FCRPS WATER MANAGEMENT STUDIES--ADULT SALMON & STEELHEAD PASSAGE INVESTIGATIONS

PURPOSE:  The purpose of this contract is to investigate salmon and steelhead passage through the hydroelectric system to validate adult survival assumptions used in estimating extinction risk and recovery potential, and to determine sources of adult fish mortality.

OVERVIEW:

During development of the FCRPS Biological Opinion, new data were presented that demonstrated that adult spring Chinook and steelhead destined to the upper Columbia River, were surviving at substantially lower rates through the lower Columbia River than previously documented.  Extinction risk and recovery potential for the endangered UCR salmon and steelhead are significantly affected by these higher mortalities.  Rather than the <2% adult mortality per COE dam that was expected, the latest PIT tag survival information demonstrated that per project mortality was 3%/dam for UCR spring Chinook and 7%/dam for UCR steelhead.  It is not clear if this higher mortality is related to hydropower operations or some other cause.

From 2008 to 2012, the Confederated Tribes of the Colville Reservation (CCT) addressed portions of the Reasonable and Prudent Alternative (RPA) 52 of the Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) (NMFS 2008).  The task of addressing portions of RPA 52 was split into two components; under the first phase, existing information was reviewed and analyzed to determine if the survival reduction for upper Columbia steelhead and spring Chinook (and differences between upper Columbia stocks and Snake River stocks) in the lower Columbia River could be explained.  Implementation of Phase II was dependent on the results of the first phase; if the conclusion was that there is not enough information to describe a survival difference between upper Columbia spring Chinook salmon and steelhead compared to Snake River fish, then a detailed study plan would be developed that outlined an approach to collect empirical information that could explain the survival discrepancies.  A draft detailed study plan was developed but never finalized or implemented because of various factors, including cost and feasibility.
This project was dormant in 2013, then CCT and a subcontractor began working on it again in 2014.   We updated the ESU specific adult survival estimates, reviewed and evaluated other studies that had been implemented that partially addressed RPA 52, and prepared a draft annual report.  This proposal for the next contract period (calendar year 2015) will essentially continue to engage in study plan developments (e.g., the SRWG process), assimilate and report on information from other studies that partially address RPA 52, update the Phase 2 study plan (if warranted), and update the evaluation of PIT tag releases in the UCR.  This project will report on past, current and likely future developments related to the implementation of studies that might address RPA 52.