Using indicators for evaluating, comparing, and communicating the ecological status of exploited marine ecosystems. 2. Setting the scene

25 pages, 1 figure, 4 tables, 1 appendixBackground is provided to the selection of ecological indicators by the IndiSeas Working Group, and the methodology adopted for analysis and comparison of indicators across exploited marine ecosystems is documented. The selected indicators are presented, how they are calculated is explained, and the philosophy behind the comparative approach is given. The combination of selected indicators is intended to reflect different dynamics, tracking processes that display differential responses to fishing, and is meant to provide a complementary means of assessing marine ecosystem trends and states. IndiSeas relied on inputs and insights provided by the local experts from participating ecosystems, helping to understand state and trend indicators and to disentangle the effect of other potential ecosystem drivers, such as climate variability. This project showed that the use of simple and available indicators under an ecosystem approach can achieve a real, wide-reaching evaluation of marine ecosystem status caused by fishing. This is important because the socio-economics of areas where fishing activities develop differs significantly around the globe, and in many countries, insufficient data are available for complex and exhaustive analysesThe IndiSeas WG was funded by the European Network of Excellence EUR-OCEANS (FP6, contract 511106), the European collaborative project MEECE—Marine Ecosystem Evolution in a Changing Environment (FP7, contract 212085), and the IRD (Institut de Recherche pour le Développement). We thank Arnaud Bertrand and Marie-Joëlle Rochet for providing data and information on the northern Humboldt ecosystem and the Bay of Biscay, respectively, and for having participated so actively in the efforts of the IndiSeas WG. We also thank Francis Laloë and Luis Tito de Morais for their input at the beginning of the project, and Pierre Lopez for providing the world map (Figure 1). The clarity of the paper was improved following reviews from Keith Sainsbury and Jake Rice. MC was supported financially by postdoctoral fellowships from the Spanish Ministry of Science and Technology, and by a European Commission Marie Curie Post-doctoral Fellowship through the International Outgoing Fellowships (Call FP7-PEOPLE-2007-4-1-IOF) for the ECOFUN project. The contribution of HO was financed by a fundamental research grant from the Estonian Ministry of Education and Research (grant SF0180005s10). LJS was supported financially by the MEECE project and Astrid Jarre's South African Research Chair in Marine Ecology and FisheriesPeer reviewe