Plankton Community Characteristic And Its Environmental Impct Factors In Southern Waters Of Miaodao Archipelago

In this study,we conducted a detailed field survey in 2012?2013 on the plankton resources in the southern waters of the Miaodao Archipelago(four voyages).Using multivariate statistical analysis techniques,we analyzed the community characteristics of phytoplankton and zooplankton.We identified a total of 131 phytoplankton taxa,with diatoms being the main phytoplankton species in four seasons.Moreover,we identified 25 species of adult zooplankton and 13 species of larval zooplankton,with copepoda being the main zooplankton species in four seasons.Our cluster analysis results for phytoplankton and zooplankton showed significant seasonal differences in the community structures.The autumn and winter phytoplankton community structures were similar,as were the winter and spring zooplankton community structures.Multidimensional scaling analysis results showed that the summer phytoplankton community structure differed significantly from those in the other seasons.However,the largest seasonal difference for zooplankton was in autumn.The seasonal variation of the phytoplankton community was as follows:diatom dinoflagellate community(autumn)?diatom community(winter)?diatom community(spring)?diatom dinoflagellate community(summer).However,the seasonal variation of the zooplankton community was as follows: chaetognatha community(autumn)?chaetognatha copepods community(winter)?copepods community(spring)?larva chaetognatha community(summer).The results of BIOENV indicated that oil had the most profound impacts on the phytoplankton community in autumn,and salinity,suspended matter and p H in winter,while spring was salinity,suspended matter and chemical oxygen demand,and summer was salinity,soluble reactive phosphate and oil.However,the best explanations among the variables affecting the distribution of zooplankton in autumn and winter were phytoplankton,suspended matter and oil respectively;in spring and summer,the corresponding variables were oil and phytoplankton,soluble reactive phosphate and chlorophyll-a respectively.Pearson correlation analysis results showed that the dominant species of zooplankton preferred to prey on dinoflagellate and there was a positive correlation between them in autumn,but diatom in winter and negative correlation between them.However,in spring and summer,the dominant species of zooplankton preferred to prey on diatom and there was a positive correlation between them.