Research On Seasonal Variations Of Zooplankton Community Structure And Environment In Coastal Waters Of The Caofeidian

This paper carried out three investigations in spring( on May,2014),summer(on August,2013), autumn(on October, 2013). It focused on the water quality and plankton in coastal waters of the Caofeidian.According to the survey, this paper studied the temporal-spatial distributions of environmental factors and biological factors. The correlation between zooplankton community structure and environmental factors was calculated by method of canonical correspondence analysis(CCA).The result can provide basic data for the ecosystem research in coastal waters of the Caofeidian.It can also provide reference value for knowing the impact of reclamation on coastal environment.Results were as follows.1. The seasonal variation of tempreture was obvious in this investigation area, the variation regulation was summer>autumn>spring.The tempreture decreased from near-shore to offshore.It showed that water depth was the main impact factor, and at the same time,land climate also influenced the water temperature. The salinity in summer was lower than those in other seasons, because of the large amount of dilute water in monsoon. The salinity in spring is the highest showing the characteristic of dry season. The concentrations of DIN and DIP were higher than those in summer and autumn. The DSi concentration in autumn was higher than those in spring and summer. The analysis on nutrient concentration and structure indicated that there was DSi limitation in spring, and DIP was absolute and relative limitation, while DIP limitation in summer and autumn. The variation regulation of cell abundance is that summer > spring > autumn.2. A total of 41 zooplankton taxa belonging to 9 categories were identified in this research. The main ecological group was comprised by coastal low salt species, and Oithona similis was dominant. The seasonal variation regulation of zooplankton species number was: summer > spring > autumn. The dominant species were Oithona similis, Paracalanus parvus, Acartia bipinnata, Corycaeus japoninus, Sagitta crassa and Noctilucidae scientillans. The dominant species were different in different seasons.3. The average of zooplankton biomass was 1954.85 mg/m3 in spring, summer and autumn. The seasonal variation regulation is: spring>autumn>summer; The average of abundance is 12495.88 ind/m3, the seasonal variation regulation is: summer>spring>autumn; The average of biodiversity was 1.47, The seasonal variation regulation is summer> spring>autumn. Planar distribution trends of zooplankton biomass and abundance were similar in the same season, while they were different between seasons.4. The correlation between community structure of zooplankton and environmental parameters(include phytoplankton)was calculated by method of canonical correspondence analysis(CCA).It showed that distribution of zooplankton assemblage was closely realated to temperature and phytoplankton in coastal waters of the Caofeidian. Zooplankton assemblage was mainly related to temperature in spring and summer, while it was mainly related to phytoplankton.