Mark/Recapture Activities and Bootstrap Analysis, 2003-2004 Biennial Report.

Technical Report · Sat Nov 01 00:00:00 EST 2003

DOI:https://doi.org/10.2172/887177· OSTI ID:887177

Berggren, Thomas J.; Franzoni, Henry; Basham, Larry R. ^[1]

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1. Columbia Basin Fish and Wildlife Authority, Fish Passage Center, Portland, OR

The Comparative Survival Study (CSS) was initiated in 1996 as a multi-year program of the fishery agencies and tribes to estimate survival rates over different life stages for spring and summer Chinook (hereafter, Chinook) produced in major hatcheries in the Snake River basin and from selected hatcheries in the lower Columbia River. Much of the information evaluated in the CSS is derived from fish tagged with Passive Integrated Transponder (PIT) tags. A comparison of survival rates of Chinook marked in two different regions (which differ in the number of dams Chinook have to migrate through) provides insight into the effects of the Snake/Columbia hydroelectric system (hydrosystem). The CSS also compares the smolt-to-adult survival rates (SARs) for Snake River Chinook that were transported versus those that migrated in-river to below Bonneville Dam. Additional comparisons can be made within in-river experiences as well as comparison between the different collector projects from which smolts are transported. CSS also compares survival rates for wild Snake River spring and summer Chinook. These comparisons generate information regarding the relative effects of the current management actions used to recover this listed species. Scientists and managers have recently emphasized the importance of delayed hydrosystem mortality to long-term management decisions. Delayed hydrosystem mortality may be related to the smolts experience in the Federal Columbia River Power System, and could occur for both smolts that migrate in-river and smolts that are transported. The CSS PIT tag information on in-river survival rates and smolt-to-adult survival rates (SARs) of transported and in-river fish are relevant to estimation of ''D'', which partially describes delayed hydrosystem mortality. The parameter D is the differential survival rate of transported fish relative to fish that migrate in-river, as measured from below Bonneville Dam to adults returning to Lower Granite Dam. When D = 1, there is no difference in survival rate after hydrosystem passage. When D < 1, then transported smolts die at a greater rate after release below Bonneville Dam than smolts that have migrated in-river to below Bonneville Dam Major objectives of the CSS include: (1) development of a long-term index of transport SAR to in-river SAR for Snake River hatchery and wild spring and summer Chinook smolts measured at Lower Granite Dam; (2) develop a long-term index of survival rates from release of smolts at Snake River hatcheries to return of adults to the hatcheries; (3) compute and compare the overall SARs for selected upriver and downriver spring and summer Chinook hatchery and wild stocks; and (4) begin a time series of SARs for use in hypothesis testing and in the regional long-term monitoring and evaluation program. Primary CSS focus in this report is for wild and hatchery spring/summer Chinook that outmigrated in 1997 to 2002 and their respective adult returns through 2004.

• Research Organization: Bonneville Power Administration (BPA), Portland, OR (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: 00006203
• OSTI ID: 887177
• Report Number(s): DOE/BP-00006203-5; R&D Project: 199602000; TRN: US200617%%582
• Country of Publication: United States
• Language: English

Related Subjects

13 HYDRO ENERGY
24 POWER TRANSMISSION AND DISTRIBUTION
54 ENVIRONMENTAL SCIENCES
ADULTS
COLUMBIA RIVER
DAMS
EVALUATION
GRANITES
HYPOTHESIS
MANAGEMENT
MONITORING
MORTALITY
POWER SYSTEMS
RIVERS
TESTING
TRANSPORT
Chinook salmon - Snake River Watershed (Wyo.-Wash.) - Mortality
Hatchery fishes - Mortality