Twice a day the tide rises and falls. There are rocks that appear at low tide and are partly or completely submerged at high tide. Many kinds of plants and animals depend on this tidal habitat to live. Seaweed and shellfish such as barnacles, periwinkles, oysters, and blue mussels all live here and many kinds of birds and fish and crabs come to the tidal rocks to feed on them.
Seaweed comes in different colors, from olive green to crimson, white, yellow, green, or dark brown and it comes in many different shapes.
Oystercatchers are medium sized birds with brown and white plumage (feathers) and thick bright orange bills. Their bills are heavy because, as their name implies, they use them to pry shellfish from the rocks and to open the shells.