Yuhei Inamori*, Yoshie Takamatsu** and Ryuichi Sudo***

* National Institute for Environmental Studies
** Doctoral Program in Agricultural Sciences, University of Tsukuba
*** Department of Civil Engineering, Tohoku University

+ Correspondence should be addressed to Yuhei Inamori:
(16-2 Onogawa, Tsukuba-shi, Ibaraki 305-0053 Japan)

Abstract

The Importance of ecotoxicological tests to evaluate and predict the effect of chemical agents on an aquatic ecosystem has been indicated. Unfortunately, the approaches commonly used to date are those containing only species like the OECD test. In this paper, the microcosm test was concluded, in which microcosms consisting of bacteria as decomposer microanimals as consumer and algae as producer, were used to evaluate the ecosystem-level effect of chemical agents and wastewater consisting micro-pollutant on an aquatic ecosystem. Reproducibility and reflectivity to the natural ecosystem were proved very high in the researches on the material cycle, energy-flow and interaction of microorganisms in the microcosm system. The microcosm system was not comparable with locations like natural lakes, ponds and rivers, but comparable with the function and structure of a natural aquatic ecosystem. Based on the above work, the above approaches were suggested and tried to be applied for predicting the effect of chemical pollutants in real natural ecosystem. It was clarified that the microcosm test was of much importance for being applied as model of biological assessment test.

Key words: microcosm system, chemical substances, landfill leachate, ecological assessment, ecotoxicology