Defining and Maintaining a Safe Operating Space for People and Reefs in Hawaii

Tipping points occur when small shifts in human pressures or environmental conditions bring about large, sometimes abrupt changes in a system – whether in a human society, an ecosystem or our planet’s climate. This talk describes a highly collaborative effort to understand and address past and future tipping points in Hawai‘i’s coral reef ecosystem and their cascading effects on coastal communities and industries that rely on healthy reefs. Our team includes ecologists, oceanographers, social scientists, resource economists and legal scholars working in partnership with Hawai‘i marine managers to design a multi-faceted research program tailored to the socio-political context of advancing ecosystem-based management in Hawai‘i.  We present results of our research to define and map reef regimes, identify the anthropogenic and climate-related drivers of tipping points between regimes and explore management solutions that minimize conflict among stakeholders and distribute costs. This body of research entailed synthesizing an unprecedented amount of fine-scale ecological data on the state of coral reefs and creating new maps of key human impacts like fishing, sedimentation and unnatural ocean warming, which have broad utility for diverse ecological and management applications.  Showcasing a suite of powerful analytical tools, we uncover evidence for the existence of previously unrecognized reef regimes across the Main Hawaiian Islands that result from non-linear reactions to particular combinations of human uses. By quantifying the threshold responses or ‘tipping points’ of human use associated with these novel reef regimes, we are able to provide a set of reference points to inform concrete management targets for reef protection and restoration. These analyses can support efforts to mitigate local stresses and enhance resilience of reefs not only in Hawaii and but throughout the Pacific. We conclude by relating these case-specific results to a general conceptual framework focused on using quantification of regimes and their thresholds to define a ‘safe operating space’ for using natural resources without crossing unwanted tipping points.  We also discuss implications for marine management and the benefits of collaborative engagement between scientists and practitioners.