Working Group on Integrated Assessments of the North Sea (WGINOSE)

The Working Group on Integrated Assessment of the North Sea (WGINOSE) aims to provide a holistic analysis of the present and future status of the North Sea Ecosystem and human activities therein. Analyses are split among 14 strata since the North Sea is a diverse ecosystem spanning the shallows of the Southern North Sea banks to the deeps of the Norwegian Trench. State-of-the-art statistical methods for trend analysis were performed on time-series data spanning 35 years (1984-2019) which show a flat (constant) or downward (declining) trend in all strata for cod, herring and haddock abundance, a consistent upward (rising) trend for temperature and dissolved oxygen, while other fish species and oceanographic variables show both upward, downward or flat trends. A method to detect ‘warning signals’ of significant change outside sta-tistical expectations was applied for the first time, but required further development and evalu-ation before practical application. A lack of consistent datasets (both spatially and temporally) from all 14 strata limited the utility of the trend and warning signal analysis, but the group aims to address this in coming years.Mental models were developed for four subregions (strata) of the ICES North Sea Ecoregion: Southern North Sea, Kattegat, Skagerrak and the Norwegian Trench. These qualitative models were developed in partnership with subregional stakeholders to identify the most relevant eco-system components to assess. Scenarios for future development of fisheries, shipping and marine protection were developed based on the mental models, and these scenarios were then imple-mented in end-to-end ecosystem models for the Skagerrak and Kattegat using Ecopath with Eco-sim. Initial comparisons between qualitative and end-to-end models show a good level of agree-ment in the overall system-level responses to scenario perturbations.Developing models through stakeholder workshops is both time and resource intensive. Ideally, stakeholders should be involved in the interpretation of scenario results and work closely when further refining models to ensure they have the best chance of being operationally applied by stakeholders. Nevertheless, effort invested by members of WGINOSE to co-develop solutions and assessment tools with end-users inspired additional projects, including some collaborative activities with other ICES Integrated Ecosystem Assessment expert groups.An interactive map of human activities and pressures for the entire Greater North Sea ecoregion was produced. This, together with the strata specific modelling and assessment work, and the trend and ‘warning signal’ analysis, will underpin future iterations of the ICES Greater North Sea Ecosystem Overviews and further refinement of existing conceptual models for the ecore-gion.