Context: Recently, the isolated UK Overseas Territory of Tristan da Cunha, which is home to the world’s most remote human settlement, declared the largest fully protected marine reserves in the Atlantic Ocean at 687,000 square kilometres. 
Historical Background

• The island group was discovered in 1506 by a Portuguese admiral, Tristão da Cunha. Two unsuccessful attempts to settle the islands during the 17th century and one in 1810 preceded the stationing of a British garrison on Tristan da Cunha in 1816, when the island group was formally annexed by the United Kingdom.

Geographical Location

• Tristan da Cunha, island and group of islands in the South Atlantic Ocean, about midway between southern Africa and South America. 
• The island group is a constituent part of the British overseas territory of St. Helena, Ascension and Tristan da Cunha. 
• The six small islands of the Tristan da Cunha group are administered collectively. Five of them—Tristan da Cunha, Inaccessible, Nightingale, Middle, and Stoltenhoff—are located within 25 miles (40 km) of one another, and the sixth, Gough, lies about 200 miles (320 km) south-southeast of the group. 
• The territory is located approximately 1,300 miles (2,100 km) to the south of St. Helena. Inaccessible, Nightingale, Middle, and Stoltenhoff are uninhabited, while a weather station is manned on Gough Island.

Biodiversity of that region

• It is inhabited by less than 300 humans is a small chain of islands over 6,000 miles from London in the South Atlantic and the water around the islands are considered to be the richest in the world.
• According to Royal Society for the Protection of Birds (RSPB), which has been working with the local community and government of Tristan da Cunha "The mountainous archipelago Tristan da Cunha is home to tens of millions of seabirds and several unique land birds that are comparable to the Galapagos island finches".
• However, some of its seabirds that are not found anywhere else in the world face threats including illegal and unregulated fishing activities, overfishing, plastic pollution and climate change. The National Geographic reported that invasive mice brought to the islands by passing ships kill over 2 million birds a year.
• The island group is also home to the World Heritage Site of Gough and Inaccessible Islands, which is one of the most important seabird islands in the world. 
• It is located about 2,000 km from the nearest land and as per the RSPB, it takes longer to sail to Tristan da Cunha from Cape Town than it took Apollo 11 to reach the Moon.
• As of now, there are two critically endangered species in the island group and over five endangered species.

Importance of announcement mean for the island group

• After joining the UK’s Blue Belt Programme, it will become the largest no-take zone in the Atlantic and the fourth largest on the planet. This means fishing, mining and any such activities will not be allowed.
• The almost 700,000 square kilometres of the Marine Protection Zone (MPZ) is almost three times the size of the UK and will safeguard the future of sevengill sharks, yellow-nosed albatrosses and rockhopper penguins. 
• Further, this development is also supported by the Blue Belt Programme, which provides over 27 million pounds over a period of five years for marine conservation around the UK Overseas Territories and international organisations. 
• MPZs involve the management of certain natural areas for biodiversity conservation or species protection and are created by delineating zones with permitted and non-permitted areas within that zone.
• As per the National Geographic Society’s Campaign for Nature Initiative, over 30 percent of the world’s oceans need to be protected to allow ecosystems to provide benefits like ample fish stocks.