BLACK LAKE OF THE ZELENGORA MOUNTAIN – SUSTAINABILITY PROBLEMS

Abstract

The paper presents results of a study on physical, chemical and some biological parameters of water quality of Black Lake in order to estimate the state and degree of eutrophication. It is the shallow lake margin covered in macrophyte vegetation that largely contributes eutrophication. The sampling was conducted at two locations on water surface and immediately above the lake bottom, as well as at the most abundant water spring located next to the lake and at the lake distributary. The study was carried out in line with the relevant procedures in August 2015. Results of the physical and chemical analyses indicated high water quality. Microbiological parameters of water quality showed that there was no continuous contact between the lake and fecal substance but the number of aerobic psychrophilic and mesophilic heterotrophic bacteria suggested that there was organic substance in the water. Values of saprobic indices indicated transition state between oligosaprobic and þ-mesosaprobic water.