ICES/HELCOM Working Group on Integrated Assessments of the Baltic Sea (WGIAB; outputs from 2024 meeting)

<p dir="ltr">WGIABs overall objectives were to identify the main drivers of food web dynamics and the consequences of changes in these drivers to the Baltic Sea food web in order to support the development of strategies for ecosystem-based fisheries management. As part of this work, we investigated Bayesian network models as tools to inform ecosystem-based management and updated the ecosystem overview for the Baltic Sea. The work on Bayesian networks continues in the 2025-2028 term. We compiled and updated long-term time-series for seven Baltic Sea basins to provide descriptions of how food web dynamics have changed over time in response to key environmental factors and human pressures. Our results show that major changes in food web structure have occurred across all basins in response to climate, nutrient availability and fishing pressure. Although common drivers of change were identified across basins, the importance of these factors varied between basins. WGIAB was responsible for producing the Baltic Sea ecosystem overview (EO), where the main pressures affecting the Baltic Sea ecosystem were identified as nutrient enrichment, selective extraction of species and contaminants, which agrees well with these results. Contributing to ecosystem-based fisheries management WGIAB developed potential Feco scaling factor(s) and produced a draft of an ecological species profile (ESP) for central Baltic herring. ESPs and Feco are being further developed in collaboration with ICES Baltic Fisheries Assessment Working Group (WGBFAS) for Baltic Sea stocks. The results of the cumulative impact risk assessment from the EO will be used in the 2025-2028 term to develop spatial cumulative assessment of impact risk for management methods (SCAIRM) for the Baltic Sea. WGIAB has developed a strong collaboration with other ICES working groups and several HELCOM expert groups and plans to extend these collaborations into the new term.</p>