Assessing the Continuous Impact of Tributyltin from Antifouling Paints in a Brazilian Mangrove Area Using Intersex in Littoraria angulifera (Lamarck, 1822) as Biomarker

Intersex is a sensitive biomarker of TBT exposure and effects in littorinid gastropods and described for the mangrove periwinkle Littoraria angulifera for the first time in this study. The objective was to describe the occurrence of intersex in L. angulifera, to propose the species as a sentinel organism to assess TBT contamination, and to characterize the contamination in mangroves. The study was carried out in 2009 by sampling at 20 stations near harbors and marinas and at a reference station on the coast of Espírito Santo Estate, Brazil. At the reference station, no intersex specimens were found, while at 20 sampling stations 51% of the females exhibited different degrees of intersex development, including the occurrence of functionally sterilized females. The highest incidence of intersex and greatest intersex intensities was found in areas close to marinas and shipyards indicating that vessel-related activities are still the main source of TBT contamination. L. angulifera collected from stations in areas with well-preserved mangroves was larger than specimens collected from other areas. These differences are attributed to environmental quality and not to occurrence of intersex. The results indicate that this region is still affected by TBT contamination and that L. angulifera has the required sensitivity to be used as a bioindicator