Transient perturbations reveal distinct strategies for reserve benefits in life history-dependent ecosystems

•Marine reserve is important in fisheries management.•Populations in equilibrium relative to that in transient dynamics with age structure.•Improving fishery yields of target species while maintaining persistence of the bycatch.•Life history and yield measurement influence fishery strategies. Marine reserves can improve fisheries yields of target species while maintaining the persistence of bycatch species. However, the prevalent equilibrium analyses prevent our understandings in transient behaviours to achieve fisheries adaptive management. By incorporating age structure, we develop high-dimensional theoretical frameworks including both target and bycatch species to compare the yields of target species under different fisheries management strategies. With practical applications to the West Coast groundfish fishery in the USA, our research suggests that strategies with reserves can perform more benefits than traditional strategies without reserves in both conservation and fisheries aspects if target species have old ages at maturity and low adult survivorships. In addition, if fisheries yields are measured by weight, fisheries management has multiple choices over short time scales, which is contrary to the conclusions when yields are measured by numbers. The generality of applying our theoretical frameworks to fisheries management is tested with hypothetical parameters. Our work can be used to choose suitable measurement metrics and design more precise optimal fisheries strategies for given natural systems with specific life histories.