This zone, commonly known as the splash zone, is the area that only gets submerged in water at the highest tides. This means that organisms in this area must cope with extended periods of exposure to air, as well as heat, cold and rain. They also face longer periods of predation by seabirds and land animals. The top of this area can be identified by the patches of dark, crusted lichens that grow there.
The littoral zone changes in water levels, water pressure, temperature and humidity at various times throughout the day. The wave action and turbulence of recurring tides, shapes, cliffs, gaps and caves, offering wide-ranging habitats for sedentary organisms.
The sublittoral zone extends from below the low tide line to the edge of the continental shelf. There is a rich variety of plant and animal life in this zone, because there is an abundance of nutrients and the sunlight can reach the bottom.
Organisms are distributed throughout the intertidal zone based on their ability to tolerate exposure to air. In the supralittoral zone organisms are closer to the cliffs and receive a tidal flushing only during the highest of the tides, approximately twice a month during the full and new moon period. In the littoral zone organisms will be submerged inundated approximately twice each day, and in the sublittoral zone they will be submerged the majority of the time. Typical inhabitants of the intertidal zone include crabs, mussels, star fish, sea anemones, barnacles, chitons and many marine gastropod mollusks such as limpets.
Despite harsh conditions and extremes of wet and dry, plant life in the intertidal zone is abundant. Most marine plants are a species of algae, and are absent of true flowers, leaves or roots. In place of the usual plant structure, algae is characterized by blades instead of leaves, stipes instead of stems, and holdfasts instead of roots. Other typical plants in this zone include kelps, oar weeds and sea palms.
