Towards ecosystem-based fisheries management

Performance measures and reference points for the management of target species are now widely used in the fisheries of the developed world. To move us closer to an ecosystem-based fisheries management framework, we look at the prospects for expanding current single-species approaches for target species, by considering nontarget species. We also examine the development of performance measures and reference points for emergent ecosystem-level properties. We conclude that the expansion of single-species reference points to take account of the nontarget species of a fishery is tractable and desirable. In contrast, the use of performance measures for a single or a small selection of ecosystem metrics is not possible at present, owing to the absence of a clear understanding of their dynamics and a lack of underlying theory to explain their behaviour. However, recent methods that aggregate a wide range of metrics to provide an overall picture of the ecosystem status show promise and have a particular attraction because they have the potential to provide a framework for establishing a dialogue on management issues between all interested parties.