engleski

Distribution and persistence of butyltin compounds (BuT) in coastal sediments from eastern Adriatic (Croatia)

Butyltins (BuTs) have been introduced into the marine environment by the use of tributyltin (TBT) as biocide in antifouling paints since 1960s. However, after it was established that TBT has various toxic effects on the non target organisms, like the appearance of imposex in gastropods at very low levels (1-2 ng L-1), the use of TBT-based antifouling paints has been banned in many countries worldwide, including the whole Europe, while in Croatia they are banned since 2006. The first measurements of BuT concentrations in seawater and mussels from the Croatian Adriatic coast, sampled during 2009 and 2010, showed a widespread pollution with TBT suggesting an ongoing use of those paints, despite restrictions (Furdek et al., 2012). In this paper we present the first data on BuT concentrations in sediments from the Croatian Adriatic coast. In order to elucidate factor influencing the level of BuT pollution, locations with different intensity of maritime activities (marinas, ports and reference sites) were selected for sampling of surface sediments. BuTs in sediments ranged from 5 to 1362 ng(Sn) g-1(d.w.), while contamination levels in marinas and ports were significantly higher than at reference sites. The far highest concentrations were found in sediments taken below the service hoists in marinas, where BuTs reached the enormous value of 66344 ng(Sn) g-1(d.w.). In addition to BuTs, the concentrations of total tin in surface sediments were also determined in order to test the hypothesis that elevated levels of inorganic tin in marine environment originate primarily from TBT that is used in antifouling paints. The strong and statistically significant correlations between BuTs and total Sn confirmed this assumption. The assessment of the level of sediment pollution was done using OSPAR criteria for TBT concentrations in sediments and enrichment factor (EF) approach for total Sn. Both criteria indicated that >75 % of sampled sites can be classified as highly polluted. Obviously, the ban of the use of TBT-based antifouling paints cannot solve the problem of BuT pollution immediately, since contaminated sediments represent a long term source of TBT in the marine environment.

tributyltin ; organotin compounds ; total tin ; sediments ; pollution

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