Implications of predator–prey dynamics for single species management Canadian Journal of Fisheries and Aquatic Sciences

Despite the large body of research suggesting that the population dynamics of fishes are affected by their predators, the majority of fisheries management authorities use single-species models that assume individual populations are independent of one another. However, research is needed to identify the relevance of predation to single-species management while accounting for the feedback between management and fish populations. We conducted a management strategy evaluation (MSE) using two multi-species models as operating models to assess the performance of single-species management. We evaluated the ability of single-species management to achieve single- and multi-species reference points, maximize catch, minimize catch variability, and reduce model bias and variance. The incorporation of predation mortality and full feedback control in our MSE allowed us to account for trophic dynamics and continued data collection and assessment. Our results demonstrate that single-species management strategies are robust to predation mortality across two systems with differing trophic dynamics. The relative performance varied depending on the assessment and harvest control rule used. The selection of an optimal management strategy will therefore depend on management objectives.