LONG-TERM INVESTIGATION OF METAL CONCENTRATIONS IN BROWN ALGAE Fucus vesiculosus FROM THE GULF OF RIGA, BALTIC SEA

The study was conducted in the coastal area of the Gulf of Riga at three stations (Ainaþi, Saulkrasti, Mçrsrags) from 1997 till 2010. Brown algae samples were collected at 3.0-m depth from a boat using scuba gear in August and September. The concentrations of metals (Cd, Pb, Cu, Ni, Zn) were determined by atomic absorption spectrophotometry method (model Spektra A 880), and of Hg by FIMS (Flow Injection Mercury System, Perkin Elmer). The aim of this investigation was to determine the concentration levels of metals (Hg, Cd, Pb, Cu, Ni, Zn) in the dominant species of macroalgae (Fucus vesiculosus) in the Gulf of Riga in different stations and years. Metal concentrations in F. vesiculosus varied between sampling years and stations, and significant differences in Hg, Pb and Ni concentrations between years were detected. In some years the concentrationsof metals in F. vesiculosus were similar in all three stations. Brown algae F. vesiculosus can accumulate metals to concentrations thousand times higher than in marine water.