Managing the Great Barrier Reef requires more than good policy design — it requires public willingness to act. Moral obligation is a well-established predictor of pro-environmental behaviour and engagement, and yet it remains largely unmeasured in Australian marine governance contexts. Drawing on the Social and Economic Long-Term Monitoring Program (SELTMP), this talk distinguishes personal moral obligation — an individual duty to reduce one's own impact on the reef — from societal moral obligation — a belief that society should protect the reef for future generations. Among GBR reef communities, both are rated highly, but societal obligation consistently outranks personal obligation across the sample. Early modelling suggests that a shared sense of motivation to act, and pride in the GBR’s world heritage status underpin both levels of moral obligation, but personal obligation is further shaped by place attachment and procedural knowledge, while societal obligation is more strongly tied to affective responses to reef decline, including grief and sadness. We find that personal moral obligation predicts responsible behaviour towards the reef, while a sense of societal obligation predicts support for higher-level governance interventions. These findings suggest that who people hold morally responsible—themselves as individuals, or society broadly—shapes their engagement with reef stewardship and governance; reef strategies that frame their appeals accordingly may gain better public support.