This research will critically analyse the spectrum of stakeholder engagement and participatory approaches employed within the marine environmental sector in the UK. In collaboration with case-study partners it will empirically examine examples of applied citizen science and engagement in marine policy and planning, to illuminate successful methods that can be applied to environmental policy more broadly. This interdisciplinary research will bridge the interface between marine science, governance and policy, and behavioural and educational theories. The application of the findings will support marine and coastal environmental management through a greater understanding of how policy and management intersect with the public.