Snails eat mussels and barnacles. Limpets look like Chinese hats and browse on algal coatings. Different species of kelp can live throughout the rocky shore ecosystem. Kelp, giant algae, grow rapidly to the ocean surface from hold fasts. Floats keep them upright in the water and they sway back and forth with the waves.
Large leaves allow the kelp to receive sunlight over a large surface area.
The kelp provides cover and attachment surfaces for many sessile and vagrant life forms of all sizes. Smal barnacles, bryozoa, foraminifera attach themselves to leaves. Many fish shelter in the forest, lay eggs, and feed n other floating or attached organisms. Some sea urchins feed on kelp. When hunters killed sea otters which feed on sea urchins, sea urchin populations grew and killed off kelp.