Forecasted climate change impacts on Norwegian Sea ecosystem and fisheries

The Norwegian Sea is a productive ecosystem increasingly affected by climate change, which is expected to alter hydrological conditions and disrupt ecosystem functioning. These changes challenge current fisheries management strategies that have been designed under past climate conditions. With the end-to-end model StrathE2E, we simulate how future climate conditions are projected to affect ecosystem functioning and alter fisheries management reference points: maximum sustainable yield (MSY) and harvest ratio at MSY (HRMSY). We developed 24 models with various sets of environmental data corresponding to two different forcing earth system models (CNRM and GFDL), two climate scenarios (SSP126 and SSP370) for 6 decades (2010-2069). We find no observable differences between the two climate scenarios, while the forcing earth-system models had a greater impact. Across all models, we observe a global decrease in the Norwegian Sea ecosystem productivity, with the fish guilds being the most affected. We project a decline in MSY and HRMSY for pelagic fish over time across all models, while changes in reference points for demersal fish vary depending on the selected earth system model. These results suggest that fisheries management would benefit from setting conservative management measures in advance of anticipated changes in the Norwegian Sea ecosystem productivity.