ECOLOGICAL BACKGROUND AND IMPORTANCE OF THE CHANGE OF CHIRONOMID FAUNA (DIPTERA, CHIRONOMIDAE) IN SHALLOW LAKE BALATON

The objectives of this research were to record the changes in composition of the open-water, bottom-dwelling chironomid fauna in Lake Balaton between 1978-1984, to examine the causes of these changes, and to discover their significance in the life of the lake. The spatio-temporal dispersion of larvae is compared with the water and sediment quality of each basin in the lake. It is established that, under present conditions, nutrient status can be regarded as the chief environmental factor. Studies of population dynamics show that chironomids play a highly important role in preserving sediment quality. Chironomids are an essential element in the organic matter circulation of the lake. They dominate a sub-system that retards water quality degradation, and thus they play a prominent role in the natural prevention of eutrophication. © 1990 Kluwer Academic Publishers.