Influence of the Changjiang River Flood on Synechococcus Ecology in the Surface Waters of the East China Sea

2013 ◽  
Vol 67 (2) ◽  
pp. 273-285 ◽  
Author(s):  
Chih-Ching Chung ◽  
Chin-Yi Huang ◽  
Gwo-Ching Gong ◽  
Yun-Chi Lin
Keyword(s):  
East China Sea ◽  
Surface Waters ◽  
East China ◽  
Changjiang River ◽  
The East China Sea ◽  
China Sea ◽  
The Changjiang River ◽  
River Flood

scholarly journals The large variation in organic carbon consumption in spring in the East China Sea

2013 ◽  
Vol 10 (5) ◽  
pp. 2931-2943 ◽  
Author(s):  
C.-C. Chen ◽  
G.-C. Gong ◽  
F.-K. Shiah ◽  
W.-C. Chou ◽  
C.-C. Hung
Keyword(s):  
Low Temperature ◽  
Organic Carbon ◽  
East China Sea ◽  
Phytoplankton Growth ◽  
East China ◽  
Changjiang River ◽  
Carbon Consumption ◽  
The East China Sea ◽  
China Sea ◽  
The Changjiang River

Abstract. A tremendous amount of organic carbon respired by plankton communities has been found in summer in the East China Sea (ECS), and this rate has been significantly correlated with fluvial discharge from the Changjiang River. However, respiration data has rarely been collected in other seasons. To evaluate and reveal the potential controlling mechanism of organic carbon consumption in spring in the ECS, two cruises covering almost the entire ECS shelf were conducted in the spring of 2009 and 2010. These results showed that although the fluvial discharge rates were comparable to the high riverine flow in summer, the plankton community respiration (CR) varied widely between the two springs. In 2009, the level of CR was double that of 2010, with mean (± SD) values of 111.7 (±76.3) and 50.7 (±62.9) mg C m−3 d−1, respectively. The CR was positively correlated with concentrations of particulate organic carbon and/or chlorophyll a (Chl a) in 2009 (all p < 0.01). These results suggest that the high CR rate in 2009 can be attributed to high planktonic biomasses. During this period, phytoplankton growth flourished due to allochthonous nutrients discharged from the Changjiang River. Furthermore, higher phytoplankton growth led to the absorption of an enormous amount of fugacity of CO2 (fCO2) in the surface waters, even with a significant amount of inorganic carbon regenerated via CR. In 2010, even more riverine runoff nutrients were measured in the ECS than in 2009. Surprisingly, the growth of phytoplankton in 2010 was not stimulated by enriched nutrients, and its growth was likely limited by low water temperature and/or low light intensity. Low temperature might also suppress planktonic metabolism, which could explain why the CR was lower in 2010. During this period, lower surface water fCO2 may have been driven mainly by physical process(es). To conclude, these results indicate that high organic carbon consumption (i.e. CR) in the spring of 2009 could be attributed to high planktonic biomasses, and the lower CR rate during the cold spring of 2010 might be likely limited by low temperature in the ECS. This further suggests that the high inter-annual variability of organic carbon consumption needs to be kept in mind when budgeting the annual carbon balance.

scholarly journals The large variation in organic carbon consumption in spring in the East China Sea

2012 ◽  
Vol 9 (11) ◽  
pp. 16533-16564
Author(s):  
C.-C. Chen ◽  
G.-C. Gong ◽  
F.-K. Shiah ◽  
W.-C. Chou ◽  
C.-C. Hung
Keyword(s):  
Organic Carbon ◽  
East China Sea ◽  
Phytoplankton Growth ◽  
East China ◽  
Community Respiration ◽  
Changjiang River ◽  
Carbon Consumption ◽  
The East China Sea ◽  
China Sea ◽  
The Changjiang River

Abstract. A tremendous amount of organic carbon respired by planktonic communities has been found in summer in the East China Sea (ECS), and this rate has been significantly correlated with fluvial discharge from the Changjiang River. However, data related to this issue in other seasons have rarely been collected. To evaluate and reveal the potential controlling mechanism of organic carbon consumption in spring in the ECS, research using stations covering almost the entire ECS shelf was conducted in the spring of 2009 and 2010. During both periods, the fluvial discharges were similar, and these rates were comparable to high riverine flow in summer. Interestingly, planktonic community respiration (CR) varied widely in both springs; in 2009, the level of CR was double that of 2010, with mean (± SD) values of 111.7 (± 76.3) and 50.7 (± 62.9) mg C m−3 d−1, respectively. The CR was positively linearly regressed with concentrations of particulate organic carbon and/or chlorophyll a (Chl a) in 2009 (all p< 0.01). These results suggest that the rate was dependent on planktonic activities, especially that of phytoplankton, in 2009. During this period, phytoplankton growth flourished due to allochthonous nutrients discharged from the Changjiang River. Furthermore, higher phytoplankton growth leaded to the absorption of an enormous amount of fugacity of CO2 (fCO2) in the surface waters, even with a significant amount of inorganic carbon regenerated via CR. In 2010, there were even more riverine runoff nutrients into the ECS than in 2009. Surprisingly, the growth of phytoplankton in 2010 was not stimulated by enriched nutrients, and its growth was likely limited by low water temperature and/or low light intensity. Low temperature might also suppress planktonic metabolism, and this could explain why the CR was lower in 2010. During this period, lower surface water fCO2 might have mainly been driven by physical process(es). To conclude, these results indicate that organic carbon consumption (i.e. CR) in the ECS in spring might be controlled by the magnitude of planktonic activities and physical factor (e.g. temperature), and that the latter is especially important during a cold spring season. This further suggests that the high intraseasonal variability of organic carbon consumption needs to be kept in mind when budgeting the annual carbon balance.

Changes in the Synechococcus Assemblage Composition at the Surface of the East China Sea Due to Flooding of the Changjiang River

2015 ◽  
Vol 70 (3) ◽  
pp. 677-688 ◽  
Author(s):  
Chih-Ching Chung ◽  
Gwo-Ching Gong ◽  
Chin-Yi Huang ◽  
Jer-Young Lin ◽  
Yun-Chi Lin
Keyword(s):  
East China Sea ◽  
East China ◽  
Changjiang River ◽  
The East China Sea ◽  
Assemblage Composition ◽  
China Sea ◽  
The Changjiang River

scholarly journals Quantifying the contributions of riverine vs. oceanic nitrogen to hypoxia in the East China Sea

2019 ◽  
Author(s):  
Fabian Große ◽  
Katja Fennel ◽  
Haiyan Zhang ◽  
Arnaud Laurent
Keyword(s):  
Oxygen Consumption ◽  
East China Sea ◽  
Open Ocean ◽  
East China ◽  
Yangtze River Estuary ◽  
Changjiang River ◽  
The East China Sea ◽  
China Sea ◽  
The Changjiang River ◽  
Nitrogen Loads

Abstract. In the East China Sea, hypoxia (oxygen ≤ 62.5 mmol m−3) is frequently observed off the Changjiang (or Yangtze) River estuary covering up to about 15,000 km2. The Changjiang River is a major contributor to hypoxia formation because it discharges large amounts of freshwater and nutrients into the region. However, modelling and observational studies have suggested that intrusions of nutrient-rich oceanic water from the Kuroshio also contribute to hypoxia formation. The relative contributions of riverine versus oceanic nutrient sources to hypoxia have not been estimated before. Here, we combine a three-dimensional, physical-biogeochemical model with an element tracing method to quantify the relative contributions of nitrogen from different riverine and oceanic sources to hypoxia formation during 2008–2013. Our results suggest that the hypoxic region north of 30° N is dominated by Changjiang River inputs, with its nitrogen loads supporting 74 % of oxygen consumption. South of 30° N, oceanic nitrogen sources become more important supporting 39 % of oxygen consumption during the hypoxic season, but the Changjiang River remains the main control of hypoxia formation also in this region. Model scenarios with reduced Changjiang River nitrogen loads and reduced open-ocean oxygen levels suggest that nitrogen load reductions can significantly reduce hypoxia in the East China Sea and counteract a potential future decline in oxygen supply from the open ocean into the region.

The impact of the Changjiang River plume extension on the nanoflagellate community in the East China Sea

2010 ◽  
Vol 89 (1) ◽  
pp. 21-30 ◽  
Author(s):  
An-Yi Tsai ◽  
Gwo-Ching Gong ◽  
Robert W. Sanders ◽  
Ciou-Jyu Wang ◽  
Kuo-Ping Chiang
Keyword(s):  
East China Sea ◽  
River Plume ◽  
East China ◽  
Changjiang River ◽  
The East China Sea ◽  
China Sea ◽  
The Changjiang River ◽  
The Impact

Monitoring of the Changjiang River Plume in the East China Sea using a Wave Glider

2018 ◽  
Vol 85 ◽  
pp. 26-30 ◽  
Author(s):  
Taejun Moh ◽  
Jin Hyung Cho ◽  
Seom-Kyu Jung ◽  
Sang-Hyun Kim ◽  
Young Baek Son
Keyword(s):  
East China Sea ◽  
River Plume ◽  
East China ◽  
Changjiang River ◽  
The East China Sea ◽  
China Sea ◽  
The Changjiang River ◽  
Wave Glider
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