The Toxicant-wildlife Complex

Familiar vertebrate wildlife comprise less than five per cent of the animal kingdom. A major proportion of the other thousands of non-insect species are aquatic and will be increasingly exposed to a wide variety of manmade and natural chemicals. Effective management of this toxicant—wildlife complex demands general and simple means for the prediction and estimation of effects and hazards. Direct, non-food exposure to toxicants is much more extensive than was expected and the bioconcentration of persistent compounds may be approximated by their lipid—water partition coefficients. Simple measures of distribution into soil organic matter and biota, environmental degradation, and toxicity then provide an estimate of relative hazard, extended and verified by both direct measurement and comparison of metabolites excreted by aquatic species and by predictive in vitro simulation of primary metabolism. These generalizations suggest that bioconcentration of stable substances usually will depend upon the fat content of individuals, may not be strongly affected by metabolism, will not inevitably lead to 'biomagnification', and will become increasingly predictive.