Butyltin compounds in liver of harbour porpoises (Phocoena phocoena) from the UK prior to and following the ban on the use of tributyltin in antifouling paints (1992-2005 & 2009)

► We measured butyltin concentrations in liver of UK harbour porpoises. ► Our aim was to determine whether recent regulation had reduced inputs of TBT. ► Concentrations of butyltins began to decline steeply as the ban took effect. ► Frequency of TBT detection has fallen sharply, showing the ban to have been effective.