Ecological status of a newly impounded sub-saharan reservoir based on benthic macroinvertebrates community (Burkina Faso, West Africa)

Abstract

In West Africa, particularly in Burkina Faso, the aquatic ecosystems are under human pressures. Therefore, for long term management of these ecosystems, the managers need baseline data for regular assessment of ecological health condition. In this regard, the structure of the benthic macroinvertebrate community was investigated and the relationship between the environmental variables and biotic indices of the Samandéni reservoir from January to December 2018, after one-year impoundment was explored. The macroinvertebrates were collected with a hand net (25 × 25 cm2 coverage area and 500 μm mesh) according to the multi-habitat sampling method. Key environmental variables such as temperature, conductivity, dissolved oxygen, pH and total dissolve solids (TDS) were measured in situ. High diversity of macroinvertebrates was reported and thirty-four (34) taxa were determined belonging to eight (8) orders dominated by insects (79.41% of all taxa). Good ecological quality of the reservoir was testified by the presence of several sensitive taxa like Ephemeroptera and Trichoptera. The trends of environmental variables also reflect good habitat conditions. The results revealed a strong and negative relationship between some abiotic variables and biotic indices. The finding of this study is of big big importance for sustainable management of the Samandéni Reservoir.