Mangroves are “an original habitat and a specific environment” consisting of trees with aerial roots that bury themselves in the mud but also of other shrubs and tree-like bushes that are distinguished by their ability to adapt to the environment and particularly to water salinity. This explains the specific location of each species within the ecosystem, known as zonation.
From Mauritania to Angola, the aerial roots of the mangrove Rhizophora are a privileged refuge where fish can spawn, and they play an important role in the economic life of the surrounding inhabitants. For them, mangroves represent an essential source of income and means of subsistence: fishing, firewood, timber, various foodstuffs, shellfish, medicines, tourism, etc. Additionally, mangroves regulate the tides and sedimentation and act as a protective barrier against storms and coastal erosion.
Scientists estimate that three-quarters of the fish caught in the tropics depend on mangroves for food or shelter. Mangroves are spawning and nursery sites both for coastal and deep-sea fish.
The northern part of Cameroun is characterized by abundant estuaries and mangroves, through which rivers flow into the sea. These mangroves act, among other things, as breeding and spawning areas for various species of fish and shellfish..
In Senegal, mangroves greatly contribute to the social, economic and cultural welfare of the inhabitants of the Saloum Delta. This is also an important rest area for numerous species of migratory birds. This wealth has earned it international status as a World Heritage site. “A unique biological diversity, today endangered by the disappearance of this natural habitat,” says Abdoulaye Diamé, of the NGO WAAME (West African Association for Marine Environment).
In Kenya, mangroves cover some 54,000 hectares and are mainly to be found in the Lamu and Tana River districts. They are a direct source of numerous wood and non-wood products. The wood products are: timber, building timber and coal, used both in urban and rural areas. Building timber is classified in various categories according to its use. It is also used to make masts for boats and traps for fish. The largest mangrove trunks are used to build traditional boats. The aerial roots serve as floats for fishing nets. The local inhabitants also make furniture with mangrove wood. Among the many non-timber products found in the mangroves are honey, medicines, crabs and fish.
Nigeria has the largest surface of mangroves in Africa: 7,386 km2 (UNEP-WCMC, 2007). The eight species of mangroves existing in the area are to be found there. The inhabitants carry out various economic activities: fishing, shrimp farming, timber production, tourism, etc. The Niger Delta mangroves are considered to be a significant conservation area for the west coast of Africa because of their extraordinary biological diversity. Studies have shown that almost 60 percent of the fish in the Gulf of Guinea breed there.
Nevertheless, mangrove extension is steadily decreasing. It is a fairly vulnerable ecosystem that is already very degraded in the areas further from the coast. Between 1980 and 2006 a quarter of the mangroves in the west of Africa disappeared and it is expected that the loss will rise to 70 percent if no measures are taken.
The degradation of these ecosystems has a considerable impact on biological diversity and the socio-economic activities depending on it: the disappearance of species of fauna and flora, poverty, unemployment, disputes, nutrition-related diseases, etc.
Two different processes affecting mangroves should be noted. In some cases their total destruction may be observed due to commercial logging, to their substitution by shrimp-ponds or their elimination by large-scale tourism undertakings. However, in other cases degradation of mangrove systems takes place – although many trees may remain standing – due to oil exploitation. That is to say, the installation of pipelines and seismic exploration cause deforestation; while oil-spills, waste dumping and gas flaring pollute the water and the air and seriously affect the ecosystem as a whole.
In Kenya for example, between 1983 and 1993 the port of Mombasa and the surrounding waters received 391,680 tons of spilled oil, affecting the Puerto Ritz and Makupa cove mangroves. Something similar has taken place in Cameroun, where pollution caused by the oil industry is endangering mangrove integrity.
However, the most serious case of large-scale mangrove degradation from oil production occurs in the Niger Delta in Nigeria, where oil giants such as Shell and Chevron extract millions of dollars worth of oil from the Niger Delta, in exchange for social and environmental destruction.
Regarding deforestation, the area of Nigerian mangroves dropped from 9,990 km2 to 7,386 km2 between 1980 and 2006.
In terms of degradation, major oil spills have occurred that have devastated rivers, killed mangroves and coastal life and affected the health and livelihoods of millions of inhabitants of the Niger Delta. As denounced by Amnesty International, the local communities rely on “the land and natural waterways for their livelihood and sustenance. Now, they have to drink, cook with and wash in polluted water and eat fish contaminated with toxins. They have lost farming land and their incomes from oil spills and breathe air that reeks of oil, gas and other pollutants.” (http://www.amnesty.org.au/action/action/21246/).
The countries of the North say that they are concerned over poverty in Africa. However, their oil companies continue to destroy the sources of food of millions of Africans whose lives depend on the health of the mangroves. More than receiving surplus food, what mangrove communities really need is for these companies to leave and before they go, to restore the mangroves they have destroyed. In this way their true wealth will return and the hunger they suffer from today will be left behind. .
Compilation of documents sent by Abdoulaye Diame, WAAME, e-mail: abdoulayediame@yahoo.com: «La mangrove, la sécheresse et le sacré”» Abdoulaye Diame; «Article sur la situation des forêts au Cameroun», Moudingo E. Jean Hude, Cameroon Wildlife Conservation Society; «Sénégal. Lutte contre la dégradation des écosystèmes de mangroves»; “Conservation and management of mangrove forests in Kenya”, Joseph K. S. Lang’at and James G. Kairo, Mangrove Reforestation Programme; “One wrong step too many: FAO supports unsustainable shrimp farming and food insecurity investments in Nigeria”, Centre for Environment, Human Rights and Development (CEHRD); « Biodiversité du Parc marin des mangroves en République démocratique du Congo: faune ichtyologique», Réseau africain pour la conservation de la mangrove (RAM), y “Niger Delta's Mangrove Communities Threatened By Continued Gas Flaring”, MAP Alert Action.