Modelled across-shore transport and connectivity in the coastal seas east of Yucatan.

Cross-shore transport and connectivity in the south-western Caribbean shelf region has important biogeochemical and ecological implications for their fragile coral reef ecosystems. Low salinity, high nutrients riverine inflows propagate from the coast towards the outer shelf, bounded by the Caribbean Current. Coastal currents transport floating Sargasso mats from offshore waters into the coastal zone until they arrive on the beach causing havoc on local ecosystems. We investigate these issues through Lagrangian particle tracking experiments driven by a high-resolution (~1 km) regional configuration of the NEMO ocean circulation model spanning the Caribbean coast of the Yucatan Peninsula. Experiments are carried out over a 20 years period (1995-2015) which allows us to investigate inter-annual variability of local circulation. Results of the Sargasso tracking simulations are compiled into monthly probability of arrival maps aimed at informing managers, stakeholders and local communities affected by this phenomenon. Modelled transport and connectivity patterns are investigated to identity the main driving processes. Biogeochemical and ecological consequences are discussed linking model results with local observations.