The Fish Passage Center has added another level of detail to its analysis of how Snake River salmon and steelhead, primarily, fare that migrate down through the Columbia/Snake River hydro system as juveniles or, alternatively, ride past the dams aboard barges.
The “Comparative survival Study of PIT-tagged Spring/Summer Chinook and Summer Steelhead 2011 Annual Report” can be found at:
The report was prepared by the Comparative Survival Study Oversight Committee and Fish Passage Center. Project leader was Michele DeHart, FPC manager.
Comments on the draft should be sent to DeHart by Oct. 15.
The CSS began in 1996 with the objective of establishing a long term dataset of annual estimates of the survival rate of 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 of whether collecting juvenile fish at dams, transporting them downstream of Bonneville Dam and then releasing them was compensating for the effect of the Federal Columbia River Power System in the Columbia and Snake basins on the survival of Snake River spring/summer chinook salmon that migrate through the hydro system, according to the report.
The completion of the 2011 annual report for the CSS signifies the 14th outmigration year of hatchery spring/summer chinook salmon marked with Passive Integrated Transponder (PIT) tags as part of the CSS. It’s also the 12th complete brood year return as adults of those PIT-tagged fish, covering adult returns from 1997-2009 hatchery chinook juvenile migrations.
In addition, the CSS has provided PIT-tags to on-going tagging operations for wild chinook since 2002 (report covering adult returns from 1994-2009 wild chinook juvenile migrations). The CSS tagged wild steelhead on the lower Clearwater River and utilized wild and hatchery steelhead from other tagging operations in evaluations of transportation, covering adult returns from 1997-2007 wild and hatchery steelhead migrations
All FPC 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