On the effectiveness of tributyltin ban: Distribution and changes in butyltin concentrations over a 9-year period in Klaipėda Port, Lithuania

Abstract

This study provides an insight on a long-term butyltin pressure, spatio-temporal changes and current tributyltin distribution in the Klaipėda Port sediments. Moreover, it examines whether the restrictions on tributyltin use led to a decreased pollution in the area. Changes over a 9-year period in tributyltin and its metabolites concentrations were analyzed in surface sediments from semi-enclosed bays of the Port. Reduction in organotin level was observed after tributyltin ban came into force: tributyltin concentration reached 3000 ng Sn g−1 d.w. in 2005 whereas 1793 ng Sng−1 d.w. was found to be the highest tributyltin concentration in 2013. The highest contamination was detected in the zones with ship maintenance activity. As late as in 2013, the latter areas still exhibited fresh tributyltin input while the progress of organotin degradation has been observed for other sampling stations along the Port.