Impact des pratiques agricoles sur les macroinvertébrés benthiques de la rivière Nyabarongo, bassin du lac Kivu, RDC

Cette étude analyse l’impact des pratiques agricoles sur la biodiversité aquatique dans le bassin du lac Kivu, en se focalisant sur les macroinvertébrés benthiques de la rivière Nyabarongo. Elle met en évidence les effets de l’érosion des sols, de l’utilisation des engrais et pesticides et de la dégradation des zones riveraines sur la qualité écologique de l’eau et la structure des communautés benthiques.

This article investigates the impact of agricultural practices on aquatic biodiversity in the Lake Kivu basin, focusing specifically on the macroinvertebrate community of the Nyabarongo River—one of the key tributaries in the region. The study starts from the observation that increasing agricultural activity around Lake Kivu has led to severe degradation of aquatic ecosystems, mainly due to soil erosion, uncontrolled use of chemical fertilizers and pesticides, and the destruction of riparian buffer zones. The methodology integrates biological sampling (macroinvertebrate collection), physicochemical water analyses (including pH, temperature, turbidity, nitrate and phosphate levels), and surveys of local agricultural practices. Findings show a strong correlation between the intensity of farming activities and the decline in macroinvertebrate diversity. Notably, pollution-sensitive bioindicator groups such as Ephemeroptera, Plecoptera, and Trichoptera (EPT) are gradually replaced by more pollution-tolerant taxa like Diptera. The article concludes that the observed biodiversity loss in the Nyabarongo River is primarily due to unsustainable agricultural land use. The authors advocate for the adoption of agroecological techniques, the establishment of vegetated riparian buffers, and the regular monitoring of water quality through aquatic bioindicators. To analyze the impact of agricultural practices on aquatic biodiversity, particularly on benthic macroinvertebrate communities, in the Nyabarongo River — a tributary of Lake Kivu — in order to understand the interactions between agricultural activities and the ecological degradation of this aquatic ecosystem. The study seeks to identify the main agricultural practices carried out within the Nyabarongo River watershed; to assess the diversity and abundance of macroinvertebrates at different sites along the river exposed to varying levels of agricultural pressure; to compare biological indicators (bioindicators) of water quality between intensively farmed areas and less disturbed zones; to analyze the correlation between the physicochemical parameters of the water and the composition of macroinvertebrate communities; and to formulate recommendations for sustainable agricultural practices compatible with the conservation of aquatic biodiversity.