Effect of domestic wastes on the benthic marine communities of southern California

Abstract

A total of 3,785 million 1 of domestic wastes is emptied into the marine waters of southern California each day. Over 85% of these wastes receive primary treatment before discharge into offshore waters. Most of these wastes are discharged at four localities: El Segundo (Los Angeles City), White's Point (Los Angeles County), Newport Beach (Orange County), and Pt. Loma (San Diego City). While some studies were conducted at these localities prior to 1970, all of these sanitation districts have been monitoring the benthic environment since 1971–1973. Some predictions on the effect of domestic discharges on benthic life were made based on the amount of primary effluent discharged per day. If the amount discharged into open oceanic waters is less than 18 million 1/day, then a biological enhancement is noted with an increase in biomass, number of species and specimens, and diversity. If the amount of discharge exceeds 40–180 millions 1/day, then the biomass, number of specimens, and area affected is increased, but the number of species, diversity, and richness is decreased. A faunal index was devised by the personnel at Southern California Coastal Water Research Project to represent these generalities graphically.