Goal-oriented modelling reveals possible paths to future successful conservation and exploitation in the Norwegian and Barents Seas

The Norwegian and Barents Seas are home to large populations of marine mammals and commercially harvested fishes. The abundance of these populations can be highly variable and they interact with each other through feeding interactions, introducing challenges to meeting multiple conservation and fisheries objectives simultaneously. The aim of this study is to assess whether multiple management targets for fish stocks and marine mammal populations can be achieved simultaneously. For this purpose, we use a goaloriented food web modelling framework to sample possible food web trajectories in the past (1988-2022) and in the future (2023–2045). Future projections assume that current management rules are maintained. The model integrates food web interactions, harvest control rules, and conservation measures to explore plausible future system trajectories. Results show that existing management regimes can deliver on multiple objectives concurrently. Under future strict adherence to management and conservation objectives, total catches are projected to remain within the range of recent decades (4–6 Mt yr⁻¹), but with shifted species composition, such as increased cod (Gadus morhua), and reduced mackerel (Scomber scombrus) catches. Marine mammal populations are expected to remain stable or slightly increase, indicating that ecosystem productivity is sufficient to support fishing and marine mammals at current levels, but maybe not higher. These findings show that current management approaches are internally consistent, but there remain large uncertainties arising from model structure and ecosystem variability, and about projected climate impacts. Goaloriented modelling provides a practical framework for evaluating the compatibility of multiple management objectives and advancing ecosystembased fisheries management.