Influence Of The Seasons On The Physico-Chemical Parameters And Nutrients Favouring The Proliferation Of Cyanobacteria In TheAghien Lagoon (Côte d’Ivoire)

Background: In Africa, freshwater ecosystems are subject to increasing anthropogenic pressures that could potentially have an impact on water quality. In Côte d'Ivoire, in the district of Abidjan, it is estimated that the population will reach almost seven and a half million in the next fifteen years, leading to a rapid increase in water consumption. In order to meet the population's drinking water needs, the Aghien lagoon has been identified by the Ivorian authorities as a likely alternative source of drinking water. The aim of this study is to identify the factors that encourage the proliferation of cyanobacteria and to analyse the influence of the seasons on these factors. Material and method: Samples were taken from June 2016 to March 2018 at six stations in the Aghien lagoon. Physico-chemical parameters were measured in situ using the YSI®EXO 2 multi-parameter probe. The water samples used for nutrient research were taken using an integrated sampler. These samples were stored and then sent to the laboratory for the various nutrient assays. Results: The results reveal that the proliferation of Cyanobacteria in the Aghien lagoon is favoured by physicochemical parameters such as temperature, hydrogen potential, conductivity, turbidity and nutrients containing phosphorus and nitrogen compounds. Conclusion: Analyses show that these factors are influenced by the seasons.