Subtidal Plant and Animal Communities of the Southern California Islands

Some of the shallow communities that can be reached with SCUBA (SelfContained Underwater Breathing Apparatus), particularly those of the Southern California Islands, are described.

Abstract

The subtidal com m u nit i e s along th e west coast of North America are particularly rich in species, including some unique elements found nowhere else in the northern hemisphere. The extensive forest-like beds of the giant kelp, Macrocystis spp., are particularly luxuriant off southern California; in the shallow sublittoral regions around the Southern California Islands occur nearly two-fifths of the 54 square miles of major kelp beds recorded for this area. The complexity and dimensions of these undersea forests (Dawson et aI., 1960; McFarland and Prescott, 1959) compare with those of tropical rain forests, and they are of great importance in understanding the biogeography of the area. The benthic flora and fauna of the mainland coasts of California have been given increasing attention by biologists in recent years, largely in studies of real and potential pollution problems from sewer outfalls and the effects of kelp harvesting upon these subtidal communities (North et aI., 1964, 1965, in press; Turner et aI., 1964, 1965). At the same time, the subtidal plant and animal communities of the Southern California Islands have not been extensively explored. This paper describes some of the shallow communities that can be reached with SCUBA (SelfContained Underwater Breathing Apparatus), particularly those of