Author(s): H. Sato; M. Umeda; T. Horii
Linked Author(s):
Keywords: Lgae biomass; Eutrophied reservoir; Field observation
Abstract: In the water quality management in closed water area, solution of problems caused by algae is a major issue. Recently, behavior of life cycle of algae has been considered to have significant impacts on the occurrence of water bloom. Currently, the ecosystem model is most often used to predict water quality. However, the accuracy of the simulation is not sufficient yet. In addition, the life cycle of algae is not considered in the most ecosystem model. In this study, toward the development of ecosystem model that takes into account the life cycle of algae, we conducted field observations to investigate algae biomass in Miharu dam, Japan. The observations were done six times from June to December in 2013, during which vertical profiles of water quality, collected and replaced sediment trap and samples of water and sediment were taken. Chlorophyll-a of Microcystis at the dam site point was relatively higher than that of green algae and diatom, and peaked in surface layer in August. So we think that growth of Microcystis impacts water quality in Miharu dam. Microcystis in dam site point dominated in the surface layer in August and increased in sediment trap from summer to autumn. And there were many Microcystis colony from October in bottom sediment. Therefore, there is the relation between these results. We considered that Microcystis in the surface layer settled from summer to autumn and transferred habitat to the bottom sediment.
Year: 2014