Previously unlisted scleractinian species recorded from the Great Reef of Toliara, southwest Madagascar

Abstract

The scleractinian biodiversity of Madagascar is mainly known from one study performed in the Bay of Toliara (SW of Madagascar) in the 1970s. In the present study, this biodiversity was re-investigated 40 years later, at 2 sites previously considered as atypical, but now subject to high anthropogenic pressures. Results showed lower species diversity compared to the previous study, and to similar sites in the Indian Ocean region, but most of the well-rep- resented genera were recorded. The occurrence of previously unrecorded species suggests that the scleractinian communities are changing, in addition to declining. The findings of the present study constitute a baseline of scle- ractinian structure studies, focused on diversity change. Further investigations on this reef must consider these changes, and management measures must be adapted to ensure greater efficiency.