Studies have shown that Diuron, Irgarol 1051 and Fenitrothion are toxic to reef building (hermatypic) corals, nontarget marine algae and a wide variety of aquatic organisms, respectively. In this study, marine samples were collected from the Seto Inland Sea, Japan, to assess the distribution of Diuron, Irgarol 1051 and Fenitrothion among water, sediments and aquatic organisms (plankton, fish and selected marine animals). Samples were cleaned and extracted by Solid Phase Extraction (SPE) and analysed with reverse phase HPLC system (Shimadzu Corporation, Japan) equipped with a UV-Vis detector. The maximum concentrations for Diuron, Irgarol 1051 and Fenitrothion were 2.18 mu gl(-1), 1.07 mu gl(-1) and 0.05 mu gl(-1) in surface waters, respectively; 0.06 mu gl(-1), 0.09 mu gl(-1) and 0.04 mu gl(-1) in bottom waters, respectively; 0.075 mu gg(-1) dry weight (dw), 0.069 mu gg(-1) dw and 0.051 mu gg(-1) dw in sediments, respectively; 2.83 mu gg(-1) dw, 2.04 mu gg(-1) dw and 0.46 mu gg(-1) dw in plankton, respectively; 4.12 mu gg(-1)dw, 3.14 mu gg(-1) dw and 0.48 mu gg(-1) dw in fish and selected marine animals, respectively. The highest concentrations of Diuron and Irgarol 1051 were found close to a port and ship building industries, whilst maximum concentrations of Fenitrothion were detected near river estuaries. The general trend was that of decreasing pesticide concentrations away from the mouth of rivers flowing into the Seto Inland Sea. Our calculated bioconcentration factors (BCFs) indicate that plankton, whole fish and selected marine animals samples bio-accumulate antifoulants and pesticides. The accumulation gradient in fish samples was viscera > liver > gills > fillet. Measured concentrations of both the antifoulant booster biocide Irgarol 1051 and the insecticide Fenitrothion in both whole fish and marine animals sampled exceeded the Japanese Maximum Residual Limits (MRLs) as did 21% of foods sampled for Diuron.
