The precipitation of the intertidal zone is an average of 118.1 inches in a year. Of that amount, 19.69 inches is attributed to fog. Water is key to intertidal life because the creatures that inhabit the intertidal zone are made up mostly of water.
The intertidal zone is the area between high and low tides. It is divided into four parts: lower intertidal zone, middle intertidal zone, high intertidal zone and spray zone. There are advantages and disadvantages for animals living in the intertidal zones. Among the advantages are plenty of food as a result of sunlight that supports varied and extensive plant life. Among the disadvantages are the drying-out effect of sunlight, a high and variable degree of salinity, and waves that upon receding, may carry animals out to sea with them.
Low intertidal zones are home to eelgrass, surfgrass, anemones and sea stars. Middle intertidal zones harbor sea sack, mussels, chitons, gooseneck barnacles, sea stars, coralline algae and urchins. High intertidal zones are home to turban snails, rockweeds and spindle shells. Spray zones give shelter to barnacles, periwinkles, limpets and lichens.
Animals survive in the intertidal zone by adopting various adaptations such as hard shells and glue-like substances that allow animals to cling to rocks to avoid being carried out to sea by receding waves.