The outcomes of integrating biological interactions into rebuilding plans depend on prey specialization

Ecosystem dynamics can lead to trade-offs between reaching harvest targets and protecting vulnerable species across fisheries management decisions. However, in the context of rebuilding overfished populations, considering predator-prey interactions might provide opportunities to minimize or reverse these trade-offs if overfished prey can recover when predators in shared habitat are harvested. To understand whether and under what conditions such opportunities might arise, we explore the effect of predator harvest on the rebuilding outcomes of a recovering prey that experiences bycatch mortality. We developed an age-structured model with predation and harvest to evaluate changes in the population dynamics of prey at steady state and in their rebuilding time under increasing harvest of predators. We parameterized our models based on yelloweye rockfish (Sebastes ruberrimus), a U.S. West Coast Groundfish stock under a rebuilding plan, and one of their known predators, lingcod (Ophiodon elongatus). We found that lingcod harvest reduced the long-term spawning biomass and increased the rebuilding time of yelloweye rockfish regardless of their prey specialization; these negative effects were due to yelloweye rockfish bycatch in the lingcod fishery. However, the degree to which predator harvest affects prey rebuilding depends on prey specialization, where the steady-state dynamics of yelloweye rockfish were less affected by lingcod harvest and rebuilding occurred more rapidly when lingcod acted as a specialist compared to a generalist predator. As efforts to leverage ecosystem attributes in fisheries management are applied to recovery strategies, we highlight the role that the nature and strength of biological interactions can play in shaping outcomes of recovery.