The wildlife and environment of the British Indian Ocean Territory are exceptional. The Territory has the greatest marine biodiversity in the UK and its Overseas Territories, as well as some of the cleanest seas and healthiest reef systems in the world which are protected by the largest no-take Marine Protected Area (MPA) in the Indian Ocean. BIOT is home to the world’s biggest arthropod, the coconut crab, which can reach up to one metre across, with densities on Diego Garcia amongst the highest globally.

The outer islands and atolls are colonised by internationally important numbers of seabirds, with many thousands of pairs of sooty terns, brown boobies and red-footed boobies regularly breeding there. Endemic species of coral and reef fish inhabit the c. 4,000 km² of shallow coral reefs, which also support over six times the amount of fish that are found on any other Indian Ocean reef.

The BIOT Administration has identified eleven conservation and environmental priorities to ensure the protection of this unique environment for the future. These priorities are the current focus of our work, both within the Administration and with our global partners:

  • Combating Illegal, Unregulated and Unreported (IUU) fishing in BIOT
  • Managing the impact of Fish Aggregating Devices and Lost and Abandoned Fishing Gear
  • Ensuring that visiting vessels do not harm BIOT’s unique environment
  • Eradicating invasive rats which threaten native seabird populations, and impact the delicate balance of BIOT’s ecosystem
  • Sustainably managing the recreational fishing allowed in the Territory
  • Protecting BIOT from invasive flora and fauna
  • Ensuring the highest possible level of environmental protocols within the Territory
  • Developing new methods for managing waste and combating plastic pollution
  • Understanding and mitigating against the effects of global climate change where possible
  • Understanding more about BIOT’s unique terrestrial environment
  • Studying our key species and habitats to ensure we are providing the best protection and stewardship

BIOT represents a nearly untouched ‘ocean observatory’ which provides researchers across the world with a place like no other for scientific research. It also provides a testing ground for new environmental management techniques with significance to other protected areas around the world.

The BIOT Administration encourages research science to explore this untapped and as yet largely scientifically undocumented area. Recent expeditions have shown the contribution sea birds make to the reef environment, and have discovered new sea grass beds that are vital for Green Turtles among other marine species. More information on our science programme can be found here.

The Administration also strongly encourages those working on Diego Garcia to take an interest in the environment of the Territory and to actively look after it. Recently, personnel have been involved in several very successful beach cleans and have also had the opportunity to tag turtles alongside our researchers. As part of the ongoing environmental messaging, BIOTA have produced a film, as well as other printed matter, which is shown to everyone stationed on the island.

The UK remains committed to implementing the United Nations Convention on the Law of the Sea (UNCLOS) Arbitral Award of 2015.

More information

Learn more about the amazing biodiversity of BIOT with the Chagos Conservation Trust!

The Bertarelli Foundation for Marine Science has information about the amazing science taking place in BIOT.