Interconnections between Coastal Sediments, Hydrodynamics, and Ecosystem Profiles on the Mexican Caribbean Coast

The interconnections between hydrodynamics, coastal sediments, and ecosystem distribution were analysed for a similar to 250 km strip on the northern Mexican Caribbean coast. Ecosystems were related to the prevailing and extreme hydrodynamic conditions of two contrasting coastal environments in the study area: Cancun and Puerto Morelos. The results show that the northern Mexican Caribbean coast has fine and medium sands, with grain sizes decreasing generally, from north of Cancun towards the south of the region. Artificial beach nourishments in Cancun have affected the grain size distribution there. On beaches with no reef protection, larger grain sizes (D-50 > 0.46 mm) are noted. These beaches are subject to a wide range of wave-induced currents (0.01-0.20 m/s) and have steeper coastal profiles, where sediments, macroalgae and dune-mangrove systems predominate. The coastline with the greatest amount of built infrastructure coincides with beaches unprotected by seagrass beds and coral reefs. Where islands or coral reefs offer protection through less intense hydrodynamic conditions, the beaches have flatter profiles, the dry beach is narrow, current velocities are low (similar to 0.01-0.05 m/s) and sediments are finer (D-50 < 0.36 mm). The results offer a science-based description of the interactions between physical processes and the role played by land uses for other tropical coastal ecosystems.