Mangroves provide a spawning ground for fish and shellfish, and provide resources for construction, weaving, and food. They also offer protection against coastal erosion and saltwater intrusion.
Dominique Halleux /Still Pictures
Small oceanic islands, such as those in the Western Indian Ocean, experience problems in controlling and regulating activities in their relatively extensive EEZ, making them vulnerable to overexploitation of their marine resources, particularly deep-water fisheries. In addition, land- and marine-based sources of pollution, associated with rapidly growing coastal populations, development of tourism and oil transportation by sea, are a further cause for concern over the state of the coastal and marine environments.
The Western Indian Ocean Islands are also experiencing accelerated rates of coastal erosion resulting from poor coastal planning and development, exacerbating their vulnerability to climate-changerelated sea level rise which threatens to inundate large areas of land and displace large populations. Sea temperature rises in the Western Indian Ocean, also associated with global climate change, may cause bleaching of the exceptionally biologically rich and economically important coral reefs.
The oceanic islands of Comoros, Madagascar, Mauritius, and Seychelles have evolved in isolation from continental Africa, and were colonized by humans only relatively recently. They are therefore unique in their physical characteristics and in terms of the biological communities they support. The fringing coral reefs and the reefs surrounding the islands include the Aldabra Atoll (Seychelles), one of the most spectacular reefs in the world and a World Heritage Site.
All the islands support well-developed tourism industries which are important sources of income and foreign exchange. Coastal tourism is, for example, the mainstay of the economy in Seychelles, contributing 46–55 per cent of GDP, 70 per cent of foreign income, and employing 20 per cent of the population (International Ocean Institute 2001).
There are also extensive seagrass beds, mangroves, diverse fisheries and seafood species, and lagoons. These resources mainly support artisanal fishermen (about 90 per cent of all fish landings are from smallscale operators (International Ocean Institute 2001). The majority of fish landed in the Western Indian Ocean Islands are from coastal waters, and molluscs, prawns, shrimp and lobster are important economically and in local diets. Mauritius and Seychelles are also exploiting open sea tuna fisheries on a more commercial scale, and shrimp fisheries, which have a high potential for foreign exchange earnings from export, are growing in importance in Madagascar.