Abstract: In order to assess the pollution status of the waters of Lake Toho, a study was carried out by collecting and analyzing water samples using a spectrophotometer. The results revealed that, on the physicochemical level, the waters of the lake are weakly mineralized and the salinity is almost zero during the sampling period. The measured values for parameters such as temperature, pH, TDS, conductivity, and turbidity comply with the standard. Nitrites, nitrates, phosphate and ammonium are in high concentration and above the standard for surface waters. These levels constitute a high risk for the aquatic organisms present in the lake. There is also a high organic matter load accompanied by high levels of total phosphorus and total nitrogen. Lake Toho is also threatened by faecal contamination revealed by indicators such as E. coli, thermotolerant coliforms, faecal enterococci. In short, Lake Toho is subject to physicochemical and bacteriological pollution linked to a strong increase in anthropogenic activities. It is urgent to set up a management and control system for actions around the lake.
Keywords: Pollution, organic matter, physicochemical parameters, Lake Toho.