Ring-tailed lemurs, Madagascar
M&C Denis-Huot/Still Pictures
The importance of conservation within oceanic islands is perhaps best expressed by the fact that they are home to around one-sixth of all plant species, and that one in three of all known threatened plant species are island endemics. The Western Indian Ocean Islands, uninhabited until the 16th and 17th centuries, are a typical example where rich land based flora and fauna have evolved in isolation from human intervention and from the intrusion of other alien species that the human presence so often brings Madagascar has the highest number of endemic species of any country in the Africa region, and ranks sixth in the world. Up to 8 000 of the 9 500 species of higher plants and over 50 per cent of all vertebrate species found in the island are known or are thought to be endemic (UNEP 1999). In Mauritius, around 50 per cent of all higher plants, mammals, birds, reptiles and amphibians are endemic to the island, and the Seychelles has the highest level of amphibian endemism of any island in the world (11 of the 12 species are found nowhere else) (WCMC 1992).
This extraordinary biodiversity of the Western Indian Ocean Islands not only contributes to their unique ecological conditions, it also provides valuable raw materials for local and commercial use. In addition to use for food, construction, clothing and shelter, many plant species are used medicinally and several species are being researched for commercial agricultural or pharmaceutical use. For example, the native Coffea sp. is being investigated for commercial production of naturally caffeine-free coffee (GOM/ERM 1998).
The Islands' internationally renowned coral reefs support a booming tourism industry and subsistence and commercial fisheries. There are also ten species of mangroves providing stabilization of the coastal zone, creating spawning and nursery grounds for many fish species, mitigating storm impacts, and providing resources for construction, weaving, and food.