The Characteristics Of Seasonal Variations And Spatial And Temporal Distributions Of Phytoplankton In Shanghai Port

Phytoplankton and environmental factors were monitored quarterly in Shanghai Port from 2012 to 2013. The seasonal variations, spatial and temporal distributions, diversity and correlation analysis of phytoplankton structure and environmental factors were analysed in Shanghai port. The results showed that:1. Phytoplankton and environmental factors were collected quarterly in the Waigaoqiao harbor district and the adjacent waters of Shanghai Port in 2012. 271 species from 96 genera were identified in the Shanghai port. The main dominant species were Skeletonema costatum, Melosira granulate, Cyclotella meneghiniana, Phormidittmter tuetents, Oscillatoria agardhii, Spirulina maxima. The Scenedesmus quadricanda of Chlorophyta was also common in the dominant species. The abundance of phytoplankton from 1.89×105 to 9.60×105 cells/L, the highest in Spring, and the lowest in Winter. The phytoplankton was mainly constituted by Cyanophyta in summer and august, and in other month was constituted by Bacillariophyta. The analysis of phytoplankton diversity showed that the Margalef point of winter is th e highest and reached 19.43, the Shannon- Wiener index and the Pielou index of sum mer achieved the highest in the year, 3.06 and 0.73 respectively. The analysis of the correlation with cell abundance and environmental factors by Redundancy Analysis, the biological density of the dominant species of Bacillariophyta in spring had positive correlation significantly with temperature and negative correlation significantly with total phosphorus. The biological density of the dominant species of Chlorophyta and Cyanophyta in summer had positive correlation significantly with total nitrogen and ammonia nitrogenand negative correlation significantly with phosphorus. Dominant species in autumn were positive related to total nitrogen and nitrate and negative related to total phosphorus except Oscillatori aagardhii. Dominant species in winter were positively correlated with total phosphorus, ammonia nitrogen and turbidity and negatively correlated with total nitrogen, temperature and nitrate. Waigaoqiao harbor district of Shanghai Port is located in the interior of Yangtze River Estuary and the phytoplankton community is composed of freshwater species and brackish water species because of the water with low salinity. The change of cell abundance of phytoplankton is monocycle and the fastigium is appearing in the spring. The temperature, total phosphorus, total nitrogen and nitrate are the main factors which influencing the growth of phytoplankton.2. 236 species were identified in six surveyes from Yangshan port area in 2013,including Bacillariophyta, Pyrrhophyta, Cyanophyta, Chlorophyta, Euglenophyta and Chrysophyta. The cell abundance of Bacillariophyta is the highest.Dominant species are mainly Skeletonema costatum, Paralia sulcata, Synedra acusvar, Cyclotella striata, Nitzschia marina, Biddulphia obtusa, Chaetoceros tortissimus, Coscinodis cus jonesianus and Cyclotella spp. The cell abundance of Yangshan port area in 2013 range in 7.47×104-1.71×105 cells/L, thereinto it is the highest in winter. Change of cell abundance, diversity and uniformity of phytoplankton at each sampling point is small, with no significant difference(p>0.05). Cell abundance of four quarters is 1.95 on average, among that the highest in winter and the lowest in autumn. The mean of diversity is 1.80, with the highest in winter and the lowest in autumn. The mean of uniformity is 0.57, also the highest in winter and the lowest in autumn. The change trend of diversity and uniformity is the same, among that in winter is the highest, and be down inturn in spring, summer and autumn.3. The phytoplankton community structure has significant correlation with Environmental factors through SPSS 16.0. Cell abundance has a very significant positive correlation with TP and nitrate(r=0.637,p<0.01;r=0.542,p<0.01).Cell abundance has a significant positive correlation with ammonia and suspended solids(r=0.500,p<0.05;r=0.496,p<0.05).The evenness index has a very significant positive correlation with diversity index(r=0.948,p<0.01).4. 134 species were identified in two Yangshan terminals. Bacillariophyta, Pyrrhophyta, Cyanophyta, Chrysophyta and Euglenophyta are 125 spieces, 4 spieces,3spieces, 1 spieces and 1 spieces spectively.Spiece number in April is the highest with 45 spieces, and in September is the lowest with 19 spieces. The change law of species number is that: summer(40 species) >spring and winter(37 species) >autumn(25 species).There is significant difference among four seasons(p<0.05), and when The similarity is 55%, the Spring and Winter is in the same group, with the Summer and Autumn in another group.