BIOLOGICAL QUALITY OF THE WATER OF THE NIGER RIVER FOR AGRICULTURE, FARANAH, GUINEA

Climate change imposes numerous constraints on agriculture. By considering the development of hydro-agriculture, the water of the Niger River could meet the challenges posed by the irreversible reduction in rainfall. Unfortunately, previous studies indicate that the water of the Niger River contains agrochemicals. Its use in agriculture presupposes its quality. It is in this context that this study was conducted on the Niger River in Faranah with the objective of understanding the biological quality of the water. Three sampling campaigns were carried out at five sites. The diversity, frequency and equability of macroinvertebrates, the ratio of Ephemeroptera Plecoptera Tricoptera, the percentages of non-dipteran insects and chironomids made it possible to know the water quality. Correlation and canonical correspondence analysis verified the suitability of the water for agriculture. The results showed that the stations are rich in macroinvertebrates (88% of species are Shannon indices ˃2 and equitability close to 1 indicate aquatic environments capable of supporting life. The correlations established between the index of taxa sensitive to pollution and the index of cosmopolitan taxa with the water quality descriptor parameters confirmed the suitability of the waters for agriculture.