Chagos

The Chagos Archipelago (formerly, Oil Islands) is a group of seven atolls comprising more than 60 individual tropical islands roughly in the centre of the Indian Ocean. The islands and their surrounding waters form a vast oceanic Environment Preservation and Protection Zone(EPPZ)/Fisheries Conservation and Management Zone(FCMZ) of 544,000 square kilometres (210,000 square miles)—an area twice the size of the UK’s land surface.

The Chagos lies about 500 km (300 miles) due south of the Maldives, its nearest neighbour, 1600 km (1000 miles) southwest of India, half way between Tanzania and Java.

Officially part of the British Indian Ocean Territory, the Chagos were home to the Chagossians for more than a century and a half until the United Kingdom and the United States expelled them in the 1960s in order to allow the US to build a military base on Diego Garcia, the largest of the Chagos Islands. The deal was sanctioned by the then British Secretary of State for Defence, Denis Healey.

The Chagos group is a combination of different coralline structures topping a submarine ridge running southwards across the centre of the Indian Ocean, formed by volcanoes above the Réunion hotspot. Unlike in the Maldives there is not a clearly discernible pattern of arrayed atolls, which makes the whole archipelago look somewhat chaotic. Most of the coralline structures of the Chagos are submerged reefs.

The Chagos contain the world’s largest coral atoll and the greatest marine biodiversity in the UK by far. It also has one of the healthiest reef systems in the cleanest waters in the world, supporting half the total area of good quality reefs in the Indian Ocean. As a result, the ecosystems of the Chagos have so far proven resilient to climate change and environmental disruptions.

Biodiversity
The biodiversity of the Chagos archipelago and its surrounding waters is one of the main reasons it is so special. But this incredible diversity is under threat – at least 60 species that call Chagos home are already on the IUCN Red List of Threatened Species.

Coral The reefs host 220 species of coral including the endemic brain coral (Ctenella chagius). The coral cover is dense and healthy even in deep water on the steep outer reef slopes. Thick stands of branching Staghorn coral (Acropora sp) protect the low lying islands from wave erosion. Despite the loss of much of the coral in a bleaching event in 1998 the recovery in the Chagos has been remarkable and overall coral cover increases year on year.

Fish

The reefs are also home to at least 784 species of fish that stay near to the shores of the islands including the endemic Chagos clownfish (Amphiprion chagosensis) and many of the larger wrasse and grouper that have already been lost from over-fishing in other reefs in the region.

As well as the healthy communities of reef fish there are significant populations of pelagic fish such as [manta rays]] (Manta birostris), sharks and tuna. Shark numbers have dramatically declined as a result of illegal fishing boats that seek to remove their fins and also as accidental by-catch in the two tuna fisheries that operate seasonally in the Chagos.

Birds

Seventeen species of breeding seabirds can be found nesting in huge colonies on many of the islands in the archipelago, and 10 of the islands have received formal designation as Important Bird Areas, by Birdlife International. This means that Chagos has the most diverse breeding seabird community within this tropical region. Of particular interest are the large colonies of sooty terns (Sterna fuscata), brown and lesser noddy’s (Anous stolidus and Anous tenuirostris) wedge-tailed shearwaters (Puffinus pacificus) and red-footed boobies (Sula sula).

Turtles

The remote islands make perfect undisturbed nursery sites for nests of green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles. The populations of both species in Chagos are of global significance given the "Critically Endangered" status of hawksbills and the "Endangered" status of green turtles on the IUCN Red List. Chagos turtles were heavily exploited during the previous two centuries, but they and their habitats are now well protected by the administration of the British Indian Ocean Territory and are recovering well.

Crabs

The coconut crab (Birgus latro) is the world’s largest terrestrial arthropod, reaching over one metre in leg span and 3.5-4 kilos in weight. As a juvenile it behaves like a hermit crab and uses empty coconut shells as protection but as an adult this giant crab climbs trees and can crack through a coconut with its massive claws. Despite its wide global distribution, it is rare in most of the areas it is found. It is primarily threatened by over-collection for food, but also as ornaments for sale to tourists and as bait for fish traps. Demand for coconut crabs as souvenirs is strong, and other threats include habitat destruction and predation from introduced species such as rats. The coconut crabs on Chagos constitute one of the most undisturbed populations in the world. An important part of their biology is the long distances their young can travel as larvae. This means the Chagos coconut crabs are a vital source for replenishing other over-exploited populations in the Indian Ocean region.

Plants

The Chagos Islands have been colonised by plants since there was sufficient soil to support them – probably less than 4,000 years. Seeds and spores arrived on the emerging islands by wind and sea, or from passing sea birds. The native flora of the Chagos Islands is thought to comprise fourty-one species of flowering plants and four ferns as well as a wide variety of mosses, liverworts, fungi and cyanobacteria.

Today, the status of the Chagos Islands’ native flora depends very much on past exploitation of particular islands. About 280 species of flowering plants and ferns have now been recorded on the islands, but this increase reflects the introduction of non-native plants by humans, either accidentally or deliberately. Because some of these non-native species have become invasive and pose a threat to the native ecosystems, plans are being developed to control them. On some islands, native forests were felled to plant coconut palms for the production of copra oil. Other islands remain unspoiled and support a wide range of habitats, including unique Pisonia forests and large clumps of the gigantic fish poison tree (Barringtonia asiatica). Unspoiled islands provide us with the biological information that we need in order to re-establish the native plant communities on heavily altered islands. These efforts will ultimately help to improve the biodiversity of the Chagos Islands.

Protection Efforts
Past

Successive UK governments, both Labour and Conservative, have supported environmental conservation of the Chagos. They have committed to treat the whole area as a World Heritage site. In 2003, the UK government established an Environment (Protection and Preservation) Zone under Article 75 of the UN Convention on the Law of the Sea. This zone extends 200 nautical miles from the islands. On eastern Diego Garcia, the largest island of the Chagos and the site of a UK–US military facility, Britain has designated the very large lagoon and the eastern arm of the atoll and seaward reefs as a “wetland of international importance” under the Convention on Wetlands of International Importance (the Ramsar Convention).

Present

An effort led by the [The Chagos Environment Network], a collaboration of nine leading conservation and scientific organisations seeking to protect the rich biodiversity of the Chagos Islands and its surrounding waters, currently urges the UK Government to declare the Chagos archipelago and waters, out to its 200 mile Environmental Preservation and Protection Zone, a full no-take marine reserve in which extractive activities such as fishing would be prohibited. The Chagos Enviornment Net work sites several reasons for supporting a protected area:

Wildlife - The Chagos no-take marine reserve would maintain the pure and unpolluted waters of Chagos, providing a safe refuge for its rich marine life, including many threatened species, such as turtles and sharks. Seabirds and nesting turtles too will benefit from the additional conservation measures that a protected area will bring. Both groups are recovering from severe depredations of the past in a way that is not possible in most places. Fisheries - World fish stocks have declined catastrophically because of destructive and unsustainable fisheries practices. The Indian Ocean has been badly affected in this regard, given its heavily populated rim of countries. A large ‘no-take’ protected area would assist fish population recovery, potentially increasing fish numbers over a much wider area. The protected area would also provide a temporary refuge for migratory species, such as tuna, from exploitation. People - In the long-term, a Chagos no-take marine reserve would contribute to a richer ocean and would benefit people living in and around that ocean, such as the coastal countries of East Africa and elsewhere. In regards to the displaced Chagossian people, whatever the outcome of legal challenges brought by Chagossian groups against the UK government, the Chagos Environment Network believes that the Chagos need conservation now and that this will be beneficial to everyone under all future legal scenarios. The Chagos Environment Network urged that the Chagos Islands and their surrounding waters be designated as a no-take marine reserve “without prejudice” to the outcome of the legal process. This designation would mean that the Chagos Islands and their resources would remain healthy no matter what the future holds, but that conservation arrangements could be modified if necessary in the light of a change in circumstances. Science- The Chagos is one of the few marine locations in the world where there are almost no ongoing, direct human impacts over almost all of its areas. The marine reserve can serve as a reference site for global scientific research to aid in our understanding of such things as climate change, tropical marine ecosystems and the impacts of commercial fisheries. Deep Ocean - The deep oceanic waters around the Chagos Islands, out to the 200 nautical mile limit, include an exceptional diversity of undersea geological features (such as 6000m deep trenches, oceanic ridges and sea mounts). These areas almost certainly harbour many undiscovered and specially adapted species. UK international commitments - The creation of the Chagos Protected Area would be an important contribution by the UK to at least seven international environmental conventions. It would also contribute to the UK’s global commitments, such as halting the decline of biodiversity by 2010, establishing marine protection networks by 2012, and restoring depleted fish stocks to sustainable levels by 2015.

The UK government has opened a three-month public consultation set to end on the 12th of February 2010 about conservation management of the Chagos Islands and its surrounding waters.

Among the three options under consideration, Option I would provide the best means to preserve one of Earths last unspoiled tropical island, reef and deep-sea ecosystems in that it would “Declare a full no-take marine reserve for the whole of the territorial waters and Environmental Preservation and Protection Zone (EPPZ)/Fisheries Conservation and Management Zone (FCMZ).” This option would establish the largest marine reserve in the world, a conservation legacy almost unrivalled in scale and significance. It would also establish the United Kingdom as a world leader in marine conservation for the benefit of all nations.