The hydrology of the Strait of Messina accommodates a variety of populations of marine organisms. The intense currents and characteristic chemistry of the waters of the Strait determine an extraordinary biocoenosis in the Mediterranean Sea with a high abundance and diversity of species; the Strait of Messina, therefore constitutes an area of fundamental importance for biodiversity. Intense and alternate currents, the low temperature and an abundance of transported nitrogen and phosphorus transported to the surface from deep waters supports both pelagic and coastal benthic populations in a cycle of organic substance.