Great sharks are disappearing from the world's oceans, the American Association for the Advancement of Science conference in Boston heard yesterday. Unregulated fishing has led to catastrophic declines - and nine shark species will be added this year to the official Red List of animals at heightened risk of extinction.

Julia Baum of the Scripps Institution of Oceanography in California said there was particular concern about the scalloped hammerhead shark, "which will be listed as globally 'endangered' [by the International Union for the Conservation of Nature] due to overfishing and high demand for its valuable fins in the shark fin trade".