Modelling the Mediterranean marine ecosystem as a whole: addressing the challenge of complexity

Abstract

EwE models have been widely used in aquatic ecosystems to describe the structure and functioning of marine ecosystems, evaluate the impact of anthropogenic activities and environmental changes and explore fishing management policy options (Coll et al., 2009; Heymans et al., 2012). Here we applied the EwE approach to describe and assess the Mediterranean marine ecosystem structure and functioning as a whole. In particular, two food web models for the 1950s and 2000s periods were built to investigate: 1) the main structural and functional characteristics of the Mediterranean food-web during these time periods; 2) the key species/functional groups and interactions; 3) the role of fisheries and its impact; and 4) the ecosystem properties of the Mediterranean Sea in comparison with other European Regional Seas. Both models included about 100 functional groups and 7 types of fishing fleets and were divided it in 4 sub-models following the four sub-regions division given by the Marine Strategy Framework Directive (MSFD; 2008/56/EC): 1) Western Mediterranean Sea (W); 2) Adriatic Sea (A); 3) Ionian and Central Mediterranean Sea (I); 4) Aegean and Levantine Sea (E) to account for differences in environmental and biological characteristics (Piroddi et al., Submitted)