Szukana fraza: [Abstrakt = "The article presents the results of the several years studies dealing with two subjects\:1\) Productivity of the Masurian lakes \(regularities and mechanisms of the abundance, biomass and production of organisms\). Investigations were carried out in several lakes with different trophy \(Tab. I\). The following were studied allochtonous matter, primary production of macrophytes, periphyton and littoral plankton, destruction in the eulittoral zone, production of pelagial phytoplankton and zooplankton, processes of destruction and sedimentation in the pelagial, production of bacteria, biomass and production of profundal benthos, and trophicrelations in benthos. On the example of Mikołajskie Lake a general scheme was made of the energy flow through the ecosystem \(Fig. 1\). Synthesis of these studies was presented in several papers at the IBP\-UNESCO Symposium on productivity problems of freshwaters \(Kazimierz Dolny, May 6–12, 1970\). 2\) The effects of artificially increased fish stocks on lake biocenosis. The following were studied\: biomass and production of phyto\- and zooplankton, food resources of the eulittoral zone and their accessibility for fish, abundance and biomass of bottom fauna and fauna living on plants and feeding habits of fish. The results were presented in several papers at the VIII Conference of Polish Hydrobiologisits \(Białystok, September 16\-20, 1970\)."]