Distribution of antifouling biocides in a coastal area of Tanabe Bay, Japan

Tributyltin (TBT) and triphenyltin (TPT) concentrations in water samples from Tanabe Bay were found to range from 4–28 ng l−1 and 3–7 ng l−1, respectively. In fishing ports, the concentrations of TBT in surface water were similar to those in bottom water. However, in aquafarming areas with poor flushing, the concentrations of TBT in bottom water were higher than those in surface water. This suggested that the TBT in water samples is re-eluted from sediment. No difference in the concentration of TPT was observed between the surface and bottom waters. The concentrations of TBT and TPT in sediment samples ranged from 3–23 μg kg−1 dry weight and 2–37 μg kg−1 dry weight. TBT and TPT concentrations ranged from 3.1–100 μg kg−1 and 3.1–7.2 μg kg−1 in oysters and gastropods, and from 1.1–4.9 μg kg−1 and ＜0.2–3.9 μg kg−1 in fish, respectively. Organotin concentrations in biota were lower than the tolerable average residue levels (TARLs). Alternative biocides – i.e. diuron, chlorothalonil, dichlofluanid, irgarol 1051 and Sea-Nine 211 – were also detected in surface water, and chlorothalonil and irgarol 1051 were detected in sediment. The concentrations of these compounds in surface water and sediment were lower than those reported previously. Dichlofluanid, chlorotharonil and irgarol 1051 were also found at low levels in oysters and gastropods, and at ranges of 325–339 μg kg−1, 268–291 μg kg−1 and 43–49 μg kg−1, respectively, in fish; the concentrations in fish were close to the TARL levels.

Booster Biocides Levels in the Major Blood Cockle (Tegillarca granosa L., 1758) Cultivation Areas along the Coastal Area of Peninsular Malaysia

Booster biocides have been rapidly growing in use, mainly in the shipping industry and in agricultural activities. The use of booster biocides is known to cause adverse effects on marine ecosystems, such as by inhibiting the photosynthesis process in marine plants, and they have the potential to accumulate in marine organisms. In the present study, booster biocides of Irgarol 1051, diuron, 3,4-dichloroaniline (3,4-DCA) and chlorothalonil were measured in the major blood cockle (Tegillarca granosa) cultivation areas along the west coast of Peninsular Malaysia. The highest Irgarol 1051 mean was found in the blood cockle with a value of 98.92 ± 13.65 µg/kg in Kapar, Selangor, while the means of diuron and its metabolites and 3,4-DCA showed the highest values of 40.31 ± 7.61 and 41.42 ± 21.58 µg/kg in Kapar, Selangor and Sungai Ayam, Johor, respectively. Sungai Ayam, Johor also exhibited the highest amount of chlorothalonil of 29.76 ± 8.80 µg/kg. By referring to sediment quality guidelines, about 72% and more than 90% of sediment samples exceeded the environmental risk limits (ERLs) and maximum permissible concentration (MPC) for Irgarol 1051 and diuron, respectively. However, referring to the risk characterization ratio (RCR), none of the blood cockle samples exceeded 1, which means that there is no potential for adverse effects to occur. Thus, the contaminants in the marine ecosystem caused by booster biocides are highlighted as a serious issue, mainly in sediment.