Introduction and background

Tropical aquatic bodies are naturally characterized by a rich and diverse assemblage of plant and animal resources, which are of great economic importance. Traditionally, these areas support the livelihood of local dwellers in the area through provision of seafoods, wood fuel, etc. However, tropical water bodies are today highly threatened by environmental degradation arising form developmental projects, erosion from deforestation, and pollution from oil and chemical spills. The effects from the degradation of these waters are widespread, inflicting damage on the natural economy, the environment, and local peoples. This situation has impacted the biodiversity, and invariably the livelihoods of the people, thus aggravating food insecurity in the area. This is critical especially when viewed against the backdrop that pollution impacts on livelihoods and biodiversity are felt mainly by people in rural riparian communities. The people whose principal vocation is artisanal fishing, are adversely affected by the rapidly declining fisheries and other effects of habitat degradation.

This research is proposed to expound the impact of environmental degradation on the biodiversity of aquatic and riparian communities in an oil polluted water body (Bodo river in Ogoni land, Nigeria) and a seawage contaminated water (Volta river in Ghana), and their restoration adopting a community-based participatory approach. In Nigeria, the oiling and the defoliation of mangrove swamps along Ogoni littoral communities and the reluctance of the oil companies that are liable, to clean up and remediate the environment has left the impacted ecosystems to the slow process of natural recovery. This process is usually not completed before recurrent spills occur in the same environment. The adverse effect on the livelihoods of the affected communities, biodiversity loss and other effects of habitat degradation, call for urgent mangrove ecosystem restoration. Also, incessant discharge of seawage and other organic matter in Volta River has resulted in hyper-eutrophication, limited flow, turbidity, organic pollution and the resulting increased emission of greenhouse gases to the atmosphere. These have serious consequences for aquatic life, human health and commerce.