Researchers from the British Antarctic Survey in Cambridge said that between 1976 and 1994 the number of seals visiting the island each summer from breeding grounds in South Georgia had leaped from fewer than 100 to 20,500.
Writing in the science journal Nature, the researchers suggest that the Southern Ocean whaling industry, which has reduced the baleen whale population by 90 per cent since 1922, may be partly responsible.
The whales feed on vast amounts of a shrimp known as krill, which are also food for seals. An abundance of krill caused by the diminished number of whales is thought to have helped promote seal population growth.
The seals, hunted to near extinction in the 19th and early present century, are now said to be causing extensive destruction of vegetation and soil erosion.