Review
Environmental Sciences
Wenlong Chen, Fang Guo, Weijie Huang, Jianguo Wang, Min Zhang, Qian Wu
Summary: Phytoplankton plays a crucial role in the estuarine ecosystem, but the Pearl River estuary (PRE) has experienced complex changes in phytoplankton community structure due to human activities. This review analyzes the variation characteristics of phytoplankton species, species diversity, and abundance in the PRE from the 1980s to 2020s. The results show a significant decrease in phytoplankton species, no significant difference in abundance, and a downward trend in species diversity. Human activities also greatly influence phytoplankton composition, with higher abundance in nearshore waters.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2023)
Article
Environmental Sciences
Xia Zhang, Lijun Cui, Songlin Liu, Jinlong Li, Yunchao Wu, Yuzheng Ren, Xiaoping Huang
Summary: This study investigated the composition and relationships of bacterial and phytoplankton communities in the Pearl River Estuary. It found that bacterial community composition varied with size fractions and salinity gradient across seasons. The study also revealed that the differences between particle-associated and free-living composition were more significant in the wet season. Additionally, positive co-occurrences were observed between phytoplankton species and bacterial populations, indicating mutual cooperation.
MARINE ENVIRONMENTAL RESEARCH
(2023)
Article
Environmental Sciences
Yujian Wen, Guodong Zhang, Yuyao Song, Guicheng Zhang, Jun Sun
Summary: The dilution experiment technique was employed in two cruises conducted in July-August and October-November 2020, with 14 stations in total. The study comprehensively investigates the grazing impact of microzooplankton on phytoplankton in the interior of Bohai Bay. Spatially and seasonally, both the microzooplankton grazing rates (m) and phytoplankton growth rates (& mu;(0)) were significantly higher in summer compared to autumn, and the growth rate of phytoplankton was positively correlated with temperature. The ratio of microzooplankton grazing rate to phytoplankton growth rate (m/& mu;(0)) showed no significant spatial and seasonal differences, indicating a consistent daily consumption of primary production by microzooplankton in the two seasons. Therefore, the research highlights a close coupling between microzooplankton grazing and phytoplankton growth in the Bohai Bay.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Environmental Sciences
Chi Hung Tang, Edward J. Buskey
Summary: Microzooplankton play a crucial role in connecting primary production and higher trophic levels in marine ecosystems. However, crude oil pollution can disrupt their grazing behavior and the relationship with phytoplankton, potentially leading to phytoplankton blooms.
MARINE POLLUTION BULLETIN
(2022)
Article
Oceanography
Michael R. Landry, Raleigh R. Hood, Claire H. Davies, Karen E. Selph, David Antoine, Mika C. Carl, Lynnath E. Beckley
Summary: This study investigated the plankton biomass structure, production, and grazing rates in the eastern Indian Ocean. The results showed that production and grazing rates increased significantly from south to north, with Prochlorococcus dominating productivity and microzooplankton accounting for most of the grazing. These findings are important for understanding the importance and changes in the marine ecosystem of the eastern Indian Ocean.
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2022)
Article
Biodiversity Conservation
Fangzhou Chen, Xiu Pei Koh, Mandy Lok Yi Tang, Jianping Gan, Stanley C. K. Lau
Summary: This study used a microbial community-based index to assess the ecological status of the Pearl River estuary in China, showing poor overall status. The index values decreased from the upper estuary to offshore areas and were positively correlated with nutrients and fecal indicator bacteria, representing eutrophication and fecal pollution levels. Machine learning analysis identified several bio-indicators at the genus level to supplement the index and improve assessment accuracy.
ECOLOGICAL INDICATORS
(2021)
Article
Environmental Sciences
Hongzhou Xu, Jian Shen, Dongxiao Wang, Lin Luo, Bo Hong
Summary: The Pearl River Estuary exhibits unique dynamics of subtidal estuarine circulation, with significant nonlinear advection effects observed, especially during spring tide. Overall, nonlinear advections play an important role in driving the circulation in the Pearl River Estuary, particularly during ebb tide.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Ecology
Marco J. Cabrerizo, Emilio Maranon
Summary: The study found that the highest grazing rates align with the highest growth rates, corresponding to medium cell sizes. There were no significant differences in growth or grazing between the smallest and largest cell sizes considered. The grazing-to-growth ratio was largely independent of cell size and C:N ratios, with low thermal dependence.
Article
Environmental Sciences
Xufei Liu, Nan Wang, Xiaopu Lyu, Yangzong Zeren, Fei Jiang, Xinming Wang, Shichun Zou, Zhenhao Ling, Hai Guo
Summary: The photochemical O3 pollution over the Pearl River Estuary is mainly affected by VOC and NOx, with different O3 formation mechanisms in two patterns.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Multidisciplinary Sciences
Guilherme Duarte Ferreira, Filomena Romano, Nikola Medic, Paraskevi Pitta, Per Juel Hansen, Kevin J. Flynn, Aditee Mitra, Albert Calbet
Summary: Mixoplankton impact grazing rate estimation, chlorophyll and cell counts are not sufficient, whole community approaches mimic reality better.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Nicole Millette, Christopher Kelble, Ian Smith, Kelly Montenero, Elizabeth Harvey
Summary: Microzooplankton grazing rates on phytoplankton were investigated in the coastal area of southern Florida, USA. The study found that microzooplankton consumed a higher proportion of primary production near the Everglades outflow compared to the Florida Keys.
Article
Geochemistry & Geophysics
Peihong Kang, Han Zhang, Zixiang Yang, Yifan Zhu, Biyan He, Qing Li, Cindy Lee, Tiantian Tang
Summary: This study measured stable carbon isotope patterns of individual amino acids in suspended particles and surface sediments from the Pearl River Estuary in China, revealing that the carbon isotope values of individual amino acids gradually increase with salinity, indicating an increase in algal-derived organic carbon along the salinity gradient. Additionally, the isotopic difference between amino acids and bulk organic carbon varied significantly, with labile organic carbon contributing more to suspended particles than sediments. Using a Lability Model, dynamic contributions of semi-labile algal-derived organic carbon and terrestrial organic carbon to estuarine particulate organic carbon were evaluated, highlighting the importance of decomposition in shaping the composition and isotopic signature of particulate organic carbon in the estuary.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Multidisciplinary Sciences
Chong Sheng, Jiu Jimmy Jiao, Xin Luo, Jinchao Zuo, Lei Jia, Jinghe Cao
Summary: Large-river deltaic estuaries and adjacent continental shelves contain a previously unknown offshore freshened groundwater body, with potential as potable water or raw water source. This offshore low-salinity groundwater, likely a global phenomenon, has great potential in alleviating water shortages in highly urbanized coastal areas.
NATURE COMMUNICATIONS
(2023)
Article
Environmental Sciences
Theresa Wing Ling Lam, Lincoln Fok, Anson Tsz Hin Ma, Heng-Xiang Li, Xiang-Rong Xu, Lewis Ting On Cheung, Ming Hung Wong
Summary: This study examined the abundance of microplastics in the stomach and intestine of marine-cultured hybrid groupers in the Pearl River Estuary. Microplastics were found in all fish samples, with a higher concentration in the intestine than in the stomach, and predominantly in the form of fiber-shaped particles.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Ecology
Mara Freilich, Alexandre Mignot, Glenn Flierl, Raffaele Ferrari
Summary: Recent observations have shown an increase in phytoplankton biomass in the North Atlantic during winter, attributed to a release from grazing pressure. Mathematical formulations of grazing as a function of phytoplankton concentration that are quadratic or decrease faster than linearly at low concentrations can reproduce the observed fall to spring transition in phytoplankton.
Article
Ecology
Bingzhang Chen, David J. S. Montagnes, Qing Wang, Hongbin Liu, Susanne Menden-Deuer
Summary: Conventional analyses suggest that heterotrophs have a higher thermal sensitivity in metabolism compared to autotrophs, leading to trophodynamic imbalances with warming. However, a new analysis reveals that 92% of the difference in thermal sensitivity between autotrophs and heterotrophs arises from within-taxa responses. Differences in fitness among taxa only partially compensate for the positive relationship between temperature and growth rate within taxa, supporting the hotter-is-partially-better hypothesis. This highlights the importance of separating within- and across-taxa responses when comparing temperature sensitivities between groups.
AMERICAN NATURALIST
(2023)
Article
Microbiology
Satheeswaran Thangaraj, Haijiao Liu, Yiyan Guo, Changling Ding, Il-Nam Kim, Jun Sun
Summary: Ocean warming and acidification have interactive effects on coccolithophore physiology and result in significant biogeochemical changes. In this study, we investigated the long-term effects of different transitional periods on the physiology of the coccolithophore Chrysotila dentata under present and projected ocean conditions. Our results showed that physiological responses of HTHC cells decreased with long-exposure, but the overall physiology of HTHC cells continued to improve with each generation. This suggests that coccolithophore resilience increases over generations under ocean warming and acidifying conditions.
ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Engineering, Environmental
Yunxue Li, Sitong Liu, Zhiyong Ji, Jun Sun, Xianhua Liu
Summary: This study systematically investigated the sorption behavior of two typical microplastics (PVC and PE) to Zn(II) and their combined toxic effects on Chlorella vulgaris. The results showed that different microplastics exhibited different adsorption capacities for Zn(II) and the combined exposure to Zn(II) and microplastics had distinct effects on cell growth and oxidative stress.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Limnology
Kailin Liu, Jun Nishioka, Bingzhang Chen, Koji Suzuki, Shunyan Cheung, Yanhong Lu, Huijun Wu, Hongbin Liu
Summary: This study investigates phytoplankton growth and microzooplankton grazing, two critical processes in marine food webs, in the subarctic western Pacific and the Bering Sea. Results show that phytoplankton growth is primarily determined by nutrient availability and temperature. In the high-nutrient, low-chlorophyll regions, iron availability is the limiting factor. In the Gulf of Anadyr and Kamchatka Strait, phytoplankton growth is mainly limited by inorganic nitrogen. Microzooplankton grazing rate is influenced by temperature and prey availability. The study reveals different food web structures in areas with and without riverine iron input.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Environmental Sciences
Yuqiu Wei, Dongsheng Ding, Ting Gu, Yong Xu, Xuemei Sun, Keming Qu, Jun Sun, Zhengguo Cui
Summary: Data on the independent or combined effects of ocean acidification and warming on coastal eutrophication and organic pollution are limited. Acidification favors eutrophication and organic pollution, while warming inhibits these two variables. However, the interaction between acidification and warming in the future may exacerbate organic pollution but mitigate eutrophication.
MARINE POLLUTION BULLETIN
(2023)
Article
Biodiversity Conservation
Kailin Liu, Siyu Jiang, David J. S. Montagnes, Hongbin Liu, Liping Zheng, Bangqin Huang, Xin Liu, Bingzhang Chen
Summary: Body size is a crucial trait for individual fitness and ecological processes. This study examined the cell size of ciliate communities across global oceans and found that cell size increased with latitude, following Bergmann's rule. The main drivers of this trend were temperature and prey size. The results highlight the importance of both biotic and abiotic factors in shaping the size distribution of marine ciliates, which are essential for pelagic ecosystem functions. The extensive dataset and predictive trends contribute to understanding the impact of climate change on pelagic ecosystems.
Article
Environmental Sciences
Zhuo Chen, Ting Gu, Jun Sun
Summary: This study investigated the distribution and changes of pico-phytoplankton in the Eastern Indian Ocean and estimated their carbon biomass contributions. Prochlorococcus, Synechococcus, and picoeukaryotes were the major picophytoplankton taxa. Their abundance varied with depth, with Synechococcus in the surface layer and Prochlorococcus and picoeukaryotes in the subsurface layer. Environmental factors such as fluorescence, temperature, dissolved oxygen concentration, and nutrients played important roles in shaping the picophytoplankton communities in this region.
ENVIRONMENTAL RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
Yingjie Mao, Jun Sun, Congcong Guo, Shuang Yang, Yuqiu Wei
Summary: The direct sinking behavior of phytoplankton is crucial for the ocean carbon cycle. After comparing different methods, the SETCOL method was chosen for studying cell sinking behavior. The study analyzed samples from the South China Sea and found that the Kuroshio Current increased sinking rates while Tropical Storms slowed them down.
JOURNAL OF MARINE SYSTEMS
(2023)
Article
Environmental Sciences
Xianfeng Li, Wenzhe Xu, Shuai Song, Jun Sun
Summary: Water quality monitoring stations are essential for detecting excess pollutants in river sections, but identifying the causes of these exceedances can be challenging, especially in heavily polluted rivers with multiple contamination sources. In this study, we used the SWAT model to simulate pollution loads from different sources in the Haihe River Basin and analyzed the spatiotemporal distribution of pollutants. The results highlight the need for targeted prevention and control policies based on the primary sources of pollution loads in different regions.
MARINE POLLUTION BULLETIN
(2023)
Article
Ecology
Zhimeng Xu, Jiawei Chen, Yingdong Li, Erfan Shekarriz, Wenxue Wu, Bingzhang Chen, Hongbin Liu
Summary: Using high-throughput sequencing data, this study reveals that cold-seep sediment harbors a higher abundance and diversity of parasitic microeukaryotes compared to non-seep regions. The study also shows that microeukaryotic community heterogeneity is larger between habitats than within habitat, highlighting the importance of cold-seep sediment as a hotspot for microeukaryotic diversity.
Article
Environmental Sciences
Xinze Shuwang, Guodong Zhang, Danyang Li, Yujian Wen, Guicheng Zhang, Jun Sun
Summary: This study investigated the effects of human activity-induced environmental heterogeneity on the chromophytic phytoplankton in Bohai Bay. The results showed that human disturbance had a greater impact on the phytoplankton communities than natural factors. The assembly of the communities was influenced by both stochastic and deterministic processes, with different importance rankings in nearshore and offshore areas. Dissolved inorganic nitrogen, eutrophication index, and chemical oxygen demand were the main environmental factors affecting the phylogenetic turnover of the phytoplankton.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Yang Liu, Xiaofang Liu, Yi Long, Yujian Wen, Chao Ma, Jun Sun
Summary: This study investigates the molecular composition and component characteristics of marine dissolved organic matter (DOM) in the eastern Indian Ocean. It reveals the presence of thousands of individual DOM formulas, including recalcitrant compounds and stable components. The study also uncovers a shift in the composition of DOM with depth, indicating the aging of the water column.
Article
Environmental Sciences
Wenzhuo Yan, Zhuo Chen, Linlin Zhang, Feng Wang, Guicheng Zhang, Jun Sun
Summary: This study used the Utermohl method and carbon volume conversion to investigate the composition and distribution of phytoplankton in the western Tropical Pacific Ocean. Four primary groups of phytoplankton were identified: dinoflagellates (181 species), diatoms (73 species), cyanobacteria (4 species), and chrysophyceae (2 species). Clustering analysis revealed that phytoplankton could be classified into four groups based on their composition, which were closely related to ocean currents. The study also found that diatoms were abundant in areas influenced by current-seamount interaction, while areas with little influence from ocean currents were dominated by Trichodesmium. The majority of phytoplankton had an equivalent spherical diameter (ESD) of 2-12 μm, with some exceeding 25 μm. Nanophytoplankton (ESD = 2-20 μm) dominated cell abundance, but microphytoplankton (ESD = 20-200 μm) contributed significantly to carbon biomass (792.295 mg m(-3)). This study provides valuable insights into the distribution and composition of phytoplankton in the western Tropical Pacific Ocean and their relationship with ocean currents, as well as fundamental information regarding cell size and carbon biomass within the region.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Environmental Sciences
Haijiao Liu, Changling Ding, Guicheng Zhang, Yiyan Guo, Yuyao Song, Satheeswaran Thangaraj, Xiaodong Zhang, Jun Sun
Summary: This study evaluated the distribution and pollution status of toxic heavy metals in seawater and sediment of the Bohai Bay coastal system. The results showed a decline in metal pollution due to recent pollution control measures. The seawater posed a moderate to high level of ecological risk, and the hydrochemical factors had different impacts on dissolved and suspended metals.
MARINE ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Marine
Lixing Wang, Yunpeng Zhang, M. Hesham El Naggar, Hao Liu, Xin Liu, Wenbing Wu, Jun Sun
Summary: This paper presents a novel CSW model to simulate the interaction between piles and cohesionless soil under lateral cyclic loads, which enhances the depiction of resistance and failure pattern of the soil. The validated model accurately predicts the response characteristics of piles under different loading conditions.
