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Adaptations of phytoplankton in the Indian Ocean sector of the Southern Ocean during austral summer of 1998-2014

Frontiers of Earth Science 2015年第4期9卷 742-752页

作者： R. K. MISHRA R. K. NAIK N. ANIL KUMAR ESSO-National Centre for Antarctic and Ocean Research Ministry of Earth Sciences (MoES) Vasco-da-Gama Goa India

This study investigates the effects of light and temperature on the surface water diatoms and chloro- phytes, phytoplankton in the Indian Ocean sector of the Southern Ocean （SO） during the austral summer of 1998- 2014. Significant longitudinal variations in hydrographic and biological parameters were observed at the Sub tropical front （STF）, Sub Antarctic front （SAF） and Polar front （PF） along 56°E-58°E. The concentrations of total surface chlorophyll a （Chl a）, diatoms, and chlorophytes measured by the National Aeronautics Space Agency （NASA） estimated by the Sea-Viewing Wide Field-of- View Sensors （SeaWiFS）, the Moderate Resolution Imaging Spectro Radiometer （MODIS）, and the NASA Ocean Biological Model （NOBM） were used in the study. Variations in the concentration of total Chl a was remarkable amongst the fronts during the study period. The contribution of diatoms to the total concentration of surface Chl a increased towards south from the STF to the PF while it decreased in the case of chlorophytes. The maximum photosynthetically active radiation （PAR） was observed at the STF and it progressively decreased to the PF through the SAF. At the PF region the contribution of diatoms to the total Chl a biomass was ≥80%. On the other hand, the chlorophytes showed a contrary distribution pattern with ≥ 70% of the total Chl a biomass recorded at the STF which gradually decreased towards the PF, mainly attributed to the temperate adaptation. This clearly reveals that the trend of diatoms increased at the STF and decreased at the SAF and the PF. Further, the trend of chlorophytes was increased at the STF, SAF and PF with a shift in the community in the frontal system of the Indian Ocean sector of the SO.

关键词： chlorophyll a diatoms chlorophytes SST,PAR Southern Ocean

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A new technique for rapid assessment of eutrophication status of coastal waters using a support vector machine

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Journal of Oceanology and Limnology 2018年第2期36卷 249-262页

作者： KONG Xianyu CHE Xiaowei SU Rongguo ZHANG Chuansong YAO Qingzhen SHI Xiaoyong Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education Ocean University of China Qingdao 266100 China

There is an urgent need to develop efficient evaluation tools that use easily measured variables to make rapid and timely eutrophication assessments, which are important for marine health management, and to implement eutrophication monitoring programs. In this study, an approach for rapidly assessing the eutrophication status of coastal waters with three easily measured parameters （turbidity, chlorophyll a and dissolved oxygen） was developed by the grid search （GS） optimized support vector machine （SVM）, with trophic index TRIX classification results as the reference. With the optimized penalty parameter C=64 and the kernel parameter y=l, the classification accuracy rates reached 89.3% for the training data, 88.3% for the cross-validation, and 88.5% for the validation dataset. Because the developed approach only used three easy-to-measure variables, its application could facilitate the rapid assessment of the eutrophication status of coastal waters, resulting in potential cost savings in marine monitoring programs and assisting in the provision of timely advice for marine management.

关键词： eutrophication assessment chlorophyll a dissolved oxygen turbidity support vector machine

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Responses of microbial activities and soil physical-chemical properties to the successional process of biological soil crusts in the Gurbantunggut Desert,Xinjiang

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Journal of Arid Land 2015年第1期7卷 101-109页

作者： BingChang ZHANG XiaoBing ZHOU YuanMing ZHANG Key Laboratory of Biogeography and Bioresources in Arid Land Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences

Biological soil crusts （BSCs） are capable of modifying nutrient availability to favor the establishment of biogeochemical cycles. Microbial activities serve as critical roles for both carbon and nutrient transformation in BSCs. However, little is known about microbial activities and physical-chemical properties of BSCs in the Gurbantunggut Desert, Xinjiang, China. In the present research, a sampling line with 1-m wide and 20-m long was set up in each of five typical interdune areas selected randomly in the Gurbantunggut Desert. Within each sampling line, samples of bare sand sheet, algal crusts, lichen crusts and moss crusts were randomly collected at the depth of 0-2 cm. Varia- tions of microalgal biomass, microbial biomass, enzyme activities and soil physical-chemical properties in different succession of BSCs were analyzed. The relationships between microalgal biomass, microbial biomass, enzymatic activities and soil physical-chemical properties were explored by stepwise regression. Our results indicate that micro- algal biomass, microbial biomass and most of enzyme activities increased as the BSCs developed and their highest values occurred in lichen or moss crusts. Except for total K, the contents of most soil nutrients （organic C, total N, total P, available N, available P and available K） were the lowest in the bare sand sheet and significantly increased with the BSCs development, reaching their highest values in moss crusts. However, pH values significantly decreased as the BSCs developed. Significant and positive correlations were observed between chlorophyll a and microbial biomass C. Total P and N were positively associated with chlorophyll a and microbial biomass C, whereas there was a significant and negative correlation between microbial biomass and available P. The growth of cyanobacteria and microorganism contributed C and N in the soil, which offered substrates for enzyme activities thus increasing enzyme activities. Probably, improvement in enzyme

关键词： chlorophyll a microbial biomass C soil enzyme physical-chemical properties biological soil crusts

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Effect　of　CeCl_3　on　the　Photosynthetic　Characteristics　of　Spirulina　Platensis

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Journal of Rare Earths 1994年第3期12卷 212-217页

作者：储钟稀牟梦华张和民高德禄吴兆明 Acad Sinica Beijing China

In this paper we report that CeCl3 could accelerate the synthesis of chlorophyll a and protein in spirulina platensis. and enhance the activity of oxygen evolution. We also found that the accelerations of CeCl3 in spirulina platensis culture solution of low NaHCO3 were more than in culture solution of high NaHCO3, therefore it was related to the concentration of NaHCO3 The absorption spectrum and low temperature (77 K) fluorescence emission spectrum of spirulina platensis with CeCl3 treated were significantly different from their controls,*** absorption peak of phycocyanin at 620 nm was higher than that of the *** absorption peak at the long wave region migrated from 676 to 680 nm, and its fluorecence emission ratios (730 nm/685～695 nm) of photosystem I(PSI) to photosystem Ⅱ(PS Ⅱ) were also higher than those of the control; the pitch of the spiral algal body became shorter, and induced structural changes too.

关键词： CeCl3 Spirulina platensis Oxygen evolution Protein chlorophyll a Phycocyanin

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Influence of mesoscale eddies on primary production in the South China Sea during spring inter-monsoon period

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Acta Oceanologica Sinica 2014年第3期33卷 118-128页

作者： HU Zifeng TAN Yehui SONG Xingyu ZHOU Linbin LIAN Xiping HUANG Liangmin HE Yinghui Key Laboratory of Marine Bio-resources Sustainable Utilization (LMB) South China Sea Institute of Oceanology Chinese Academy of Sciences University of Chinese Academy of Sciences Marine Biology Research Station at Daya Bay Chinese Academy of Science State Key Laboratory of Tropical Oceanology (LTO) South China Sea Institute of Oceanology ChineseAcademy of Sciences

Mesoscale eddies have been suggested to have an impact on biological carbon fixation in the South China Sea （SCS）. However, their overall contribution to primary production during the spring inter-monsoon pe riod is still unknown. Based on large-scale biological and environmental in situ observations and synchro nous remote sensing data, the distribution patterns of phytoplankton biomass and the primary production, and the role of mesoscale eddies in regulating primary production in different eddy-controlled waters were investigated. The results suggested that the surface chlorophyll a concentrations and water column inte grated primary production （IPP） are significantly higher in cyclonic eddies and lower in the anticyclonic eddies as compared to that in non-eddy waters. Although eddies could affect various environmental factors, such as nutrients, temperature and light availability, nutrient supply is suggested to be the most important one through which mesoscale eddies regulated the distribution patterns of phytoplankton biomass and pri mary production. The estimated IPP in cyclonic and anticyclonic eddies are about 29.5% higher and 16.6% lower than the total average in the whole study area, respectively, indicating that the promotion effect of mesoscale cold eddies on the primary production was much stronger than the inhibition effect of the warm eddies per unit area. Overall, mesoscale eddies are crucial physical processes that affect the biological car bon fixation and the distribution pattern of primary production in the SCS open sea, especially during the spring inter-monsoon period.

关键词： mesoscale eddies chlorophyll a primary production vertically generalized production model,remote sensing South China Sea

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Developing water quality retrieval models with in situ hyperspectral data in Poyang Lake,China

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Geo-Spatial Information Science 2016年第4期19卷 255-266页

作者： Fangyuan Chen Di Xiao Zhuochao Li School of Resource and Environmental Sciences Wuhan UniversityWuhanChina State-owned Assets Supervision and Administration Commission of Caidian District WuhanChina

Applying remote sensing techniques to develop the retrieval models and further to obtain the spatiotemporal information of water quality parameters is necessary for understanding,managing,and protecting lake *** study aimed to calibrate and validate the retrieval models for estimating the concentrations of chlorophyll a(C_(CHL)),suspended particulate matter(C_(SPM)),and dissolved organic carbon(C_(DOC))with the in situ hyperspectral measurements in Poyang Lake,China in 2010 and *** model calibration and validation results indicated that:(1)for C_(CHL)retrieval,significantly strong and moderate correlations existed between the measured and estimated values(with the correlation coefficient r=0.92 and r=0.76)using the exponential model and the three-band model,respectively,with biased estimation observed for the exponential model;(2)for retrieving C_(SPM),there was a strong correlation between the measured and estimated values(r=0.95)using the exponential model;and(3)no significant correlation between measured and estimated C_(DOC)values was found with our developed *** work is needed to allow the water quality of Poyang Lake to be accurately and steadily estimated,especially for C_(CHL)and C_(DOC).

关键词： chlorophyll a suspended particulate matter dissolved organic carbon exponential model three-band model remote sensing reflectance

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Transcriptional response of Microcystis aeruginosa to the recruitment promoting-benthic bacteria

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Journal of Oceanology and Limnology 2022年第1期40卷 153-162页

作者： Juan WANG Yuande PENG Zhi WANG Wansheng ZOU Xianjin PENG Qisheng SONG College of Life Sciences Hunan Normal UniversityChangsha 410081China Institute of Bast Fiber Crops Chinese Academy of Agricultural SciencesChangsha 410205China Department of Life Science Hunan University of Arts and ScienceChangde 415000China Division of Plant Sciences University of MissouriColumbia 65211MOUSA

Blooms of Microcystis aeruginosa occur frequently in many freshwater ecosystems around the world,but the mechanism of recovery has not been fully *** our previous study,three benthic bacterial species(***013,***06,and ***24)were identifi ed capable of promoting the recruitment of ***,we further investigated the transcriptional response of *** to the benthic bacteria in early phase of recruitment by means of RNA-Seq *** total,5803803 unigenes on average length of 404 bp were obtained from the transcriptome of *** were 54982 unigenes identifi ed as benthic bacteria-responsive unigenes based on the expression level *** of the protein-protein interaction analysis(PPI)show that the hub genes of the benthic bacteria responsive unigenes mediated network were ribosomal proteins of 30S and 50S,and the most signifi cant functional module of the network was related to the *** the unigenes encoding the translation initiation factors(IF-2,IF-3)and elongation factors(lepA,fusA,and tufA)were up-regulated to respond benthic ***,it indicates that the benthic bacteria have a positive infl uence on activating the ribosome during the early recovery stage of ***.

关键词： Microcystis aeruginosa ribosome benthic bacteria chlorophyll a

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Micro-phytoplankton distribution and biomass in and around a channel-based fish farm: implications for sustainable aquaculture

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Acta Oceanologica Sinica 2014年第12期33卷 180-191页

作者： SADALLY S. B NAZURALLY N TALEB-HOSSENKHAN N BHAGOOLI R Department of Biosciences Faculty of Science University of Mauritius Department of Marine and Ocean Science Fisheries and Mariculture Faculty of Ocean Studies

Micro-phytoplankton density, genera composition, chlorophyllaconcentration, and physico-chemical pa-rameters were investigated at five stations （S1-near the coast; S2 and S4-at the edges of the aquaculture set-up; S3-in the center of the set-up; and S5-nearby patch of corals） in and around a coastal channel-based fish farm. The highest total micro-phytoplankton density （TPD）, including diatoms, dinoflagellates and cyanobacteria, was recorded at S3 （（6.28±2.00）×10^6 cells/L） followed by S4 （（5.87±2.81）×10^5 cells/L）, S1 （（4.92×10^5±8.70×10^4） cells/L）, S5 （（3.54×10^5±5.33×10^4） cells/L） and S2 （（2.60±1.14）×10^5cells/L）. chlorophyll a and nutrient concentrations were highest at S3 and were positively correlated with TPD. Among the 35 genera documented in this study,Chaetoceros spp. was the dominant diatom whilePeridinium spp. was the most dominant dinoflagellate. Very low densities of toxic bloom-forming dinoflagellates were encountered during this study. These results suggest that occurrence of non-bloom densities of micro-phytoplankton, possibly due to the natural flushing of the existing lagoonal channel at the aquaculture site, yielded in little environmental impact and can represent an appropriate sustainable approach for future aquaculture de-velopment.

关键词： chlorophyll a micro-phytoplankton physico-chemical parameters sustainable aquaculture

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Community structure of aerobic anoxygenic phototrophic bacteria in algae-and macrophyte-dominated areas in Taihu Lake,China

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Journal of Oceanology and Limnology 2022年第5期40卷 1855-1867页

作者： Limei SHI Yuanfeng CAI Xiaoli SHI Min ZHANG Qingfei ZENG Fanxiang KONG Ping XU State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China The Philips Institute of Oral and Craniofacial Molecular Biology Virginia Commonwealth UniversityRichmondVA 23298-0566United States of America

Aerobic anoxygenic phototrophic bacteria(AAPB)repre sent a major group of bacterioplankton assemblages in many water systems and some are assumed to be closely associated with ***,studies on relationships between AAPB and cyanobacterial blooms are in *** dynamics of the abundance and diversity of AAPB was compared based on pufM gene in Meiliang Bay(featured by cyanobacterial blooms)and East Bay(featured by macrophyte)of Taihu Lake,a shallow subtropical lake in the East China *** abundance was not significantly different between the two sites,and they were positively correlated with dissolved organic carbon(DOC)*** ratios of AAPB to total bacteria varied from 3.4%to 11.5%and peaked in winter in both site *** significant differences of AAPB community compositions were detected between the two sites,but there was a separation between warm seasons(June,August,and October)and cold seasons(December,February,and April).Rhizobiales and Limnohabitans-like pufM sequences were significantly contributors for the difference between two seasons,and specially enriched in cold *** a(Ch1 a)and DOC were the most significant variables influencing the AAPB community ***,Porphyrobacter and Rhodospirillales-like pufM sequences were positively correlated with Ch1 a,indicating potential influence of cyanobacterial blooms on these AAPB *** results suggested that diverse AAPB ecotypes coexisted in Taihu Lake,and their ecological role in carbon cycling in the lake may not be ignored.

关键词： aerobic anoxygenic phototrophic bacteria cyanobacterial blooms dissolved organic carbon Alphaproteobacteria chlorophyll a

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Distribution of dissolved oxygen and causes of maximum concentration in the Bering Sea in July 2010

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Acta Oceanologica Sinica 2014年第6期33卷 20-27页

作者： SUN Xiuwu LIN Cai CHEN Yong ZHANG Yuanbiao WANG Jigang JI Weidong Third Institute of Oceanography State Oceanic Administration College of Ocean and Earth Sciences Xiamen University

According to data obtained in the Bering Sea during the 4th Chinese National Arctic Research Expedition, the distribution of dissolved oxygen （DO） was studied, causes of its maximum concentration were discussed, and the relationships between DO and other parameters, such as saliniW, temperature, and chlorophyll a were analyzed. The results showed DO concentration ranged from 0.53 to 12.05 mg/L in the Bering Sea basin. The upper waters contained high concentrations and the maximum occurred at the depth range from 20 to 50 m. The DO concentration decreased rapidly when the depth was deeper than 200 m and reached the minimum at the depth range from 500 to 1000 m, and then increased slowly with the depth increasing but still kept at a low level. On the shelf, the DO concentration ranged from 6.53 to 16.63 mg/L with a mean value of 10.75 mg/L, and showed a characteristic of decreasing from north to south. The DO concentration was higher in the area between the Bering Sea and Lawrence Island and was lower in the southeast and southwest of Lawrence Island at the latitude of 62°N. The formation of maximum DO concentration was concerned with phytoplankton photosynthesis and formation of the themocline. To the south of Sta. B07 in the Bering Sea basin, the oxygen produced by photosynthesis permeated to the deeper water and the themocline made it difficult to exchange vertically, and to the north of Sta. B07, the maximum DO concen- tration occurred above the themocline due to phytoplankton activities. On the shelf, the oxygen produced by phytoplankton photosynthesis gathered at the bottom of the thermocline and formed the DO maximum concentration. In the Bering Sea basin, the DO and salinity showed a weak negative correlation （r=0.40） when the salinity was lower than 33.1, a significant negative correlation （r=-0.92） when the salinity ranged from 33.1 to 33.7, and an irregular reversed parabola （r=0.95） when the salinity was greater than 33.7. Key words： Bering Sea, dissolved

关键词： Bering Sea dissolved oxygen maximum concentration stratification chlorophyll a

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