The environmental impacts of mining on Gishwati Protected Reserve in Rwanda

Gishwati forest is part of Gishwati-Mukura National Park. It has a long history of degradation due to human activities. Despite many efforts initiated to restore and protect this concession, the mining activities continue to affect its biodiversity. This study aims at assessing the impact of mining on the landscape, quality of water, soil, and vegetation in Gishwati and its vicinity. Data were collected from five mining sites and one non-mined control site. Methods included direct field observations of the landscape, physico-chemical analysis of water, mine tailings analysis and vegetation inventory, and measurement of the concentrations of metals/metalloids in both water and soil (mine tailings). The findings revealed that mining has accelerated the erosion and the stream/river sedimentation and has created new landforms around some mining sites. The physico-chemical properties of mine tailings piled and scattered on mining sites are not conducive for biodiversity, and the concentrations of metals and metalloids in the water and soil are generally higher on mining sites than on the non-mined area and even higher than international standards. Such high metal/metalloid concentrations threaten both aquatic and terrestrial life as they are likely to cause the extinction of a good number of vegetation species on mining sites. They may also cause toxicity and lead to migration of a variety of animals living in Gishwati. The study recommends the use of mining best practices to safeguard biodiversity in the Gishwati area.