1. Describing the seashore between low and high tide marks that is exposed alternately to air and water. It may be muddy, sandy, or rocky. The size of the zone varies with the slope of the coast and the height of the tides. Typical plants are brown algae of the order Fucales.
2. Describing the area of a lake or pond that extends from the edge to the lower limit of rooted aquatic plants. There may be three distinct zones of plants: emergent plants at the water's edge; plants with floating leaves in deeper water; and finally completely submerged plants. Certain mosses, notably Fontinalis, can grow at lower light intensities than higher plants, and may form meadows on the lake bed.
3. Describing organisms that live in the littoral zone.