The Coral Triangle Initiative: What are we missing? A case study from Aceh

The Coral Triangle Initiative (CTI) is an ambitious attempt to conserve the marine biodiversity hotspot known as the Coral Triangle (CT). However, the reef fauna in many nearby regions remains poorly explored and consequently, the CT focus risks overlooking other areas of high conservation significance. One region of potential significance, Aceh, Indonesia, has not been visited by coral taxonomists since the Dutch colonial period. Here, we document the species richness of scleractinian corals of Pulau Weh, Aceh, an important component of biodiversity. In addition, we also quantitatively compare the species richness of the Acropora at 3-5 sites in 9 regions in Indonesia and Papua New Guinea. While dominated by widespread Indo-Pacific species, the coral fauna of Pulau Weh is also the eastern and western boundary for many Indian Ocean and Pacific Ocean species, respectively. We identified a total of 133 scleractinian species; of these three were previously recorded only in the western Indian Ocean and five are presently undescribed. The mean species richness of the Acropora at Pulau Weh was similar to regions within the CT. This high species richness plus the high proportion of endemics suggests that the Andaman Sea is of similarly high conservation value to the CT. We suggest that an international initiative similar to the CTI is required to conserve this region that includes the territorial waters of six countries