Nationwide monitoring of organotins using bivalves in the marine environment of Korea (1995-1998 and 2001 survey)

Abstract

Organotin compounds are one of the most widely used organometallic chemicals. They are actively applied to antifouling paints as biocidal additives to prevent adherence of sedentary organisms to ship hull and other structural surfaces immersed in water. Since their deleterious effects on non-target organisms were revealed in the early 1980’s, many industrialized countries have placed regulations of ban on use of organotin compounds, especially tributyltin (TBT) and triphenyltin (TPT) compounds, in ships. South Korea is one of the major ship building industries in the world, and boating activities are relatively high as a peninsula. Korean government has banned the use of both TBT and TPT based antifouling paint on ships less than 400 tonnage from 2000. Bivalve organisms such as mussels and oysters have been used as monitoring organisms due to their high accumulation of organotins, sessile characteristics and wide distribution. Tributyltin, triphenyltin and their degradation products in mussel or oysters were quantitatively determined around the coast of Korea during the 1995 – 1998 (67 sites) and 2001 (40 sites) surveys, respectively. Concentrations of TBT and TPT in bivalves during 1995 – 1998 ranged from 16 to 2800 ng/g and not detected to 1820 ng/g, respectively. Relatively high butyltin and phenyltin concentrations were found near harbours and shipyards. In 2001, TBT concentrations (32 – 2460 ng/g) were in similar range, while TPT levels decreased steeply with the range of not detected - 134 ng/g. In addition, frequency of phenyltin detections decreased from 62% in the 1995 – 1998 survey down to 18% in the 2001 survey. Cumulative probability distribution curves of TBT concentrations in both the surveys appeared very similar. However, the median TBT concentration in 2001 (281 ng/g) was slightly less than that of in 1995 – 1998 (399 ng/g). These TBT body residues are still high enough to cause adverse effects on marine orga