[Advances in research of biological purification of eutrophic water body]

Eutrophication is a global problem, and the key of its controlling is to manipulate the structure of aquatic ecosystem, to recover the function of natural, healthy and stable aquatic ecosystem, and to improve the biological purification capability of eutrophic water body. Aquatic higher plant and vegetation is the most important primary producer in aquatic ecosystem, because of its large individual, long life cycle, and strong capability of absorbing nutrients. Maintaining and restoring a certain amount of aquatic plant could restrain the growth of phytoplankton, improve the biodiversity of aquatic ecosystem, and stabilize its structure. Aquatic animal plays an important role in material and energy cycles of aquatic ecosystem. Zooplankton and benthos can graze phytoplankton directly, so as to controll the number of phytoplankton. It is possible to improve the number of zooplankton by changing the structure of fish population, which might control the serious reproduction of phytoplankton, and achieve the goal of controlling eutrophication. The research of biological purification is still at its initial stage in China. In future, the following two aspects of researches should be enforced: the key technology of biological purification of aquatic higher plant and vegetation; the new model of breed aquatics. These technologies will have a important significance to controlling eutrophication and in sustainable utilization of water body.