Hawaii FEP - Western Pacific Fishery Council

uplifted limestone. Henderson Island is the largest in the group; however, Pitcairn Island is theonly one that is inhabited.Easter Island, a volcanic high island located approximately 2,185 miles west of Chile, is thoughtto be the eastern extent of the Polynesian expansion. Easter Island, which is governed by Chile,has a total land area of 63 square miles and a population of approximately 3,790 people.The northern extent of the Polynesian expansion is the Hawaiian Islands, which are made up of137 islands, islets, and coral atolls. The exposed islands are part of a great undersea mountainrange known as the Hawaiian-Emperor Seamount Chain, which was formed by a hot spot withinthe Pacific Plate. The Hawaiian Islands extend for nearly 1,500 miles from Kure Atoll in thenorthwest to the Island of Hawaii in the southeast. The Hawaiian Islands are often grouped intothe Northwestern Hawaiian Islands (Nihoa to Kure) and the Main Hawaiian Islands (Hawaii toNiihau). The total land area of the 19 primary islands and atolls is approximately 6,423 squaremiles, and the over 75 percent of the 1.2 million population lives on the island of Oahu.3.3 Biological EnvironmentThis section contains general descriptions of marine trophic levels, food chains, and food webs,as well as a description of two general marine environments: benthic or demersal (associatedwith the seafloor) and pelagic (the water column and open ocean). A broad description of thetypes of marine organisms found within these environments is provided, as well as a descriptionof organisms important to fisheries. Protected species are also described in this section. Thissection is intended to provide background information on the ecosystems which will be givenconsideration in managing the fisheries of the Hawaii Archipelago.3.3.1 Marine Food Chains, Trophic Levels, and Food WebsFood chains are often thought of as a linear representation of the basic flow of organic matterand energy through a series of organisms. Food chains in marine environments are normallysegmented into six trophic levels: primary producers, primary consumers, secondary consumers,tertiary consumers, quaternary consumers, and decomposers.Generally, primary producers in the marine ecosystems are organisms that fix inorganic carboninto organic carbon compounds using external sources of energy (i.e., sunlight). Such organismsinclude single-celled phytoplankton, bottom-dwelling algae, macroalgae (e.g., sea weeds), andvascular plants (e.g., kelp). All of these organisms share common cellular structures called“chloroplasts,” which contain chlorophyll. Chlorophyll is a pigment that absorbs the energy oflight to drive the biochemical process of photosynthesis. Photosynthesis results in thetransformation of inorganic carbon into organic carbon such as carbohydrates, which are used forcellular growth.Primary consumers in the marine environment are organisms that feed on primary or higher levelproducers, and depending on the environment (i.e., pelagic vs. benthic) include zooplankton,corals, sponges, many fish, sea turtles, and other herbivorous organisms. Secondary, tertiary, andquaternary consumers in the marine environment are organisms that feed on primary consumers49