Tidal flat

Abstract

Tidal flats are tidally exposed surfaces, underlain by a variety of substrates, and variably vegetated depending on climate and tidal level. The entire surface between ELWS and EHWS is the tidal zone, and any low-gradient surface between these levels is a tidal flat. Tidal flats are not always simple uniformly sloping surfaces; they often have variation as determined by hydrodynamic setting, e.g., low hummocks of sand on mud flats, low relief cheniers, or tidal creeks, as well as variable substrates. These smaller-scale variations influence the development of small-scale habitats and the distribution of biota across the tidal flat. In providing variable habitats for organisms related to sediment types, tidal levels, and hydrochemistry, for a given biogeography and climate setting, tidal flats form the foundation for coastal biodiversity.