Chagos Marine Protected Area

Hawksbill sea turtle by a coral reef in the Chagos Islands

The Chagos Marine Protected Area, located in the central Indian Ocean in the British Indian Ocean Territory, is one of the world's largest officially designated marine protected areas, and one of the largest protected areas of any type (land or sea) on Earth. It was established by the British government on 1 April 2010 as a massive, contiguous, marine reserve, it encompasses 247,100 square miles of ocean waters, including roughly 70 small islands and seven atolls of the territory's Chagos Archipelago.

An exemption in the terms of establishment of the Marine Protected Area allows people from the American naval base on Diego Garcia to continue fishing, and in 2010, more than 28 tons of fish were caught for use by personnel on the base.

The Chagos Marine Protected Area is administered with assistance from the Chagos Trust, funded by donations and the British Government. Tourist visitors are generally not permitted, although as of 2016 private yachts sailing across the Indian Ocean may apply for mooring permits outside the strict nature reserve areas.

Description

The Chagos marine reserve protects the world's largest coral atoll (the Great Chagos Bank) and has one of the healthiest reef systems in the cleanest waters of the world, supporting nearly half the area of good quality reefs in the Indian Ocean. No-take marine reserves are areas of the sea in which there is no fishing allowed and as little other human disturbance as can be reasonably arranged.

Establishment

Previous to the establishment of the marine reserve, the Chagos Archipelago had been declared an Environmental (Preservation and Protection) Zone with legislation in place to protect much of the area's natural resources. Commercial fishing, however, was licensed for both reef fish and tuna. Though the UK government has opposed the area being proposed as a World Heritage Site, it has agreed to treat it as such in order to preserve its environmental value.

The case for a large scale marine reserve in the Chagos was first put forward by a consortium of conservation organisations led by the Chagos Environment Network, a collaboration of nine leading scientific and conservation organisations, in "The Chagos Archipelago: Its Nature and the Future" which was launched in March 2009. The Chagos Environment Network was the leading advocate for the reserve during the consultation period and organised two of the major petitions in favour of the reserve being set up.

From 10 November 2009 to 5 March 2010, a public consultation was carried out by the UK government to take views on whether or not a marine protected area (MPA) should be established in the archipelago. Respondents were asked not only whether they believed that the MPA should be established but also to what degree they thought it should be protected, either to establish a fully no-take marine reserve or a less protected marine protected area that would allow some fishing.

The response to this consultation was high, with over 250,000 people expressing their views on the issue either through the use of petitions or more lengthy written replies. Over 90% declared their support for greater marine protection, with the majority believing that it should be a no-take marine reserve. The loss of the approximately £800,000 a year earned from tuna licensing was frequently raised as a possible hurdle to the designation of the marine reserve. In the final months leading up to the designation, the Bertarelli Foundation offered to fill the funding gap left by the absence of fisheries income and thereby contribute to the costs of an enforcement boat for a period of five years. Following this response, the total area of the Chagos’ Exclusive Economic Zone was declared a fully no-take area, with the exception of a 3-mile zone around the island of Diego Garcia.

The establishment of the Chagos Marine Protected Area and first five years of protection has been supported by major funding from the Bertarelli Foundation.

Ecology and biodiversity

Ninety percent of the United Kingdom's biodiversity lies in its Overseas Territories, and the Chagos archipelago is by far the most biodiverse marine area in the United Kingdom's waters. Its habitats include extensive shallow limestone reefs and associated environments, about 300 seamounts and a deep sea trench - an underwater canyon more than 16,000 feet deep.

Coral

One of the most unusual aspects of the Chagos marine environment is its extremely healthy and diverse coral cover, which is dense even in deep water and on the steep outer slopes of reefs. The area hosts 220 species of coral including the Ctenella chagius, a variety of brain coral believed to be endemic to the atoll, and staghorn coral which is important to protecting low-lying islands from wave erosion. Chagos provides an important benchmark for coral conservation, and is a 'natural laboratory' in which we can study the functioning of these wonderfully complex ecosystems.

Fish

The fish of the region are equally diverse, with at least 784 different species having been identified including the Chagos clownfish (Amphiprion chagosensis) which is endemic to the archipelago. The strictly no-take Chagos Marine Reserve has freed Chagos' fish populations from fishing pressure within the reserve's boundaries. The marine reserve is an important refuge for overfished pelagic species such as manta rays, sharks including whale sharks, tuna and is of particular importance for globally threatened species, such as the silky shark. It is also believed, based on results of research on similar deep water and diverse underwater terrain in other parts of the world, that the deep water trench is very likely to harbour a variety of previously undiscovered species.

Turtles

The islands of the archipelago provide vital nesting sites for green and hawksbill turtles (Chelonia mydas and Eretmochelys imbricata). Since the hawksbill turtle is labelled ‘critically endangered’ and the green turtle ‘endangered’ on the IUCN Red List, the Chagos populations are considered to be of international importance. It is estimated that 300-700 hawksbill and 400-800 green turtles nest annually across the 55 islands of the archipelago.

Mammals

Environments of Chagos Archipelago provides rich biodiversity and support varieties of cetacean species within the vicinity, such as three populations of blue whales and toothed whales (such as sperm, pilot, orca, pseudo-orca, risso's and other dolphins such as spinners). Regional extinct dugongs were historically seen in the archipelago: Sea Cow Island was so named due to the presences of the species.

Birds

The breeding seabirds of the Chagos are considered to be of international importance. The archipelago harbours eighteen different species of breeding birds and ten of its islands have been designated as Important Bird Areas by Birdlife International, making the region the most diverse breeding seabird community in this tropical region, though the presence of human-introduced rats on several of the other islands severely hinder seabird nesting on these.

Five species are considered to be breeding in internationally significant numbers: the sooty tern (Sterna fuscata); the brown and lesser noddy (Anous stolidus and Anous tenuirostris); the red-footed booby (Sula sula) and the wedge-tailed shearwater (Puffinus pacificus).

Coconut crabs

The world's largest terrestrial arthropod, the coconut crab (Birgus latro) is abundant on the islands of the Chagos archipelago, with an overall density in the conservation area on Diego Garcia of 298 crabs per hectare – the highest ever recorded. Due to the long distances which the larvae of the coconut crab can travel, the Chagos population is considered important in replenishing numbers in other areas of the Indian Ocean.

Scientific research

Scientific and conservation efforts are being undertaken to tell us more about these islands, remove invasive plant and animal species, and restore native vegetation. These initiatives are all an important contribution to the conservation of Chagos, and global biodiversity. In February and March 2013, a research expedition was undertaken in the Chagos Marine Protected Area (MPA). The expedition, which was sponsored by the Bertarelli Foundation, in partnership with Stanford University and the University of Western Australia, piloted an electronic tagging project to examine the feasibility of using remote technologies to monitor the movement of important pelagic species in the region. Five different types of electronic tags were deployed in this study, with a total of 99 electronic tags placed on 95 animals, along with the installation of an acoustic receiver array around two northern atolls to detect animal movements.

Location

• Location: 6°10’0"S, 72°0’0"E

Outside links

• Chagos Conservation Trust
• Zoological Society of London's Chagos pages