supralittoral

The supralittoral zone, also called the supratidal or spray zone, is the coastal region lying above the high-tide line. It is not regularly submerged by seawater, but can be wetted by sea spray during storms or exceptionally high waves. This zone forms the upper boundary of the littoral environment and adjoins the land, with its exact extent varying by coast, weather, and tidal regime.

Environmental conditions in the supralittoral zone include strong sun exposure, wind, and periodic desiccation. It experiences salt spray and high evaporative demand, leading to microhabitats in rock crevices and sheltered ledges that retain moisture. The zone is typically drier and more variable than sublittoral and intertidal habitats, creating a selective environment for specialized organisms.

Flora in the supralittoral zone is dominated by salt-tolerant communities such as lichens and some algae that can withstand spray and drying. Fauna includes invertebrates adapted to desiccation and high salinity pulses, notably crustaceans such as Ligia oceanica (sea slaters) and other supralittoral amphipods and isopods. Birds may also utilize shelves and crevices for roosting or foraging near the upper shore.

Ecological significance lies in its role as a transition between land and sea, influencing colonization patterns and community structure on rocky shores. It is a useful reference in coastal ecology and biogeography for understanding species distributions shaped by spray, desiccation, and salt exposure.