Temperature - European Investment Bank

WEST AFRICAN POWER POOL (WAPP) PÖYRY ENERGY LTD.
Mount Coffee HPP ESIA and RAP 2012-09-18
ESIA Report Page 55
II. THE BIOLOGICAL ENVIRONMENT
The biological diversity of an area is made up by the number of species of plants and
animals that exist there, and by the number and extent of habitat types which they
inhabit and help to form. Furthermore, some areas contain a high number of endemic
species, i.e. species that exist only in this area and nowhere else on earth.
A large number of species have become very rare or even extinct through the
progressive shrinking of specific habitat types as e.g. primary forests or wetlands,
sometimes in combination with other influences like hunting. Species that are rare by
nature, as the large predators, especially attractive for one reason or another, as
furbearers or “trophy animals”, or that depend entirely on a specific, threatened habitat
type as amphibians (wetlands) are especially vulnerable.
Hydropower projects can affect biodiversity mainly in the following ways:
� direct destruction of habitats, mainly by submerging large areas through
formation of a reservoir;
� indirect disturbance through improved access to hitherto inaccessible areas or
through the resettlement of the people living in the reservoir area to formerly
natural areas;
� disruption of a river by formation of a lake (reservoir), by impeding migrations
of aquatic species through construction of a dam; and by changing the
downstream flow pattern in this river.
The first two points affect mainly terrestrial vegetation and fauna, while the third point
refers to impacts on hydrobiology (fish and other aquatic life). In addition to these
points, the construction phase can have a major impact on specific species, e.g. by
increasing pressure on certain plants or animals, mainly be collecting or (usually illegal)
hunting carried out by the work force.