An ambitious plan to preserve the pristine ocean habitat of the Chagos Islands by turning them into a huge marine reserve on the scale of the Great Barrier Reef or the Galapagos will be unveiled at the Royal Society next Monday.
Unpopulated for 40 years since the British government forcibly evicted inhabitants so the Americans could build a strategic military base on Diego Garcia, the Chagos Islands offer a stunning diversity of aquatic life.
The absence of human habitation has been a key factor in the preservation of the pristine coral atolls, the unpolluted waters, rare bird colonies and burgeoning turtle populations that give the archipelago its international importance.
The plan will be launched in London by the Chagos Environment Network, which includes the Chagos Conservation Trust, the RSPB, the Zoological Society and the Pew Environmental Group, a powerful US charity which successfully lobbied the Bush administration for marine reserves in America.
The Chagos Islands, which belong to the British Indian Ocean Territory, were emptied of about 2,000 residents between 1967 and 1971 to meet US demands that the islands be uninhabited. Most islanders were exiled to Mauritius and the Seychelles, where many ended up in poverty. Proposals for the new reserve tentatively broach the possible return of some of the Chagossian refugees to their homeland as environmental wardens.
"It is going to be compatible with defence and do something for the Chagossians," said William Marsden, the chairman of the Chagos Conservation Trust, adding that the islands were "by far Britain's richest area of marine biodiversity" and that at 250,000 square miles, the reserve would be in the "big league" globally.
Professor Callum Roberts, a marine biologist at the University of York, said the plan would mean far better environmental monitoring, especially where incursions from Sri Lankan fishing boats had depleted fish stocks. "The attitude of the British towards the Chagos Islands has been one of benign neglect," he said.
A formidable hurdle lies in the shape of US security fears and the refugees' continuing legal battles with the British Government over the court rulings that have prevented them going home.
Refugee groups say that of the 5,000 people eligible to return, half wished to do so permanently. Resettlement plans have called for the construction of a small airport and limited development to allow environmentally sustainable tourism, raising fears that designation as a reserve would be a further blow to the islanders' hopes. In 2000, the Chagossians won the right to return to 65 of the islands - although not Diego Garcia, the largest - only to see the ruling nullified in 2004 by the Government, using the Royal Prerogative.
The islanders succeeded in overturning that action in the High Court and the Court of Appeal, but in June last year the Government went to the House of Lords, arguing that allowing the islanders to return would damage defence and security.
The Government appeal was allowed by the law lords in October, and now experts say the case may be taken to the European Court of Human Rights. The Diego Garcia base has been used for bombing raids on Iraq and Afghanistan, and as a staging post in CIA "extraordinary rendition" flights.
A Foreign Office spokesman told Economist.com that the Government "welcomes and encourages recognition of the global environmental importance of the British Indian Ocean Territory", adding that it would "work with the international environmental and scientific community to develop further the preservation of the unique environment".
Haven of safety: Species at risk
Red-footed booby (Sula sula)
This seabird is the smallest of all the boobies, with distinctive red legs and pink and blue bill and throat. The spectacular diver has elaborate greeting rituals between mates.
Green turtle (Chelonia mydas)
Endangered; feeds mostly on seagrass; has found the waters around the Chagos Islands a haven. Elsewhere, it has suffered from habitat loss, pollution and fishing nets.
Variable flying fox (Pteropus hypomelanus maris)
A species of "megabat", it feeds on fruit and roosts in large colonies in forests, usually on small islands or near the coast. Under threat elsewhere because of deforestation and hunting.
Cuvier's beaked whale (Ziphius cavirostris indicus)
Also known as the goose-beaked whale, this mammal was thought in the Middle Ages to have a fish's body and an owl's head. Can live up to 40 years and grow to seven metres long. Occasionally seen off western and northern Scotland.