PERIPHYTON DIATOM DIVERSITY AND WATER QUALITY EVALUATION IN POJSKA TRANSECT, (OHRID LAKE)

Abstract: Aim of this paper is analysis of the composition for the periphyton communities on Macrophyte species (Chara) in Pojska transect (Ohrid Lake). The lake has underwater resources, which contribute to the creation of endemic species-specific habitats as they supply oxygen, nutrients, and create conditions for the development and growth of endemic species. Changes in diatom community structures suggest a change in environmental conditions such as, for example the deterioration of trophic status observed in Ohrid lakes. Estimation of diatom species based on two standards: EN 13946:2003 and EN 14407:2004, we calculate biodiversity variations (Shannon index) between different depths. The Saprobic Index fluctuated from oligosabrob to oligo- β-mesosaprob but Trophic Diatom Index (TIDIA) fluctuated from mesotroph to meso-eutroph. The structures of the diatom communities reflect real environmental changes.