A Practical Approach for Containing Ecological Risks Associated with Fish Stocking Programs

The costs and benefits of fish stocking programs can be more favorably balanced if undesirable risks can be contained. Risk assessment identifies potential undesirable outcomes, but there is often uncertainty about the actual risks of a given stocking program. Uncertainty requires greater precaution to assure undesirable outcomes do not occur, possibly at the expense of some or all of the benefits of a stocking program. It may be possible to reduce risk or uncertainty and increase the likelihood of an acceptable outcome by taking additional steps to detect and limit impacts. In this article, we describe a practical approach for containing ecological risks of fish stocking. This approach consists of six tasks that are arranged into a stepwise decision framework: (1) determine whether risk containment is necessary; (2) determine whether important impacts are detectable; (3) determine if practical measures to contain impacts are available; (4) monitor to detect impacts; (5) act to contain impacts if necessary; (6) reassess risks and uncertainty to plan the next cycle. Tasks 1–3 are completed before stocking and, if stocking is the chosen alternative, tasks 4–6 occur during and after stocking. These tasks build upon risk assessment, risk minimization, and uncertainty resolution that establish the level of risk and uncertainty prior to stocking. The approach is an iterative process of detection, containment, and reassessment of risk that limits the probability of impacts exceeding acceptable limits. In addition to the potential of limiting impacts, the information gathered during risk containment monitoring can clarify risk and resolve uncertainties, and may help identify a better balance of costs and benefits. Specific examples of the risk containment approach are described for salmon supplementation in the Yakima Basin, Washington.