Kelp forests are among the most beautiful and highly productive habitats of the marine environment. They occur in cold, nutrient-rich waters. Large kelp forests are found in temperatures lower than 20 °C, extending to both the Arctic and Antarctic Circles. Because of their dependency upon light for photosynthesis kelp forests are restricted to shallow open waters and are found rarely deeper than 15-40 m. Kelp forests are often characterized by extremely high growth rates, in southern California, for example, the species Macrocystis can grow 30 cm per day and may extend many meters from the bottom towards the surface. Using finger-like holdfasts kelp attaches to rocky surfaces, however, they are vulnerable to uprooting during high water motion associated with storms.
Kelp forests provide habitat to a large variety of species, including invertebrates, fishes, birds, and mammals. These are found distributed along the three main regions of the kelp forests: the surface canopy, the midwater region, and the substrate. Polychaetes, amphipods, decapods, and gastropods can be found within microhabitats in the holdfasts of giant kelps. Sessile sponges, tunicates, anemones, cup corals are commonly found in the outside of these holdfasts. Sea urchins, gastropods, sea stars, snails, and crabs are also important inhabitants of kelp forests.
Many species of fish, some of economic importance in commercial and sport fishing, occur within kelp forests. The heterogeneous environment of these habitats provides an important source of food and protection to many fish species including the señorita, the surfperch, rockfish, and the blacksmith. Among the mammals and birds that use kelp forests for protection or feeding include seals, sea lions, whales, sea otters, gulls, terns, snowy egrets, great blue herons, cormorants, and shore birds.
