South Island, African Banks has been eroded by the sea. At St Joseph Atoll, Banc de Sable and Pelican Island have also eroded, while Grand Carcassaye and Petit Carcassaye have merged to form one island. There are also several unnamed islands at Aldabra, St Joseph Atoll and Cosmoledo. Pti Astove, though named, failed to make it into the Constitution for unknown reasons. Bancs Providence is not a single island, but a dynamic group of islands, comprising four large and about six very small islets in 2016.