Environmental Status and geochemical assessment Sediments of Lake Skadar, Montenegro Vlatko Kastratović & Željko Jaćimović & Miljan Bigović & Dijana Đurović & Slađana Krivokapić Received: 7 March 2016 /Accepted: 27 June 2016 # Springer International Publishing Switzerland 2016 Abstract The environmental mobility and geochemical partitioning of ten metals were examined in sediments collected from the six locations around Lake Skadar in Montenegro. A three-step sequential extraction proce- dure was used to determine the distribution of the metals in various substrates of lacustrine sediments, and the concentrations were measured in the liquid extract by ICP-OES. The largest portion of the total amount of cadmium, strontium and manganese can be found in sediment bound to the hydrated iron and manganese oxides; cobalt, lead, copper and nickel in the oxidizable fraction and the highest portion of chromium, vanadium and zinc are in the residual fraction. The most mobilized and potentially mobile metals are strontium, cadmium and cobalt while the most immobilized metals are chro- mium, vanadium and zinc. Based on geochemical pa- rameters, an assessment of sediment contamination by the investigated metals was performed and the results showed potential risks ranging from Bno risk^ to Blow risk^ to the environment. Keywords Lake Skadar . Sediment . Environmental status . Sequential extraction Introduction Large quantities of different kinds of elements are discharged into the environment as contaminants each year by human activities. Lake sediments are one of the major reservoirs for all kinds of contaminants, including heavy metals. Due to their toxicity, lack of biodegradability and their long lasting duration in the environment while entering the food chain, heavy metals are considered to be one the most serious potential pollutants of the aquatic ecosystem (Jovi ć et al. 2011; Pakzad et al. 2016). Undoubtedly, natural sources come from physical and chemical weathering of parent materials (rocks and minerals) of the lake area and anthropogenic sources include municipal wastewa- ters, household garbage, industrial and vehicle dis- charges due both to rapid urbanization and strong wildlife populations, so that consequently, the quality of sediment is being polluted. There are two general methods of assessing the metal burden of sediment samples—the Btotal^ metal content and the Bpotentially bioavailable^ metal content. The use of the total concentrations as a criterion to assess the potential effects of sediment concentration implies that all forms of a given metal have an equal impact on the environment; such an assumption is clear- ly untenable (Tessier et al. 1979; Adami et al. 2000). Environ Monit Assess (2016) 188:449 DOI 10.1007/s10661-016-5459-0 V. Kastratović (*) : M. Bigović : S. Krivokapić Faculty of Natural Sciences and Mathematics, University of Montenegro, G. Washington Street P., 81000 Podgorica, Montenegro e-mail: vlatkok@ac.me Ž. Jaćimović Faculty of Technology and Metallurgy, University of Montenegro, G. Washington Street P., 81000 Podgorica, Montenegro D. Đurović Institute of Public Health of Montenegro, Ljubljana bb, 81000 Podgorica, Montenegro