Butyltin Compounds and Imposex Levels in Ecuador

Abstract

The first appraisal of butyltins(BT)contami- nation linked with imposex incidence in the Pacific coast of South America was performed in the current study.Imposex occurrence was analyzed in three muricid species (Thaisbiserialis, T.brevidentata,and T.kiosquiformis) distributed along 14 sites from the coastal areas of Ecuador. All studied muricids species showed imposex, which was observed in 11 out of 14 sites. The highest imposex levels were observed in T.kiosquiformis collected inside the Gulf of Guayaquil[relative penis length index(RPLI) 9.0–40.7],where as RPLI values for T.biserialis and T.brevidentata ranged from 4.0 to 26.1 and 0.0 to 1.9, respectively. Additionally, BT compounds[tributyltin (TBT), dibutylin(DBT),and monobutylin(MBT)]were determined in surface sediments collected in 6 of the sites(main harbor areas), and values ranged between 12.7 and 99.5 ng Sng-1(dry weight)for TBT, 1.8 and 54.4 ng Sng-1 for DBT,and 44 and 340 ng Sng-1 for MBT. Although BT degradation indexes suggested an aged input of TBT,the high imposex levels detected in the current study suggest that international restrictions on TBT based antifouling paints were still not effective in Ecuador. Considering that the southern coast,especially near by harbors inside the Gulf of Guayaquil,have shown to be contaminated by BTs,a combination of T.kiosquiformis and T.biserialis (themost sensitive species)can be used for future biomonitoring of Ecuador coastal areas.