Dynamic and structure of phytoplankton community and environment in the lake Taabo (Côte d’Ivoire)

This study evaluated some parameters of Water quality and phytoplankton growth in order to ascertain its seasonality in the lake Taabo (South East of Côte d'Ivoire). Seasonality was mainly due to significant variations in parameters such as conductivity, turbidity, transparency and nutrients (mean values of nitrate and orthophosphate were respectively equal to 1.62 and 10 mg/L). The lake downstream presented some features: oxygenation and mineralization were higher than upstream, at the time. Chlorophyll a ranged from 4.8 to 16.5 mg/L. For algal species composition, 118 taxa distributed into 5 main groups and 45 genera were identified. The algal assemblage was dominated by Chlorophyceae (30.5%), followed by cyanobacteria (27.1%). Conditions prevailing in this biotope favoured a massive phytoplankton growth, dominated by Chlorophyta and Cyanobacteria. Spatial and temporal analysis of nutrient and the composition of phytoplankton community revealed a seasonal variability in the ecosystem of the lake of Taabo which was under anthropogenic stress. This hydro system is growing towards a dystrophic state, thus implies an urgent need for restoration, followed by rehabilitation and process of elimination of solid materials in the lake catchment