Temporal and spatial distribution of red tide outbreaks in the Yangtze River Estuary and adjacent waters, China

Liu, Lusan; Zhou, Juan; Zheng, Binghui; Cai, Wenqian; Lin, Kuangfei; Tang, Jiakui

doi:10.1016/j.marpolbul.2013.04.002

Cited by 99 publications

(38 citation statements)

References 7 publications

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“…This coastal zone has suffered from considerable anthropogenic influences in recent decades. With abundant nutrients (such as N and P) discharged into Hangzhou Bay and the East China Sea by point or nonpoint source contamination, the study area has the highest frequency of red tides in China (Liu et al ). Aquatic eutrophication directly leads to rapid increase of algal biomass, which can cause not only reductions in dissolved oxygen levels, but also accumulations of toxic metabolites (Conley et al ; Xiao et al ).…”

Section: Resultsmentioning

confidence: 99%

Assessing the severe eutrophication status and spatial trend in the coastal waters of Zhejiang province (China)

Jiang

et al. 2018

Limnology & Oceanography

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The eutrophication of the coastal waters of Zhejiang Province has become one of the main contamination threats to the region's coastal marine ecosystems. Accordingly, the comprehensive characterization of the eutrophication status in terms of improved quantitative methods is valuable for local risk assessment and policy making. A novelty of this work is that the spatial distributions of chemical oxygen demand, dissolved inorganic nitrogen, and dissolved inorganic phosphorus were estimated across space by the Bayesian maximum entropy (BME) method. The BME estimates were found to have the best cross‐validation performance compared to ordinary kriging and inverse distance weighted techniques. Based on the BME maps, it was found that about 25.95%, 19.18%, 20.53%, and 34.34% of these coastal waters were oligotrophic, mesotrophic, eutrophic, and hypereutrophic. Another novelty of the present work is that comprehensive stochastic site indicators (SSI) were introduced in the quantitative characterization of the eutrophication risk in the Zhejiang coastal waters under conditions of in situ uncertainty. The results showed that the level of the eutrophication index (EI) increased almost linearly with increasing threshold values; and that 71%, 51%, and 19% of coastal locations separated by various spatial lags experience considerable mesotrophic, eutrophic, and hypereutrophic risks, respectively. The average EI values over the subregions of the Zhejiang coastal waters graded as “oligotrophic or higher,” “eutrophic or higher,” and “hypereutrophic” were about 11.14, 14.28, and 25.34, respectively. Our results also revealed that the joint eutrophication strength between coastal locations in the Zhejiang region was consistently greater than the combined strength of independent eutrophications at these locations (we termed this situation “positive quadrant eutrophication dependency”). It was found that a critical eutrophication threshold ζcr ≈ 8.38 exists so that below ζcr the spatial eutrophication dependency in the Zhejiang coastal waters increases with ζ, whereas above ζcr the opposite is true. Moreover, the eutrophication dependency decreases as the separation distance δs increases. Interestingly, at distances δs smaller than a critical distance δscr ≈ 15 km, the eutrophication locations are concentrated in the coastal waters of the Zhejiang province rather than being dispersed (this observation holds even for large thresholds ζ). Elasticity analysis of eutrophication indicators offered a quantitative measure of the excess eutrophication change in the Zhejiang coastal waters caused by a threshold change (the larger the elasticity is, the more sensitive eutrophication is to threshold changes). The above findings can contribute to an improved understanding of seawater quality and provide a practical approach for the identification of critical coastal water regions.

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Section: Resultsmentioning

confidence: 99%

Assessing the severe eutrophication status and spatial trend in the coastal waters of Zhejiang province (China)

Jiang

et al. 2018

Limnology & Oceanography

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“…in the rivers and their connected stagnant systems, as well as in coastal zones [ Heisler et al , ]. The situation is evolving quickly in Asian countries, especially in China where harmful algal blooms are already currently observed [ Heisler et al , ; Liu et al , ; Xinyan et al , ; Strokal et al , ]. Considering Prorocentrum minimum as a good indicator of eutrophication in the world, Heisler et al [] showed that ASEAN‐8 countries are not yet encountering high eutrophication, as shown for the Chinese and European coastal areas.…”

Section: Discussionmentioning

confidence: 99%

Phosphorus budget in the water‐agro‐food system at nested scales in two contrasted regions of the world (ASEAN‐8 and EU‐27)

Garnier

Lassaletta

Billen

et al. 2015

Global Biogeochemical Cycles

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Phosphorus (P) plays a strategic role in agricultural production as well as in the occurrence of freshwater and marine eutrophication episodes throughout the world. Moreover, the scarcity and uneven distribution of minable P resources is raising concerns about the sustainability of long-term exploitation. In this paper we analyze the P cycle in anthropic systems with an original multiscale approach (world region, country, and large basin scales) in two contrasting world regions representative of different trajectories in socioeconomic development for the 1961-2009 period: Europe (EU-27)/France and the Seine River Basin, and Asia (ASEAN-8)/Vietnam and the Red River Basin. Our approach highlights different trends in the agricultural and food production systems of the two regions. Whereas crop production increased until the 1980s in Europe and France and has stabilized thereafter, in ASEAN-8 and Vietnam it began to increase in the 1980s and it is still rising today. These trends are related to the increasing use of fertilizers, although in European countries the amount of fertilizers sharply decreased after the 1980s. On average, the total P delivered from rivers to the sea is 3 times higher for ASEAN-8 (300 kg P km À2 yr À1) than for EU-27 countries (100 kg P km À2 yr À1) and is twice as high in the Red River (200 kg P km À2 yr À1) than in the Seine River (110 kg P km À2 yr À1), with agricultural losses to water in ASEAN-8 3 times higher than in EU-27. Based on the P flux budgets, this study discusses early warnings and management options according to the particularities of the two world regions, newly integrating the perspective of surface water quality with agricultural issues (fertilizers, crop production, and surplus), food/feed exchanges, and diet, defining the so-called water-agro-food system.

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“…Skeletonema costatum ( S . costatum ) frequently causes algal bloom in coastal and estuarine waters around the world (Bochdansky and Bollens, ), including the Yangtze River estuary (Liu et al ., ). As a result of its vital ecological significance, S .…”

Section: Introductionmentioning

confidence: 97%

Impact of silver nanoparticles on marine diatom Skeletonema costatum

Huang

Cheng

2016

J of Applied Toxicology

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When silver nanoparticles (AgNPs) are used commercially at a large scale, they infiltrate the environment at a rapid pace. However, the impact of large quantities of AgNPs on aquatic ecosystems is still largely unknown. In aquatic ecosystems, the phytoplanktons have a vital ecological function and, therefore, the potential impact of AgNPs on the microalgae community has elicited substantial concern. Therefore, in this study, the impacts of AgNPs on a marine diatom, the Skeletonema costatum, are investigated, with a focus on their photosynthesis and associated mechanisms. Exposure to AgNPs at a concentration of 0.5 mg l À1 significantly induces excess intracellular reactive oxygen species (ROS, 122%) and reduces 28% of their cell viability. More importantly, exposure to AgNPs reduces the algal chlorophyll-a content. Scanning electron microscopy (SEM) was conducted, which revealed that AgNPs obstruct the light absorption of algae because they adhere to their surface. The maximum photochemical efficiency of photosystem II (Fv/Fm) demonstrates that exposure to AgNPs significantly inhibits the conversion of light energy into photosynthetic electron transport. Moreover, the genes of the photosystem II reaction center protein (D1) are significantly down-regulated (P < 0.05) upon exposure to 5 mg l À1 AgNPs. These results suggest that the physical adhesion and effects of shading of AgNPs on algae might affect their light energy delivery system and damage the crucial protein function of PSII. The photosynthesis inhibition effect of AgNPs is largely different from Ag + . This study shows that AgNPs at higher concentrations might have serious consequences for the succession of the phytoplankton communities and aquatic ecosystem equilibrium.

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Temporal and spatial distribution of red tide outbreaks in the Yangtze River Estuary and adjacent waters, China

Cited by 99 publications

References 7 publications

Assessing the severe eutrophication status and spatial trend in the coastal waters of Zhejiang province (China)

Assessing the severe eutrophication status and spatial trend in the coastal waters of Zhejiang province (China)

Phosphorus budget in the water‐agro‐food system at nested scales in two contrasted regions of the world (ASEAN‐8 and EU‐27)

Impact of silver nanoparticles on marine diatom Skeletonema costatum

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