Abstract
On the example of 14 lake-type water bodies distributed over different latitudes of the northern hemisphere, it was shown that the efficiency of phytoplankton production transformation through heterotrophic bacterioplankton and non-predatory zooplankton to predatory zooplankton and planktivorous fish increases in the direction from eutrophic to oligotrophic water bodies. The highest ratios between autotrophic and heterotrophic organism production were found for lakes and reservoirs, where the contribution of allochthonous substances to the total energy flow is relatively high. Bacterioplankton utilizing allochthonous DOM is an additional source of energy for zooplankton, which, in turn, serves as a food object for planktivorous fish. Therefore, to predict the total biological productivity and production of the fish community, it is necessary to take into account the production of not only autotrophic plankton, but also that part of heterotrophic bacterioplankton that specializes in the utilization of DOM entering the water body from outside.