Toxic paint in ships are causing imposex or superimposition of male sexual characters in females of marine life especially snails, says Dr A Murugan, Senior Lecturer of Suganthi Devadson Marine Research Institute, Tuticorin.
Dr Murugan told the
, “The paints are usually used to curb attachment of fungi, bacteria and other organisms to the submerged hulls of ship.”
“The toxic effect of paints containing biocide like Tributyltin (TBT) has been well established. It is considered as the most toxic compound ever deliberately introduced into the natural environment,” he added.
“Tributyltin an endocrine disruptor in mollusks, causes imposex universally at very low concentrations. Imposex is prevalent in places close to ports, shipyards and mariculture facilities where TBT is used in these paints,” he said.
Monitoring of occurrence of imposex along Southern coast of India has been carried out under the Ministry of Environment and Forests funded project, he added.
In India, he said, imposex has been recorded in molluscs like Cronia konkanensis from Marmagoa harbour, Thais and Ocenebra species from Gujarat on the west coast and Thais biserialis and Chicoreus virgineus from Tuticorin harbour on the east coast, he said.
Imposex have also been recorded in sea shells like Babylonia spirata, Babyloni zeylanica, mollusks like Chicoreus virgineus, shells like
along Chennai, Valinokkam and Tuticorin areas of Tamil Nadu coast, he said.
Imposex has been reported in over 118 species in 63 genera of marine life world wide, he added.
The development of male sexual characters in female snails in extreme cases causes the genital pore to be closed leading to sterility in females and sometimes results in premature mortality due to rupture of capsule gland due to build up of egg capsules, he said. Dr Murugan said, “In view of the threat to the marine environment, the International Maritime Organisation (IMO) proposed phasing out of TBT by 2008.”