Limnological situations in two shallow Greek Lakes (Kastoria and Mikri Prespa lakes)

Abstract

The shallow Kastoria lake supports an important fishery but the effluent discharges from the local town renders the lake polluted and eutrophic. From a limnological point of view, its water exhibits unstable thermal stratification, dimictic as well as meromictic situations, low concentrations of dissolved oxygen close to its bottom sediments and rather high nutrient concentrations. The internationally important wetland of Mikri Prespa lake belongs to the dimictic lacustrine type. The lake is directly influenced by runoff from nearby agricultural land as well as by the organic matter produced mainly in the luxuriant bank vegetation of reeds.