Abstract:
Butyltin componuds (BTs) comprising of tributyltin (TBT). dibutyltin (DBT) and monobutyltin (MBT) were analysed in seawater, sediments and some organisms collected from the coastal areas of the eastern Gulf Thailand. The sampling stations were from the Bangpakong river. Chachengchao province to Sriracha, Chonburi province (October 1996 and April 1997) and from BAnbangsay, Chonburi province to the Trat river. Trat province (around July to September 2000). The contamination by BTs have been widespread along the eastern Gulf with concentration of MBT, DBT and TBT in seawater ranging from 137.23-1,864.33, 38.47-324.70 and 43.13-277.08 ng/l, respectively. The contents on dry weight basis of these compounds in surface sediments were in the range of 7.43-91.35, 5.55-50.54 and 2.34-114.54 ng/g, respectively. High TBT concentrations were associated with areas of large sea-going vessels and high fishing boat while the levels at areas of coastal mariculture were low. The contamination of butyltin compounds was also found in surface sediments from the Bangpakong river to Sriracha in 1996-1997. The concentration of BTs in rainey season were higher than those in the dry season. The BTs levels were correlated with organic carbon (%) content in sediments. However, the concentration of TBT in sediments from this study was low to mederate level. The degradation of TBT was higher seawaters than in the surface sediments in the order of butylting compositions in seawaters MBT>TBT>DBT and in surface sediments TBT>MBT>DBT. The high level in the organisms found in this study was in Saccosstrea sp. of 73.40 ng/g wet weight basis. Among the organisms from the same area, the level of TBT found in Saccosstrea sp. was the highest.