AbstractMarine and estuarine management requires an excellent understanding of the interacting, interrelated and interdependent sub-systems comprising ecological, societal and management complexity. Managing such a complex system sustainably relies on knowing what aspects can be managed, and conversely what aspects are outside the control of the manager. Accordingly, by taking elements from existing environmental management approaches, especially in Europe and Canada, here we propose an integrated systems analysis approach which links 14 component sub-systems. Using these cases shows that while all elements exist, they have hitherto not been combined into a holistic decision support system. These components are linked here in a cycle of three Parts - (A) defining the policy problems facing the seas, (B) obtaining the relevant and fit-for-purpose natural and social sciences data and information, and (C) creating an input for policy and decision-making which involves stakeholders. The component sub-systems are: an Underpinning Framework Sub-system (1), which then leads to the Issue Sub-system (2), which is vision-related and includes causes and/or consequences of pressures to be managed. The Ecological Sub-system (3) links the biota and its environment to the Socio-ecological Sub-system (4) and the Socio-economic subsystem (5), which considers the macroeconomic aspects. The Resources and Delivery Sub-system (6) considers which scientists do what and how do they do it and the Provenance Sub-system (7) checks that there is a fit-for-purpose and defendable science evidence base. The Governance Sub-system (8), incorporates policies and politics as well as horizontally and vertically integrating the Legislative (8A) and the Administrative Sub-systems (8B). The Communication (8C) and Stakeholder Sub-systems (8D) ensure involvement across the stakeholder typology (of formal and informal actors). Finally, the Achievement Sub-system (9) and the Feedback Sub-system (10) ensures that all of these actions achieve successful and sustainable marine resource management.