Ecology of Diatoms in Yangtze River Basin, Hubei : Implications for Assessment of Water Quality

摘要

Diatoms are commonly used for the assessment to determine the unending rivers and lakes due to their broad distribution and its integrative nature. As it is, the corresponding evolution of species and quantity will come into being in diatom communities with the variation of physicochemical characteristics and the pollution of organic, which can indicate directly the local ecological status of aquatic environment. Water samples were collected from 32 sites in unending streams and lakes along with the Yangtze River and its cardinal branches during the mid-July last year, in order to analyze the feature of its distribution and communities. Biological diatom index BDI and the diversity index H' were used to assess the degree of water eutrophication. We concluded that a great many biometrical indexes are valuable tools for the assessment and future monitoring of waters, combined with the ecological theory, the species of Cyclotella meneghiniana, Stephanodiscus parvus and Navicula subminiscula manifest to be very good indicators for the outbreak of eutrophication in the middle reach region of the Yangtze River and the Han River.