Temporal and spatial variations of phytoplankton community and environmental factors in Laizhou bay
SUN Hui-hui1,2, LIU Xi-han1,2, SUN Xi-yan1, WANG Yu-jue1, LIU Dong-yan3
1. Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China;
2. University of Chinese Academy of Science, Beijing 100049, China;
3. State Key Lab of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
Abstract:An ecological survey was carried out in May and September 2014 in the Laizhou bay, with the aim of exploring temporal and spatial variations of phytoplankton community and their correlation with environmental factors. The results showed that differences of the average salinity, concentrations of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP) in the two months were not obvious, with the differences of 0.80, 4.90 μmol/L and 0.01 μmol/L, respectively. Compared to the values in May, the average of temperature and dissolved silicate (DSi) concentrations increased 11.0℃ and 6.02 μmol/L, and declined gradually from the inshore to offshore waters in September, corresponding to the increased freshwater loading. The analysis of nutrient structure indicated that no sites appeared nitrogen limitation in two surveys. Up to 80% sites showed absolute and relative limitation in DSi, while DIP limitation only appeared in one sites in May. In contrast, 86.7% of the sites had DIP limitation but only one site had DSi limitation in September. The reason might be related to increased precipitation and silicate loadings during the water and sediment regulation of Yellow River in July. Phytoplankton responded to environmental changes and higher diversity and biomass of phytoplankton appeared in September. The results of Canonical Correspondence Analysis between phytoplankton assemblages and environmental factors indicated that increased temperature and concentrations of DSi were dominant factors related to the temporal and spatial variation of phytoplankton. Dinoflagellates had a higher sensitivity to changes of temperature and salinity than diatoms.
SUN Hui-hui,LIU Xi-han,SUN Xi-yan et al. Temporal and spatial variations of phytoplankton community and environmental factors in Laizhou bay[J]. Marine Environmental Science, 2017, 36(5): 662-669.
ZHANG J,LIU S M,REN J L,et al.Nutrient gradients from the eutrophic Changjiang (Yangtze River) Estuary to the oligotrophic Kuroshio waters and re-evaluation of budgets for the East China Sea Shelf[J].Progress in Oceanography,2007,74(4):449-478.
[2]
GUENTHER M,ARAÚJO M,FLORES-MONTES M,et al.Eutrophication effects on phytoplankton size-fractioned biomass and production at a tropical estuary[J].Marine Pollution Bulletin,2015,91(2):537-547.
[3]
KEMP W M,BOYNTON W R,ADOLF J E,et al.Eutrophication of Chesapeake Bay:historical trends and ecological interactions[J].Marine Ecology Progress Series,2005,303:1-29.
ZHANG J,SU J L.Nutrient dynamics of the China Seas:the Bohai Sea,Yellow Sea,East China Sea and South China Sea[M].In:Robinson, A.R.,Brink,K.H.(Eds).The Sea,Harvard University Press, Cambridge,2006:637-671.
WANG H J,YANG Z S,LI Y H,et al.Dispersal pattern of suspended sediment in the shear frontal zone off the Huanghe (Yellow River) mouth[J].Continental Shelf Research,2007,27(6):854-871.
LIU S M.Response of nutrient transports to water-sediment regulation events in the Huanghe basin and its impact on the biogeochemistry of the Bohai[J].Journal of Marine Systems,2015,141:59-70.
[11]
冯士筰,张 经,魏 皓.渤海环境动力学导论[M].北京:科学出版社,2007.
[12]
JUSTI? D,RABALAIS N N,TURNER R E,et al.Changes in nutrient structure of river-dominated coastal waters:stoichiometric nutrient balance and its consequences[J].Estuarine,Coastal and Shelf Science,1995,40(3):339-356.
[13]
LORENZEN C J.Determination of chlorophyll and pheo-pigments:spectrophotometric equations[J].Limnology and Oceanography,1967,12(2):343-346.
LIU S M,LI L W,ZHANG G L,et al.Impacts of human activities on nutrient transports in the Huanghe (Yellow River) estuary[J].Journal of Hydrology,2012,430/431:103-110.