A decision support system for setting legal minimum lengths of fish

Abstract  The use of legal minimum lengths is one of the oldest forms of regulation in fisheries management. Management objectives using minimum legal lengths are varied, often conflicting and generally poorly communicated. This paper introduces a decision support system that will assist fisheries managers in determining optimal legal minimum lengths. The system uses multi-criteria decision analysis to enable the integration of objective scientific and biological information into a system that assesses the success of any potential length limit in achieving each of the management objectives. The system can also document trade-offs between options that achieve management objectives and short-term socio-economic impacts. The decision support system is demonstrated using 13 commercially and recreationally important coastal species from New South Wales, Australia.