BIOLOGICAL CONDITIONS OF THE LAKE SHKODRA AND THE BUNA RIVER

摘要

An evaluation of the biological status of the lake Shkodra and the Buna river in accordance with Annex V of Water Framework Directive is given. The investigation is based on the results of the last 3-year field monitoring and different publications. The main criteria used are: biological elements as chlorophyll a, microalgae (phytoplankton and phytobenthos), aquatic and wet land macrophytes, benthic invertebrates and fishes. Also, some hydromorphological elements (water level fluctuation, water flow, substratum), climatic elements (mean water temperature) and physicochemical elements (Sechi disc, conductivity, pH, dissolved oxygen content and nutrient loads) are used to clarify the biological condition. According to biological elements values, the ecological status of the Shkodra lake and the Buna river can be classified as good to moderate. The destruction and disturbance of the natural habitats by flooding and intensive human activities, as the discharge of untreated sewage waters and wastewater into lake and river, the occupation of a large surface by invasive plant species, introduced of aggressive fish species and decrease of populations of consumed fish species showed for disturbed conditions of the both water ecosystems.