The International Union of Biological Sciences; This is ICSU; Introduction; Microbial indicators of environmental water quality: the role of microorganisms in the assessment and prediction of changes in the marine environment induced by human activities; Plants as bioindicators; Animals as bioindicators; Cell biological methods as indicators of environment; The use of comparative physiological and biochemical methods in bioindication of the natural environment; Biological monitoring for aquatic pollution; Selected methods of bioindication in terrestrial ecosystems; List of the Advisory Board and Steering Committee