The littoral zone is the part of a sea, lake or river that is close to the shore. In coastal environments the littoral zone extends from the water mark. It always includes this intertidal zone and is used to mean the same as the intertidal zone. However, the meaning of littoral zone can extend well beyond the intertidal zone, what is regarded as the full extent of the littoral zone, and the way the littoral zone is divided into subregions, varies in different contexts. The use of the term varies from one part of the world to another. For example, military commanders speak of the littoral in ways that are different from marine biologists. The adjacency of water gives a number of characteristics to littoral regions. The erosive power of water results in particular types of landforms, such as sand dunes, the natural movement of the littoral along the coast is called the littoral drift. Biologically, the availability of water enables a greater variety of plant and animal life. In addition, the local humidity due to evaporation usually creates a microclimate supporting unique types of organisms. The word littoral is used both as a noun and an adjective and it derives from the Latin noun litus, litoris, meaning shore. In oceanography and marine biology, the idea of the zone is extended roughly to the edge of the continental shelf. Starting from the shoreline, the zone begins at the spray region just above the high tide mark. From here, it moves to the region between the high and low water marks, and then out as far as the edge of the continental shelf. These three subregions are called, in order, the zone, the eulittoral zone and the sublittoral zone. The supralittoral zone is the area above the high tide line that is regularly splashed. Seawater penetrates these elevated areas only during storms with high tides, organisms here must cope also with exposure to fresh water from rain, cold, heat and predation by land animals and seabirds. At the top of this area, patches of dark lichens can appear as crusts on rocks, some types of periwinkles, Neritidae and detritus feeding Isopoda commonly inhabit the lower supralittoral
Image: Littoral Zones
The littoral zone of an ocean is the area close to the shore and extending out to the edge of the continental shelf.