Status and trends of biodiversity, including benefits from biodiversity and ecosystem services
The content of this biodiversity profile is still draft. The text below has been prepared by SCBD and remains subject to final approval by the Party concerned.
The four volcanic islands (Grande Comore, Mohéli, Anjouan, Mayotte) of Comoros form part of the Madagascar hotspot and are characterized by their remarkable endemic biodiversity. However, biodiversity in general is being degraded. Strong pressure placed on the land from a constantly increasing population has led to the degradation of natural vegetation, decline in soil productivity, soil erosion, drying up of rivers and the degradation of coastal ecosystems (coral siltation), most particularly in Anjouan and Mohéli. The disappearance of natural habitats, together with a lack of environmental protection measures and legislation to control the illegal trade of plants (e.g. orchids) and animals (e.g. sea cucumbers, birds, lizards), threaten the species of the entire archipelago. Nowadays, initial vegetation formations exist in the form of residual fragments only. In 2008, the FAO estimated that the forest could completely disappear over the next 10 years. Tree steppes/savannas are threatened by their clearing for land use, especially for cash crop cultures (e.g. clove, ylang-ylang, vanilla, pepper). Unsustainable forest and agricultural practices, including slash-and-burn, and overexploitation for firewood or timber, have destroyed the possibility for natural forest and endemic plant species regeneration. The status of many plant species remains unknown, with many of them threatened or having already disappeared.
Natural forests are being lost at an estimated rate of 500 ha per year. Between 1973 and 1983, 12,700 ha of forest cover disappeared due to the expansion of land for cultivation purposes. A 1987 study revealed the rates of land use to be excessively high. Relative to the total area of each island, cash crops and food crops and reforestation accounted for 61% in Grande Comore, 77% in Mohéli and 88% in Anjouan (these figures equaled or exceeded the cultivable area estimated by the Agricultural Research Institute).
Precious woody species have become rare, or have completely disappeared. The latter is the case with the endemic mahogany tree (Khaya comorensis) that has completely disappeared from La Grille forest in the north of Grande Comore. Agroforestery management under the Karthala forest canopy prevents any regeneration of natural vegetation. The use of chemical fertilizer and pesticides in tree savannas has depleted soils of their nutrients and promoted the incursion of invasive species.
Forest ecosystems of Mount Karthala and La Grille are threatened by the intensive use of wood for distilling ylang-ylang, charcoal production and timber. The ecosystem is also weakened by land occupation, the legality of which is questionable in certain instances, resulting in the increased rate of forest resources destruction and the disruption of the ecological balance as a whole. The loss of forest cover is also causing soil erosion which in turn is affecting terrestrial and marine environments. Fragile marine ecosystems are also at risk of disappearing, threatened by climate change and growing infrastructure development on the coastal perimeter. Sand removal for construction purposes has led to the disappearance of more than 18 of the 40 beaches present on the islands, with substantial impact on the potential for tourism. This has promoted coastal erosion and silting of coral reefs and sea grass beds, disrupting many habitats and their wildlife. Rising ocean temperatures have also contributed to coral bleaching not to mention the loss of natural coastal spaces being spontaneously converted into disposal sites. The pollution generated is greatly affecting mangrove ecosystems and marine wildlife. The Mohéli Marine Park in Nioumachoua is the only officially protected area in the country. This sanctuary includes 10 marine reserves and covers a surface area of around 40,000 ha. However, notably, sea turtle populations on Mohéli beaches have been increasing. Wildlife is also threatened by overfishing and destructive fishing methods such as the use of tephrosia for small fish, and the use of insecticide (Decis) for capturing shrimp in the river. The livestock sector is also submitted to a high risk of pest attacks and epidemics (e.g. theileriosis). As a result of animals being imported from Tanzania without proper sanitary control, two waves of epizootic disease emerged in Grande Comore in 2003. Biodiversity is a key element in the country’s economy and represents a great potential for ecotourism development. The forests provide energy fuel for households and ylang-ylang distillation, timber for construction, and medicinal and aromatic plants. Cash crops are an important source of income. A study in 2007 revealed that the country was the leading producer of ylang-ylang, while also being a significant player in the trade of vanilla and clove. Also, marine and coastal ecosystems provide great resources for the fishing industry. While the coast experiences pressure from overexploitation, the high seas remain underexploited. The motorization of the artisanal fishery sector has increased fish production, increasing to 16,000 tons in 2004 from only 6,000 tons per annum in 1985.
Main pressures on and drivers of change to biodiversity (direct and indirect)
The content of this biodiversity profile is still draft. The text below has been prepared by SCBD and remains subject to final approval by the Party concerned.
The limited natural resources of the archipelago are deteriorating rapidly under increasing anthropogenic pressure and a fragile economy. Pressures on biodiversity include forest and mangrove deforestation, unsustainable land use for agriculture (land clearance, bushfires, crop culture in peripheral forest zones), poaching and illegal trade of exotic species, invasive alien species and high energy costs. Pollution (discharge of pesticides, dumping of sewage and solid waste) and anarchic coastal urbanization are contributing to the increased vulnerability of marine and coastal biodiversity. The sea coast often serves as an improvised dump. Inland, wastes are disposed in vacant lots or natural spaces surrounding towns and villages. Also, rural and urban areas are highly polluted by waste of any kind and emanations generated by motor vehicles, with 90% of vehicle engines lacking proper purification devices. Moreover, lack of garbage collection services forces some city dwellers to eliminate solid waste by incineration. It is also feared that high vulnerability to climatic changes and natural disasters will have a substantial impact on coral reefs, fisheries and agricultural production.
