Annual Dynamics Of Characteristics Of Community Structures Of Phytoplankton In The Yangshan Port

This thesis is based on the investigation of the phytoplankton communityin Yangshan Port during the January to December in2012. The investigationsin the Xiao Yangshan sea area and Da Yangshan sea area are both occuredmonth by month, while the investigation in the Yangshan Port channel isoccurred in February (winter), May (spring), August (summer) and November(autumn). Through identifying the kind of phytoplankton, calculating cellabundance of phytoplankton and analyzing the diversity of phytoplankton, theauthor discusses the annual dynamic change of phytoplankton communitystructure characteristics of the Yangshan Port. We attempt to gain insight intothe response from phytoplankton to Marine ecological environment by usingStatistical Program for Social Science (SPSS) and CANOCO4.5. Thestatistical analysis of environmental factors and phytoplankton may serve as auseful baseline and data for the Port construction and protection of ecologicalenvironment in Yangshan.The main results as below:1. Phytoplankton community structure of XiaoYangshan sea area wasinvestigated and analyzed from January to December in2012. A total of183 phytoplankton species, belonging to7phyla and77genera, were identified.Bacillariophyta, including51genera and143species which accounted for78.14%of species richness, was the main phytoplankton group.The annualaverage cell abundance of phytoplankton was (35.07±23.62)×104cell/L.Skeletonema costatum and Paralia sulcata were the main dominant speciesthrough the year, while Thalassiosira leptopus, Nitzschia frustulum,Rhaphoneis rhomoides and Cyclotella meneghiniana were the commonspecies. Based on analysis of diversity, the annual average values ofShannon-Wiener index, Margalef index and Pielous index were2.59±0.75,4.00±1.44and0.55±0.15, respectively. The average number of Diatoms Indexwas1.06±0.20. Redundancy analysis (RDA) showed that salinity, watertemperature, dissolved oxygen and suspended solids concentration were themain environmental factors playing great influences on phytoplankton.2. Phytoplankton community structure of DaYangshan sea area wasinvestigated and analyzed from January to December in2012. A total of141phytoplankton species, belonging to6phyla and62genera, were identified.Bacillariophyta, including43genera and110species which accounted for78.01%of species richness, was the main phytoplankton group.The annualaverage cell abundance of phytoplankton was (37.86±39.79)×104cell/L.Skeletonema costatum and Paralia sulcata were the main dominant speciesthrough the year, while Thalassiosira leptopus, Nitzschia frustulum and Cyclotella meneghiniana were the common species. Based on analysis ofdiversity, the annual average values of Shannon-Wiener index, Margalefindex and Pielous index were2.83±1.21,2.59±0.97and0.45±0.19,respectively. The average number of Diatoms Index was0.99±0.15.Redundancy analysis (RDA) showed that suspended solids concentration,salinity, water temperature and dissolved oxygen were the mainenvironmental factors playing great influences on phytoplankton.3. Phytoplankton community structure of Yangshan Port channel sea areawas investigated and analyzed in February (winter), May (spring), August(summer) and November (autumn) in2012. A total of136phytoplanktonspecies, belonging to5phyla and64genera, were identified. Bacillariophyta,including47genera and110species which accounted for80.88%of speciesrichness, was the main phytoplankton group.The annual average cellabundance of phytoplankton was (32.75±2.58)×104cell/L. Skeletonemacostatum, Paralia sulcata, Nitzschia frustulum, Cyclotella meneghiniana andThalassiosira leptopus were the main dominant species through the year.Based on analysis of diversity, the annual average values of Shannon-Wienerindex, Margalef index and Pielous index were2.87±0.69,4.30±1.06and0.58±0.10, respectively. The average number of Diatoms Index was0.86±0.12.Redundancy analysis (RDA) showed that salinity, water temperature,dissolved oxygen and total nitrogen were the main environmental factors playing great influences on phytoplankton.4. Bacillariophyta was the main phytoplankton group in Xiao Yangshan,Da Yangshan and Yangshan Port channel, while others kinds of phytoplanktonwere unevenness. The proportion of bacillariophyta of species richnessspecies richness in Yangshan Port channel was the biggest, and vaule in DaYangshan sea area was the smallest. Annual cell abundance in three surveywaters presented Da Yangshan＞Xiao Yangshan＞Yangshan Port channel.One-way analysis of variance (ANOVA) showed that Shannon-Wienerindex(H′), Pielous index (J) and Margalef index had significant difference（P<0.01）both in Xiao Yangshan and Da Yangshan sea area, while thesethree indexes had no significant difference in Yangshan Port channel. H′inthese three areas was showed the same seasonal trend: winter＞spring＞autumn＞summer. Although D and J expressed different seasonalcharacteristic, the minimum value was both appeared in summer. Salinity,suspended solids concentration and water temperature were the mainenvironmental factors playing great influences on phytoplankton.