EVALUATION OF PHYTOPLANKTON BIOMASS AND COMPOSITION BASED ON CHLOROPHYLL PIGMENTS AT WATERS OF SHKODRA LAKE, ALBANIA

Lake of Shkodra is among the important water ecosystems of northern Albania. The quality of waters has been object of a number of studies, which take in consideration the nutrients, trophic state, level of saproby based on indicator macrophytes, indicator microalgae, indicator protozoans, etc. In this paper we present the evaluation of phytoplankton biomass and composition based on chlorophyll pigments during the period 2009-2010. Water subsamples were filtered through Whatman GF/F filter. The material retained on the filters was used for pigment analysis. After pigment extraction the content of chlorophyll a, b, and c was determined according to the trichromatic methods using the equations based on the absorption maxima for each component, respectively. Ratios pigment : chl a were estimated and used to evaluate the taxonomic makeup of the abundance of main algal classes for each sample. The graphic presentation of the pigment ratios from month to month were used to explain the contribution of major algal components to total chlorophyll a, and to understand changes in the composition of phytoplankton biomass throughout the year.