Bank systems, clusters of shallow banks and associated channels located in the shallow waters between Florida Bay and the Florida Keys, are distinctive benthic features of Florida Keys National Marine Sanctuary (FKNMS). The banks are aggregations of Porites coral rubble and Halimeda sand covered with a veneer of seagrass, macroalgae and a wide diversity of invertebrate taxa. Bank systems provide a mosaic of essential fish habitat, such as juvenile nurseries and foraging and sheltering grounds for adults, including high densities of economically important reef fishes.