The inland water fishes of Africa
| , ,Impacts of human activities
Résumé
Continental aquatic ecosystems are particularly affected by human activities including the modification or elimination of habitats because of territorial planning works, pollution from different sources, and overfishing. The consequences of these activities, now amplified by population growth and increasingly heavy pressure on natural resources, endanger ichthyological fauna the world over. Long spared these impacts, Africa is now feeling their effects even though pollution, for instance, is still relatively limited in extent.
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Extrait du texte
A number of anthropogenic threats to freshwater ecosystems are recognized to operate at the continental scale, including habitat loss or transformation, water extraction and hydrological disruption, invasive alien species, pollution, and overexploitation (Dudgeon et al., 2006).
Given the unpredictable rainfall, very high evaporation rate (around 65% of rainfall), and low conversion of rainfall to runoff, it is clear that large areas in Africa face water management difficulties. In an effort to meet the increasing demand for water and power, many large wetlands have been affected by developments such as dams, flood control measures, or direct abstraction, and their ecological function has been impaired (Postel & Richter, 2003; Richter et al., 2003). Groundwaters are also being used, most often to provide irrigation for agriculture, at a faster rate than they can be replenished such that the water table is being lowered and wetland areas are disappearing (Darwall et al., 2009; Garcia e...
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