Fisheries management has long relied upon the biological concept of maximum sustainable yield (MSY). The concept defines the maximum level of harvest and results in the maximum growth rate of the fish stock. For example, in the EU common fisheries policy, the general target is to maintain harvested fish stocks above MSY levels. Aside the biological target, the EU common fisheries policy states that economic, social and employment benefits must be consistently taken into account. The challenge is that no precise formulation of ‘above MSY’ stock level is given, and further, the economic, social and employment aspects are not well-defined in the directive. Reaching these multiple goals is highly unlikely, if the goals themselves are only implicitly defined.
The research article compares the outcomes of an economic and biological management target to find out whether a concept of maximum economic yield (MEY) could be a candidate for a target that accurately defines a level ‘above MSY’ and simultaneously takes into account the economic realities of fishing. A bioeconomic model is used to analyze the age-structured fish stock and the fisheries operations. The MEY maximizes the sum of discounted net present value of the fishery over time. Thus the effects of catch price, fishing costs and discounting are internalized in the management principle. Results suggest that the MEY performs better than the MSY in both conserving the stocks and providing economic viability for the fishermen.
Essentially, fishing activity under MSY is limited only by the size of the fish stock. Under MEY, fishing activity is also limited by the cost of fishing, which means that putting more effort into fishing also increases the costs. In general, this usually makes the effort lower under MEY compared to the effort under MSY. Our results show that accurate description of human activities and economic realities should not be disregarded in the ecosystem-based management.
Reference: Holma, M., Lindroos, M., Romakkaniemi, A., Oinonen, S. 2019. Comparing economic and biological management objectives in the commercial Baltic salmon fisheries. Marine Policy 100, 207-214. https://doi.org/10.1016/j.marpol.2018.11.011