Temporal and Spatial Variations of Phytoplankton Community and Their Controlling Factors in the Luanhe-Beidaihe Coastal Waters in Summer and Autumn
In recent years,the ecological health of the Luanhe-Beidaihe coastal waters has been under threat from red tides and hypoxia.Phytoplankton plays a crucial role in the processes of red tides and hypoxia.Therefore,in-vestigating the temporal and spatial variations of the phytoplankton community and their relationships with environ-mental factors is of great significance for protecting the health of the coastal ecosystem.This study conducted two surveys in November 2019 and August 2020 respectively to obtain the environmental factors and net phytoplankton in the Luanhe-Beidaihe coastal waters.The species composition,cell abundance,dominant species,diversity,and distribution of the phytoplankton community were analyzed.Cluster analysis was employed to study the temporal and spatial patterns of the phytoplankton community,while redundancy analysis(RDA)was used to explore the re-lationships between the phytoplankton community and environmental factors.The results showed that a total of 69 species of phytoplankton belonging to 3 phyla and 34 genera were identified,mainly composed of diatoms,with relatively fewer dinoflagellates and chrysophytes.The dominant species in summer were mainly Eucampia zodia-cus,while in autumn they included Chaetoceros lorenzianus,Odontella chinensis,etc.In summer,average cell a-bundance(309.94×104 cells·m-3)was higher than in autumn(14.15×104 cells·m-3),but average values of the Shannon-Wiener diversity index and Pielou evenness index(2.60 and 0.66,respectively)were lower than in autumn(3.54 and 0.95,respectively).The cluster analysis indicated significant seasonal differences between summer and autumn,and significant spatial differences between the Beidaihe area and its southern sea areas in summer,which were caused by the proliferation of E.zodiacus near the Beidaihe waters.The RDA analysis revealed that the key factors influencing the spatial variation of the phytoplankton community in summer were seawater temperature,sa-linity,and dissolved inorganic nitrogen,while in autumn it was mainly chemical oxygen demand.Furthermore,coastal currents and scallop feeding may potentially affect the spatial variations of the phytoplankton community.
Luanhe-BeidaiheQinhuangdaophytoplanktontemporal and spatial variationenvironmental factor
万方数据
维普
