Ecotoxicology is the science that seeks to predict the impacts of chemi-
cals upon ecosystems. This involves describing and predicting ecological
changes ensuing from a variety of human activities that involve release
of xenobiotic and other chemicals to the environment. A fundamental
principle of ecotoxicology is embodied in the notion of change.
Ecosystems themselves are constantly changing due to natural processes,
and it is a challenge to distinguish the effects of anthropogenic
activities against this background of fluctuations in the natural world.
With the frustratingly large, diverse, and ever-emerging sphere of envi-
ronmental problems that ecotoxicology must address, the approaches to
individual problems also must vary. In part, as a consequence, there is
no established protocol for application of the science to environmental
prob- lem-solving. The conceptual and methodological bases for
ecotoxicology are, how- ever, in their infancy, and thus still growing
with new experiences. In- deed, the only robust generalization for
research on different ecosystems and different chemical stresses seems
to be a recognition of the necessity of an ecosystem perspective as
focus for assessment. This ecosystem basis for ecotoxicology was the
major theme of a previous pUblication by the Ecosystems Research Center
at Cornell University, a special issue of Environmental Management
(Levin et al. 1984). With that effort, we also recognized an additional
necessity: there should be a continued develop- ment of methods and
expanded recognition of issues for ecotoxicology and for the associated
endeavor of environmental management.
