Rock pools on the Tasmanian seashoreThe seashore is the place where the land meets the sea. It can consist of rocky cliffs, a sandy beach or mudflats bordering a river mouth or estuary. The animals and plants that live there must be able to survive the tides that cover them in salt water at certain times of the day, and leave them exposed to the air at other times. They live at different levels on the seashore according to how well they can survive out of water.
Different kinds of seaweed
Many kinds of seaweed dry out easily, and are found low down on the shore where they are covered with water all the time. Other more hardy varieties live farther up the shore. They do not put down roots into the ground, but anchor themselves to rocks to stop themselves being pulled away at high tide. They are covered with mucus to hold in moisture when the tide goes out. This provides small animals with shelter from the Sun.
Seaweeds belong to one of several groups of algae: brown algae (including kelp and the wracks, such as bladderwrack), red algae (including Irish moss) and green algae (including sea lettuce). They have stem-like parts and leaf-like blades, called fronds, but they are not true plants. In many parts of the world, seaweed is harvested and used as a food or a food additive.