When the tide goes out on rocky seashore, pools of water are left behind in holes in the rocks. These then become home to a huge range of plants and animals, such as shellfish and sea anemones.

As the tide recedes, not the entire coast is left behind dry. Depending on the type of rock, one can find shallow or deep rock pools. They offer better survival chances for animals and plants that need to be submerged all the time. Because each rock pool is different, they invite different communities. Deep rock pools near the low tide, have few survival problems, whereas shallow rock pools near the high tide, have many. Thus the pool’s placing on the shore as well as its depth and size are important factors.

Deep rock pools provide shelter from waves, allowing fragile organisms to live on an otherwise exposed rocky shore. Fragile animals are: sea slugs, shrimps, camouflage crabs, sea eggs, and small fishes. Fragile sea weeds are: Neptune’s necklace, pillow weed, cystophora, sea lettuce and many others.

For the snails that are able to survive in between high and low tide (periwinkle, nerita, melagraphia, cats eye) a rock pool is not necessarily a better place because their predators are found there (dark rock shell, white rock shell, trumpet shell). Large fish and octopus may find the rock pools too small, lacking oxygen for breathing. Rock pools may collect fresh water during rain storms, which is worse for shallow rock pools high up the shore where organisms must wait longer for the tide to return.

 

Picture Credit : Google