Working Group on Multispecies Assessment Methods (WGSAM)

Valerio Bartolino*, Sarah Gaichas*, Alan Baudron, Vanessa Trijoulet, Floor Soudijn, Isaac Kaplan, Sean Lucey, Pierre-Yves Hernvann, Igor Celic, Alfonso Perez-Rodriguez, Andrea Belgrano, Liesa Celie, Kiersten L. Curti, Francisco de Castro, Thomas Del Santo O’Neill, Robert Gamble, Daniel Howell, Nis Sand Jacobsen, Alexander Kempf, Ronald KlaskyNataliia Kulatska, James Martindale, Cristina Perez, Miriam Püts, Anna Rindorf, Alexandra Silva, Laurel Smith, Anika Sojundóttir, Michael Spence, Robert Thorpe, Howard Townsend, Ching Villanueva, Morten Vinther, Zampieri Carlo

*Corresponding author for this work

Research output: Book/ReportReportResearch

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The Working Group on Multispecies Assessment Methods (WGSAM) aims to advance the operational use of knowledge on predator-prey interactions for advice on fisheries and ecosystem management.

This report summarises the achievements of a 3-year cycle during which the group consolidated criteria to evaluate key-runs and more in general the skills assessment of multispecies models, released key-runs for the Baltic Sea, North Sea and Irish Sea all evaluated with those criteria, progressed in the areas of multiple models comparison, ensemble modelling and on the estimation of biological reference points in the context of multispecies interactions. The updated keyruns for the North Sea and the Baltic Sea provided the best available estimates of predation mortality for a number of key commercial stocks in these two ecoregions which have been already integrated into the stock assessments throughout benchmarks and inter-benchmarks. Analyses accumulate showing that ignoring strong trophic interactions may lead to bias in the perception of stocks status and in the calculation of reference points. Evaluations show advantages of using multi-model ensembles to capture the dynamics of the main stocks and the system overall. Results accumulated so far suggest that the benefits of ensemble modelling exist for both simple models, i.e. multispecies production models, as well as more complex ecosystem models. Various approaches are available to the practice of ensemble modelling, including a fully Bayesian ensemble framework suitable also for multi-model forecasts.

The report includes also progresses with software developments to enhance accessibility of some complex routines, including ensemble modelling beyond “just a simple average approach” and computation of multispecies reference points, to a broader group of modellers and users. The group sees these developments as a great opportunity to work more towards cross-platform comparisons and further on multispecies skill assessment which will remain important themes for continuation of the work. To further progress the use of multispecies and ecosystem models, collection of ecosystem data remains highly relevant, with priority on stomach data and other information on processes affecting trophic interactions and trophodynamics of ecosystems (i.e., predator-prey overlap, temperature-dependent consumption, availability of other food).
Original languageEnglish
Place of PublicationCopenhagen, Denmark
PublisherInternational Council for the Exploration of the Sea (ICES)
Number of pages50
Publication statusPublished - 2021
SeriesICES Scientific Report


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