||The Port of Kaohsiung is the biggest harbor in Taiwan and also the fourth largest harbor in the world. There are several shipyards and fishing ports in the Port of Kaohsiung, therefore, the pollution of organotin should be very serious in the harbor area. In addition, there are Love River and Chien-Chen River pouring into the Port of Kaohsiung. This may be the second source of organotin pollution of the harbour of Kaohsiung. Seawater and sediment samples in the harbor of Kaohsiung were gathered in this research. Analysis on organotin contents were conducted to understand the distribution of the organictin in the Port of Kaohsiung.|
In seawater, the concentration of tributyltin (TBT) is between 170~480 ng/L, the concentration of dibutyltin (DBT) is between 150~400 ng/L and the concentration of monobutyltin (MBT) is between 80~283 ng/L. Working Duck and The Third Duck are among the serious areas of TBT pollution where the concentrations of TBT in seawater are over 350 ng/L. Concentrations of DBT and MBT are also the highest at the Working Duck. In the estuary areas, the concentrations of DBT and MBT are higher than TBT. It is probably due to the input of domestic sewage (Love River) and industrial wastewater (Chien-Chen River) which may bring extra DBT and MBT into the estuary areas.
The highest TBT concentration in sediment is observed at Working Duck with average value of 25.3 mg/kg. This concentration is 4.5 times higher than that of Chien-Chen Fishing Port and 5.3 times higher than that of The Third Duck. All the concentrations of these three areas are over 10-d LC50 to bivalve (2.6 mg/kg) and amphipoda (2.1 mg/kg). The highest DBT and MBT concentrations are also observed in sediment of Working Duck, and the average concentration of DBT is 12.4 mg/kg and MBT is 9.7 mg/kg. In the estuary areas the concentration of organotins are lower than 1.2 mg/kg, therefore, the pollution of organotins is lesser serious in the estuary areas than the other sampling areas in Kaohsiung Harbor.
The composition of organotins is mainly TBT in Working Duck, The Third Duck and Chien-Chen Fishing Port, and TBT accounts for more than 50%. TBT percentage decreases with sediment depth, however DBT and MBT percentage increases with sediment depth. It shows that TBT will be degraded for DBT and MBT gradually in the sediment. The trend that TBT percentage decreases with the sediment depth is not obvious in the estuary area, and the probable reason is that the source of DBT and MBT is not only from TBT degrading, but also from the input of city sewage and industry wastewater.
According to this study, the content of organotins in sediment in the Port of Kaohsiung is indeed higher than other large-scale harbor (Barcelona and Port of Osaka). By comparing smaller areas, the content of organotins in Chien-Chen Fishing Port is also higher than marina of Hong Kong and German. It is concluded that the pollution of organotins in the Port of Kaohsiung is very serious in comparison with most other areas in the world.