Prediction for temporal changes of cell concentration of the cyanobacterium Microcystis in Tenryu River, using the fluid dynamic model of cyanobacteria

Abstract

A toxic cyanobacterial bloom caused by Microcystis occurs from spring to autumn in Lake Suwa, a eutrophic lake in Japan. The distribution of Microcystis cells in the Tenryu River flowing from Lake Suwa was investigated, and those cells were observed in the river during the investigation period. Since temporal changes in the flow rate of Microcystis were to be expected, we developed an advection-diffusion model “the fluid dynamic model of cyanobacteria” to analyze the temporal changes in Microcystis cell concentrations in the river; this model can be used to predict those changes downstream of the river and produce risk assessments of cyanobacterial toxin.