Molecular, cellular and physiological effects of oil-derived hydrocarbons on molluscs and their use in impact assessment

Abstract

The impact of pollutants on an organism is realized as perturbations at different levels of functional complexity. This presentation considers responses to oil-derived hydrocarbons at the molecular, subcellular, cellular and whole animal levels of organization, with particular emphasis on the use of marine molluscs as sentinel organisms for assessing pollutant effects. A number of biological effects measurements are described which have been used in the development of early-warning systems based upon reactions to hydrocarboninduced damage. These include those of the microsomal cytochrome P-450 dependent monooxygenase system involved in metabolism of organic xenobiotics, functional and structural responses of lysosomes to hydrocarbons, quantitative structural alterations in the cells of the digestive and reproductive systems and effects on physiological scope for growth and parallel correlations of this latter parameter with ecological parameters such as species diversity. Aspects of recovery processes are also considered. Examples of both laboratory and field studies are cited to illustrate both the application of these approaches and the functional integration of the responses at the various levels of biological organization. This ability to link the various parameters in a functional manner is believed to strengthen the rationale for their use in impact assessment.