Public literacy around systemic disasters: A case study of the South Australian coastal harmful algal bloom

As the Earth's climate system approaches critical tipping points, systemic and chronic disasters are becoming more frequent and severe. The harmful algal bloom (HAB) affecting South Australian (SA) coastal waters from early 2025 is one such disaster. What do Australian citizens know about this sort of coastal disaster? How concerned is the community about HABs, and who do they think should be responsible for mitigation and response? To address these questions, we conducted a nationally-representative survey of 1,031 Australian residents. Findings highlight critical gaps in public understanding of systemic and chronic disasters which can affect coasts, which is striking given 87% of Australia’s population lives within 50km of the coast. Results reveal low awareness and literacy, especially compared with disasters such as bushfires and floods. Despite relatively low baseline awareness, exposure to information about the SA HAB prompted substantial concern amongst all respondents, and measurable behavioural change among South Australian respondents. This, combined with high public expectations that governments are responsible for action on coastal HABs and other disasters, suggests that targeted risk communication could support timely protective action by governments rather than amplifying alarm.