Contamination of sediments in Varna Lake and Varna Bay

Abstract

Varna Bay is one of the hot spots along the Black Sea coastal zone. Its ecological state is strongly influenced by the connection with the Varna Lake. Along the lake coast are located many sources of pollution such as rivers, ports, chemical industry, WWTPs. The shipping is another pressure on the environment. The study was carried out in the western part of the Varna Lake and Varna Bay. The following parameters: heavy metals, polichlorinated biphenyls, chlororganic pesticides, phenols, petroleum hydrocarbons were analysed in sediments. The high content of the last one is indicative for an extremely unfavourable long-year exploitation of the lake as a water route. The metals concentration in lakes sediments shows the influence of anthropogenic inputs. Comparative analysis of the sediments shows higher concentrations of contaminants in Varna Lake. and near the ports. As a consequence of the worsened state of the bottom a very poor benthic community characterizes a part of the investigated area in the lake.