Modeling coral disease outbreak, Southeast Florida Coral Reef

Dobbelaere, Thomas [UCL] Hanert, Emmanuel [UCL] Gramer, Lew [NOAA]

The goal of this work is to understand coral connectivity and how disease might be progressing along the reef tract using modelling. To see if it is possible for diseased mucus and tissue to be transported by the currents, we used SLIM with a fine-grained sediment model to trace plumes and particle tracker, with an unstructured mesh with high resolution around islands that can capture small-scale phenomena like circulation eddies. This model is able to capture water movement around and between islands of the Florida Keys, but one of the issues is that biological material can be positively buoyant, and thus be subject to wind speeds atop the surface layer, or can be negatively buoyant and be effected by Ekman’s transport. Both will change the SLIM output. We can modify the model for near-bottom and near-surface transport, and run the particle tracker for transport in the surface layer, in the water column, and in the bottom layer, for different degradation rates, and then simulate disease spread in the obtained networks. This can then produce a potential connectivity matrix, with a habitat map superimposed on the mesh to see where reefs are. These connectivity matrices can then be used in an epidemiology model to simulate disease dispersal during the month.