The Mahe, Alphonse and Amirantes Plateau consist of two areas within the Republic of Seychelles. These include the inner island groups, which make up the Mahe Plateau, and the Amirantes group of islands to the south of the Mahe Plateau. The plateau is important for numerous biological processes, including spawning, breeding, recruitment, connectivity and provision of nursery and foraging areas (Kiszka et al., 2009) (Seychelles Fishing Authority, 2010). This area is a centre of abundance of numerous species, including threatened and endangered turtle species (Eretmochelys imbricata and Chelonia mydas) (Mortimer, 2004), numerous cetaceans, including killer whales (Kiszka et al, 2009), a number of seabirds (Catry et al, 2009) and numerous pelagic and demersal fish, amongst which are sharks and tunas (Seychelles Fishing Authority, 2010).

Between 50º00’E and 58º00’E and between 0º00’S and 10º00’ S.

This area is high in habitat diversity and is important for cetaceans, comprising cetacean breeding sites, feeding sites, nurseries and migratory paths.  It is a very important feeding site for killer whales (Kiszka et al., 2009).  Here can be found feeding sites for pelagic fish, including tunas and sharks, which are found in abundance in this area.  It is an important source of larvae and fish-spawning sites. It is also an important nursery site for sea cucumber and fish, especially due to the mangroves, which are important as nurseries for juvenile fish species (Seychelles Fishing Authority, 2010). These mangroves also help protect the coral reefs from sedimentation and runoffs. These are very important feeding, nesting and reproduction sites for seabirds and are therefore important for their conservation (Catry et al., 2009). Islands within this group are also important turtle-nesting sites for both hawksbill and green turtles, and the Mahe plateau is the third-most-important site in the world for hawksbill turtle nesting, while the Amirantes Plateau is the fourth-most important site for green turtle nesting (Mortimer, 2004).

This area includes shallow coral reefs, which are mostly fringing reefs, patch reefs, coral banks, canyons and caves, as well as seagrass beds. The Amirantes and Alphonse belong to the group of Seychelles southern-most islands, with the highest percentage of coral coverage in Seychelles (Stoddart, 1984). The Mahe Plateau is a unique example of granitic island coral reef formation and hosts spawning aggregations of coral fish (Baker, 1963). It has the highest primary biological productivity in the Western Indian Ocean. This plateau is also important as an abundant site for demersal and pelagic fish, especially mackerel, small tunas and jacks (Seychelles Fishing Authority, 2010).

This is an area under pressure. Tuna fisheries remove about 300,000 tonnes of tuna per year, and this in turn has an impact on seabirds and their feeding habits. At the same time, sea cucumber fisheries are concentrated in this area (Seychelles Fishing Authority, 2010). There is also anthropogenic pollution, as well as lost fishing gears that carry out ghost fishing in areas of the Amirantes basin. Dangers also exist for marine turtles and cetaceans through the presence of debris and shipwrecks (Kiszka et al., 2009). Other vulnerabilities include seismic oil exploration, threats from alien invasive species, overfishing of sea cucumber and demersal fish species, habitat degradation, and illegal fishing (Seychelles Fishing Authority, 2010). These zones have also been affected by coral bleaching, with slow recovery of corals (Ateweberhan et al,. 2011).

At the same time, there is no effective management system in place for part of this area, and there is a lack of information on the ecosystems, especially those found around the Amirantes oceanic basin. While the African Banks within this area is a marine protected area, management is lacking. The other six marine protected areas within this group are managed efficiently, although there are some threats. At the same time, the Mahe plateau is prone to sedimentation from urbanization, which poses a threat to the coral reefs (Bijoux et al. 2008).