The Ecological Study Of Phytoplankton In Yangshan Port

This thesis is based on the investigation of the phytoplankton community inYangshan Port during the January to December in2009and2011. The pattern of spatialand temporal variation of the species composition, the dominant species, the cellsdensity of phytoplankton were analyzed based on the data from17sampling stations inthree different sea area in Yangshan Port. We attempt to gain insight into theenvironmental factors influencing phytoplankton composition by analyzing thecorrelativity between the changes characteristics of phytoplankton community and theenvironmental factors, to serve as a useful baseline and data for the Port constructionand protection of ecological environment in Yangshan. The main results are as follows:1. Atotal of292phytoplankton species was detected, which belonged to92genera,7phyla. There were112phytoplankton species belonged to58genera of5phyla in thedock of Yangshan. The phytoplankton composition was dominated by Bacillariophytaand Pyrrophyta and their species numbers were94species belonging to45genera and10species belonging to6genera, respectively. In the Yangshan Port channel, there were109phytoplankton species belonging to51genera of6phyla. Among them, thephytoplankton composition was also dominated by Bacillariophyta, which speciesnumbers were99species belonging to42genera, about90.8%. And in the shore ofYangshan Port, there were239phytoplankton species belonging to81genera of7phyla.The phytoplankton composition was also dominated by Bacillariophyta, which speciesnumbers were209species belonging to59genera, about87.4%. The numbers ofspecies to other phyla were quite low.2. The changes of species numbers which were collected in different samplingseasons in dock of Yangshan Port were significant with the annual pattern: winter(68species)>autumn(62species)>spring(46species)>summer(36species). The spatialcharacters of the changes in phytoplankton species number is more in the dock of XiaoYanshan. The pattern of the changes in species numbers of phytoplankton in YangshanPort channel were shown as winter(60species)>autumn(53species)>summer(46species)>spring(44species). The spatial characters of the changes in phytoplanktonspecies number were shown as the pattern of anchorage within the Port>external port>port internal. The species numbers of phytoplankton in the shore of Yangshan Port weremost in Yangshan. The seasonal distribution were winter(139species)>spring(120species)>autumn(105species)>summer(85species), which species were more in DaYangshan in the spatial distribution characters. 3. The dominant species in dock of Yangshan Port was acted by Paralia sulcata,Planktoniella blanda, Coscinodiscus radiatus, Coscinodiscus granii, Cyclotella striata,Cyclotella comta, Thalassionema nitzschioides, Pseudo-nitzschia pungens as well asAchnanthes brevipes. The difference is not obvious between the two sampling stations,which were constituted by Bacillariophyta. In Yangshan Port channel, the dominant speciescomposition were difference in different seasons,8dominant species in winter andspring, the number decreased to4in summer, and6in autumn. At the same time, thedominant species also constituted by Bacillariophyta, and the Skeletonema costatumplay an important role in the dominant species, but it was difference in different season,the dominance was highest in autumn.4. The cell density was greatest in November, and October was the lowest, twohigh peaks were finded in the dock of Yangshan, play22.56%to the November. Thecell density of phytoplankton in Yangshan Port channel showed the characters of spring>winter>summer>autumn. At the seam time, October showed the highest cell densityand January was lowest in the shore of Yangshan Port, which species was higher in DaYangshan in the spatial distribution characters.5. The variation tendency was quite different between different sampling stations.Three different diversity index were used to show the diversity of phytoplankton in thethesis. Shannon-Wiener diversity index (H), Marglef’s diversity index (D) and Pielousevenness index (J) showed the variation range of1.77~2.66,0.56~1.67,0.77~0.87and0.76~2.31,1.73~3.93,0.25~0.73and0.10~2.54,4.08~10.62,0.28~0.56, respectively inthe dock of Yangshan, Yangshan Port channel and the shore of Yangshan Port. Especially inYangshan Port channel, the Shannon-Wiener diversity index (H) and Pielous evennessindex (J) show the same seasonal trend: winter>spring>autumn>summer. But theMarglef’s diversity index (D) was spring>winter>autumn>summer. The water wasevaluated as moderate polluted watershed according to the diversity index evaluationstandards of water quality.6. The main influenced environmental factors to the diversity indexes ofphytoplankton in Yangshan Port were water temperature, dissolved oxygen, totalnitrogen, Cla a, conductivity, pH, salinity, which was analyzed by SPSS.