The intertidal zone, also known as the foreshore and seashore and sometimes referred to as the littoral zone, is the area that is above water at low tide and under water at high tide. This area can include different types of habitats, with many types of animals, such as starfish, sea urchins. The well-known area also includes rocky cliffs, sandy beaches. The area can be a strip, as in Pacific islands that have only a narrow tidal range. Organisms in the zone are adapted to an environment of harsh extremes. The intertidal zone is home to many several species from different taxa including Porifera, Annelids, Coelenterates, Mollusks, crustaceans, Arthropods. Water is available regularly with the tides but varies from fresh with rain to highly saline, wave splash can dislodge residents from the littoral zone. With the intertidal zones high exposure to the sun, the range can be anything from very hot with full sun to near freezing in colder climates. Some microclimates in the zone are ameliorated by local features. Adaptation in the littoral zone allows the use of nutrients supplied in high volume on a basis from the sea. Edges of habitats, in this land and sea, are themselves often significant ecologies. Along most shores, the zone can be clearly separated into the following subzones, high tide zone, middle tide zone. The intertidal zone is one of a number of biomes or habitats, including estuaries, neritic, surface. Marine biologists divide the region into three zones, based on the overall average exposure of the zone. The low intertidal zone, which borders on the shallow subtidal zone, is exposed to air at the lowest of low tides and is primarily marine in character. The mid intertidal zone is exposed and submerged by average tides. The high intertidal zone is covered by the highest of the high tides. The high intertidal zone borders on the splash zone, on shores exposed to heavy wave action, the intertidal zone will be influenced by waves, as the spray from breaking waves will extend the intertidal zone
Image: Newport beach
Bancao Beach at Low Tide showing Intertidal Zone from about 200 m from the beach
Tide pools at Pillar Point showing zonation on the edge of the rock ledge
A rock, seen at low tide, exhibiting typical intertidal zonation, Kalaloch, Washington, western United States.