Intertidal zone
Intertidal zone along a rocky shore
Intertidal zone along a rocky shore

The gravitational pull of the moon and to a lesser extent the sun causes tides. Twice each day the tide moves in and out. That means that there are two high tides and two low tides. Because the moon rotates around the Earth every 28 days, the time it is high and low tide changes.

The area between high and low tide is called the Intertidal zone. It gets bashed by waves, scorched by the sun and becomes very salty when it dries out. The waves wash up dead and drifting plants and animals. Lots of animals like crabs scavenge in this zone.

Have you been bashed around by waves? How would it be living in this zone being knocked around every day?