Effects of Anthropogenic Activities and Eutrophication along River Chanchaga, Minna, Nigeria

River Chanchaga is the major source of drinking water in Minna, Nigeria. This river has been a medium to an increasing pollution loads from contaminated runoff from different land uses degrading aquatic ecosystem and water quality in the river.This paper investigates the threat of anthropogenic influence on river environment and aquatic ecosystem distortion of River Chanchaga, Minna, Nigeria. Field work which include interview and observation methods were used to collect data on effect of anthropogenic and eutrophication along the study area. A total of Two Hundred and Fifty (250) people accounting for 0.5% of the total population were interviewed, making it eight per each community in thirty settlements along the study area. Physical observation of deforestation around sample sites spatially distributed along River Chanchaga depicted in Figure 2 was carried out to study mining activities, farming practice, crop types, and fallow duration to generate the mean and percentages of different anthropogenic activities along the study area. The findings revealed that deforestation is links to high demand for fire wood, lumbering, irrigation farming bank-side mining for sand and gold as depicted in Plat 1 and 2. Eutrophication at the upper course of river is links to high inflow of agricultural wastes and seasonal nature of the river from site A to C evident from Table 4 and constant flow from site C to K as a result of released water from Tagwai Dam that keeps (site C, the confluence of River Chanchaga and River Numui) middle and lower courses of River Chanchaga with sustainable moving water. The result further indicated that continue increase of pollution has a direct relationship to an increasing level of human activities like deforestation, mining activities and agricultural practices along the study area. The result also shows that there is decline in fallow duration as indicated in Table 1 and increase environmental related issues such as soil erosion, water floor (depth) reduction and distortion of river morphology of the study area. It is therefore recommended that the identified anthropogenic activities that lead to pollution and eutrophication such as river-side deforestation, irrigation farming, mining and other related environmental problems should be regulated and discourages to avoid further increase of pollution and distortion of river environment of the study area.