Working Group on the Integrated Assessments of the Norwegian Sea (WGINOR; outputs from 2019 meetings)

The Working Group on Integrated Ecosystem Assessments for the Norwegian Sea (WGINOR) advances understanding of the Norwegian Sea ecosystem and develops an operational approach for integrated ecosystem assessment for the region that is applicable to management. This in-cludes research on functional connections and linkages within the ecosystem, compiling time-series on absolute abundance of major components of the physical ecosystem and the biological ecosystem, and the development of models suitable for integrated ecosystem assessment, includ-ing socio-economical elements. This report contains the group’s activities, progress, and results from 2019. An interim assessment of the Norwegian Sea ecosystem suggests gradual changes in ocean cli-mate in recent years compared to the period from 2000 to 2016. Since 2017, signs are seen of waters becoming fresher due to increasing inflow of Arctic waters from the East Iceland current and with freshening inflowing Atlantic waters. Concurrently, suitable physical environment for major pelagic fish species has declined in size. Zooplankton biomass, in spring, remains low as it has since 2003, and biomass of all major pelagic stock shows a declining trend. Development of a framework for ecosystem warning signals was initiated by performing a trend estimation and an outlier detection analysis of 24 physical and biological ecosystem time-series. Future work is to evaluate which time-series contain valuable information for monitoring status of the ecosystem. Furthermore, a new statistical methodology, to present ecosystem status to stakeholders, managers, and policy-makers, was explored using common trend analysis to present 33 time-series as visual icons. The next step is to advance the common trend analysis results into a product that effectively communicates ecosystem status to a wide audience. Capacity of statistical models of the physical environment in the Norwegian Sea to forecast some ocean climate indices one or two years into the future was discussed. Future work is to define which ocean climate variables impact biological processes and to develop the models to forecast these identified variables. Two statistical methods were introduced as possible tools to develop foodweb assessment of the pelagic ecosystem in the Norwegian Sea, empirical dynamic modelling and modelling based on principles of chance and necessity. Future work involves evaluating these models capture mechanical foodwed relationships and assess whether they are useful tools to make short term forecast for foodweb status. Finally, work on revising the Norwegian Sea ecosystem overview (EO) was initiated to address feedback from ICES Advice Drafting Group; this revision will be finalized in 2020.