The authors propose to PIT tag upstream migrating chinook, steelhead, and sockeye as well as taking samples from these fish for GSI analysis. From this they expect to gain information on stock-specific upstream migration timing, estimate stock-specific mortality (and approximate location), estimate straying rates, and get a measure of fallback. The proposal makes a good case for the importance of this work, the results of which will certainly be useful in modeling fish movement up through the hydrosystem.

This project has the potential to yield valuable information, but the ISRP concludes that clarification is needed that PIT tagging sample sizes (number of PIT-tagged and tissue sampled fish) are adequate to produce enough recoveries to make the results statistically valid. A better justification for the sockeye salmon genetic stock identification element would be helpful. The explanation of the sample sizes and sampling scheme is not sufficient to judge whether the data will have sufficient precision.

The ISRP qualifies this fundable recommendation because this proposal, if funded, should consider thoroughly the sample sizes for PIT tagging, the scope of the genetic investigation, and the basis for using genetic methods to identify stocks of sockeye salmon since there are only two stocks in the basin. This information is needed so the project can show that the number of fish proposed for tagging is adequate to yield sufficient recoveries as adults migrate through the mid- and upper rivers. Additionally, the proposal does not describe how adjustments to the number of PIT-tagged fish will be accomplished if tag recoveries are not living up to expectations.

The proposal briefly states that other projects monitoring PIT-tagged fish will find the adults PIT-tagged in this study useful, but it does not provide details. Two PIT tag detectors are going to be purchased, and one will possibly be used at Wells and Tumwater Dams. In general the discussion of the locations needed for PIT tag detections to estimate the various metrics is not presented. The adequacy of the current arrays is needed.

It also does not mention the potential relationship of the genetic stock identification portion of this project to other genetics studies in the Columbia River Basin. The proposal mentions that a genetic baseline of Chinook populations has been created but does not give it. It would have been helpful to see what has been done to date.

If only two significant stocks of sockeye are present in the basin, and they can be partitioned by migration over Rock Island only versus Rock Island and Tumwater, what is gained by the genetic analysis? Could some of the effort to genotype the sockeye be directed elsewhere? How was it determined that using Chinook salmon microsatellite loci would be adequate to assign sockeye salmon to these two stocks?