A basis for understanding fishery management dynamics

Fishery management complexity conspires to defeat seemingly obvious solutions to overfishing. Management may not adequately include decisions of fishers, management, and politicians. A new, simple, but acceptably complex fish population model is meshed with both fishery activities and management decision making. The population component is based on the common single stock biomass dynamic model. Modifications allow biomass feedback on rates of addition to the stock due to growth and to entry of young fish. Delayed and seasonal entry of new fish biomass is possible. A co‐flow structure tracks age of biomass without using cohorts. Fishers enter the fishery only if catch rates are sufficiently high. When catch rates are low fishers improve their efficiency. Excessive fishing damages ecosystem support of the fish population. Managers attempt to maintain fish stocks at acceptable biomass levels, but lobbying by fishers and varying support of politicians limits their efforts.