The Impact of Environmental Pollutants on Wildlife — an Overview

Abstract

In spite of the current wave of interest, the impact of environmental pollutants on wildlife is surprisingly difficult to assess. The acute effects of toxic substances on birds, fish, and large mammals are easy to discern. Acute effects on small mammals, reptiles and amphibians are only rarely reported, possibly because these animals are less readily noticed by casual observers. The chronic effects of only a few pollutants have received significant study with regard to their effects on wildlife. It is tempting to ascribe many declines of wildlife populations to the effects of toxic substances. However, in many cases concurrent changes in the wildlife habitat have comlicated these evaluations. To date, major declines in some species or birds seem to have been prompted by some chlorinated hydrocarbon pesticides. For other species the evidence is often ambiguous. Oil spills, mercury, and lead have clearly contributed to local declines in wildlife populations. However, in many instances the impact on wildlife populations is not clear. There is a need for increased study in the field of ecological toxicology, a need to bridge the gap between laboratory studies and field observations, and to integrate the vast quantities of monitoring data into a conceptual framework based on principles of ecological toxicology.