ABSTRACT
The use of increasing amounts of toxic chemicals by society has created a need for information on the fate, transport, and effects of these substances in the environment. While historically the main source of this information has been toxicological tests on single species, more recently there has been a move toward use of multispecies tests in model ecosystems, including artificial streams. 15 The model ecosystem approach is seen as a bridge between the controlled environment of the laboratory and the uncontrolled environment of the field, with its numerous interactions and indirect effects. 6 Several authors 6 - 10 have described an “integrated” toxicological research program in which work elucidating the basic environmental chemistry of a toxicant is followed by single species tests and then multispecies tests to determine toxicities, transfer coefficients, bioconcentration factors, etc. The next step is construction of a mathematical model which predicts the impacts of the toxicant. Validation of this model is done first in replicated model ecosystems and then in the field. Giesy 11 argues that multispecies tests are strongest in this validation role. Finally, the validated model is used to assist long-term field monitoring.
