Bringing marine ecosystems into policies for sustainable development requires better information on the causal connections between human pressures and the changing state of the systems. This is particularly important at a time when the European Community is expanding, re-examining its agricultural and chemical policies, implementing a new fisheries policy and exploring new ways to protect marine systems. ELME will enhance understanding of causality, forecast the impacts of divergent development scenarios and inform evolving Community policies. Current interdisciplinary knowledge linking lifestyles with their marine environmental consequences is widely dispersed. ELME brings together a necessarily large consortium, covering all relevant disciplines and regions. It integrates existing knowledge of environmental state changes, sectoral pressures and social and economic drivers using a common conceptual model. It will select contextual indicators for each causal level and model the relationships between them. These models will be applied to plausible development scenarios with particular focus on the accession process, to explore possible consequences for the stated four marine ecosystems. Results will be diffused to all relevant stakeholders.