Pelagic fishes are highly migratory and are not commonly found along the inshore portion of the outfall pipes. Their numbers increase in relation to the ocean depth. It has been suggested that these fish might use the pipes as points of reference for their schools. Rocky bottom fish such as bass and surfperch are common among rocky areas of the sea bottom and kelp beds. The Hyperion outfall pipes serve as a hard surface and attract many of the rocky bottom fish. Demersal fishes are often used as a point of reference for the effects of human activity on the environment. This is because they are less migratory than Pelagic Fishes and because their habitat is generally soft sea bottoms, where most of the sewer outfalls discharge. The first study done on the effects of sludge on bay fishes was done in 1957 after the completion of the seven-mile outfall. There was a decline in small fishes in the bay inn 1959, which was blamed on El Nino. The small fish population recovered next year. Certain species appeared to be attracted to the both the 5 and 7-mile outfalls, however, the California Tonguefish were found absent in the area around the outfalls. The Santa Monica Bay is low in species richness and abundance compared to other areas of the California coast. Certain pollution indicator fish such as the white croaker and shiner perch were present at the end of the 7-mile outfall. Since the end of sludge discharge from the 7-mile outfall the population of these species has declined in the area. Toxic substances have been detected in the effluent released by the Hyperion plant and in the life surrounding the Hyperion outfalls. The toxic substances include but are not limited to certain metals such as cadmium, chromium, lead and zinc as well as chlorinated hydrocarbons such as DDT and PCB. By 1987 the Hyperion plant had met the State allowances for all of the metals and hydrocarbons. A study in 1982 confirmed that Santa Monica Ba...
