The governance of Europe’s marine environment concerns the relationship between two systems: a ‘system-to-be-governed’ made up of the natural system and a ‘governing system’ made up of institutions and organizations with a functional responsibility to steer the system-to-be-governed towards a set of goals (see Jentoft and Chuenpagdee 2015 in this volume). Both are complex in the sense that they are often diverse, multifaceted, dynamic and vulnerable. Science and policy meet at the interface between the two systems, but the traditional ideal that science, e.g. via scientific committees, speaks objective truth to directly responsive politicians has been questioned (e.g. Nowotny et al. 2001). This is not least the case when it comes to the governance of large-scale marine environmental risks such as overfishing, eutrophication and hazardous chemicals, where the demarcation between the two domains of science and policy is far from clear-cut due to scientific uncertainty and disagreements among stakeholders (Wilson 2009, Karlsson et al. 2011, Linke et al. 2014).