Trace metals assessment in seawater, sediment and seagrasses Posidonia oceanica (L.) Delile and Cymodocea nodosa (Ucria) Asch. from the Montenegrin coast

This paper reports on the content of heavy metals Cu, Zn, Mn, Pb, Cd and Hg in the seawater, sediment and sea grasses Posidonia oceanica and Cymodocea nodosa sampled from five locations along the Montenegrin coast in summer 2016. The pollution status was evaluated by using indexes such as CF, BCF, BSAF, MPI and PLI. Bigger values of PLI and MPI indexes were determined for sediment and sea grasses sampled on the locations within Boka Kotorska Bay comparing to the locations which are under influence of the open sea. Location Sv. Stasije was the most polluted while Žanjice was the least polluted location. Correlation analysis of the content of heavy metals in seawater, sediment and both sea grasses showed that Cu, Zn, Mn, Cd and Hg in Posidonia oceanica originate from the sediment, while Pb originates from the water column. Mn and Cd in Cymodocea nodosa originate from sediment, while Cu, Zn and Hg come from natural or anthropogenic sources. Therefore, Posidonia oceanica can be used as a bioindicator for Cu, Zn, Cd, Mn, and Hg content in sediment and Pb in seawater, while Cymodocea nodosa can be used as a bioindicator of Mn and Cd content in the sediment.