Jonathan Hall is the RSPB's Partner Development Officer for the UK's Oversea's Territories, in this guest blog he reveals the riches of the seas around Ascension Island

The UK Overseas Territory of Ascension in the tropical Atlantic is perhaps most well-known as the site of the British naval garrison set up to prevent Napoleon - imprisoned on St Helena, 800 miles to the southeast - from being rescued by the French.

An oceanic island, Ascension is a vital nesting site for a range of tropical Atlantic seabirds. A recent success story for Ascension's wildlife was in 2002, when the RSPB achieved eradication of the large feral cat population, which was devastating local seabird numbers.

But despite these successes on land, there has to date been sparse conservation action in Ascension's waters. The island's waters have been little-fished: a brief and poorly managed commercial long-line fishery, suspected of shark-finning, turtle by-catch was closed in 2013. A review of all management options for Ascension’s vast (440,000 square km) maritime area is now underway by the Ascension Island Government, with a report due in August. The RSPB believes this review offers the perfect opportunity for the British government to consider designating a large and highly-protected marine reserve within Ascension's waters.

Ascension straddles the Mid-Atlantic ridge, an area of great geological dynamism and little-understood deep-sea marine biodiversity, and is known for its populations of big ocean predators, including migratory tuna stocks (shared with developing West African nations), dolphins, sharks, and whales.

 Known as the “Jurassic Park of the mid Atlantic” by sports fishermen, thanks to its frequent habit of producing record-breaking catches, Ascension's fishy inhabitants remain surprisingly little studied by the scientific community. An exception to this is the work undertaken by the Shallow Marine Surveys Group and the Ascension Island Government in 2012 and 2013. Of the 132 species of coastal fish documented, 8% are found nowhere else on earth and an additional 12% are found only around St Helena and Ascension.

Ascension is, however, famous for its turtles, boasting the second-largest nesting site for green turtles in the Atlantic (the other being in Costa Rica), and the biggest green turtles in the world. However, even these impressive facts may not adequately convey how important Ascension is for these endangered icons of the sea. There are so few suitable nesting islands elsewhere in the region, that without Ascension, it is possible they would have nowhere else to go.


Photo: Ascension's beaches are furrowed by hundreds of turtle tracks Credit: Jonathan Hall

 Last year at the International Marine Protected Areas Congress, Sylvia Earle's Mission Blue Foundation has named Ascension as one of its new “Hope Spots” for the ocean, marking it out for special attention for the conservation community and a high profile candidate for protection. Unlike the Pacific, Indian and Southern oceans, which have seen a marked increase in the number of large highly protected marine reserves in recent years, the Atlantic Ocean remains virtually ignored. The no-take zone around the UK Territory of South Georgia in the Southern Atlantic, at less than 14,000 square km, is currently the largest such highly-protected area in the Atlantic. At an estimated 440,000 square km, a highly-protected marine reserve around Ascension would represent a step-change in the conservation of biodiversity in the Atlantic.

 Although the life beneath the waves around Ascension remains poorly understood, the information we do have offers an exciting glimpse of a near-pristine and abundant marine environment. By creating a world-class marine reserve around Ascension, the UK can create a sanctuary for biodiversity for the wider tropical Atlantic and make a world-leading contribution to global conservation.