Field notes: who eats whom?

On a rocky shore, seaweed uses sunlight to make its own food. Tiny drifting algae are also producers. Blue mussels and barnacles filter tiny algae and other food particles from the water. Sea snails graze on seaweed. Crabs eat sea snails and mussels, and a coastal fish can eat small crabs. Many shore animals also face changing water levels, waves and drying out at low tide.