Studies On Community Structure And Biodiversity Of Meiofauna In The Changjiang (Yangtze River) Estuary And Its Adjacent Waters

Quantitative studies on the community structure and biodiversity of meiofauna in the Changjiang (Yangtze River) estuary and its adjacent waters are based on the samples collected from 36 stations during the cruises in Jun. 2003 and Sep. 2004. This paper deals with meiofauna abundance and biomass, community structure and biodiversity of free living marine nematodes, and benthic habitat of meiofauna in the Changjiang (Yangtze River) estuary and its adjacent waters. The comparative studies on changes of benthic and biotic factors between the 200306 and 200409 cruises has been made. This is the first time to discussing meiofauna community structure systematically in the Changjiang (Yangtze River) estuary and its adjacent waters. It also conducts some studies on nematode community responses to natural disturbance and community changes in low oxygen habitats.The dominant sediment types of the sampling stations are silt-clay (TY) and clay-silt (YT). The sedimentary environments of the studied stations vary with the seasonal changes of Changjiang (Yangtze) river runoff. In June, the average content of chlorophyll a(Chl-a), phaeophorbide a (Pha-a) and organic matter are high, which are 2.469±0.565mg/Kg, 5.656±0.899mg/Kg and 8.09%±2.00% respectively. Compared with that, Chl-a and Pha-a hold little differences in September, 2004, averaging at 1.784±0.525mg/Kg and 5.689±1.761mg/Kg respectively. However, the content of sediment organic matter reduces drastically in September, and accounts for only 1/10 (0.92%±0.41%) of that in June. Pearson's correlated analysis among environmental factors shows that Chl-a, Pha-a and organic matter content are correlated with granulate parameters, water depth, bottom-water temperature and salinity (p<0.01 or 0.05). They are influencing the quantities and distributions of Chl-a, Pha-a and organic matter in the studied area. Among the influencing factors,...