As with most other sustainability problems today (e.g. climate change, deforestation), marine sustainability issues have their roots in human behaviour. For example, the main reason for overfishing is the lack of information and awareness. Management solutions, however, often overlook the essential role that households’ behaviours play, tending to focus instead on technological breakthroughs and structural changes within our societies. This keynote focuses on behaviour change as a solution to marine sustainability issues. It will introduce the audience to behavioural insights - an approach to policymaking that combines insights from psychology, behavioural economics and cognitive science. It will discuss the key psychological factors that drive human behaviour and how an understanding of these can assist in the design of policy interventions to address marine sustainability issues. Compared to technological developments, structural changes or price-based policy tools, interventions based on behavioural insights represent a lower-cost, lighter-touch approach.