Butyltin accumulation in the liver and kidney of seabirds

Concentrations of butyltin compounds were determined in the kidney and liver of various seabirds collected from Japan, Korea, the North Pacific Ocean and the southern Indian Ocean. These compounds were detected in most of the samples, which indicated widespread contamination in higher trophic aquatic animals even in remote areas. The highest mean residue concentrations of butyltins in the kidney (300 ng/g wet wt) and liver (280 ng/g wet wt) were in common cormorants from Lake Biwa, Japan. Laysan albatross from the North Pacific Ocean accumulated higher butyltin residues in the liver (43 ng/g wet wt) among open-ocean birds. Even though the number of samples analysed was small, it can be suggested that birds inhabiting inland to coastal areas had higher exposure to butyltins than those in the ocean. To our knowledge, this is the first study reporting on butyltin pollution in seabirds in global terms.