BIOLOGICAL MONITORING OF TOXIC POLLUTANTS IN OCEAN WATERS: PHYSIOLOGICAL STRESS TESTING OF BAY AND COASTAL MUSSELS IN CALIFORNIA

This report describes the results of the first two years of a study designed to assess the health of marine ecosystems; the Biological Effects Assessment Study. Using the mussel (Mytilus sp.) as a representative marine organism, the effects of exposure to chronic, low levels of toxic trace metals, pesticides and petroleum hydrocarbons were determined by a method of physiological stress testing, Scope for Growth.; The Scope for Growth (SFG) index is the theoretical amount of energy available to an organism for growth and reproduction after maintenance requirements are taken into account. The more energy available, the higher the index, the healthier the organism. Low or negative values indicate the organism is stressed. Four commonly measured physiological parameters are used to calculate the SFG index: oxygen consumption, ammonia excretion, assimilation efficiency, and clearance rate.; Although there are several aspects that require additional study, the SFG index is a promising method for assessing the health of marine mussels.; The report includes the results of the first two years of the Biological Effects Assessment Study, the background for State Water Resources Control Board's involvement in the field of pollution monitoring, a brief discussion of the methods, materials and calculations used to determine the SFG index, a discussion of the factors that influence the Scope for Growth index, and the future of the program.