Representatives of the world's governments are meeting to decide whether to ban a chemical used to coat the bottoms of ships which is causing female dog whelks to grow penises, thus endangering the species. The chemical is also building up in other sea life and has been found in people who eat fish.
Dog whelks, which mainly live on beaches between the high and low tide marks, have long been one of Britain's commonest seaside creatures. But they have disappeared from large areas because of their bizarre transformation.
Scientists collecting whelks discovered to their surprise that they could only find male ones. Close inspection revealed that half were females who had unaccountably grown penises.
The scientists suspected that tributyltin, the anti-fouling paint most widely used on the hulls of boats and ships, was to blame. Sure enough, when they painted the shells of unfortunate females with the chemical, penises sprouted and grew to alarming lengths.
The sex change females cannot mate, and die painfully if they do before the transformation as their new penises block the ovary ducts where their eggs go on growing inside them until they explode.
Dr Sian Pullen, head of the marine programme at World Wide Fund for Nature- UK, says: "This is a very powerful chemical. It has been well documented that it causes dramatic changes in marine wildlife. Japan is very concerned about it in humans."
The use of the chemical on small boats under 75ft long was banned in Britain and other European countries in the 1980s but it is still used on large ships.
Tomorrow a committee of the International Maritime Organisation will consider a recommendation that the chemical should be banned completely by 2006.Reuse content