Imposex occurrence in Nassarius vibex from South America: a potential bioindicator in estuarine environments

Abstract

Research on organotin compounds (OTCs) contamination in South America is focused on sand/rocky environments; estuarine areas have not yet been investigated. Imposex is an important tool to evaluate OTC contamination. The aim of the present study was to assess the sensitivity of a typical estuarine species to OTC contamination and to biomonitor the spatial extent of such compounds in the estuary. Sampling was conducted along the Ceara´ River estuary (north-eastern Brazil) and imposex expression was quantified in Nassarius vibex females. Imposexed females developed small papillae or penis, with smaller lengths compared to males. Passive monitoring was conducted on 10 sampling stations around 2 shipyards using imposex quantification indices. Imposex percentage in the population ranged from 0 to 33.3% and relative penis length index ranged from 0 to 26.4%. The present research is the first application of N. vibex as a bioindicator of organotin compounds in Brazil. Keywords: bioindicator, imposex, Nassarius vibex, Ceara´ River