PATTERNS OF SPATIAL-DISTRIBUTION OF PHOSPHORUS REGENERATION BY ZOOPLANKTON IN A RIVER LAKE TRANSITORY ZONE

Studies on phosphorus regeneration by zooplankton occupying the Krutyn ia River - lake Kujno transitory zone showed the zone to consist of th ree parts. In the first one, under strong impact of river waters, P re generation rate was low and dominated by small, pelagic rotifers. Spec ies diversity index calculated for phosphorus regeneration was also lo w. In the second part, densely covered with macrophytes, the role of l arge-bodied littoral zooplankton in P regeneration became more importa nt and the rate of the process and species diversity index markedly hi gher. The third part, a type of littoral-pelagic belt, was characteriz ed by the highest P regeneration and species diversity index and a rel atively higher contribution of pelagic forms of zooplankton to the pro cess of phosphorus regeneration.