The Chagos contains the world’s largest coral atoll and the greatest marine biodiversity by far under UK jurisdiction. 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 Chagos have so far proven resilient to climate change and environmental disruptions. The Chagos Marine Reserve is as important as the Galapagos or the Great Barrier Reef, and with the whole of its territorial waters included, is the world’s largest marine reserve.

Reefs
The Chagos Marine Reserve protects one of the world’s most resilient coral reefs at a time when scientists recognise that reefs face rapid decline due to pollution, warming and ocean acidification. If Chagos is managed well, these reefs may provide an opportunity for marine life to seed recovery of degraded reefs elsewhere.

Wildlife
The Chagos Marine Reserve helps to 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, and globally important populations of seabirds.

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. This large ‘no-take’ protected area assists fish population recovery, potentially increasing fish numbers over a much wider area. The Chagos Marine Reserve also provides a temporary refuge for migratory species, such as tuna, from exploitation.

People
In the long-term, the Chagos Marine Reserve will contribute to a richer ocean and should benefit people living in and around that ocean, such as the coastal countries of East Africa and elsewhere.

Science
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.

Seabirds
Over 175,000 pairs of seventeen species of seabirds breed on the atolls, and ten of the islands have formal Birdlife International recognition as Important Bird Areas. Seabirds and nesting turtles too will benefit from the additional conservation measures that the Chagos Marine Reserve will bring. Both groups are recovering from severe depredations of the past in a way that is not possible in most places.

UK international commitments
The creation of the Chagos Marine Reserve represents an important contribution by the UK to at least seven international environmental conventions. It also contributes 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.