The response to the ISRP addressed the questions posed in the preliminary review, but for the most part the answers were unconvincing and affirmed the initial concerns. In the preliminary review, the ISRP noted that it appeared that the Corp projects that had installed and used a radio-tagging array to monitor upstream migration of adult salmon had been finalized and that scientists using the array were searching for a purpose to continue to collect radio-telemetry data. The sponsors affirm the ending of this project funded by the Corp and argue that radio-telemetry is a useful way to collect important vital statistics on adult salmon including data on in-river harvest, pre-spawning mortality, and "turn-off" into tributaries. The sponsors provide some detail on the limitation of other methods to enumerate these parameters using PIT tags and redd counts.

The responses to ISRP's concern were not very concise and leave a lingering concern that the proponents are doing work that might be more suitable for agencies that are directly concerned with harvest management. As the proponent states:

"Generating reliable harvest estimates within the Columbia River is problematic but is critical to NMFS, Pacific Salmon Commission (PSC), TAC, States and Tribes for effective management and recovery of salmon/steelhead stocks" and if so, these agencies should step up to the plate. Perhaps they are already involved in funding or in-kind support, but this was not clear from the response.

While the radio tagging studies will no doubt provide some very interesting and useful data on straying, pre spawn mortality, fall back etc, some of these questions could be addressed with specific hypotheses and investigations. Perhaps a subset of the large array of devices could be used in such studies.

The project sponsor did a reasonable job of elaborating on the justification for radio tagging adult salmon to assess certain survival, harvest, and straying questions.
There was insufficient explanation of the sample sizes and the number of stocks that would be evaluated. The 600-800 transmitters for spring-summer Chinook and steelhead, respectively, seems to be a rather small sample of the total number of fish passing Bonneville. If they don't achieve a 25% recovery rate of deployed tags as anticipated, they may be looking at a transmitter shortage. There is a lack of specificity about which stocks they will monitor and why. Specifically, sponsors suggest that 600 to 800 tags are needed per stock to evaluate straying, pre-spawn mortality, etc. Yet they are only asking for only 1300 tags, and hope to re-use 200 or so from early in the season. This means only two stocks will be evaluated each year. With eight or so listed ESUs, migrating above Bonneville, they don't justify how this effort will be sufficient, how the monitoring will be sequenced by stock over the years. This certainly cannot be sufficient to support a basinwide estimate of adult survival. It is not clear that this will have direct linkage to management decisions that provide benefits to fish.