A REVIEW OF MANGROVE AND COASTAL ECOSYSTEMS IN WEST AFRICA AND THEIR POSSIBLE RELATIONSHIPS

Mangrove forest, which in West Africa covers an area of over 27 000 km2 of deltas, estuaries and lagoons, is intimately linked to the offshore coastal ecosystem. Regularly influenced and disturbed by seasonal freshwater and diurnal tidal flooding, it exhibits features of an immature ecosystem, namely low species diversity and high productivity. The excess organic production is exploited by many marine species especially fishes and crustaceans that enter the mangrove environment as juveniles and return to the sea as adults for reproductive purposes. The beneficial effects on marine fisheries of this net energy outflow are at risk from anthropogenic influences causing pollution or destruction of the mangrove ecosystem. Intense interdisciplinary work on this problem is in progress on the lagoons of the Ivory Coast but further research on other parts of the West African mangrove ecosystem, especially on the Niger delta, needs to be undertaken to provide the scientific basis for the proper management of this valuable natural resource. © 1990.