Sex-change pollutant in Solent study
Posted by Science Oxford on October 2, 2009 | comments
Interesting stuff: Did you know Tributyltin (TBT) paints cause female dog-whelks to grow a penis and other sex organs. This is a phenomenon known as imposex. The below article will tell you all about it:
Visit this page »Tributyltin (TBT) paints, used to prevent sea vessels becoming encrusted with barnacles and other marine life, causes the female dog-whelk to develop a penis and other male sex organs—a phenomenon known as imposex.
The male organs block the egg-laying tube or oviduct, causing a build-up of eggs, a potentially fatal situation that results in a rapid decline of dog-whelk populations once reproducing females are lost.Scientists have now discovered that ten years after the ban of TBT antifouling paints on small craft, populations of dog-whelks around some parts of the Isle of Wight coast have not yet recovered. The findings will be presented at the Solent Science Conference tomorrow (21 – 22 September) at the Southampton Oceanography Centre. ‘In 1987, a survey around the Isle of Wight revealed that while still common on the south coast, dog-whelk populations on the Solent shores had become extinct or reached dangerously low levels. The degree of imposex was higher in populations closer to the Solent. Exposure of TBT at one nanogram per litre—that’s around one teaspoonful in a swimming pool—can initiate imposex,’ explains Roger Herbert of the Isle of Wight-based Medina Valley Centre. Later that year, TBT paints were banned for use on craft under 25 metres in length.
Ten years on, dog-whelk populations around the Isle of Wight have been re-surveyed. ‘We have found evidence of a rapid recovery in some populations but a decline in others. Imposex levels at Bembridge have fallen dramatically with a corresponding rise in dog-whelk populations. But at locations on the south coast, imposex levels are dropping surprisingly slowly-populations at Ventnor are actually decreasing,’ says University of Southampton’s Simon Bray.
The researchers hope to carry out more studies to help explain these differences. ‘Dog-whelks are an important indicator of the extent of TBT pollution and provide evidence of contamination at sites which have not been chemically sampled. Further research needs to be carried out to fully clarify the long-term effect of TBT on the Solent’s marine life,’ concludes Roger Herbert.
Article Credit: AlphaGalileo
What do you think?