EFFECT OF FILTERING ACTIVITY OF DREISSENA-POLYMORPHA (PALL) ON THE NUTRIENT BUDGET OF THE LITTORAL OF LAKE MIKOLAJS']JSKIE

The effect of filtering activity of D. polymorpha on nutrient dynamics in Lake Mikolajskie depended mostly on population density: D.polymorpha was important in N and P cycling in periods when its population density was medium or high. The amounts of N and P accumulated in mussel populations at medium density may be similar to those in emergent and submerged macrophytes. However, mussels remove nutrients from cycling matter for a much longer time than do macrophytes. The amounts of nutrients accumulated in a mussel population are several times lower than the quantities which flow through it.