Characteristics of phytoplankton community in the offshore area of Sanya Bay
In order to study the characteristics of phytoplankton community and water quality in Sanya Bay,Hainan Province,net sampling surveys were conducted in April 2020 and 2021,respectively.Samples of phytoplankton and seawater were collected in 4 stations,and their community characteristics and water quality and environmental status were analyzed and evaluated by using Shannon-Wiener diversity index,Pielou evenness index,dominance index and richness index.Microscopic examination results showed that 98 species in 4 phyla of phytoplankton were identified in 2020 and 65 species in 3 phyla in 2021.Diatoms were the dominant group in both surveys.The number of dominant phytoplankton species was 8 in 2020 and 9 in 2021.Cluster analysis and Kruskal-Wallis test showed that the phytoplankton community structure in 2020 was significantly different from that in 2021.The diversity index and richness index in 2020 are 3.35 and 3.72,respectively,both of which are higher than those(3.27 and 2.5,respectively)in 2021,while the evenness index is 0.59,which is lower than that(0.66)in 2021.The average phytoplankton cell density in 2021 was 41.95%lower than that in 2020.The redundancy analysis(RDA)showed that ammonia nitrogen,conductivity and total phosphorus were the main environmental factors affecting the phytoplankton community structure in Sanya Bay in 2020 and 2021.All the results showed that the sea water in Sanya Bay is generally excellent ecologically in 2020 and 2021.The phytoplankton community structure is mainly composed of diatoms.The sea water has poor nutrients,indicating no possibility of occurrence of red tides or eutrophication.
NETL
NSTL
万方数据
维普
