How do the Australian public perceive the risks and benefits of novel restoration and adaptation interventions on coral reefs?

Ecosystem degradation due to climate change is driving increasing demand for innovative interventions for ecosystem protection, restoration, and adaptation. Understanding public perceptions of risks and benefits associated with these interventions is crucial for their successful implementation. This study examines Australian residents’ perceptions of risks and benefits associated with the potential deployment of six novel coral reef interventions on the Great Barrier Reef, including marine cloud brightening, fogging, rubble stabilization, coral seeding, natural breeding, and genetic engineering. Using longitudinal survey data collected in 2018, 2022, and 2024 from over 8000 participants, this paper investigates how perceptions of ethics and safety, feasibility, and social impact changed over time, across interventions, and between demographic groups. All interventions were perceived as beneficial. However, restorative interventions (rubble stabilization and coral seeding) received lower risk scores across all risk/benefit domains, while genetic engineering was viewed as slightly less ethical and safe than other interventions. Factors such as proximity to the Great Barrier Reef, age, Indigenous status, and self-reported understanding of the interventions significantly influenced public risk perceptions. Enhancing public understanding and addressing ethical concerns are critical to building support for innovative reef interventions. Empirical insights reveal the complex dynamics of public risk perceptions and their underlying factors, highlighting their role in shaping support. The methodological approach of assessing perceived risks and benefits over time offers a valuable framework for evaluating public acceptance of environmental technologies across various contexts, supporting the development of responsible management strategies for global ecosystems. • Ethics and safety enhance perceptions of an intervention's feasibility and impact. • Public perceptions of risks and benefits remain consistent over time, supporting long-term intervention planning. • Demographics, reef proximity and levels of understanding shape public risk perceptions.