Best Management Practices – A Tool Not a Rule

Salmon hatcheries in the Pacific Northwest were originally constructed to mitigate for impacts of human development (dam construction and habitat destruction). In the past twenty years hatcheries have evolved to meet both conservation and harvest objectives.  Multiple expert panel reviews have produced generalized management principles for hatcheries aimed to minimize hatchery fish risks to natural populations.  Recently two groups, the Hatchery Science Review Group (HSRG) and Hatchery Review Team (HRT), developed best management practice recommendations for hatcheries in the Columbia River basin.  Even though the HSRG and HRT acknowledged that alternative actions exist and should be considered, policy and funding entities are considering adopting/requiring the HSRG and HRT recommendations. Many of the recommendations require additional funding for infrastructure modification and/or increased operational complexity. In most cases, implementing the full suite of best management principles (BMPs) is either cost prohibitive or logistically infeasible. 

Several common BMPs for recovering natural populations include: achieving 100% marking on hatchery production, implementing selective harvest regimes, maximizing natural origin fish utilized in hatchery broodstock, and minimizing hatchery fish on spawning grounds. Failure to fully implement one or all of these is commonly perceived as a death sentence for the natural population.  We utilize ESA listed Snake River fall Chinook to explore “how good is good enough”?  Only 50% of Snake River fall Chinook hatchery production is adipose fin clipped and 22% release unmarked; 30% or higher are subject to non-selective harvest; and  utilization of natural origin fish in hatchery broodstocks was intentionally avoided for the first 30 years of the program. During the last ten years hatchery fish have constituted 67% of natural spawner escapement. Yet, natural origin abundance has increased 10 fold since the 1980’s. The current 10 year geometric mean of natural origin abundance  averages 5,000 fish; exceeding the recommended ESA delisting abundance criteria.