ECOLOGICAL STATUS ASSESSMENT OF SHKODRA LAKE USING AQUATIC MACROPHYTES

Macrophytes, or aquatic plants, are among the major groups of organisms that the Water Framework Directive (WFD) recommends that should be used in assessing the status of natural lakes. A survey of macrophyte composition and abundance at Shkodra lake was carried out during June 2013. Sampling was conducted along six transects selected within Albanian side of Shkodra lake. A total of 21 species were sampled and identified along all transects, from shore to water depth of 6m. Potamogeton lucens, Potamogeton perfoliatus and Najas marina were the most common macrophytes in the lake being found respectively at 62.8%, 55.2% and 30.4% of sampling points with vegetation in June 2013. Macrophyte index (MI), which reflect the nutrient status of a lake, was calculated and used as indicator of ecological status for Shkodra lake. The results indicate that the both sides of the lake, although differently, are impacted from human activity. The nutrient enrichment in northeastern side resulted to be “immense”, meanwhile in southwestern side the macrophyte index indicate “heavy” nutrient enrichment.The mean MI of Shkodra Lake (all transects investigated) that correlates with its total phosphorus concentration during circulation time, results 3.49 and indicates an “immense” nutrient load, which corresponds to eutrophic conditon.