Maximising net economic returns from a multispecies fishery

The Australian Commonwealth Harvest Strategy and Policy identifies maximising net economic returns as the primary objective of fisheries management. This has largely been interpreted as maximising the net economic yield (MEY) in fisheries. For multispecies fisheries, this has been based on maximising the net present value of total profit in the fishery over all stocks. The estimation of MEY has largely focused on the benefits to the fishing industry. This may potentially have adverse effects on consumers if achieving MEY results in lower catches and higher prices. At the same time, not all costs are considered when estimating profits to the industry. Costs such as the non‐market value of species caught as bycatch are generally ignored. In this report, we examine how including benefits to consumers and the non‐market costs associated with bycatch affect the definition of MEY (and how it relates to net economic returns). Identifying MEY is just one part of the challenge facing fisheries managers. How to achieve MEY in multispecies fisheries is another. A major part of the study was how we might implement MEY in a multispecies fishery. Using a model based on the Southern and Eastern Scalefish and Shark Fishery (SESSF), we examine the effectiveness of different harvest strategies in achieving fishery wide MEY, and also how different approaches to estimating MEY affect the outcomes.