Study of the content of copper in waters and Zebra mussel (Dressena polymorpha) from Ovcharitsa Dam, Stara Zagora region, Bulgaria

Elica Valkova

Abstract: The present study aims to determine the levels of the heavy metal copper (Cu) in the water and muscles of Zebra mussel (Dreissena polymorpha) inhabiting Ovcharitsa Dam, Stara Zagora, Bulgaria. The preparation, archiving and storage of samples of water and muscles is conducted in August and November 2015 to January and March 2016. The determination of Cu concentrations is performed using a modern method for measuring macro- and microelements with an atomic absorption spectrometer, which is characterized by high selectivity, speed and sensitivity. Concentrations of copper measured in the waters of Ovcharitsa Dam in August 2015 are three times higher (67.4%) compared to the SCC requirement according to Ordinance H-4 of the Bulgarian legislation. The registered data show the presence of a potential copper pollution of the waters of the studied water body, which has a permanent character during all months of research except for January 2016. The higher Cu levels are characterized by the mussels which inhabited Ovcharitsa Dam in January and March 2013. The content of this heavy metal in all samples tested is far below the MAC as defi ned in Ordinance 31 (30 mg / kg for molluscs). In the present study, the recorded values of Cu in the Zebra mussel samples, which inhabited Ovcharitsa Dam during the studied period, are several times higher than those observed in the waters of the same water body. Concentrations of copper found in the water can show the state of the hydroecosystem at the time of sampling. However, hydrobionic representatives in the face of Dreissena polymorpha have the ability to accumulate heavy metals over time, making them a more reliable biological indicator of contamination of water bodies.

Keywords: copper; hydroecosystem; musculature; water body; Zebra mussel

Date published: 2019-12-31