The increasing incidence of imposex in Stramonita haemastoma (Mollusca: Gastropoda: Muricidae) after the establishment of the Pecém Harbor, Ceará State, Northeast Brazil

Abstract

Imposex is characterized by the development of masculine sexual organs in neogastropod females, caused by organotin contamination of the seawater. These compounds, as tributyltin (TBT), are used world-wide as biocidal agents in antifouling paints, commonly used to covering boats and off shore metallic structures. Five sampling sites were determined along the coast of Ceará State, Northeast Brazil in March 2001. In each site were collected 50 adults of neogastropod Stramonita haemastoma and indexes that quantify imposex (% imposex, RPLI, RPSI and VDSI) were observed. Other two collecting times were conducted (April 2003 and March 2004) at the same sites and imposex indexes were observed again. The indexes observed in the three collecting times showed an increase in the incidence of imposex at the sampling sites, probably caused by the establishment of Pecém Harbor and its increasing shipping activities