A sandy beach is made up of minute grains of sand or crushed shells and rock. Because it is grainy, wind and water reshape a beach every day. Sandy shores are exciting places with life in and underneath the water. The intertidal zone is the area exposed between high and low tides. In the intertidal zone, part of the day is spent in open air and the rest of the day is spent covered in ocean water.
High tide brings with it nutrients and food.
When it goes out, the tide takes with it waste products and disperses eggs and larvae. Because of the shifting sands, organisms living in the intertidal zone on a beach have adapted to these changing conditions. Without the cover of water, many animals simply shut down during low tide. Some of the animals spend most of their life buried under the sand. Others burrow into the sand when the tide is low or when the crashing waves hit the shore.