ABSTRACT
(1) The works in the field of substantiating and implementing the systems of integrated (abiotic and biotic) monitoring of various parts of the Baikal Lake and of the Lake as a whole started at the beginning of seventies. It was then that basic principles of observational systems of the natural environment pollution in the Baikal Lake Region and also problems of the assessment of observational results in order to apply them to prediction and control were put forward in the course of discussing global and regional monitoring systems. (2) In the next few years coordinated field and theoretical research work within the framework of the problem was carried out. As a result it proved possible to scientifically substantiate and start the implementation of practical integrated monitoring programs on the Baikal Lake. Another result of this research was a development of methods for analysing and predicting the economic activities impact on the state of natural environment in the region (long-term prediction for 20-25 yr). (3) The Paper describes preliminary results of multidisciplinary researches in the aspect of synthesising these works into an integrate picture to substantiate the integrate monitoring in the Baikal Lake Region, including the following questions: - analysis of natural environment pollution sources in connection with the current and planned economic activities in the region; - hydrometeorological conditions and mathematical modelling of pollutant transfer in natural compartments (air and water flows, atmospheric precipitation, soils); - analysis of the existing system for environmental state observations; - description of ecological situations; - working out recommendations for the control of natural compartments pollution on the basis of pollutant balance and ecosystem response to pollution.