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Chen Y, Shen C, Zhao H, Pan G. The impact of marine heatwaves on surface phytoplankton chlorophyll-a in the South China Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175099. [PMID: 39079642 DOI: 10.1016/j.scitotenv.2024.175099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 07/26/2024] [Accepted: 07/26/2024] [Indexed: 08/05/2024]
Abstract
According to previous studies, marine heatwaves (MHWs) significantly suppress the phytoplankton chlorophyll-a concentration (Chl a) in tropical oceans. However, pre-MHW Chl a has rarely been considered as a reference value. In this study, the Chl a for the periods preceding and during MHWs events was used to explore the impact of MHWs on Chl a from 1998 to 2022 in the South China Sea (SCS). The Chl a response to MHWs in different regions was further discussed based on the Chl a variation characteristics. The results showed that the Chl a response to MHWs exhibited regional variability. Interestingly, there was a large proportion of positive Chl a anomalies (∼0.55) in the estuary and offshore regions during MHWs; however, Chl a anomalies were mostly negative in the upwelling regions. These different response patterns are related to background conditions, including nutrient concentrations, wind-driven dynamics, and light availability. In upwelling regions, negative Chl a anomalies were primarily due to the weakening of wind speeds, Ekman pumping velocities, and upwelling intensities. In estuarine regions, positive Chl a anomalies were caused by enhanced light availability, whereas in offshore regions, there were attributed to the increased atmospheric wet deposition. These results have improved our understanding of the impact of MHWs on marine ecosystems.
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Affiliation(s)
- Yingjun Chen
- College of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China
| | - Chunyan Shen
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China
| | - Hui Zhao
- College of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China; Cooperative Research Center for Nearshore Marine Environmental Change, Guangdong Ocean University, Zhanjiang 524088, China; Research Center for Coastal Environmental Protection and Ecological Resilience, Guangdong Ocean University, Zhanjiang 524088, China.
| | - Gang Pan
- College of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China; Cooperative Research Center for Nearshore Marine Environmental Change, Guangdong Ocean University, Zhanjiang 524088, China; School of Humanities, York St John University, York, United Kingdom
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Xia J, Hu H, Gao X, Kan J, Gao Y, Li J. Phytoplankton Diversity, Spatial Patterns, and Photosynthetic Characteristics Under Environmental Gradients and Anthropogenic Influence in the Pearl River Estuary. BIOLOGY 2024; 13:550. [PMID: 39056742 PMCID: PMC11273628 DOI: 10.3390/biology13070550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/14/2024] [Accepted: 07/19/2024] [Indexed: 07/28/2024]
Abstract
The Pearl River Estuary (PRE) is one of the world's most urbanized subtropical coastal systems. It presents a typical environmental gradient suitable for studying estuarine phytoplankton communities' dynamics and photosynthetic physiology. In September 2018, the maximum photochemical quantum yield (Fv/Fm) of phytoplankton in different salinity habitats of PRE (oceanic, estuarine, and freshwater zones) was studied, revealing a complex correlation with the environment. Fv/Fm of phytoplankton ranged from 0.16 to 0.45, with taxa in the upper Lingdingyang found to be more stressed. Community composition and structure were analyzed using 18S rRNA, accompanied by a pigment analysis utilized as a supplementary method. Nonmetric multidimensional scaling analysis indicated differences in the phytoplankton spatial distribution along the estuarine gradients. Specificity-occupancy plots identified different specialist taxa for each salinity habitat. Dinophyta and Haptophyta were the predominant taxa in oceanic areas, while Chlorophyta and Cryptophyta dominated freshwater. Bacillariophyta prevailed across all salinity gradients. Canonical correlation analysis and Mantel tests revealed that temperature, salinity, and elevated nutrient levels (i.e., NO3--N, PO43--P, and SiO32--Si) associated with anthropogenic activities significantly influenced the heterogeneity of community structure. The spatial distribution of phytoplankton, along with in situ photosynthetic characteristics, serves as a foundational basis to access estuarine primary productivity, as well as community function and ecosystem health.
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Affiliation(s)
- Jing Xia
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China; (J.X.); (H.H.); (X.G.)
| | - Haojie Hu
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China; (J.X.); (H.H.); (X.G.)
| | - Xiu Gao
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China; (J.X.); (H.H.); (X.G.)
| | - Jinjun Kan
- Stroud Water Research Center, 970 Spencer Rd., Avondale, PA 19311, USA;
| | - Yonghui Gao
- Key Laboratory of Polar Ecosystem and Climate Change, Ministry of Education, School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
- Key Laboratory for Polar Science, Polar Research Institute of China, Ministry of Natural Resources, Shanghai 200136, China
| | - Ji Li
- Key Laboratory of Polar Ecosystem and Climate Change, Ministry of Education, School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
- Key Laboratory for Polar Science, Polar Research Institute of China, Ministry of Natural Resources, Shanghai 200136, China
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Zhang K, Li K, Hu F, Xin R, Fan P, Lu Y, Wang N, Qin M, Li R. Occurrence characteristics and influencing factors of antibiotic resistance genes in rural groundwater in Henan Province. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:16685-16695. [PMID: 38319424 DOI: 10.1007/s11356-024-32258-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 01/25/2024] [Indexed: 02/07/2024]
Abstract
This study determined the antibiotic-resistant gene (ARG) contents of 34 groundwater samples in Henan Province collected from September to October 2022, then assessed the roles of both water quality parameters and intI1 in ARG propagation in groundwater. The results show that there existed universal ARG pollution in groundwater, and sulfonamides-, β-lactem-, and tetracycline-resistance genes were the most prevalent gene types during the time. Sul1 contributed the majority proportion of the total resistance genes (TARGs). The prevalence of ESBLs gene blaTEM and the occurrence of Carbapenems resistant gene blaOXA-1 suggests the pollution of high-risk ARGs in groundwater demands more attention. IntI1 is prevalent and had a significantly positive correlation with almost 50% ARGs, indicating its contribution to ARG propagation in groundwater. Well types contribute little to ARG propagation in rural groundwater of Henan, which means the protective facilities established by the local government for public wells can effectively prevent contamination from exogenous ARGs. However, the economic level has no impact on the abundance of ARGs in rural groundwater, which suggests the local government should pay greater attention to investment in controlling ARG pollution in Henan rural areas.
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Affiliation(s)
- Kai Zhang
- School of Geographic Sciences, Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution, Xinyang Normal University, Xinyang, 464000, China.
| | - Kuangjia Li
- Development Research Center, Ministry of Water Resources of People's Republic of China, Beijing, 100032, China
| | - Feiyue Hu
- College of Ecology and Environment, Zhengzhou University, Zhengzhou, 450000, China
| | - Rui Xin
- School of Marine Science and Technology, Tianjin University, Tianjin, 300072, China
| | - Penglin Fan
- School of Geographic Sciences, Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution, Xinyang Normal University, Xinyang, 464000, China
| | - Yarou Lu
- School of Geographic Sciences, Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution, Xinyang Normal University, Xinyang, 464000, China
| | - Ningning Wang
- School of Geographic Sciences, Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution, Xinyang Normal University, Xinyang, 464000, China
| | - Mengyuan Qin
- School of Geographic Sciences, Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution, Xinyang Normal University, Xinyang, 464000, China
| | - Ruojing Li
- School of Geographic Sciences, Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution, Xinyang Normal University, Xinyang, 464000, China
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Wang Y, Gao L, Ming Y, Zhao L. Recent Declines in Nutrient Concentrations and Fluxes in the Lower Changjiang River. ESTUARIES AND COASTS : JOURNAL OF THE ESTUARINE RESEARCH FEDERATION 2023; 46:1-19. [PMID: 37362862 PMCID: PMC10196314 DOI: 10.1007/s12237-023-01216-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 06/28/2023]
Abstract
To elucidate nutrient variation patterns and trends over various timescales under combined effects of human activities and climate change, nutrient concentrations were monitored monthly in Lower Changjiang (Yangtze) River from November 2016 to August 2020. They were also monitored daily during an extreme flood in July 2020. Over daily and seasonal timescales, the Changjiang River discharges had a dominant influence on nutrient concentrations. By combining existing data over recent decades with those from the current study, we found that turning points for concentration trends for most nutrients emerged in the recent decade (2010-2020), i.e., 2012 for NO3-, PO43-, and NH4+ and 2014 for SiO32-. After these turning point years, NO3-, SiO32-, and PO43- concentrations decreased at annual rates of 2.953, 3.746, and 0.108 μM/year, respectively. Regarding NO3- and PO43-, their concentrations and fluxes increased from 1960s to 2012, similar to the increasing trends of anthropogenic N and P fertilizer inputs from the drainage basin. After 2012, concentrations and fluxes of NO3- and PO43- showed significant decreasing trends, largely due to the control of N and P fertilizer usage. A comparison among eight rivers in East and South China (including the Changjiang River) indicated that basin latitudes were essential to determining areal nutrient yields, implying that latitude-related factors, such as temperature, precipitation, and areal population density, significantly impacted nutrient fluxes. This study emphasized that the deteriorating Changjiang River aquatic environment (which lasted from 1960s to 2010) has been successfully terminated over the last 10 years in 2010s.
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Affiliation(s)
- Yao Wang
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200241 China
| | - Lei Gao
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200241 China
| | - Yue Ming
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200241 China
| | - Lingbin Zhao
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200241 China
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