WP1 will identify linkages between pressures and their effects on the marine ecosystems of the Southern European Seas (SES) through data analyses, process studies (experiments and modeling), and GIS (Geographic Information Systems) techniques coupled with numerical analysis. Targeted studies are designed to determine currently insufficiently resolved mechanisms through which natural and human-induced pressures impact the ecosystems at basin and sub-basin-scale. In order to be able to trace the paths from pressures to impacts, experiments and modelling approaches will show and document leading influences of key elements on the functioning of the ecosystem in each basin or sub-basin, or on the system as a whole. In addition the effect of these pressures will be analysed and assessed in socioeconomic terms.WP1 will thus identify and evaluate basin and sub-basin scale patterns of natural and human-made interacting pressures on the SES ecosystem, study the processes transmitting the pressures to the marine ecosystem, investigate the interactions among natural and human pressures and finally will assess their collective impacts on marine ecosystems through field research and modelling and socioeconomic analysis.