Large-scale interventions may delay decline of the Great Barrier Reef

On the iconic Great Barrier Reef (GBR) the cumulative impacts of tropical cyclones, marine heatwaves and regular outbreaks of coral-eating crown-of-thorns starfish (CoTS) have severely depleted coral cover. Climate change will further exacerbate this situation over the coming decades unless effective interventions are implemented. Evaluating the efficacy of alternative interventions in a complex system experiencing major cumulative impacts can only be achieved through a systems-modeling approach. We have evaluated combinations of interventions using a coral reef meta-community model. The model consisted of a dynamic network of 3753 reefs supporting communities of corals and CoTS connected through ocean larval dispersal, and exposed to changing regimes of tropical cyclones, flood plumes, marine heat waves and ocean acidification. Interventions included reducing flood plume impacts, expanding control of CoTS populations, stabilising coral rubble, managing solar radiation, and introducing heat tolerant coral strains. Without intervention, all climate scenarios resulted in precipitous declines in GBR coral cover over the next 50 years. The most effective strategies in delaying decline were combinations that protected coral from both predation (CoTS control) and thermal stress (solar radiation management) deployed at large scale. Successful implementation could expand opportunities for climate action, natural adaptation and socioeconomic adjustment by at least 1-2 decades.

Methods
The datset consists of the model plus model generated outputs associated with the publication: Large-scale interventions may delay decline of the Great Barrier Reef (RSOS-201296). 

NetLogo code for the Coral Community Network (CoCoNet) model: CoCoNet2_RSOS.nlogo (NetLogo version 6.04 or later: http://ccl.northwestern.edu/netlogo/).
GIS files used by the CoCoNet code: GBR_reef_* and Coastline.*

Excel file containing model outputs (averaged over all reefs) covering the historical period used for model calibration: Condie et al 1985-2020 model data.xlsx

Excel file containing model outputs (averaged over all reefs) covering the future projection period used to test interventions: Condie et al 2000-2070 model data with interventions.xlsx