THE DEVELOPING FRAMEWORK OF MARINE ECOTOXICOLOGY - POLLUTANTS AS A VARIABLE IN MARINE ECOSYSTEMS

Marine ecosystems include a subset in which at least some interrelated geochemical, biochemical, physiological, population and community cha racteristics are changed by pollutants. Moderate contamination is rela tively widespread in coastal and estuarine ecosystems, so the subset o f ecosystems with at least some processes affected could be relatively large. Pollutant influences have changed and will probably continue t o change on time scales of decades. Biological exposures and dose in s uch ecosystems are species-specific and determined by how the species is exposed to different environmental media and the geochemistry of in dividual pollutants within those media. Bioaccumulation models offer s ignificant promise for interpreting such exposures. Biological respons es to pollutants need to be more directly linked to exposure and dose. At the level of the individual this might be improved by better under standing relationships between tissue concentrations of pollutants and responses to pollutants. Multi-discipline field and laboratory studie s combined with advanced understanding of some basic processes have re duced the ambiguities in interpreting a few physiological/organismic r esponses to pollutants in nature. Recognition of pollutant-induced pat terns in population responses could lead to similar advances. A ration al framework for ecotoxicology is developing, but its further advance is dependent upon better integration of ecotoxicology with basic marin e ecology and biology.