FY07-09 proposal 199700100

Jump to Reviews and Recommendations

Section 1. Administrative

Contacts

Section 2. Locations

Province / subbasin: Mountain Snake / Salmon

Section 3. Focal species

Section 4. Past accomplishments

Section 5. Relationships to other projects

Section 6. Biological objectives

Section 7. Work elements (coming back to this)

Section 8. Budgets

Itemized estimated budget

Total estimated FY 2007-2009 budgets

Cost sharing

Section 9. Project future

Future O&M costs: This program serves as a cash cost share for the Redfish Lake Sockeye Salmon Captive Broodstock Program (199107200). Discussions to resolve how to offset the loss of this cost share should begin prior to the sunsetting of this program.

Termination date: 2012
Comments: This program serves as a cash cost share for the Redfish Lake Sockeye Salmon Captive Broodstock Program (199107200). Discussions to resolve how to offset the loss of this cost share should begin prior to the sunsetting of this program.

Final deliverables: The final program completion report will include the development of recommendations on the efficacy of the captive rearing approach to maintaining populations of anadromous fish experiencing high levels of demographic and/or genetic risk.

Section 10. Narrative and other documents

Reviews and recommendations

ISRP PRELIMINARY REVIEW (Jun 2, 2006)

Recommendation: Response requested

NPCC comments: The Idaho Captive Rearing program collects naturally produced Chinook salmon parr or eyed eggs from redds in the Lemhi, West Fork Yankee Fork Salmon, and the East Fork Salmon rivers. The experimental strategy was developed to increase the number of naturally spawning adults while attempting to avoid the impacts of multigenerational hatchery culture. Over nine years, 1276 adult salmon were released in the treatment streams (an average of 142 fish per year). Through 2005, 149 redds produced by captive-reared Chinook salmon have been documented. Approximately 1/4 of the 558 known females released to spawn constructed redds. Forty-six redds have been sampled for live eggs. Approximately 60 percent of sampled redds contained fertilized embryos, most of which had reached the eyed-stage of development. For redds containing fertilized eggs, egg survival to the eyed-stage of development averaged about 50 percent. A succinct summary of the collection of eggs and fry, their survival in culture to smolts and adults, and their mating in the wild is provided. The picture presented here is much more positive than reported previously -- little attention paid to dead eggs excavated from redds, asynchronous development compared to natural fish, and poor rigor on the part of males. There was no indication of improvement and explanation of the changes in perspective over the last couple years. The proposal indicates that this experimental effort will be terminated by 2112. In the remaining years, the sponsors propose evaluating whether the eggs deposited by captive reared adults produce fry and smolts and whether any of these fish successfully migrate to the ocean and return as adults. Once that is completed this type of captive propagation can be fully described and evaluated. On the understanding that continuation of this project is to complete cycles essential for a final evaluation, it warrants consideration. In the ISRP view it is not yet clear whether this captive propagation technology can be used to benefit salmon. In their response sponsors should first focus on the reproductive success and pedigree experiments. The response should provide the time-line for stocking the adults, evaluating the parr and smolts, and returning adults, so the ISRP can clearly see this can be completed before 2112. Secondly, a justification for the evaluation of gene diversity needs to be presented. There is no need to worry about gene diversity if the strategy is not likely to produce a demographic benefit to the focal species. Finally, a quantification of any potential benefit to the VSP parameters of the focal species ESU is needed. The objective is the successful natural production of natural parr, smolts, and adults, to preventing extirpation of the populations, and rebuilding to self-sustaining levels. But even if there is some benefit to one or two local populations, how does this affect the broader scale status of the ESU? Is the benefit too little and too localized? The participants do a good job of regularly giving presentations at regional meetings and publishing in the peer-reviewed literature. The response should review/consider information in the ISRP programmatic summary concerning captive rearing.

ISRP FINAL REVIEW (Aug 31, 2006)

Recommendation: Fundable

NPCC comments: The Idaho Captive Rearing program collects naturally produced Chinook salmon parr or eyed eggs, and then rears them in captivity to adults for release to increase the number of naturally spawning salmon. The proposal indicates that this experimental effort will be terminated by 2012. The sponsors request funding to complete the evaluation of this captive rearing strategy. The ISRP raised several questions in the preliminary response. The principal query was for an outline of the timeline of juvenile rearing and adult release, and the subsequent natural parr, smolt, and adult production, to ensure that the time frame for the data collection and analysis was sufficient. The sponsors provided an answer to this question that was sufficient. A secondary question was about the natural spawning performance of the captive stock. In earlier proposals, the sponsors reported asynchrony in the spawning of natural and cultured adults, and poor egg viability in natural redds produced from captive stock. No mention of this was in the current proposal and the ISRP requested an update. The sponsors provided a review of the recent observations on asynchrony, reporting that during the last funding cycle this was not a problem. Egg viability was not tested during this time period. No explanation was provided for the improvement in synchrony between natural and cultured spawning adults. Finally, the ISRP asked about the quantitative benefits from a program like this to an entire ESU, under circumstances such as the spring and summer run Chinook in the Snake River that consist of an appreciable number of spawning units. That is, assuming there is a demographic benefit in the treated tributary, what are the quantitative consequences in the Viable Salmonid Population metrics for the ESU, from these improvements in individual sites. Sponsors responded that: "It remains difficult for us to comment on whether the potential added adult production from this program will elevate VSP abundance or productivity parameters to a status level more desirable than the current ‘High Risk’ standing. Nevertheless, added adult production will help ensure that a continuum of spawning from one generation to another occurs. Preventing cohort loss will slow the loss of critical population genetic variation and preserve future recovery options." The ISRP appreciates this candid appraisal, but emphasizes that addressing this larger issue is critical when considering using this technology to support ESUs consisting of multiple independent populations or spawning aggregates. When you have 30 to 40 independent populations in an ESU, what aggregate demographic benefit are you getting if you can improve the status by these intensive actions in one or two of the individual populations? What is the short and medium term benefit from this type of action? The final reports and analyses should include this later consideration of the quantitative benefits at the ESU level if benefits are demonstrated at the independent population level.