40 priority questions to advance understanding of the risks and opportunities of UK marine heatwaves

Marine heatwaves (MHWs) are periods of anomalously warm sea temperatures that are becoming increasingly recognised as ocean stressors. Globally, MHWs have impacted marine ecosystems, with significant socioeconomic implications for coastal communities and industries. The unprecedented MHW that occurred in the waters surrounding the UK and Ireland in summer 2023 highlighted a crucial gap in our understanding of the region-specific characteristics of MHWs and their impacts on marine ecosystems, the services they underpin, the blue economy and society. Using diverse expert opinion, we propose 40 priority questions for interdisciplinary research in the UK that must urgently be addressed to prepare for future risks and potential opportunities associated with MHWs. The targeted questions are listed under a broad range of themes. Recommendations to policy makers and those influencing the strategic direction and allocation of funding and resources are also suggested to assist decision-makers towards evidence-based action and guide funding streams.