Application of decision theory to conservation management: recovery of Hector's dolphin

Abstract

Decision theory provides an organised approach to decision making in natural resource conservation. The theory requires clearly stated objectives, decision alternatives and decision-outcome utilities, and thus allows for the separation of values (conservation and other societal objectives) from beliefs. Models express belief in the likely response of the system to conservation actions, and can range from simple, graphical representations to complex computer models. Models can be used to make predictions about likely decision-outcomes, and hence guide decision making. Decision making must account for uncertainty, which can be reduced but never eliminated. Uncertainty can be described via probabilities, which in turn can be used to compute the expected value of alternative decisions, averaging over all relevant sources of uncertainty. Reduction of uncertainty, where possible, improves decision making. Adaptive management involves the reduction of uncertainty via prediction under two or more alternative, structural models, comparison of model predictions to monitoring, and feedback via Bayes' Theorem into revising model weights, which in turn influences decision making. As part of a 3-day workshop on structured decision making (SDM) and adaptive resource management (ARM), we constructed a prototypical decision model for the recovery for Hector's dolphin (Cephalorynchus hectori), an endangered dolphin endemic to New Zealand coastal waters. Our model captures several steps in the process of building an SDM/ARM framework, and should be useful for managers wishing to apply these principles to dolphin conservation or other resources problems.

Spatial patch occupancy patterns of the Lower Keys marsh rabbit

“…Managing natural resources often requires the use of models to understand the impact of management on resource dynamics and predict the consequences of alternative actions to make the best decisions relative to management objectives (Williams et al 2002, Pielke and Conant 2003). The abundance of a target organism is commonly used as a state variable for predictive models in evaluating the outcome of management actions (MacKenzie and Nichols 2004, Conroy et al 2008). The proportion of sites occupied by a focal species, however, is often closely correlated with abundance and may be preferable as a state variable for conservation management programs (Hanski 1991, Gotelli 2000, Carrete et al 2002, MacKenzie and Kendall 2002, Royle et al 2005).…”

Complex decisions made simple: a primer on stochastic dynamic programming

“…In such case, one needs the most accurate predictions to optimize future allocation of monitoring and management effort (Williams, Nichols & Conroy ; Conroy et al . ). Adaptive management is a sequential action process, specifically designed for conservation problems dealing with structural uncertainty (Runge ).…”

Adaptive management in the U.S. National Wildlife Refuge System: Science-management partnerships for conservation delivery

“…By "adaptive management," we mean a decision-theoretic approach to making a sequence of decisions by which uncertainty about decision making is reduced over time through comparison of predictions of outcomes by competing models against observed values of those outcomes (Williams,1997;Kendall, 2001;Moore and Conroy, 2006;McCarthy and Possingham, 2007;Conroy et al, 2008). Development of the idea traces back to operations research in the 1950s (Bellman,1957(Bellman, ,1961; Walters and Hilborn (1978) and Walters (1986) described its use in natural resource applications.…”