ABSTRACT
As ecological risk assessment moves to incorporate increasing levels of biological complexity, it is confronted by the same issues of uncertainty and imperfect knowledge that have faced the fields of natural resource management and conservation biology for decades. In a similar vein, conservation biology and natural resource management are only slowly beginning to recognize that chemical impacts on the natural environment go well beyond DDT, and need to be considered as one of many factors that may cause plant and animal population declines. The dynamics of natural populations and the behavior of ecosystems are dependent on environmental factors that vary in time and space and that are influenced by changes in other related variables. Conservation and resource management are primarily concerned with the status of populations of organisms in natural communities. Population models are useful tools available to risk assessors to investigate population-level effects of contaminant exposure of organisms.
