Tony Lass, an expert at Cadbury's, warned: 'There is a real danger of the loss of important cocoa genes because of the destruction of cocoa trees in the wild and the abandoning of cultivated crops.'
Caribbean cocoa trees were cultivated from strains developed by the Aztecs. John Warren, a British plant breeder, believes a fungal epidemic in 1725 decimated them and forced the islands to re-stock from different sources, creating today's rich genetic diversity.
'Through a quirk in colonial history - the islands could not trade with each other - the region gave rise to a wonderful range of dark chocolate varieties, with exotic flavours unique to each island,' he said.
Now growers are abandoning cocoa crops, which are labour-intensive, for alternative sources of income such as tourism. Growers who continue with cocoa crops are abandoning flavour for higher-yielding hybrid varieties. These trends are resulting in a loss of genetic diversity, says Dr Warren.
'Cocoa trees have already gone from several islands. The world may never know what a bar of St Vincent's chocolate tasted like.'
The last hope of preserving exotic varieties is in two 'gene banks' on Trinidad and Costa Rica. Both centres, however, are short of funds.