Riverine nutrient fluxes and environmental effects on China's estuaries

Wu, Guanghua; Cao, Wenzhi; Wang, Feifei; Su, Xiaoling; Yan, Yongke; Guan, Qingsong

doi:10.1016/j.scitotenv.2019.01.120

Cited by 58 publications

(24 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hypoxia was first reported in 1959 (Zhu et al, 2011). Interannual increases in NPP has led to increases in the spatial extent of bottom water hypoxia over the inner shelf from ∼1,800 km 2 in 1959 to ∼ 13,700 km 2 in 1999 and > 15,400 km 2 in 2006 (Levin et al, 2009;Li et al, 2011;Wang et al, 2015;Qian et al, 2107), a trend that has been attributed to elevated nutrient inputs due to fertilizer use in the Changjiang watershed (Wu et al, 2019). Bottom water hypoxia now covers > 15% of the ECS making it one of the largest coastal hypoxic zones in the world (Chen et al, 2007;Wang et al, 2016;Zhu et al, 2016).…”

Section: East China Sea (Ecs)mentioning

confidence: 99%

The Globalization of Cultural Eutrophication in the Coastal Ocean: Causes and Consequences

2020

View full text Add to dashboard Cite

Coastal eutrophication caused by anthropogenic nutrient inputs is one of the greatest threats to the health of coastal estuarine and marine ecosystems worldwide. Globally, ∼24% of the anthropogenic N released in coastal watersheds is estimated to reach coastal ecosystems. Seven contrasting coastal ecosystems subject to a range of riverine inputs of freshwater and nutrients are compared to better understand and manage this threat. The following are addressed: (i) impacts of anthropogenic nutrient inputs on ecosystem services; (ii) how ecosystem traits minimize or amplify these impacts; (iii) synergies among pressures (nutrient enrichment, over fishing, coastal development, and climate-driven pressures in particular); and (iv) management of nutrient inputs to coastal ecosystems. This comparative analysis shows that "trophic status," when defined in terms of the level of primary production, is not useful for relating anthropogenic nutrient loading to impacts. Ranked in terms of the impact of cultural eutrophication, Chesapeake Bay ranks number one followed by the

show abstract

Section: East China Sea (Ecs)mentioning

confidence: 99%

The Globalization of Cultural Eutrophication in the Coastal Ocean: Causes and Consequences

2020

View full text Add to dashboard Cite

show abstract

“…Estuarine eutrophication has become a widespread matter of concern over the past few decades [54]. The level of eutrophication in the PRE varied from 0.004-184.71 (10.12 ± 20.60) in the entire estuary (Figure 9).…”

Section: Environmental Effects Of Nutrient Over-enrichmentmentioning

confidence: 99%

Implications of Nutrient Enrichment and Related Environmental Impacts in the Pearl River Estuary, China: Characterizing the Seasonal Influence of Riverine Input

Niu

Gelder

Luo

et al. 2020

Water

View full text Add to dashboard Cite

The Pearl River estuary is an ecologically dynamic region located in southern China that experiences strong gradients in its biogeochemical properties. This study examined the seasonality of nutrient dynamics, identified related environmental responses, and evaluated how river discharge regulated nutrient sink and source. The field investigation showed significant differences of dissolved nutrients with seasons and three zones of the estuary regarding the estuarine characteristics. Spatially, nutrients exhibited a clear decreasing trend along the salinity gradient; temporally, their levels were obviously higher in summer than other seasons. The aquatic environment was overall eutrophic, as a result of increased fluxes of nitrogen and silicate. This estuary was thus highly sensitive to nutrient enrichment and related pollution of eutrophication. River discharge, oceanic current, and atmospheric deposition distinctly influenced the nutrient status. These factors accordingly may influence phytoplankton that are of importance in coastal ecosystems. Phytoplankton (in terms of chlorophyll) was potentially phosphate limited, which then more frequently resulted in nutrient pollution and blooms. Additionally, the nutrient sources were implied according to the cause–effect chains between nutrients, hydrology, and chlorophyll, identified by the PCA-generated quantification. Nitrogen was constrained by marine-riverine waters and their mutual increase-decline trend, and a new source was supplemented along the transport from river to sea, while a different source of terrestrial emission from coastal cities contributed to phosphate greatly.

show abstract

“…Damming usually decreases SIL load, which makes SIL a potential limiting nutrient in coastal waters [51,52], such as Guadiana estuaries in Mediterranean [53], Sweden, Finland [54], and the Baltic Sea [14]. The sharp decrease of SIL flux caused higher frequency of occurrence of harmful algal bloom [55,56]. In addition, low SIL concentration limited the silicification ability of DIA, and then reduced their absorption of Cd in the seawater, which finally resulted in heavy metal pollution [57] and toxin enrichment through the aquatic food chain [58].…”

Section: Implications and Limitationsmentioning

confidence: 99%

Influences of Nutrient Sources on the Alternation of Nutrient Limitations and Phytoplankton Community in Jiaozhou Bay, Southern Yellow Sea of China

et al. 2020

View full text Add to dashboard Cite

A marine ecosystem box model was developed to reproduce the seasonal variations nutrient concentrations and phytoplankton biomasses in Jiaozhou Bay (JZB) of China. Then, by removing each of the external sources of nutrients (river input, aquaculture, wastewater discharge, and atmospheric deposition) in the model calculation, we quantitatively estimated its influences on nutrient structure and the phytoplankton community. Removing the river input of nutrients enhanced silicate (SIL) limitation to diatoms (DIA) and decreased the ratio of DIA to flagellates (FLA); removing the aquaculture input of nutrients decreased FLA biomass because it provided less dissolved inorganic nitrogen (DIN) but more dissolved inorganic phosphate (DIP) as compared to the Redfield ratio; removing the wastewater input of nutrients changed the DIN concentration dramatically, but had a relatively weaker impact on the phytoplankton community than removing the aquaculture input; removing atmospheric deposition had a negligible influence on the model results. Based on these results, we suppose that the change in the external nutrients sources in the past several decades can explain the long-term variations in nutrient structure and phytoplankton community. Actually, the simulations for the 1960s, 1980s, and 2000s in JZB demonstrated the shift of limiting nutrients from DIP to SIL. A reasonable scenario for this is the decrease in riverine SIL and increase in DIP from aquaculture that has reduced DIA biomass, promoted the growth of FLA, and led to the miniaturization of the phytoplankton.

show abstract

Riverine nutrient fluxes and environmental effects on China's estuaries

Cited by 58 publications

References 42 publications

The Globalization of Cultural Eutrophication in the Coastal Ocean: Causes and Consequences

The Globalization of Cultural Eutrophication in the Coastal Ocean: Causes and Consequences

Implications of Nutrient Enrichment and Related Environmental Impacts in the Pearl River Estuary, China: Characterizing the Seasonal Influence of Riverine Input

Influences of Nutrient Sources on the Alternation of Nutrient Limitations and Phytoplankton Community in Jiaozhou Bay, Southern Yellow Sea of China

Contact Info

Product

Resources

About