Notice of Retraction: A study of distribution variation of chlorophyll a and regulatory effects of environmental factors in the Yellow Sea nearshore area of Shandong province

Author(s):  
Douyong ◽  
Wangyou ◽  
Zhoubin ◽  
Tang Xue-xi
2014 ◽  
Vol 11 (3) ◽  
pp. 779-806 ◽  
Author(s):  
J. Sun ◽  
X. Y. Gu ◽  
Y. Y. Feng ◽  
S. F. Jin ◽  
W. S. Jiang ◽  
...  

Abstract. This paper describes the distribution of living coccolithophores (LCs) in the Yellow Sea and the East China Sea in summer and winter, and its relationship with environmental factors by canonical correspondence analysis (CCA). We carried out a series of investigations on LCs distribution in the Yellow Sea and the East China Sea in July and December 2011. 210 samples from different depths were collected from 44 stations in summer and 217 samples were collected from 45 stations in winter. Totally 20 taxa belonging to coccolithophyceae were identified using a polarized microscope at the 1000 × magnification. The dominant species of the two seasons were Gephyrocapsa oceanica, Emiliania huxleyi, Helicosphaera carteri, and Algirosphaera robusta. In summer the abundance of coccolithophore cells and coccoliths ranged 0–176.40 cells mL−1, and 0–2144.98 coccoliths mL−1, with the average values of 8.45 cells mL−1, and 265.42 coccoliths mL−1, respectively. And in winter the abundance of cells and coccoliths ranged 0–71.66 cells mL−1, and 0–4698.99 coccoliths mL−1, with the average values of 13.91 cells mL−1 and 872.56 coccoliths mL−1, respectively. In summer, the LCs in surface layer were mainly observed on the coastal belt and southern part of the survey area. In winter, the LCs in surface layer had high value in the continental shelf area of section P. The comparison among section A, section F, section P and section E indicated lower species diversity and less abundance in the Yellow Sea than those in the East China Sea in both seasons. Temperature and the nitrate concentration may be the major environmental factors controlling the distribution and species composition of LCs in the studying area based on CCA. Abbreviations: LCs: Living Coccolithophores; CCA: canonical correspondence analysis; DCM: Deep Chlorophyll Maximum


2016 ◽  
Vol 13 (1) ◽  
pp. 127 ◽  
Author(s):  
Yue Liu ◽  
Chun-Ying Liu ◽  
Gui-Peng Yang ◽  
Hong-Hai Zhang ◽  
Sheng-hui Zhang

Environmental context Dimethylsulfide (DMS) is a climatically important biogenic trace gas that is emitted from oceans. This research focuses on the spatiotemporal distributions of DMS and its related compounds, i.e. dimethylsulfoniopropionate (DMSP) and acrylic acid (AA), and the influencing factors in the Yellow Sea and the Bohai Sea during autumn. In addition, the sea-to-air flux of DMS, kinetic responses of DMSP consumption as well as DMS and AA production are also investigated. This study is helpful in understanding the marine sulfur cycle in marginal seas in China. Abstract The biogeochemistry of dimethylsulfoniopropionate (DMSP), dimethylsulfide (DMS) and acrylic acid (AA) in the Yellow Sea (YS) and the Bohai Sea (BS) was investigated in November 2013. The concentrations (and ranges) of total DMSP (DMSPt), dissolved DMSP (DMSPd), DMS and AA in surface waters were 30.71 (1.07–122.50), 6.60 (0.85–35.67), 1.48 (0.53–5.32) and 42.2 (13.8–352.8) nmol L–1 respectively. The concentrations of DMSPd and AA were positively correlated with chlorophyll-a levels, which suggests that phytoplankton biomass has an important function in controlling DMSPd and AA distributions. Furthermore, DMS and AA concentrations revealed significant positive relationships with DMSPd concentrations. The average ratios of AA/(DMSP+AA) and DMS/AA were 53.98 and 7.62% respectively. The vertical profiles of DMSP, DMS and AA were characterised by high concentrations that mostly occur near the surface. Even under highly variable hydrographic conditions, a positive relationship was observed between DMSPt and chlorophyll-a concentrations. The rates of DMSPd consumption, as well as DMS and AA production, significantly varied with marine environments. The sea-to-air fluxes of DMS from the YS and the BS to the atmosphere were estimated to be in the range of 3.01 to 6.91μmol m–2day–1.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10538
Author(s):  
Xiaoxiang Miao ◽  
Jie Xiao ◽  
Qinzeng Xu ◽  
Shiliang Fan ◽  
Zongling Wang ◽  
...  

Massive floating green macroalgae have formed harmful green tides in the Yellow Sea since 2007. To study the early development and the associated environmental factors for the green tide, a field survey was carried out in the Subei Shoal, southwestern Yellow Sea. Multiple species were identified in both floating green macroalgae and micro-propagules , while their abundances showed distinct spatial variations. The floating macroalgal biomass was widespread in the northern Subei Shoal and most abundant at 34°N. Ulva prolifera dominated (91.2% in average) the floating macroalgae, and the majority (88.5%) of U. prolifera was the ‘floating type’. In comparison, the micro-propagules were most abundant around the aquaculture rafts, and decreased significantly with the distance to the rafts. The dominant species of micro-propagules was U. linza (48.5%), followed by U. prolifera (35.1%). Their distinct distribution patterns and species diversity suggested little direct contribution of micro-propagules for the floating macroalgae. The spatial variation of the floating macroalgae was probably a combined result from the biomass source and environmental factors, while the abundance of micro-propagules was closely associated with the rafts. A positive correlation between the floating macroalgae and DO was observed and suggested active photosynthesis of the initial biomass in Subei Shoal. This study revealed specific distributional pattern and relationships among the floating macroalgae, micro-propagules and the environmental factors in the source region, which helps understanding the early blooming dynamics of the green tides in Yellow Sea.


2021 ◽  
Vol 299 ◽  
pp. 01012
Author(s):  
Lei Qiu ◽  
Ying Cao ◽  
Jingyi Huang

In view of the increased vulnerability of water resources system caused by seawater intrusion in the coastal areas of the Yellow Sea and Bohai Sea, this paper based on the VSD(Vulnerability Scoping Diagram) model to construct the water resource vulnerability evaluation index system of “exposure-sensitivity-adaptive capacity” under seawater intrusion. Then use entropy-TOPSIS method to evaluate water resource vulnerability and divide the levels. In addition, take Longkou City of Shandong Province as an example to conduct empirical research. The results show that the water resource vulnerability of Longkou City is at a strong vulnerability level. The water resources system is under obvious pressure. Population density, per capita GDP, temperature and precipitation change are the main factors of the system pressure. Seawater intrusion has a high degree of impact on water resources vulnerability and water resource system is more sensitive to groundwater level, chloride concentration and other stimuli. The improvement of water use efficiency and scientific and technological investment contribute to the significant enhancement of the adaptability of the water resources system of Longkou City.


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