Historically, beds of giant kelp (Macrocystis pyrifera) along the Orange County coastline were dense and covered much of the available rocky substrate from the shallow subtidal area down to 20m and deeper. These beds supported a diverse assortment of fish, invertebrates, and other plants, many of which were of significant interest to commercial and sport fisherman. The warm waters brought by the El Niño of 1982-1983 caused the loss of most giant kelp stands leaving only a few surviving patches along the Orange County shoreline. Additional stressors to kelp populations included urbanisation, low water quality, storms and overfishing.