This is a well-justified project that will help to fill important data gaps for natural origin summer steelhead in the Tucannon River. If critical assumptions are met and objectives are successfully achieved, information will be available to improve management decisions for recovering Tucannon steelhead. The ISRP cautions that analysis and interpretation of straying and migration data may prove difficult because (1) a certain % of straying for steelhead is common/normal, and (2) not all detected cases of unexpected migration may be attributed to hydrosystem effects. (See comments in Section 3, below.) 1. Technical Justification, Program Significance and Consistency, and Project Relationships This project proposes to PIT tag emigrating natural origin summer steelhead collected from the Tucannon smolt trap and utilize an existing PIT tag detection array to estimate smolt to adult (SAR) of summer steelhead and thus escapement as a measure of population status. As this is a critically depressed population and accurate estimates are not available, this appears to be a high priority and well justified project. The data collected by this project are also expected to contribute to a better understanding of the relationship between hatchery and natural fish abundance in the Tucannon. The proponents note that past smolt monitoring results have been effective in obtaining a relative measure of natural origin steelhead production from the Tucannon River. Part of the justification is that adult numbers are needed to meet management and population VSP monitoring criteria. An additional justification is that these data will contribute to continued monitoring of unexpected migration patterns to aid in understanding hydrosystem effects on the Tucannon River steelhead population for management decisions in the future. This project appears consistent with the 2008 Washington State Steelhead Management Plan, the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) (RPAs 50.6, 50.7, and 62.4), and the Snake River Salmon Recovery Plan for Southeast Washington (2006). Only one project (#201002800 currently proposed) is specifically stated as related to this one in the narrative, but the Administrative Form lists four other projects that this project is related to. The relationships of how this coordination and data sharing with these projects will be done are adequately described. 2. Project History and Results This is a new project but will use an existing PIT tag array installed in the Tucannon River by the USFWS for monitoring bull trout behavior. The array was given to WDFW because the bull trout work has been completed. Efficiency of detections by array (for bull trout if available) would be helpful to compare with steelhead detection data. 3. Objectives, Work Elements, and Methods The primary objective of the proposed project is to estimate the annual abundance of natural origin summer steelhead returning to the Tucannon River. The objective is clearly stated and measurable, the methods brief, but adequate, and the ISRP liked to see that the critical assumptions were included. Secondary objectives are: (1) monitor the straying of natural origin Tucannon steelhead within the Snake River and its tributaries; Comment: However, a certain percent of straying for steelhead is common/normal so interpretation may be difficult. (2) describe and quantify the hydrosystem effects on this population; Comment: For this secondary objective it seems that all detected cases of unexpected migration may be attributed to hydrosystem effects, and this may not be a valid interpretation. (3) monitor the proportion of hatchery and wild steelhead returning to the river to assess the potential affects of the hatchery program on the natural spawning population structure (pHOS). Comment: The length of the project is stated as 8 to 10 years, to cover two generations—why not three generations? At least three generations may be needed to assess full potential effects of hatchery fish on wild fish. In sum, the monitoring of migration paths of adults at dams and PIT tag detectors in the Tucannon and other locations with subsequent evaluation appears to be well planned. The project personnel appear highly qualified to carry out this project, and if critical assumptions are met, the project has a good likelihood for success.

Figure 1.  Anticipated precision of SAR estimates as a function of PIT-tag release size for wild steelhead .  Precision defined as the anticipated half-width of a   100% confidence interval.

Figure 2.  Anticipated precision of SAR estimates as a function of PIT-tag release size for hatchery spring Chinook salmon.  Precision defined as the anticipated half-width of a   100% confidence interval.

Figure 3.  Anticipated precision of estimates of straying probability as a function of PIT-tag release size for wild steelhead.   Precision defined as the anticipated half-width of a  100% confidence interval

Figure 4.  Anticipated precision of estimates of straying probability as a function of PIT-tag release size for hatchery spring Chinook salmon.  Precision defined as the anticipated half-width of a 100% confidence interval.