Iron enrichment from hypoxic hypolimnion supports the blooming of Raphidiopsis raciborskii in a tropical reservoir.

Occurring worldwide, blooms of Raphidiopsis raciborskii threaten the use of water resources especially in tropical and subtropical waterbodies. Its high flexibility in the uses of light and macronutrients (C, N, P) frustrates any bloom prediction and control based on macronutrients regulation. To identify the critical factors promoting periodic blooms of R. raciborskii, the trends of meteorological, hydrodynamic, physical, and chemical variables (including macro- and micronutrients: N, P, Fe) were analyzed in a Chinese tropical large reservoir (Dashahe reservoir) over five years. It was hypothesized that Fe availability, mediated by the mixing pattern of the reservoir, played a crucial role…