Abstract :
One of the fundamental problems conservation biologists face when they provide advice to managers is how to characterise and account for the uncertainties which result from measurement and estimation error, model mis-specification and simple lack of knowledge. Computer-intensive techniques, initially developed in the 1970s, can now be used to incorporate all these sources of uncertainty into a rigorous statistical framework. Risk assessment combined with decision analysis provides a methodology for quantifying these uncertainties and a framework for making management decisions in an uncertain world. In the last decade they have been applied widely in economics, epidemiology and fisheries management. Their potential use in conservation biology is reviewed here using two examples: population viability analysis and the reduction of the by-catch of small cetaceans in fishing gear.