Jiaxing Liu

• PhD
• Research associate at Chinese Academy of Sciences

The major marine nitrogen‐fixing cyanobacterium, Crocosphaera watsonii, is restricted to warm tropical and subtropical oceans, while the underlying mechanisms remain unclear. C. watsonii fixes nitrogen (oxygen‐sensitive) and carbon (oxygen‐evolving) during night and day, respectively. By diel analyses of physiological rates and transcriptome at its...

Phytoplankton, the main contributor to ocean carbon and nitrogen fixation, responds rapidly to physicochemical changes caused by hydrodynamics. To understand the response of phytoplankton community succession to monsoon‐driven hydrographic changes, we analyzed the phytoplankton and environmental data of four cruises in the southern South China Sea...

The northeastern South China sea (NESCS) is characterized by highly dynamic currents regulated by monsoonal variability. To understand the responses of copepods to local currents, two cruises were conducted in the NESCS during the 2015/16 El Niño event in summer and winter. In the shelf waters off the NESCS, coastal upwelling (CU) occurs in summer...

Microorganisms are significant drivers of organic matter mineralization and are essential in marine biogeochemical cycles. However, the variations and influencing factors in prokaryotic communities from cold-seep sediments to the water column and the specific role of these microorganisms in biogeochemical cycles in the water column above cold seep...

Dinitrogen (N2) fixation is a crucial source of bioavailable nitrogen in carbon-dominated cold seep systems. Previous studies have shown that diazotrophy is not necessarily dependent on sulfate-dependent anaerobic oxidation of methane for energy, and diverse catabolism can fuel the high-energy-demanding process in sediments. However, it remains unc...

Labyrinthulomycetes play an important role in marine biogeochemical cycles, but their diversity, distribution patterns, and key regulatory factors remain unclear. This study measured the abundance and diversity of Labyrinthulomycetes in the Pearl River Estuary (PRE) to understand its distribution pattern and relationship with environmental and biol...

Dissolved organic phosphorus (DOP) is an important nutrient for phytoplankton growth in oligotrophic oceans. However, little is known about the impact of DOP on phytoplankton growth in eutrophic waters. In the present study, we conducted field monitoring as well as in situ and laboratory experiments in the Pearl River estuary (PRE). Field observati...

Marine diazotrophs convert dinitrogen (N2) gas into bioavailable nitrogen (N), supporting life in the global ocean. In 2012, the first version of the global oceanic diazotroph database (version 1) was published. Here, we present an updated version of the database (version 2), significantly increasing the number of in situ diazotrophic measurements...

Diazotrophic organisms are vulnerable to physical dynamic processes. However, the interactions and mechanisms of multiple dynamic processes on nitrogen fixation remain unclear. This study aimed to investigate one of these interactions; we conducted field investigations and bioassay experiments in the northeastern South China Sea, which faces the Ku...

The Indo-Pacific Convergence Zone (IPCZ) has a complex ocean dynamical system. All scale processes are active and interplay from small-scale turbulent mixing to basin-scale circulation. The IPCZ acts as an “oceanic bridge” for the inter-basin mass transports and basin-scale planetary waves, closely linking basin-scale circulations in the Pacific an...

Cluster 5 Synechococcus is one of the most important primary producers on earth. However, ecotypes of this genus exhibit complex geographical distributions, and the genetic basis of niche partitioning is still not fully understood. Here, we report distinct distributions of subcluster 5.1 (SC5.1) and subcluster 5.2 (SC5.2) Synechococcus in estuarine...

We analyzed picoeukaryotes during the Luzon winter bloom, in combination with remote sensing, flow cytometry and high throughput sequencing. Satellite images showed a seasonal increase in phytoplankton in the study area during winter, and the in situ campaign observed an extremely high abundance of photosynthetic picoeukaryotes, which were the main...

To understand zooplankton community changes in the context of climate change and anthropogenic disturbances, we analyzed mesozooplankton samples from four seasons in the subtropical Daya Bay, which is susceptible to perceived disturbances in the South China Sea. The zooplankton community was found to be divided into two clusters, namely the Outer-b...

Recognizing the prokaryotic community and its functions in hypoxic (>5 to ≤60 μM O 2 ) environments before further expansion of OMZs is critical. We demonstrate the prokaryotic community and its potential functions in nitrogen metabolism in the Bay of Bengal (BoB), where oxygen concentration is barely above suboxic level.

Kuroshio intrusion into the South China Sea (SCS) varies seasonally and interannually under different climatic conditions. To characterize the intensity of the climate‐driven Kuroshio intrusion and its impact on the phytoplankton community in the northeastern South China Sea (NESCS), two cruises were conducted during the 2015/16 El Niño event. In s...

Daya Bay is a eutrophic coastal region with dynamic physico-chemical conditions influenced by terrestrial inputs and seawater intrusion. Zooplankton is a crucial trophic intermediary for energy transfer and fishery resources. In this study, we assessed the distribution and composition of zooplankton in Daya Bay during summer and winter of 2015. We...

Spatial variations in summertime phytoplankton community structure from 1991 to 2017 in Daya Bay, China were investigated in this research. The abundance of total phytoplankton and diatoms signifcantly increased during the study period in all regions of the bay while an increase in dinoflagellates abundance was only signifcant in the inner and middl...

Regional studies in marine science.

Large amounts of aluminum (Al) enter the ocean through atmospheric dust deposition and river runoffs. However, few studies have reported the effects of Al on marine phytoplankton, especially nitrogen-fixing cyanobacteria. By using the isotope tracer method and quantitative reverse transcription PCR (RT-qPCR), we examined the physiological effect of...

This study examines the physiological responses of the Symbiodinium voratum (clade E) to two types of phosphates having different chemical bonds—phosphoesters (C-O-P bonds) and phosphonates (C-P bonds) to explore Symbiodinium cell growth and the molecular perspective of the P utilization process. Alkaline phosphatase (AP), PhnX, PhoA and PhoX expre...

The genus Symbiodinium is an important primary producer in coral reef ecosystem and plays a key role in coral reef construction. Yet knowledge of growth kinetics of these photosynthetic endosymbionts and their physiological responses is limited. To study the physiological responses to temperature and light intensity of Symbiodinium, Symbiodinium vo...

We present the first concurrent measurements of N 2 fixation rates ( ¹⁵ N 2 uptake), primary production ( ¹⁴ C uptake), dissolved organic carbon (DOC) concentrations, and diazotrophic community composition derived from nitrogenase (nifH) abundance in the subtropical Daya Bay (DB) of the coastal northern South China Sea (NSCS) from 2015 to 2017. N 2...

根据2014 年9 月(秋季)、12 月(冬季)、2015 年4 月(春季)、2016 年7 月(夏季)在南澳岛与东山岛之间的近 海海域进行的生态环境调查, 分析了该海域叶绿素a 浓度和初级生产力的时空变化特征。结果表明, 叶绿素a 浓度 变化范围为0.37~14.9 μg/L, 平均值分别为: 夏季(8.2 μg/L)>秋季(4.9 μg/L)>冬季(1.52 μg/L)>春季(1.47 μg/L)。表层 初级生产力的波动范围为0.6~45 mg(C)/(m ³ ·h), 平均值分别为: 秋季20.3 mg(C)/(m ³ ·h) > 夏季18.2 mg(C)/(m ³ ·h)>春 季14.4 mg(C)/(m ³ ·h)>冬季5.6 mg(C)/(m ³ ·h)。水柱初级生产力变动范围为...

Nutrients’ concentration, phytoplankton biomass, and primary productivity were investigated in six coral atolls in the central South China Sea during the southwest monsoon in the early summer. Nutrients’ concentrations were generally very low in these atolls, and showed no obvious variation among outer reef slope, reef flat, and lagoon. The spatial...

The influence of anthropogenic nutrient loading on the stable isotopic signatures (δ¹³C and δ¹⁵N) in the suspended particulate organic matter (SPOM) is still not fully understood. Water quality and the values of δ¹³C and δ¹⁵N in the SPOM were investigated in the surface water of Daya Bay during the spring of 2016 and 2017. The results indicated tha...

The dependence of a biological variable (metabolic rate, etc.) on body mass (volume and biomass, etc.) is typically characterized by an allometric scaling law. This relationship can be applied to populations, communities and ecosystems after scale conversion. The marine environment is very complex and the plankton metabolic rate is not only affecte...

The Pearl River Estuary is the second largest estuary in China. This study reported the species composition and size structure of mesozooplankton in the upper and lower Pearl River estuary in the dry and wet seasons. The normalized biovolume size spectrum of mesozooplankton was constructed to analyze the trophic structure of the community. Copepods...

Based on in situ physical and biological data collected in different seasons between 2014 and 2015, we described systematically the spatial-seasonal characteristics of chlorophyll a (Chl a) and primary production (PP) in the Pearl River Estuary (PRE) and their relationships with environmental factors. The results indicated that the average values o...

Estuarine oxygen depletion is one of the worldwide problems, which is caused by the freshwater-input-derived severe stratification and high nutrients loading. In this study we presented the horizontal and vertical distributions of dissolved oxygen (DO) in the Pearl River estuary, together with temperature, salinity, chlorophyll a concentration and...

Compared to extensive studies reporting the aluminum (Al) toxicity to terrestrial plants and freshwater organisms, very little is known about how marine phytoplankton responds to Al in the field. Here we report the marine phytoplankton responses to Al enrichment in the South China Sea (SCS) using on-deck bottle incubation experiments during eight c...

In this study, we used flow cytometry and 16S rRNA gene pyrosequencing to investigate bacterioplankton (heterotrophic bacteria and picocyanobacteria) abundance and community structure in surface waters along the Pearl River Estuary. The results showed significant differences in bacterioplankton dynamics between fresh- and saltwater sites and betwee...

Although a large amount of aluminum enters the ocean through atmospheric dust deposition every year, the effect of aluminum on marine phytoplankton is seldom examined. Few studies focused on the effects of aluminum on marine nitrogen-fixing cyanobacteria, which play important roles in nitrogen and carbon cycling in the ocean. In this study, a unice...

In order to study the release and distribution characteristics of the nutrients and the distribution of Chlorophyll and Pheophorbide-a in the water and sediments during the algal blooms, we took the samples in the Pearl River Estuary in January. The results showed that the content of NO3-Nand NH4-N in the water were higher and accounted for 59 % an...

Nutrient concentration and phytoplankton biomass were investigated in Huangyan Atoll in May 2015. The concentrations of nutrients were very low, and dissolved inorganic nitrogen was composed mainly of ammonia. Nitrogen likely was the primary limiting factor for phytoplankton growth. The spatial variation of phytoplankton biomass was significant amo...

To understand the distribution of aluminum (Al) under the influence of mesocale eddies in the western South China Sea (SCS), sea level anomaly, geostrophic current, environmental parameters and reactive Al were investigated in the western SCS in August 2013. The highest reactive Al concentration ((180±64) nmol/L) was observed in the surface waters,...

Biological N2 fixation rate and primary productivity in surface seawater were measured using 15N and 14C tracer assays, respectively, at 28 stations in the northeastern South China Sea during October 2014. Combined with variables including temperature and salinity, dissolved nutrients and chlorophyll a, the spatial distribution of N2 fixation rate,...

Effects of marine aluminum (Al) on phytoplankton are controversial, making it important to elucidate the mechanisms underlying Al effects. This study was aimed at identifying the effects of Al on the growth, chlorophyll a (chl a) content and the antioxidant mechanism of cyanobacteria Synechococcus sp. WH7803. The growth rate increased from 0.33 to...