Niger Delta Swamp Forests

Category: Forest Biomes.

Geographic Location: Africa.

Summary: This biodiverse forest ecosystem is threatened by oil exploration and deforestation.

The Niger Delta Swamp Forests biome is located in the largest wetland in Africa, laden with rich diversity in people, culture, fossil-fuel reserves, and biological resources, representing massive economic and ecological significance to the local people and all of Nigeria.

However, oil exploration, with frequent oil spills and gas flaring, is causing untold environmental disaster to the region’s people. Worse, deforestation and the spread of an invasive forest plant are increasing at an alarming rate, threatening this remaining tract of primary forest in Nigeria. A small portion of the ecoregion is reserved and protected, but the most effective conservation method is animal worship—which in some of the communities includes snakes.

The Niger Delta region is a vast floodplain built up by the accumulation of silt washed down the Niger and Benue rivers. It is composed of four main ecological zones—coastal barrier islands, mangroves, freshwater swamp forests, and lowland rainforests—whose boundaries vary according to the patterns of seasonal flooding.

The Niger Delta swamp forests are categorized as both mangrove and freshwater swamp forests. These forests are rich in plant and animal diversity, and are part of the Guinean forests of West Africa, numbered among the 25 biological hot spots in the world.

The local climate is tropical, with fairly consistent temperatures averaging 75 degrees F (24 degrees C) during the coolest month to 79 degrees F (26 degrees C) during the warmest month. The ecoregion is extremely humid, with the wet season lasting 10–11 months; December is usually the only dry month. At Forcados, in the western part of the delta, rainfall averages 149 inches (3,800 millimeters) per year, but decreases eastward to Port Harcourt, where the annual rainfall is 97 inches (2,480 millimeters).

Biodiversity

The mangrove forest of Nigeria is the third-largest in the world and the largest in Africa, covering 2.5 million acres (997,700 hectares). Nigerian mangroves are dominated by red and white mangroves (Rhizophora and Avicennia), and a few other mangrove species, most of which are thickly clustered shrubs, making the area almost impenetrable.

A variety of birds, mammals, and reptiles inhabit the mangroves, including a few endemic (found nowhere else) species, such as Sclater’s guenon and the Nile Delta red colobus monkey. About 200 fish species have been identified in the ecoregion; the mangroves are habitat and nursery grounds for many fish, crustacean, and mollusk species that are harvested locally and in offshore fisheries. Nigerian shrimp farming is especially strong, and shrimp are now being exported to many developed countries.

Local residents also use the mangroves for firewood and for dyeing their fishing nets, in addition to several other forest products collected from the understory. However, the mangroves are being destroyed for the construction of navigation canals and oil rigs.

Freshwater swamp forests cover 4.1 million acres (1.7 million hectares), which is more than half of the whole Niger Delta, and are the most extensive such forests in west and central Africa. The freshwater swamp forests are storehouses of biological diversity and appear to be the largest tract of remaining primary forests in Nigeria. They help in regulating coastal water flow and eliminating silt, sediment, and pollutants from moving water.

The region supports diverse animal populations, which include several species of monkeys, otters, civet cats, mongooses, leopards, warthogs, duikers, pythons and other snakes, antelopes, crocodiles, monitor lizards, snails, turtles and tortoises, and large numbers of bird species. Some of these species are endemic to the area, including the white-throated guenon and fawn-breasted waxbill; a number of birds here are highly endangered.

The fertile soil supports agriculture, which makes the area notable for production of cassava, palm oil, pineapple, cocoyam, and rubber, among many other crops.

Similarly, the freshwater swamp forests occurring around the creeks support fishing; gathering seafood and fuelwood; distilling gin from raffia palm trees; collecting wild fruits; and weaving mats and other items from screw pine, rattan palms, and bulrushes. Vast natural bamboo plantations in the region are being used locally for fuelwood, houses, furniture, and arts and crafts.

Environmental Threats

The freshwater swamp forests—initially protected from deforestation because of their relative inaccessibility arising from the swampy nature of the ecosystem—are now being destroyed at an alarming rate for expansion of agriculture, fuel-wood collection, timber harvesting, urbanization, and petroleum exploration. Dredging also has a negative effect on the mangroves.

The Niger Delta covers 12 percent of Nigeria’s surface area and supports about 30 million people within 40 different ethnic groups, living in 13,329 communities, only 98 of which are urban centers. The main ethnic groups include Izon, Efik, Ijaw, Itsekiri, Urhobo, Ndoni, Ikwerre, Ibibio, and Ogoni. Local occupations involve fishing, arts and crafts artisans, alcoholic beverage production, and farming. Solid minerals such as limestone, marble, lignite, clay, gold, and granite are found in large quantities in the region.

The discovery of crude oil in the region in 1956 marked a turning point in Nigeria’s economy. The delta’s natural-gas reserves are ranked seventh in the world and the highest in Africa. A huge reserve of bitumen (as asphalt) was discovered in the late 1990s. Crude-oil exploration forms up to 80 percent of Nigeria’s total income and 95 percent of its foreign-exchange earnings.

However, the oil has been a source of environmental disaster and poverty. Most communities do not have access to clean water; many sources have become polluted by oil, while lands have become too toxic for any meaningful farming. Fishing, which is the primary occupation of some of the ethnic groups, has been significantly reduced by surface water pollution, and the number of fishers working has also been reduced. Fishing is becoming an endangered occupation in the area.

Worse, oil spillage and gas flaring characterize oil exploration in the region. A United Nations Development Programme (UNDP) report stated that there were 6,817 oil spills between 1976 and 2001. In 2010, another source reported that 9 million to 13 million barrels have been spilled in the Niger Delta since 1958. The effects of petroleum spills on mangroves are known to acidify the soils, halt cellular respiration, and starve roots of vital oxygen.

As the soils supporting mangroves become too toxic, a nonnative invasive species of palm, nipa palm (Nypa fruticans), quickly colonizes the area. This invasive species has some benefits, such as the edible nuts and flowering stalks, but it has a shallower root system that destabilizes the banks along the waterways, impedes navigation, and reduces fishing potential. Researchers found between 2007 and 2017 nipa palm cover increased by 694 percent, while mangrove cover decreased by 12 percent.

The volume of gas flaring in Nigeria is the highest in Africa and second-highest in the world, after Russia. About 2.5 billion cubic feet (70 million cubic meters), or about 70 percent of the 3.5 billion cubic feet (100 million cubic meters) of associated gas produced annually, is wasted via flaring. This equals about 25 percent of the United Kingdom’s total natural-gas consumption and is equivalent to 40 percent of the entire African continent’s gas consumption in 2001.

Gas flaring releases large amounts of methane, which has high global-warming potential. Gas flares have potentially harmful effects on the health and livelihoods of the people in their vicinity, as they release a variety of poisonous chemicals that can cause cancer and severe respiratory problems. Despite legal actions in recent years, gas flaring has not stopped nor been significantly reduced in Nigeria.

Bibliography

Akani, Godfrey C., Luca Luiselli, and Edoardo Politano. “Ecological and Conservation Considerations on the Reptile Fauna of the Eastern Niger Delta (Nigeria).” Herpetozoa 11, nos. 3–4 (February 1999).

Blench, Roger. “Mammals of the Niger Delta, Nigeria.” Cambridge, UK: Kay Williamson Education Foundation, 2007.

Sunday, Orji. "Niger Delta Mangroves in 'Grave Danger' from Oil Spills, Poverty, Invasive Species." Mongabay, 22 Aug. 2022, news.mongabay.com/2022/08/niger-delta-mangroves-in-grave-danger-from-oil-spills-extraction-invasive-species/. Accessed 30 Aug. 2022.

United Nations Environment Programme (UNEP). “Environmental Assessment of Ogoniland.” http://postconflict.unep.ch/publications/OEA/UNEP‗OEA.pdf.