Contamination status of butyltin compounds in Indonesian coastal waters

Indonesia as an archipelago country relies on shipping for multipurpose transportation, and therefore has a potential risk of butyltin (BT) based biocide contamination. The available data were limited to BT accumulation in surface sea water, sediment, bivalves and fish collected sporadically at restricted areas in 1998 and 2001-2005 showing the presence of ‘hot spots’ in the country. BT concentrations in sediments (dry wt), bivalves (wet wt) and fish (wet wt) in hot spots (big harbors in Bitung, Jakarta, Surabaya and Medan were in range of 209-425, 23-320, 5-64 and 0.41-19 ng g, respectively, mostly in order of TBT>DBT>MBT. Occurrence of imposex in gastropods (Thais spp) has been also detected in 1989 in a remote island, Ambon Island. Among locations surveyed, commercial harbors and marina are highly contaminated, and in particular BTs levels in sediments of harbors are hundreds folds that in the fisheries areas, indicating the major input of BTs are from antifouling paints of ships. Sediments are of great concern as the deposited BTs could be potential sources in the future, even if after the global ban had been effectively implemented. Moderate levels of BTs in aquaculture areas have revealed the usage of BTs as biocides in aquaculture industries as well. This review shows the BT contamination has been in critical levels, since no restriction applied in this country, fresh input of BTs into the marine environment perhaps continues, and could expand and threaten continuously aquatic ecosystem in Asia-Pacific region, considering the geographical position of Indonesian waters. Monitoring program and ecotoxicological risk assessment with more range of ecosystem compartments are obviously necessary