Connectivity between coral reefs is critical to ensure their resilience and persistence against disturbances. It is driven by ocean currents, which often have very complex patterns within reef systems. Estimating coral connectivity over large systems composed of hundreds of reefs is a very complex task that can hardly be addressed with observations alone. Biophysical models that simulate both the ocean currents and the life-history traits of larvae transported by these currents can fill this gap. However, biophysical model results critically depend on the spatial resolution at which ocean currents can be simulated. Here we use the high-resolution unstructured-mesh coastal ocean model SLIM to model coral connectivity in both the Great Barrier Reef (GBR) and the Florida Reef Tract (FRT) up to a spatial resolution of about 100m. By using different connectivity measures and clustering methods, we can highlight the fine-scale details of the connectivity pathways. We then introduce new indicators, based on the PageRank algorithm, to identify reefs that should be protected in priority and those that are best suited to coral restoration projects. Such a fine-scale information can provide knowledge-based decision support to allocate conservation and restoration resources optimally.
Antoine Saint-Amand holds a Master in Bioscience Engineering degree from UCLouvain (Belgium) and is currently doing a PhD. Antoine works on multi-scale connectivity modelling with the ocean model SLIM. His supervisor, Emmanuel Hanert, is professor at UCLouvain. Before moving back to Belgium, Emmanuel was a lecturer at the University of Reading (UK) in the Departments of Mathematics and Meteorology. He is interested in the development and application of multi-scale ocean circulation models.