Necessity of Adaptive Risk Management for Fisheries and Wildlife

Abstract

The conventional theory of ecosystem and population management does not include the concept of risks. In risk management, survival rates and reproductive rates are taken into account in mathematical models describing conditions of the ecosystem, and uncertainty and environmental variation when measuring are taken into account when predicting population sizes. As a result, future prediction can only be made in a probabilistic way. Even when a general prediction is made about the future, therefore, it is rare to predict it accurately. Risk evaluation to show a prediction range with some allowance is required. Moreover, if management measures are predetermined, it is impossible to cope with a contingency. Adaptive management is therefore recommended as a management method to cope with uncertainties. This entails making a management plan based on unverified assumptions, continuously monitoring changes in the situation while implementing the plan, adjusting the management measures as required, and verifying the appropriateness of the assumptions used. It is important to predetermine how the measures will be adjusted and the assumptions verified. In this chapter, we highlight the difference in thinking before and after adaptive risk management is established, describing two cases: management of fisheries resources and wildlife management. Numerical calculations that appear in the figures in this chapter can be obtained through the website ( http://risk.kan.ynu.ac.jp/matsuda/2014/SLER.html ) and additional tests can be conducted with Excel files. Eager readers are strongly recommended to try this.