The use of Reference Points in Fisheries Management: A short review

The evaluation of a range of fixed-effort scenarios (undertaken as part of the recently completed project " Development of an operating model and evaluation of harvest strategies for the Eastern Tuna and Billfish Fishery ") provided guidance on identifying an appropriate initial Total Allowable Effort (TAE) for the longline fleet in the ETBF. However, ideally, any harvest strategy adopted for the ETBF should incorporate some form of feedback decision rule whereby the status of the fishery is regularly assessed, and the harvest strategy is updated and applied depending on the results. Without management feedback loops, high levels of combined effort may lead to overexploitation and/or overcapitalisation in the fishery. Alternatively, if effort levels can be adjusted in an appropriate manner, the risk of not achieving either the conservation and/or economic objectives should be diminished. Decision rules used in fisheries management usually involve the use of reference points. Reference points act as benchmarks against which the performance of the fishery can be measured and are most widely used to achieve precautionary management objectives. Whilst the concept of Maximum Sustainable Yield (MSY) is a well known reference point which was widely adopted in the past, over the past decade a multitude of alternative reference points have been developed. This background paper briefly discusses the main issues involved in the adoption of performance measures and reference points in fisheries management. 2. Definitions 1) Performance Indicators and Measures: A performance indicator conveys information about some aspect of the system under study (eg. the biomass of the swordfish population in the SW Pacific) while a performance measure conveys information about how well the system is performing relative to some management objective (eg. it compares the performance indicator with some reference value or benchmark, say 30%B o). Performance indicators are usually based on quantities estimated during the assessment and are generally useful only if a stock assessment method can estimate them reliably. 2) Target and Limit Reference Points The reference values or benchmarks against which fisheries performance is measured could be target values that identify desirable conditions at which management should aim (target reference points, TRP) and/or threshold or limit Background paper on Reference Points in Fisheries Management, November 2003 2 values that identify critical levels which if exceeded result in potentially adverse fishery situations (limit reference points, LRP). A schematic representation defining the relationship between a performance indicator, a performance measure and an associated reference …