Geography and Location

Saint Brandon is an isolated South West Indian Ocean archipelago situated on the Mascarene Plateau, about 430km Northeast of Mauritius composed of sandbanks, shoals and around thirty islands.  The islands are low-lying and prone to substantial submersion in severe weather and by annual tropical cyclones which can cause considerable damage.

The total area of the islets, sandbars etc is approximately 5 km2, which are spread over an area of 1,232 km2. The main lagoon is approximately 300 km2 with a coral reef of 130 km in length. Albatross Island is the highest point at 6 m (20 ft) above sea level and the largest of the islands in the group.  The archipelago is dynamic, with each storm, islands form, split, join and change size.

Ecological profile of St Brandon

St. Brandon has more than 200 km2 of reef habitat, possibly one of the most biodiverse ecosystems on earth holding over 25% of known marine species when these cover less than 1% of the sea floor..
In the West, there is a coral bank and a fringing reef, dominated by staghorn Acropora,  classified as threatened by the US National Marine Fisheries Service in 2014. To the East of the atoll, there is a greater coral diversity including a rare species of the Pavona coral. There are persistent, but as yet unproven rumours, of the presence of rare brain corals in St. Brandon waiting to be discovered and preserved for posterity.

Fauna and Flora

The isolated islands serve as important seabird nesting grounds at a national and international level and, for this reason, have been recommended for a Marine Protected Area by the World Bank and are classified as a Marine Important Bird Area under the Nairobi Convention and as an Important Bird Area in Africa by BirdLife International. Up to a million birds can be based on the atoll, at any one time. This isolation has produced a high degree of endemism among marine flora and fauna such as the well-known violet spider conch Ophioglossolambis violacea (Swainson, 1821) and may present future opportunities for the discovery of other endemics.

On land, native coastal vegetation provides essential nesting sites and shelter for the Critically Endangered Hawksbill turtle. The surrounding marine environment includes a vast array of sharks, sea turtles, dolphins and sea rays.

Ecological Threats

Despite their remote location, the St. Brandon Islands are not immune to ecological disaster. Their proximity, as one this world’s Key Biodiversity Areas, to Southeast Asian shipping lanes, to human pollution and to climate change makes their unique ecosystem extremely vulnerable to a variety of existential threats.

These threats also include ongoing rust & heavy metal seepage from shipwrecks onto coral reefs, cyclones with high winds and associated massive flooding. In addition, outbreaks of disease caused by Invasive Alien Species could also cause severe damage to the islands’ fauna and flora, if left unchecked.

One of the most compelling  aspects of the Saint Brandon Islands is their critical role in the conservation of endangered species, in particular the conservation of the critically  endangered Hawksbill turtle (Eretmochelys imbricata) which nests on the islands.

Beyond these endangered turtles, the islands are instrumental in the preservation of many hundreds of thousands of threatened seabirds as well as several other vulnerable or threatened species.

On 5 December 2022, a 41 Metre Taiwanese industrial fishing boat, the 41 FV YU FENG 67, foundered on St. Brandon reef. Seventy tons of Diesel Oil and forty tons of rotten baitfish subsequently leaked into the lagoon. Rotting baitfish creates hydrogen sulphide and hydrogen arsenic which are toxic to all forms of aquatic life.

Endangered Species

Among the most compelling aspects of the Saint Brandon Islands is their important role in the conservation of endangered species. The Endangered green sea turtle (Chelonia mydas, the only species in the genus Chelonia) finds sanctuary for its nesting sites here. Much higher in priority is the Critically Endangered Hawksbill turtle (Eretmochelys imbricata – IUCN 2014) which also visits the islands.

The green turtle’s range extends more into temperate seas to the north and south of the tropics than that of the hawksbill turtle. If these turtles were to be scientifically confirmed as being genetically different from those further North, in the Chagos islands and the Seychelles, it would add an additional urgency to the need to protect these turtle nesting sites.

Beyond these magnificent marine creatures, the islands are instrumental in the preservation of many hundreds of thousands of endangered birds of many species that are either vulnerable or near-threatened some of which are also of national and regional importance.