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Investigation of seasonal variability of CDOM fluorescence in the southern Changjiang River Estuary by EEM-PARAFAC

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Acta Oceanologica Sinica 2015年第10期34卷 1-12页

作者： BAI Ying SU Rongguo HAN Xiurong zhang chuansong SHI Xiaoyong Key Laboratory of Marine Chemistry Theory and Technology of Ministry of Education Ocean University of China

The southern Changjiang River Estuary has attracted considerable attention from marine scientists because it is a highly biologically active area and is biogeochemically significant. Moreover, land-ocean interactions strongly impact the estuary, and harmful algal blooms （HABs） frequently occur in the area. In October 2010 and May 2011, water samples of chromophoric dissolved organic matter （CDOM） were collected from the southern Changjiang River Estuary. Parallel factor analysis （PARAFAC） was used to assess the samples＇ CDOM composition using excitation-emission matrix （EEM） spectroscopy. Four components were identified： three were humic-like （C1, C2 and C3） and one was protein-like （C4）. Analysis based on spatial and seasonal distributions, as well as relationships with salinity, Chl a and apparent oxygen utilization （AOU）, revealed that terrestrial inputs had the most significant effect on the three humic-like Components C1, C2 and C3 in autumn. In spring, microbial processes and phytoplankton blooms were also important factors that impacted the three components. The protein-like Component C4 had autochthonous and allochthonous origins and likely represented a biologically labile component. CDOM in the southern Changjiang River Estuary was mostly affected by terrestrial inputs. Microbial processes and phytoplankton blooms were also important sources of CDOM, especially in spring. The fluorescence intensities of the four components were significantly higher in spring than in autumn. On average, C1, C2, C3, C4 and the total fluorescence intensity （TFI） in the surface, middle and bottom layers increased by 123%-242%, 105%-195%, 167%-665%, 483%-567% and 184%-245% in spring than in autumn, respectively. This finding corresponded with a Chl a concentration that was 16-20 times higher in spring than in autumn and an AOU that was two to four times lower in spring than in autumn. The humification index （HIX） was lower in spring that in autumn, and the fluorescence index （F

关键词： southern Changjiang River Estuary chromophoric dissolved organic matter fluorescence excitationemission matrix spectroscopy parallel factor analysis humification index fluorescence index

Assessing the dynamics of chromophoric dissolved organic matter(CDOM) in the Yellow Sea and the East China Sea in autumn by EEMs-PARAFAC

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Science China Chemistry 2012年第12期55卷 2595-2609页

作者： YAN LiHong SU RongGuo zhang chuansong SHI XiaoYong ZHU ChenJian Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationOcean University of ChinaQingdao 266100China

In this study we have successfully characterized the fluorescent components of chromophoric dissolved organic matter(CDOM) in the Yellow Sea and the East China Sea in autumn using excitation-emission matrix fluorescence spectroscopy(EEMs) combined with parallel factor analysis(PARAFAC).PARAFAC aids the characterization of fluorescence CDOM by decomposing the fluorescence matrices into individual *** humic-like components(C1,C2,C3,and C4),one marine biological production component(C6),and two protein-like components(C5 and C7) were identified by *** researched the distributional patterns of fluorescence intensity,regression analyses between salinity,chlorophyll a concentration and fluorescence intensities of individual fluorophore,and regression analysis between salinity and fluorescence intensities percent of individual *** results revealed that C2 and C4 showed conservative mixing behavior,while C1 and C3 possessed conservative mixing behavior in high salinity region and additional behavior in low and middle salinity region,which were considered to be derived from riverine and degradation of organic matter from resuspended and/or sinking particles and show non-conservative mixing *** addition to riverine sources,the tryptophan-like C5 may receive widespread addition(likely from photo-degradation or biodegradation),while the most likely sources for the one marine humic-like C6 and tyrosine-like C7 were biological activity and microbial processing of plankton-derived CDOM,which were suggested to be of autochthonous origin and biologically *** application of EEM-PARAFAC modeling presents a unique opportunity to observe compositional changes,different mixing behavior and temporal variability in CDOM in the Yellow Sea and the East China Sea.

关键词： chromophoric dissolved organic matter fluorescence excitation emission Matrix spectroscopy PARAFAC model the Yellow Sea the East China Sea Yangtze Estuary conservative mixing behavior non-conservative mixing behavior

Temporal and spatial distribution of dissolved copper,lead,zinc and cadmium in the Changjiang Estuary and its adjacent waters

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Acta Oceanologica Sinica 2008年第4期27卷 73-82页

作者： WANG Changyou WANG Xiulin WANG Baodong zhang chuansong SHI Xiaoyong ZHU Chenjian College of Chemistry ＆ Chemical Engineering Ocean University of China Qingdao 266100 China First Institute of Oceanography State Oceanic Administration Qingdao 266061 China

Heavy metal concentrations were measured in the Changjiang Estuary and its adjacent waters. Results from a systematic survey in April 2002 to March 2003 indicate that the ranges of the concentrations of dissolved copper, lead, zinc and cadmium in the study waters are 1.01 - 6.86, 0. 10 - 0.39,3.17 - 9.12 and 0.011 - 0. 049 μg/dm^3 , respectively. Similar to zinc, the behavior of dissolved copper was essentially conservative, but high scatter has been observed for high salinity samples, which can be attributed to the decomposition or mineralization of organic matter by bacteria. Dissolved lead may have active behavior with an addition at high salinity. Overall concentrations of dissolved cadmium increase with salinity. The mean values of these dissolved metals calculated for the surface waters were higher than those for the middle and bottom ones. External inputs of dissolved heavy metals to the surface waters were the likely explanation for these higher values. The maximum seasonal average values of dissolved copper and zinc were found in summer, reflecting higher amounts of riverine input in this season. In contrast, the maximum seasonal average values of dissolved lead and copper were found in winter and the lowest ones in summer, respectively, which might be asso- ciated with a combination of low concentration with heterogeneous scavenging. Concentrations of these dissolved metals found for the Changjiang Estuary fall in the range observed for the other estuaries but are noticeably higher than those from uncontaminated rivers, except for cadmium. Compared with observations for the Changjiang Estuary in the last two decades, it is clear that the Changjiang estuarine waters has been contaminated with copper, lead, zinc and cadmium during China＇ s industrialization, but concentrations of them have decreased in the last few years.

关键词： heavy metals distribution biological activity East China Sea Changjiang Estuary

Seasonal Changes in Phytoplankton Biomass and Dominant Species in the Changjiang River Estuary and Adjacent Seas:General Trends Based on Field Survey Data 1959-2009

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Journal of Ocean University of China 2014年第6期13卷 926-934页

作者： YANG Shu HAN Xiurong zhang chuansong SUN Baiye WANG Xiulin SHI Xiaoyong Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationOcean University of China Yellow Sea Fisheries Research Institute Chinese Fisheries Science AcademyKey Laboratory of Sustainable Development of Marine FisheriesMinistry of Agriculture Agricultural Engineering College Weifang Vocational College National Marine Hazard Mitigation Service SOA

The characteristics of seasonal variation in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas were discussed based on field investigation data from 1959 to 2009. The field data from 1981 to 2004 showed that the Chlorophyll-a concentration in surface seawater was between 0.4 and 8.5 ktg dm-3. The seasonal changes generally presented a bimodal trend, with the biomass peaks occurring in May and August, and Chlorophyll-a concentration was the lowest in winter. Seasonal biomass changes were mainly controlled by temperature and nutrient levels. From the end of autumn to the next early spring, phytoplankton biomass was mainly influenced by temperature, and in other seasons, nutrient level （including the nutrient supply from the terrestrial runoffs） was the major influence factor. Field investigation data from 1959 to 2009 demonstrated that dia- toms were the main phytoplankton in this area, and Skeletonerna costatum, Pseudo-nitzschia pungens, Coscinodiscus oculus-iridis, Thalassinoema nitzschioides, Paralia sulcata, Chaetoceros lorenzianus, Chaetoceros curvisetus, and Prorocentrum donghaiense Lu were common dominant species. The seasonal variations in major dominant phytoplankton species presented the following trends： 1） Skeletonema （mainly S. costatum） was dominant throughout the year; and 2） seasonal succession trends were Coscinodiscus （spring） →Chaetoceros （summer and autumn） → Coscinodiscus （winter）. The annual dominance of S. costatum was attributed to its environmental eurytopicity and long standing time in surface waters. The seasonal succession of Coscinodiscus and Chaetoceros was associated with the seasonal variation in water stability and nutrient level in this area. On the other hand, long-term field data also indicated obvious interannual variation of phytoplankton biomass and community structure in the Changjiang River Estuary and adjacent seas： average annual phytoplankton biomass and dinoflagellate proportion bo

关键词： the Changjiang River Estuary and adjacent seas phytoplankton biomass dominant species seasonal variation

Nutrient composition and distributions in coastal waters impacted by the Changjiang plume

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Acta Oceanologica Sinica 2008年第5期27卷 111-125页

作者： WANG Xiulin WANG Baodong zhang chuansong SHI Xiaoyong ZHU Chenjian XIE Linping HAN Xiurong XIN Yu WANG Jiangtao College of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 China First Institute of Oceanography State Oceanic Administration Qingdao 266061 China

Four cruises were conducted during 2002--2003 in the Changjiang Estuary and adjacent coastal areas. The data presented show a clear coast to open sea gradient in nutrients related to the river inputs. Maximum values of chlorophyll a were typically observed at intermediate salinities at surface water and coincided with non-conservative decreases in nutrients along the salinity gradient, indicating that removal of nutrients was related to phytoplankton uptake. The seasonal variations of nutrient concentrations were just opposite to those of chlorophyll a, indicating that the seasonal variations of nutrients were mainly controlled by phytoplankton uptake, whereas riverine inputs merely weakened or balanced its extent. During the estuarine mixing, phosphate demonstrated some remobilization during all the four cruises; whereas both conservative and non-conservative behaviors for dissolved inorganic nitrogen and silicate were observed in the study area, indicating that both biotic and abiotic events may affect their behaviors during the estuarine mixing. Under the influence of freshwater inputs with high value of ratio of nitrogen to phosphorus, the estuarine and coastal waters impacted by the Changjiang plume were high （〉 30） in ratio of nitrogen to phosphorus, but rates of primary production were apparently not constrained by any kind of nutrient elements. However, the low （〈 1 ） ratio of silicate to nitrogen in most of the study area might be linked with the rapidly increasing frequency of harmful algal bloom （HAB） incidents in recent years in the coastal waters impacted by the Changjiang plume.

关键词： nutrients chlorophyll Changjiang River (Yangtze River) eutrophication mixing nutrient limitation

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

Distribution and germination of viable diatom resting stage cells in sediments of the East China Sea

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Acta Oceanologica Sinica 2010年第5期29卷 121-128页

作者： zhang Yuyu LU Songhui zhang chuansong GAO Yahui Key Laboratory of Ministry of Education for Coast and Wetland Ecosystems School of Life Sciences Xiamen University Xiamen 361005 China Research Center for Harmful Algae and Aquatic Environment Jinan University Guangzhou 510632 China College of Life Science South China Normal University Guangzhou 510631 China College of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 China

The abundance and temporal patterns of viable diatom resting stage cells in sediments of the East China Sea in 2006 have been *** abundance of viable resting stages was enumerated with the most probable number（MPN） ***,25 diatom species（including varieties） belonging to 16 genera were *** resting stage cells were common,on the order of 103 to 106 cells/g dry *** abundant taxa included Skeletonema marina,***,Chaetoceros curvisetus and Thalassiosira spp.,with Skeletonema accounting for 83.3% of the *** effects of temperature（10,15,20,25 ℃）,salinity（20,25,30,35 psu） and light intensity（0,300,4 000,8 000 lux） on the germination of resting stages in sediment samples were also *** results showed that light intensity had a significant positive effect on the germination of diatom resting stage cells（p 〈0.01） and that diatoms could not germinate in *** and salinity had no noticeable effects on the *** present study suggests that there are abundant diatom resting cells in sediments of the East China Sea,which could serve as a ＂seed bank＂ in the phytoplankton population succession and contribute to the initiation of algal blooms.

关键词： diatom germination MPN resting stages seed bank sediment

Nutrient distribution and variation in the Changjiang estuary and adjacent seas in recent 50 years

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Nutrient distribution and variation in the Changjiang estuar...

中国海洋湖沼学会第十次全国会员代表大会暨学术研讨会

作者： Dai Aiquan zhang chuansong Huang Jiangchan Shi Xiaoyong College of Chemistry and Chemical Engineering Ocean University of China Marine Chemistry Theory and Technology Key Laboratory of Ministry of Education

Since the mid-20th century, the nutrient concentration and productivity have undergone significant changes in waters of estuaries and the continental shelf in many countries. A lot of studies were focus on the nutrients in the Changjiang （Yangtze） River estuary and adjacent seas. Nevertheless, so far, due to the limitations of the scope of investigation, special study in depth in a larger scale of time and space is still scare. Based on above, this paper analyzed the distribution, seasonal variation, the average annual concentration and changes in nutrient structure of DIN, PO4-P and SiO3-Si in the year 1959,1984,1998 and 2007. Concentration distribution and changes in a long term of the nutrients in Changjiang River estuary and adjacent waters were studied. Through compared the nutrient character of the past 50 years, we concluded the following conclusions: The nutrient concentration of the Changjiang estuary and adjacent seas descend from coast to far offshore. High nutrient value area appeared in the Changjiang estuary and Zhoushan islands waters, and the isolines were dense. In summer, the high concentration range was very large, but in winter, the concentration was lower and the high value range was small. Nearly 50 years, the variation characteristics of DIN concentration in Changjiang estuary and adjacent seas basically presented as stage style. Nearly 50 years, the N/P ratio annual average of the Changjiang estuary and adjacent seas presented as stage style.

关键词： Changjiang River estuary nutrient distribution change

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基于光谱相似性指数的赤潮藻荧光识别技术

中国激光 2008年第1期35卷 115-119页

作者：胡序朋苏荣国张传松王修林中国海洋大学海洋化学理论与工程技术教育部重点实验室山东青岛266100

东海原甲藻(Prorocentrum dentatum)、裸甲藻(Gymnodinium stein)和中肋骨条藻(Skeletonema costatum)是近几年我国东海频繁引发赤潮的藻种。基于这三种赤潮藻的活体叶绿素荧光激发光谱,通过计算光谱相似性指数对其进行识别。结果表明,... 详细信息

东海原甲藻(Prorocentrum dentatum)、裸甲藻(Gymnodinium stein)和中肋骨条藻(Skeletonema costatum)是近几年我国东海频繁引发赤潮的藻种。基于这三种赤潮藻的活体叶绿素荧光激发光谱,通过计算光谱相似性指数对其进行识别。结果表明,活体叶绿素荧光激发光谱在平行测量和不同生长期的相对标准偏差(RSD)分别小于3%和5%;光谱混合及混合海藻荧光光谱与标准谱之间的光谱相似性指数与混合比例之间存在线性关系。通过计算混合藻的荧光光谱与标准谱之间的相似性指数能够定性地识别引发赤潮的藻种,并半定量地估计赤潮藻种的相对含量。当噪声小于25%时,噪声基本不会对赤潮藻的识别分析产生影响。

关键词：光谱学识别相似性指数荧光激发光谱赤潮藻