The concentrations of heavy metals (Cu, Zn, Cr, Pb, Cd and As) were measured in sea water and mussels at location in the Boka Kotor Bay which selected as result of increased anthropogenic impacts from land. Sampling was performed at three locations, Sv. Stasije, Herceg Novi and Žanjice in the fall 2006 and spring 2007. The majority of the microelements registered in higher concentrations in fall samples in 2006 than in spring samples 2007. The concentration of metals in the studied samples was present at different levels, and is beloved the maximum level allowed, except for yinc and lead in some locations.

This paper provides an assessment of the Mlava River on the Danube River sediment quality. The contents of Zn, Cu, Pb, Cr, Ni, Cd and As were detected in the surface sediment. Based on the obtained concentrations of these seven metals sediment quality pollution category was determined with respect to PLI (pollution load index) and I geo (geo-accumulation index). It is found that M4 site, according to PLI and I geo (As and Cd) values can be classified as very highly polluted.

The aim of this study was to analyze nine heavy and trace elements (Zn, Fe, Al, As, Cu, Sr, B, Cd and Ba) of the three tissues (muscle, liver and gills) in sterlet (Acipenser ruthenus), black sea shad (Alosa immaculata) and barbel (Barbus barbus). All three species were sampled on the Danube (1173, 1319 and 863 rkm) in Serbia. The obtained concentations of heavy metals and trace elements were used for obtaining an overview of the presence of the abovementioned elements in a descending order and calculate the value of MPI (Pollution Metal index), which represents the total quantity of heavy metals and trace elements per tissue and species. In all the analyzed specimens iron (Fe) and zinc (Zn) were dominant, followed by strontium (Sr) and aluminum (Al), and the other trace elements and heavy metals. The least represented metals were barium (Ba) and cadmium (Cd). MPI values were the highest in liver, followed by gills and muscle of all species; with the exception of barbel, which had extremely high MPI values in the gills.

Investigation in this study should indicate to importance of aquatic macrophytes in accumulation of toxic metals in aquatic ecosystems and control of their pollution, as well as to establish which plants are well hiperacumulators and test species for remediation, in order to protection, regeneration and conservation of the Gruža lake as reservoir that is important for water supply and as particular natural ecosystem. Obtained results showed that species Lemna gibba L. was reliable indicator of surrounding conditions (environment), as well as good accumulator of heavy metals, so it could be used to remediate aquatic ecosystems.

The paper presents the results of different methods of sequential extraction of metal in sediment of the Great Backa canal in order to obtain data on the total, available and potentially available contents of heavy metals as well as risk assessment in aquatic systems. Based on the results of sequential extraction of metals was found that sediment does not have the risk to the environment in terms of Cr, Cu and Pb concentration while the contents of Ni, Zn and Cd sediment indicates a moderate risk. Results of sequantial extraction of metals indicate that the risk to the aquatic ecosystems decreases in risk assessment based on the pseudo total metal content in the sediment. Thus the results suggest that not all detected metals are bioavailable and that not only on the basis of total metal content of the actual risk may be overestimated.