Waiting for a flourishing Baltic cod (Gadus morhua) fishery that never comes: old truths and new perspectives

Abstract

Abstract Contrary to the declared recovery of the stock, the density-dependent growth of Eastern Baltic cod (Gadus morhua, Gadidae), probably related to increased gear selectivity, may have disrupted the size structure and substantially lowered the productivity of the stock. This naturally affects the profitability and future development of industry as well as ecosystem objectives in relation to policies such as the Marine Strategy Framework Directive. As a result, current management frameworks need to be reconsidered with a clear priority on setting objectives related to both socio-economic and ecosystem considerations. We explore various management options, using bioeconomic modelling to visualize potential trade-offs, and form an integrated decision support to inform managers regarding potential yield in biomass, revenue at both the fleet and individual levels, and environmental impact of fishing. We also investigate the consequences of preventing density-dependence by lowering selectivity, Lc, while optimizing for economic revenue and minimizing ecosystem impacts. Our findings indicate that new strategies need to be adopted by reducing Lc as well as fishing mortality, F, to restore individual growth and, hence, stock productivity. We also note that these more risk-averting strategies are positively linked to better profitability at both the individual and fleet levels as well as with enhanced ecosystem functioning and lower ecological stress.