The authors propose to study the relationship between temperature stress on both juvenile and adult Chinook salmon and their reproductive success. They make a good case for the importance of the study based on the literature review and what is known about increasing summer temperatures in the river. Although this is a new proposal, the investigators have done earlier work that is relevant to this effort; limited research supported by Anadromous Fish Evaluation Program (AFEP) looked at the relationship between temperature exposure history in the lower Snake River and gamete quality.

The proposal provides an excellent description of objectives and work elements. They are using a reasonable, systematic approach that is likely to yield valuable information. The authors should consider the value of cold-water controls, representative of pre-impoundment conditions. I.e., they are using the sub-lethally warm temperature histories that the fish provide, but how will they know the lipid content of fish that swam in the unimpounded river? How would they sort out the effect of previous ocean experience on egg count or other such "longer term" parameters?

The work elements are clearly laid out and linked to biological objectives. The authors did a nice job of suggesting alternatives and pointing out why they chose the elements that they did. They've worked out contingency plans if cost sharing of radio receivers (from USACE or PSC) is not available; they would just use the temperature recorders and not radio tracking.

The investigators should put some thought into how their findings can be directly applied to altering hydrosystem operations. If they find a sublethal temperature effect, will that dictate exactly how to change flow releases to improve temperature (because each fish will have a unique temperature history)? What if the cause is low water velocity and not high temperatures? Can other factors be sorted out so that there are clear directions for the hydrosystem operators? The adult component looks better than the juvenile component of the proposed research. Relating the reproductive success of adults based on exposure as juveniles is a stretch. Nonetheless, their studies will yield good information about salmon biology.