This report is a deliverable of work package 4 (WP4 – Ecosystem models and assessment models) of the FP7 MareFrame research project. One of the aims of the MareFrame project is to identify management strategies which will achieve Good Environmental Status (GES) by applying a minimum of two ecosystem models on each of eight different case studies across Europe, namely: West of Scotland, the Baltic Sea, Iceland, the Strait of Sicily, the North Sea, South western waters, the Chatham rise, and the Black Sea (see MareFrame deliverable 4.1 (D4.1) for the description and parameterisation of the models employed in each case study). In this report we focus on the GES indicators which can be derived from the outputs generated by the first model employed in each case study (see D4.1 for a full description of what these outputs are for each model). The GES indicators calculated from the ecosystem models used in MareFrame cover 4 of the 11 GES descriptors defined by Marine Strategy Framework Directive (MSFD). Due to the type of the models employed and the format of the associated outputs, most of the indicators described here are based on two generic outputs: fish size and trophic levels. The Ecopath with Ecosim (EwE) model employed in the West of Scotland, Baltic and Black Seas case studies is a foodweb model. While this end-to-end model covers a wide range of trophic levels and, therefore, allows for relevant trophic indicators, it is not a size-based model and so any size-based indicator is approximated at best. By contrast, the GADGET model employed in the Iceland, South Western Waters and Black Sea is size-based, but can only include a limited number of species and is, therefore, more suited for size-based indicators than for trophic indicators. The Sicily case study is modelled with Atlantis for which only trophic indicators can be computed. The North Sea case study is modelled with the Stochastic Multi-Species (SMS) model, which allows for both biomass and size-based indicators to be calculated.
