Occurrence of butyltin compounds in tissues of water birds and seaducks from the United States and Canada

Tributyltin and its breakdown products, mono-and di-butyltin, were determined in water birds collected from Lake Huron (the Gnat Lakes), marine coastal United States, and the west coast of British Columbia, Canada. Concentrations of butyltins in the liver of birds collected from Lake Huron were less than or equal to 27 ng/g, wet wt, whereas those from marine coastal areas contained up to 90 ng/g, Relatively higher concentrations were found in seaducks collected from coastal British Columbia, with concentrations as great as 1,100 ng/g. Mollusk-feeding seaducks seemed to accumulate greater concentrations of butyltins than predatory birds feeding on fish, other birds and small mammals. Hepatic concentration ranges of butyltins in birds from the United States and Canada were compared with those reported for the UK, Netherlands, Japan, and Poland. Exposure of birds to butyltin compounds continues to occur in harbors and marinas where TBT is used on vessels greater than 25 m in length.