In response to the Council’s March 1, 2013 request, the ISRP reviewed the Draft Columbia Basin White Sturgeon Planning Framework (February 2013). The Council called for preparation of the Sturgeon Planning Framework to address ISRP comments in the Research, Monitoring, and Evaluation and Artificial Production Category Review regarding sturgeon in the lower Columbia River (ISRP 2010-44). The ISRP provided a favorable review of specific sturgeon projects but noted that an effective basinwide management plan for white sturgeon was needed for planning future research and restoration.
As described in the preface to the Sturgeon Planning Framework, the Council recommended that sturgeon hatchery planning projects implemented by the Columbia River Inter-Tribal Fish Commission (2007-155-00) and the Yakama Nation (2008-455-00) lead development of the comprehensive management plan. The lower Columbia sturgeon monitoring and mitigation project (1986-050-00) sponsored by the Oregon and Washington Departments of Fish and Wildlife, the Inter-Tribal Fish Commission, and other agencies and tribes involved with related sturgeon projects also collaborated in the plan development. The planning area includes the mouth of the Columbia upstream to Priest Rapids on the mainstem and up to Lower Granite Dam on the Snake River. The plan was also to include summary information for sturgeon areas above Priest Rapids and Lower Granite.
Beginning in 2009, three regional sturgeon workshops were convened that have led to the development of the Sturgeon Planning Framework. ISRP members attended these workshops and found them very useful in identifying key issues, strengths, and weaknesses in the sturgeon programs, projects, and activities basinwide.
The Draft Columbia Basin White Sturgeon Planning Framework document (Framework) is a commendable effort and a positive step by the planning group, contributors, and workshop participants. The Framework is a comprehensive document incorporating much of what is known about white sturgeon life history, status, and fisheries in the Columbia River Basin. It also includes many useful references.
However, the document only partially responds to several of the five data gaps identified by the ISRP in their last review of the sturgeon projects (ISRP 2010-44), as follows:
- An effective basinwide management plan for white sturgeon is still lacking and is the most important need for planning future research and restoration. Now that general information gaps and research needs have been identified, specific studies designed to meet those needs should be developed and incorporated into the Framework. This brings with it two challenges. First, how will research goals be prioritized? And second, once prioritized, decisions on how, where, and who will do the work will need to take place. Resolving these issues will require coordination among Columbia River white sturgeon managers, researchers, and the Action Agencies.
- Study designs for investigating specific factors affecting recruitment of white sturgeon are lacking. Factors affecting recruitment are poorly understood and remain a serious roadblock to natural long-term restoration. The Framework authors recognize that the highest priority data gap is to understand why there is inadequate recruitment above Bonneville Dam. At the sturgeon workshops they theorized “with a high degree of certainty that this is due to: (1) low diversity, (2) lack of adults, and (3) flow levels that were either too low or not the right type or time. They also identified predation as a likely factor.” These hypotheses need to be evaluated with specific, well-designed studies including population genetics studies, flow-survival studies, and more focused predation studies. The lack of accurate age determination methods also continues to limit understanding variations in annual recruitment and its causes. The general recommendations developed in the framework are not sufficiently detailed to provide clear guidance for a strategic research plan.
- The Framework document does not thoroughly address the importance of the estuary and ocean in sturgeon production below Bonneville Dam including the possible importance to sturgeon production in upriver areas prior to dam construction and potential to limit upriver restoration efforts. The description of white sturgeon use of estuarine habitats should include more detail, and the literature review and synthesis on anadromy of the species is incomplete. Factors associated with estuary and ocean use, versus only freshwater use, do not seem to be well understood. Additional studies should be proposed to fill knowledge gaps. The document gives the impression that estuarine habitat is less heterogeneous than freshwater habitat, but this is not necessarily the case.
- The productivity of the newly created pools above Bonneville Dam for sturgeon is poorly understood. The Framework document provides little coverage of this topic indicating that productivity above Bonneville is low, perhaps due to lack of dam passage, poor recruitment, and lack of anadromy. It would be helpful to have an expanded narrative on this issue and recommendations for obtaining the needed information.
- Consideration of adaptive management approaches should include a review of harvest regulations with the intent of facilitating the efficient, low-cost acquisition of creel data needed for stock assessment. The Framework document does provide a good detailed description of the current and planned harvest regulations. For the lower Columbia River harvest management unit, the Oregon Department of fish and Wildlife (ODFW) has developed a well-reasoned conservation plan with a population viability analysis model to monitor the status of the population below Bonneville. However, a more critical, creative assessment is needed of harvest management approaches such as specific time-area closures and harvest caps to develop a harvest strategy designed to provide optimal information for sustainability. The ISRP suggests that the unique life history aspects of white sturgeon calls for more pro-active and creative adaptive harvest management approaches.
The move to fast-track sturgeon hatcheries and supplementation is strongly emphasized in the Framework. That emphasis may be warranted in specific locations, but the ISRP has concerns that release of hatchery juvenile sturgeon in the mainstem Columbia River above Bonneville may pose risks to the large self-sustaining sturgeon population below Bonneville. This self-sustaining segment below Bonneville is the foundation of future natural reproductive capability in the basin and perhaps throughout the range of the white sturgeon. Maintaining its viability should be the highest priority. Further justification for a hatchery approach and a discussion of risk assessment and monitoring should be added. Comments regarding the apparent success of hatchery programs (e.g., Kootenai) should be qualified in terms of the ability to hatch, rear, and release post age-0 fish. These successes, while impressive, do not necessarily equate with long-term viability of hatchery-reared fish as future successful parents of viable, naturally spawning fish.
Similar questions need to be asked about the relative reproductive success of hatchery origin sturgeon as are being asked for salmon and steelhead. Studies need to be designed to determine if hatchery sturgeon and their progeny are as reproductively competent as those originating from wild sturgeon. Unlike salmonids, where such an assessment can be evaluated in 10-15 years, a similar appraisal for sturgeon may take half a century. Perhaps of more importance are the genetic ramifications of using artificial culture. Due to their high fecundity and scarcity, relatively few sturgeon are used at any one time for broodstock. This means that sturgeon populations supplemented by hatchery fish may be susceptible to a Ryman-Laikre effect. That is, genetic diversity may be significantly reduced because the higher survival of hatchery fish causes an over representation of their genes in a population. Recent success at collecting naturally produced 14-day old sturgeon larvae offers a potential improvement. Genetic analyses of these fish indicated that 200 such individuals possessed 90% of the genetic diversity of their population. Collected larvae are then artificially reared and eventually released using procedures similar to those employed in a standard sturgeon hatchery. A full discussion that compares the pros and cons of using larval collections, standard hatchery methods, and translocation as supplementation tools should be added to the Framework. In addition to the potential benefits to hatchery programs of collecting wild larval sturgeon, the benefits to understanding the ecology of wild larval and juvenile fish and factors affecting their inter-annual abundance can be even greater in the long run.
See the full report for details.