TRIBUTYLTIN CONTAMINATION OF MARINE-SEDIMENTS OF HONG-KONG

A study was conducted to assess the degree of tributyltin (TBT) contam ination of sediments in local marinas and shipyards. An experimental d esign was formulated to address specific hypotheses concerning TBT dis tribution in relation to the size and type of the boats serviced. Tran sect and random sampling were selectively applied on different site ge ometries. Surface sediment samples were collected from eight shipyard sites and six marina/mooring sites in July 1994. Sediment samples clos e to shipyards and marinas showed very high contamination with TBT and corresponding decay products. The spatial variation of TBT was quite large. A decreasing trend of TBT level with distance was found for shi pyards located in shallow and calm water. Sediments at shipyard and ma rina sites were not significantly different in TBT levels, suggesting that small boats might still be a source of TBT.