While the archipelago has not fully escaped the ravages of climate change, it remains home to at least 300 types of coral and is critically important to global coral conservation efforts.
The reefs in the Indian Ocean have been hit hard by human activities, but almost half of those that remain in good condition are located in the Chagos Archipelago.
Reefs are exceptionally diverse ocean habitats. They offer vital protection of coastlines, and provide nutrients that nourish the marine food chain. But 19% of the world's reefs have already been lost, and a further 35% could be gone by 2050. Rising sea temperatures, over-fishing and acidification are very real threats to those that remain.
One of the biggest threats to coral reefs is coral bleaching, which is caused by factors such as rising seawater temperatures. A single event in 1997/98 devastated as much as 16% of the world's reefs. While some reefs recovered following this event, bleaching is now happening so frequently that few reefs have time to recover between incidents.
“It’s not just that the reefs are beginning to die” said Dr Mark Spalding, Senior Marine Scientist at The Nature Conservancy, "It’s what they take with them. These are the rainforests of the sea, but they are also critical to people. They may be the first and most sensitive ecosystems to succumb to climate change, but they will not be alone.”
The archipelago is home to the endemic brain coral (Ctenella chagius) and thick strands of branching staghorn coral (Acropora sp). It is a vital natural laboratory for scientists to learn how a healthy reef lives, and key to replenishing ecosystems in other threatened locations.