Benthic - Hard Bottom



	HARD BOTTOM HABITATS in Santa Monica Bay include the shallow kelp-covered areas adjacent to rocky headlands, submarine canyon walls, and the deep-water plateau called Short Bank. (Map of Hard Bottom) Hard bottom habitat also includes man-made features such as wastewater treatment plant outfall pipes, artificial reefs, and breakwaters. Although hard bottom habitat is scarce in the Bay, it supports a unique and productive ecosystem. Impacts from pollutant loading and over-harvesting of fish are the issues of most concern on the Bay's hard bottom habitat. Pollutant loading associated with storm water runoff and point source discharges can cause excessive sedimentation and turbidity, both of which negatively impact the growth of kelp. For more information on kelp habitat, visit Problems & Solutions, Kelp Beds. There is also increasing concern that the commercial and recreational fishing of some fish species may cause long-term damage to the living community in the hard bottom habitats. Evidence suggests that many rockfish species have been experiencing significant population declines along the entire West Coast, including Santa Monica Bay, due to overfishing. For example, according to federal assessments, one type of rockfish, Bocaccio, has declined to about 5 percent of its historic abundance. Many management approaches have been taken to protect and enhance the Bay's hard bottom habitats and the associated living resources. Beginning in the 1960s, the California Department of Fish and Game (CDFG), in cooperation with other agencies, built a series of artificial reefs to attract hard bottom species and enhance sport-fishing opportunities in the Bay. The reefs, totaling almost 20 acres, are located between Malibu Point and the Palos Verdes Peninsula. A variety of materials, including concrete, rock and gravel ballast, car bodies, streetcars, and barges, were used to create these man-made habitats. To protect fish populations from the impacts of over-fishing, the National Marine Fisheries Service (NMFS) and the California Department of Fish and Game (DFG) have enacted regulations banning or limiting the amount of fish that can be caught by commercial fishermen and recreational anglers. In 1998, NMFS cut catch limits on 83 species of groundfish. In 2002, the DFG enacted strict new regulations on rockfish slashing catch limits and closing additional areas to fishing. Currently, the State is in the process of establishing a network of Marine Protected Areas (MPAs) "to protect habitats and preserve ecosystem integrity, among other things." Allowable activities within MPAs vary according to the classification of the particular areas. MPA classifications include Marine Life Reserves (State Marine Reserves), State Marine Parks, and State Marine Conservation Areas. If you would like to learn more about the hard bottom habitat in the Bay, visit our Habitats and Species page.