ASSESSMENT OF Pb, Cd, B AND Ba CONTENT IN WATER AND ALGAE FROM THE REGION OF MAKARSKA RIVIERA IN CROATIA.

The capacity of macroalgae for bioaccumulation of harmful elements is beneficial from the point of view of water treatment processes. Nevertheless, it is a threat to marine biocenoses, particularly to organisms on the individual levels of the trophic chain. Since algae have a great potential to bind trace elements, these organisms are often used as indicators of marine environment pollution. The aim of this study was to assess the content of Pb, Cd, B and Ba in water and algae collected in the region of Makarska Riviera. To achieve the pursued objective, in August 2016 samples of water and algae (Cystoseira barbata and Ulva rigida species) were collected from nine sampling points located in the following towns: Makarska, Podgora, Baška Voda, Split (John Paul II Street), Stobreč, Podstrana, Omiš, Mimice and Drvenik. The laboratory samples of algae were subjected to wet mineralization in a closed system with the use of microwave energy. The content of elements in the water and in the digested algae samples was determined using the emission spectrometry, on Optima 7600 DV manufactured by Perkin Elmer. The results of the conducted research indicate slight anthropogenic water enrichment with all the investigated elements. Generally, the highest content of the studied elements was determined in the water collected in Split, Stobreč, Podstrana and Omiš, compared to samples from other sampling points. On the other hand, the content of elements in the algae does not point to a risk to the natural environment and is characteristic for unpolluted regions. The content of the studied elements in the water decreased in the order: B > Pb > Ba > Cd; in the biomass of algae of the Cystoseira barbata species in the order: B > Pb > Ba > Cd; and of the Ulva rigida species – B > Ba > Pb > Cd. With the exception of cadmium, considerable differences in the concentration of the studied elements with respect to the algae genus were recorded. Higher amounts of boron were determined in the biomass of Cystoseira barbata, whereas Ulva rigida contained more lead and barium. The mean bioaccumulation factors of individual elements in the biomass of the algae ranged between 15.39 and 3728. The highest value of the bioaccumulation factor was determined in the case of barium, whereas the lowest – in the case of boron. [ABSTRACT FROM AUTHOR]