Environmental and trophic conditions in Lake Pogubię Wielkie after disappearance of submerged vegetation

Abstract

Physico-chemical and biological investigations of the polymictic lake Pogubie Wielkie revealed its outstanding eutrophy. This was demonstrated by a high accumulation of nutrients and organic matter in water and in sediments, low transparency, very intensive phytoplankton blooms, great number and biomass of small, non-predatory crustaceans and scarce bottom fauna and low abundance of phytophilous fish. Shifts in the trophic status are to be related to the gradual subsidence of water level since nineteen seventies and to the nearly total disappearance of submerged plants.