Spatial and temporal distributions of microorganisms and their role in the evolution of Erhai Lake eutrophication

The spatial and temporal distributions of sediment microorganism populations as well as their role in the evolution of Erhai Lake eutrophication were addressed in this study. Our results show that the microorganisms’ distribution is linked to many factors (e.g., temperature, substrate content, depth, aquatic macrophytes, etc.). In addition, it is likely that sediment fungi numbers indicate the degree of area source pollution to a certain extent. A high proportion of sediment actinomycetes (25.1–67.0 %) may inhibit nutrient release from the sediment, leading to a high nutrient level in sediment but relatively good water quality in the lake. Furthermore, an analysis of the depth profiles of microorganisms elucidates the development of Erhai Lake eutrophication. This study is the first to link the sediment microorganism population with the evolution of Erhai Lake eutrophication and may also provide useful information for managing lake eutrophication in the near future.