CHOOSING A MANAGEMENT STRATEGY - 2 STRUCTURED DECISION-MAKING METHODSFOR EVALUATING THE PREDICTIONS OF STOCHASTIC SIMULATION-MODELS

We describe two structured decision-making methods-one using a hierarc hy of goals and a second using ranking on the sum of weighted criteria -that may be useful for many practical conservation problems, particul arly when advisory groups evaluate the output of simulation models. We illustrate both methods by applying them to the problem of choosing a management strategy to address the ''mobbing''problem in endangered H awaiian monk seals. Both methods require estimates of the probabilitie s of various outcomes, such as a population size of more than 400 seal s after 20 years under a specific management regime. We used a simulat ion model of a small monk seal population to generate these probabilit ies. Both methods Provide an explicit well-documented and reproducible decision process that helps justify the decision Furthermore they are easy for those untrained in decision analysis to understand and use t hey focus discussion on management objectives, they facilitate an exam ination of trade-offs in the light of multiple and sometimes conflicti ng objectives they are suitable for use in workshops, and, at least in our example, they lead to management recommendations that are not hig hly sensitive to minor changes in probability estimates or other facto rs.