This project will provide useful information on the response of Chinook and steelhead to a commonly utilized enhancement method. Accounting for density-dependent effects is an unusual aspect of this study design and an important aspect ignored by most other projects that have attempted to assess fish response to habitat improvements. There may be some difficulties in extending results to larger spatial scales. Although the ISRP is not requesting a response, the project would be strengthened by addressing the following comments.

Technical and scientific background: The background provided is complete and does indicate that there are some interesting questions that can be addressed at the habitat/reach scale at which this project will be conducted. The background information greatly benefits from data collected during a pilot study. However, the relationship of the responses observed in this project to responses at much larger spatial scales (subbasin, ESU, etc.) is unclear. The statement is made that variability in responses at the microsite or reach scale will indicate if it is likely that a response to treatment at larger spatial scales are likely to be detected. However, this assumes that the treated and control sites used for the experiment are representative of all reaches in the Entiat. It is entirely possible that the underlying conditions at the study sites will constrain a response to wood addition, but in other areas of the watershed such treatments might elicit a large response. Some clearer description of how the results of this study will be extended to larger spatial scales should be included in the proposal.

Rationale and significance to subbasin plans and regional programs: Placement of wood or other materials in stream channels to increase pool habitat and cover is an action identified in the Entiat subbasin plan. Therefore, this experiment can provide valuable information on the effectiveness of this approach for Chinook and steelhead. The issue with extending the microsite and reach level responses to more relevant spatial scales for salmon recovery remains an issue, but the project does align well with regional programs.

Relationships to other projects: This project is aligned with some of the United States Forest Service (USFS) and other projects being implemented in the Entiat.

Objectives: The proposal provides a single, clear objective and specific hypotheses (objectives) to be tested. The objective is to assess the response of Chinook and steelhead to placement of instream structures. This restoration strategy is being widely applied across the Columbia basin.

Tasks (work elements) and methods: The methods are fully described; they are also quite innovative in that the study explicitly accounts for density dependent effects in assessing fish response to the placement of in-stream structures. Failure to account for density dependence has been a problem with many studies conducted on this subject.

There are two specific points related to the methods that the authors may want to consider:
1) The reliance on snorkel surveys and seining to estimate population levels may pose a problem. Increasing structural complexity of habitat will make the proposed census techniques less effective; it is harder to see or net fish if they have lots of places to hide. As the fish will be tagged anyway, why not recapture fish by seining the day after they have been tagged and develop a mark-recapture estimate of population size? This would be more accurate than relying on the snorkel estimates.
2) The enclosure experiments are likely to expose the experimental fish to many different conditions than would be the case if they were free to move about the pool. The ability of the fish to move from feeding to resting locations may play a role in determining their performance. The experimental fish may be prevented from using some important microhabitat types. The enclosures also will prevent predation.

If this mechanism is an important determinant of habitat carrying capacity, it will not be captured by the enclosure experiments. Could entire pools be used for these manipulative experiments (i.e., isolate the pools with screens or nets and manipulate density by adding or removing fish from nearby habitats)? This approach would avoid some of the artificial properties introduced by using cages.

Monitoring and evaluation: This is a monitoring and evaluation effort. As noted above, most components of this proposed study are technically very good.

Facilities, equipment, and personnel: The personnel are well qualified and facilities appear adequate.

Information transfer: Information will be communicated through standard scientific channels. There is no mention of a process to communicate results directly to restoration practitioners in the Entiat of other subbasins.

Benefits to focal and non-focal species: The knowledge generated by this study will be of value in guiding future in-stream habitat enhancement projects. The problems related to extending the results to spatial scales of primary relevance to recovery efforts are a potential issue. There may be very minor impacts on non-focal species in the areas where sampling occurs or where habitat is manipulated. These impacts should be very short-lived. There may be positive effects for non-focal species that utilize pool habitat in streams.