Journal of Ocean University of China

Marine and Atmospheric Sciences

  • The 9–11 November 2013 Explosive Cyclone over the Japan Sea-Okhotsk Sea: Observations and WRF Modeling Analyses

    FU Gang;JING Miaomiao;LI Pengyuan;

    During the period from 9 to 11 November 2013, an explosive cyclone(EC) occurred over the Japan Sea-Okhotsk Sea. This EC initially formed around 18 UTC 9 November over the Japan Sea and developed over the Okhotsk Sea when moving northeastward. It had a minimum sea level pressure of 959.0 hPa, a significant deepening rate of central pressure of 2.9 Bergeron, and a maximum instantaneous wind speed of 42.7 ms~(-1). This paper aims to investigate the conditions that contributed to the rapid development of this low-pressure system through analyses of both observations and the Weather Research Forecasting(WRF) modeling results. The evolutionary processes of this EC were examined by using Final Analyses(FNL) data, Multi-Functional Transport Satellites-1 R(MTSAT-1R) data, upper observation data and surface observation data. WRF-3.5 modeling results were also used to examine the development mechanism of this EC. It is shown that the interaction between upper-level and low-level potential vorticity seemed to be very essential to the rapid development of this EC.

    2020年05期 v.19 989-1004页 [查看摘要][在线阅读][下载 7478K]
  • Interannual Variability of Shelf and Slope Circulations in the Northern South China Sea

    LIU Na;GENG Bingxu;XUE Huijie;XIU Peng;WANG Qiang;WANG Dongxiao;

    The northern South China Sea(NSCS) is a dynamically complex region whose shelf and slope currents are driven by different mechanisms. In this study, we used field measurements to identify clear interannual variations in the circulation related to the El Ni?o-Southern Oscillation cycle. To investigate the modulation mechanisms, we used a high-resolution numerical model that covers the shelf and slope regions of the NSCS. The results indicate that the stronger southwestward slope current during La Ni?a and stronger northeastward shelf current during El Ni?o in summer and winter are largely related to changes in wind forcing. The Kuroshio intrusion into the NSCS does not appear to significantly affect the circulation in the southwestern shelf region.

    2020年05期 v.19 1005-1016页 [查看摘要][在线阅读][下载 2674K]
  • Estimation and Prediction of Typhoons and Wave Overtopping in Qingdao, China

    WANG Zhifeng;LI Songtao;HAO Yan;MA Yan;WU Kejian;

    This study aims to estimate and predict the impact of climate change on typhoons and wave overtopping during typhoon progresses in Qingdao, China. The SWAN wave model is used to simulate wave elements. The scale coefficients of wave overtopping are estimated using an empirical prediction formula. A total of 75 tropical cyclones affected Qingdao from 1949 to 2019. These tropical cyclones can be grouped into eight categories according to typhoon tracks. Typhoon wind speed during Track G is projected to decrease, and those of the other seven typhoon progresses will increase by 0.35% – 0.75% in 2025, 0.69% – 1.5% in 2035, and 1.38% – 3.0% in 2055. The significant wave height and wave overtopping outside the bay are greater than those inside the bay. Among the 506 typical points selected, the maximum values of the significant wave height and wave overtopping inside the bay are mainly distributed in the range of 0 – 2 m and 0 – 60 m~3 km~(-1) s~(-1), respectively. The increments of the significant wave height and wave overtopping of Track F are most obvious. The significant wave height of Track F will increase by 50.5% in 2025, 51.8% in 2035, and 53.4% in 2055. In the 2℃ scenario, the maximum value of wave overtopping of Track F will increase by 21.9% in 2025, 24.3% in 2035, and 29.5% in 2055. In the 4℃ scenario, the maximum value of wave overtopping of Track F will increase by 21.9% in 2025, 24.3% in 2035, and 29.5% in 2055.

    2020年05期 v.19 1017-1028页 [查看摘要][在线阅读][下载 3363K]
  • Estimating Design Loads with Environmental Contour Approach Using Copulas for an Offshore Jacket Platform

    ZHAO Yuliang;LIU Dahui;DONG Sheng;

    Jacket-type offshore platforms are widely used for oil, gas field, and energy development in shallow water. The design of a jacket structure is highly dependent on target environmental variables. This study focuses on a strategy to estimate design loads for offshore jacket structures based on an environmental contour approach. In addition to the popular conditional distribution model, various classes of bivariate copulas are adopted to construct joint distributions of environmental variables. Analytical formulations of environmental contours based on various models are presented and discussed in this study. The design loads are examined by dynamic response analysis of jacket platform. Results suggest that the conditional model is not recommended for use in estimating design loads in sampling locations due to poor fitting results. Independent copula produces conservative design loads and the extreme response obtained using the conditional model are smaller than those determined by copulas. The suitability of a model for contour construction varies with the origin of wave data. This study provides a reference for the design load estimation of jacket structures and offers an alternative procedure to determine the design criteria for offshore structures.

    2020年05期 v.19 1029-1041页 [查看摘要][在线阅读][下载 1092K]
  • Real-Time Position and Attitude Estimation for Homing and Docking of an Autonomous Underwater Vehicle Based on Bionic Polarized Optical Guidance

    CHENG Haoyuan;CHU Jinkui;ZHANG Ran;GUI Xinyuan;TIAN Lianbiao;

    As an important tool for marine exploration, the autonomous underwater vehicle(AUV) must home in and dock at a docking station(DS) to be recharged, repaired, or to exchange information at set intervals. However, the complex and hostile underwater environment makes this process challenging. This study proposes a real-time method based on polarized optical guidance for determining the position and attitude of the AUV relative to its DS. Four polarized artificial underwater landmarks are positioned at the DS, which are recognized by the AUV vision system. Compared with light intensity, the polarization of a light beam is known to be better maintained at greater propagation distances, especially in underwater environments. The proposed method, which is inspired by the ability of marine animals to communicate, calculates the pose parameters in less than 10 ms without any other navigational information. The simulation results reveal that the angle errors are small and the position errors are no more than 0.116 m within 100 m in the coastal ocean. The results of underwater experiments further demonstrate the feasibility of the proposed method, which extends the operating distance of the AUV beyond what is currently possible while maintaining the precision of traditional optical guidance.

    2020年05期 v.19 1042-1050页 [查看摘要][在线阅读][下载 690K]
  • Geochemistry and Petrogenesis of Volcanic Rocks from the Continent-Ocean Transition Zone in Northern South China Sea and Their Tectonic Implications

    XU Yue;YANG Yaoming;YU Hongjun;GAO Wei;GAO Xiangxing;LIU Baohua;TIAN Xu;YANG Jichao;ZHANG Wenquan;

    Miocene–Pliocene(22–5 Myr) volcanism and associated seamounts are abundant in the continent-ocean transition(COT) zone in the margin of the north South China Sea(SCS). The petrogenesis of volcanic rocks from these seamounts and regional tectonic evolution of COT zone are poorly known. In this paper, we obtained whole-rock major and trace element compositions and Sr-Nd-Pb isotopic data for these volcanic rocks from the Puyuan and Beipo seamounts within COT zone, in northeastern SCS. Based on the geochemical analyses, the volcanic rocks are classified as alkaline ocean island basalts(OIB) and enriched mid-ocean ridge basalts(E-MORB). The OIBs from the Puyuan seamount are alkaline trachybasalts and tephrites that show enrichment of the light rare earth elements(LREE) relative to heavy rare earth elements(HREE) and more radiogenic Sr-Nd isotopic compositions, and have significant ‘Dupal isotopic anomaly'. In contrast, the E-MORBs from the Beipo seamount are tholeiitic basalts that have less enrichment in LREE and less radiogenic Sr-Nd isotopic compositions than the counterparts from the Puyuan seamount. Petrological and geochemical differences between the OIBs and MORBs from these two seamounts can be explained by different mantle sources and tectonic evolution stages of the COT zone. Syn-spreading OIB type basalts from the Puyuan seamount were derived from an isotopically ‘enriched', and garnet facies-dominated pyroxenitic mantle transferred by the Hainan mantle plume. In contrast, post-spreading E-MORB type basalts from the Beipo seamount are considered to be derived from the melting of isotopically ‘depleted' pyroxenite mantle triggered by lithosphere bending and subsequent post-rifting at the lower continental slope of the northern margin.

    2020年05期 v.19 1051-1061页 [查看摘要][在线阅读][下载 1007K]
  • Study on the Geo-Environmental Evolution of the Laolonggou Lagoon Under the Impacts of the Caofeidian Reclamation Project in Hebei Province

    YIN Cong;YE Siyuan;FENG Xiuli;YIN Yanhong;

    The Caofeidian Reclamation Project has been the biggest reclamation project in China so far, in which 310 km~2 sea areas were reclaimed along the coast of Hebei Province, and it also bring about many problems and defects for large reclaiming area. The study focuses on the influences of the engineering exerted on evolution of the Laolonggou Lagoon with the methods of topographical measurement and surface sediment analysis. The results demonstrate that the topographical changes in the Laolonggou Lagoon had been controlled obviously by the engineering at three stages. Besides, blocking and reopening of the shoal tidal channel also affected the geological environment of the lagoon area. In the aspect of topographical change, the Laolonggou Inlet first experienced deposition after the shoal tidal channel was blocked, followed by short-time eroding for quarrying and cofferdam construction in the east, then depositing slowly after the reclaiming activity ceased, and finally eroding after the shoal tidal channel was reopened. The project, particularly cofferdam construction led to the movement of the Laolonggou Inlet axis from west to east for 50 – 100 m. In the aspect of sediment variation, the reclamation project and hydrodynamic change resulted in the variation in compositions and distribution pattern. The western lagoon area has become land mainly constituted by silt, while the sediments in the eastern area have turned finer in size. After the shoal tidal channel was reopened, the current velocity in the Laolonggou Inlet has been enhanced, making the sediments at the bottom become coarser. The sediments around the Caofeidian foreland went through a process of changing in grain size from fine to coarse and back to fine again, and the sediments are mainly constituted by silt at present.

    2020年05期 v.19 1062-1072页 [查看摘要][在线阅读][下载 1330K]
  • Operational Laboratory Methods for GDGTs Groups Separation

    LIU Zhan;LI Li;HE Juan;CHEN Lingdi;WANG Junjian;JIA Guodong;

    Glycerol dialkyl glycerol tetraethers(GDGTs), specific membrane lipids synthesized mainly by bacteria and archaea, can be divided into isoprenoids and methyl branched alkyl GDGTs(i GDGTs and brGDGTs, respectively). Three GDGTs groups(i GDGTs, brGDGTs, and other membrane lipids) in a peat sample were separated and collected in this study using semi-preparative high-performance liquid chromatography(HPLC) and silica gel column chromatography. The obtained recoveries for the whole analytical procedure were 85% – 55% using semi-preparative HPLC and 70% – 20% using gel column chromatography. In addition, in each method, the recoveries of brGDGTs and iGDGTs were similar, regardless of the huge difference in their contents. High purity was found in the fractionated groups, determined based on ether cleavage and reduction. Moreover, the semi-preparative HPLC method could realize a better separation efficiency than the silica gel method, but it was time-consuming and required expensive equipment, while the silica gel chromatography method featured merits of time saving and convenient operation at the cost of a slight reduction in separation efficiency. The advantages of the silica gel method make it an operational laboratory method for batch experiments and isotopic studies.

    2020年05期 v.19 1073-1080页 [查看摘要][在线阅读][下载 621K]
  • Fuzzy Sliding Mode Active Disturbance Rejection Control of an Autonomous Underwater Vehicle-Manipulator System

    WANG Hongdu;LI Xiaogang;LIU Xin;KARKOUB Mansour;ZHOU Liqin;

    In this paper, a fuzzy sliding mode active disturbance rejection control(FSMADRC) scheme is proposed for an autonomous underwater vehicle-manipulator system(AUVMS) with a two-link and three-joint manipulator. First, the AUVMS is separated into nine subsystems, and the combined effects of dynamic uncertainties, hydrodynamic force, unknown disturbances, and nonlinear coupling terms on each subsystem are lumped into a single total disturbance. Next, a linear extended state observer(LESO) is presented to estimate the total disturbance. Then, a sliding mode active disturbance rejection control(SMADRC) scheme is proposed to enhance the robustness of the control system. The stability of the SMADRC and the estimation errors of the LESO are analyzed. Because it is difficult to simultaneously adjust several parameters for a LESO-based SMADRC scheme, a fuzzy logic control(FLC) scheme is used to formulate the FSMADRC to determine the appropriate parameters adaptively for practical applications. Finally, two AUVMS tasks are illustrated to test the trajectory tracking performance of the closed-loop system and its ability to reject and attenuate the total disturbance. The simulation results show that the proposed FSMADRC scheme achieves better performance and consume less energy than conventional PID and FLC techniques.

    2020年05期 v.19 1081-1093页 [查看摘要][在线阅读][下载 858K]
  • Design of Full-Ocean-Depth Self-Floating Sampler and Analysis of Factors Affecting Core Penetration Depth

    REN Yugang;LIU Yanjun;DING Zhongjun;LIU Baohua;ZHANG Jianhua;

    The hadal zone(ocean depths of 6 – 11 km) is one of the least-understood habitats on Earth because of its extreme conditions such as high pressure, darkness, and low temperature. With the development of deep-sea vehicles such as China's 7000 m manned submersible Jiaolong, abyssal science has received greater attention. For decades, gravity-piston corers have been widely used to collect loose subsea-sediment long-core samples. However, the weight and length of the gravity sampler cables and the operating environment limit sampling capacity at full ocean depths. Therefore, a new self-floating sediment sampler with a spring-loaded auto-trigger release and that incorporates characteristics from traditional gravity-driven samplers is designed. This study analyzes the process by which a gravity-piston corer penetrates the sediment and the factors that affect it. A formula for obtaining the penetration depth is deduced. A method of optimizing the sampling depth is then developed based on structure design and parametric factor modeling. The parameters considered in the modeling include the sampling depth, balance weight, ultimate stress friction coefficient, dimensions of the sampler, and material properties. Thus, a new deep-sea floating parametric sampler designed based on virtual prototyping is proposed. Accurate values for all the design factors are derived from calculations based on the conservation of energy with penetration depth, analyses of the factors affecting the penetration depth, and analyses of the pressure bar stability. Finally, experimental data are used to verify the penetration-depth function and to provide theoretical guidance for the design of sediment samplers.

    2020年05期 v.19 1094-1102页 [查看摘要][在线阅读][下载 673K]
  • Facile Route to Synthesize Pore Expanded Platelet SBA-15 for Enhanced Amidoxime-Functionalization and Efficient Extraction of U(Ⅵ) from Aqueous Solution

    JI Guojia;WANG Xingjun;ZHU Guiru;SONG Chenghao;YUAN Junsheng;GAO Congjie;

    Short channel platelet SBA-15 mesoporous material is one of the effective adsorbent for the recovery of U(Ⅵ) from aqueous solution. Nevertheless, the defect is that the mesoporous size limits the total stripping of attached U(Ⅵ) in recycling use and the increasing densities of organic groups after functionalization. Thus, a simple and controllable method was adopted to prepare SBA-15-type material with expanded pore channel by adding trimethylbenzene in synthesis procedure. The structure, morphology and functional groups were characterized by scanning electron microscope, powder X-ray diffraction, thermogravimetric analysis, transmission electron microscope, FTIR and N_2 adsorption-desorption isotherm analysis. Furthermore, the adsorption behavior of obtained product was test under various factors such as initial concentration, pH, elution rate and contact time. The pore expanded platelet SBA-15 exhibited higher U(Ⅵ) adsorption capacity, higher elution rate, and more bearing of amidoxime groups. Due to the higher amidoxime groups, the adsorption capacity of U(Ⅵ) on the amidoxime functionalized pore-expanded SBA-15 was 674 mg-Ug~(-1). The results show that the simple and controllable pore-expanded method is an effective strategy to enhance the elution effect and increase grafting amount of organic groups on the mesoporous materials.

    2020年05期 v.19 1103-1115页 [查看摘要][在线阅读][下载 1015K]

Life and Fisheries Sciences

  • Inhibition of Breast Cancer Resistance Protein(BCRP) by Ko143 Can Affect Pharmacokinetics of Enrofloxacin in Exopalaemon carinicauda

    ZHAI Qianqian;XU Yang;LI Cuiping;FENG Yanyan;CUI Yanting;MA Li;LI Jian;

    Adenosine triphosphate-binding cassette transporter breast cancer resistance protein(BCRP) exists highly in the apical membranes of epithelia, and is involved in drug availability. Ko143 is a typical inhibitor of BCRP in rodents. The synthetic antibacterial agent enrofloxacin(ENRO) is a fluoroquinolone employed as veterinary and aquatic medicine, and also a substrate for BCRP. BCRP gene highly expressed in the hepatopancreas and intestine of Exopalaemon carinicauda as was determined with real-time quantitative reverse transcription-polymerase chain reaction(RT-q PCR) method. The effects of Ko143 on the abundance of BCRP m RNA and ENRO pharmacokinetics in E. carinicauda were studied. The m RNA abundance of BCRP decreased significantly in hepatopancreas and intestine(P < 0.05) after Ko143 treatment. Co-administration of Ko143 significantly changed the pharmacokinetics of orally administered enrofloxacin, which was supported by higher distribution half-life(t_(1/2α)), elimination half-life(t_(1/2β)), area under the curve up to the last measurable concentration(AUC_(0-t)), peak concentration(C_(max)) and lower clearance(CL/F). These findings revealed that Ko143 downregulates BCRP expression in hepatopancreas and intestine, thus affects the pharmacokinetics of orally administered enrofloxacin in E. carinicauda. The drug-drug interaction can be caused by the change in BCRP activity if ENRO is used in combination with other drugs in shrimp.

    2020年05期 v.19 1116-1124页 [查看摘要][在线阅读][下载 400K]
  • Growth and Distribution of Amphioctopus fangsiao(d'Orbigny, 1839–1841) in Haizhou Bay, Yellow Sea

    PANG Yumeng;TIAN Yongjun;FU Caihong;REN Yiping;WAN Rong;

    Octopus fisheries have prospered in many areas of the world ocean over the last six decades. Despite degradation and overexploitation of Chinese coastal ecosystems, octopus has become a stable Chinese domestic fishery species. Among the octopus species in the Bohai and Yellow, East and South China Seas, Amphioctopus fangsiao(d'Orbigny [in Férussac & d'Orbigny], 1839–1841) plays an increasingly important role both economically and ecologically. However, no systematic research has been conducted on its biology and population dynamics in the China Seas. In this study, we characterized the growth and distribution of A. fangsiao in Haizhou Bay, Yellow Sea based on four years of trawl survey data. As the results, A. fangsiao is characterized by allometric growth and an overall sex ratio of 0.97 with a slight male bias. Small octopus can be observed through a whole year, suggesting that A. fangsiao may have an extended or continuous spawning season. A. fangsiao may migrate short distances along with seasonal changes and coastal currents, considering they overwinter in the offshore water and spawn in the inshore water. In addition to fishing pressure, annual variations in the population structure and biomass appeared to be influenced by ambient water temperature. These results provide basic biological information for a better understanding of the population dynamics and the ecological importance of A. fangsiao.

    2020年05期 v.19 1125-1132页 [查看摘要][在线阅读][下载 577K]
  • Possible Use of Lumpfish to Control Caligus elongatus Infestation on Farmed Atlantic Salmon: A Mini Review


    In this mini review, we systematized current knowledge about the number of Caligus elongatus on farmed Atlantic salmon in relation to the use of lumpfish as cleaner fish. The review was prompted by reports of an unusually large number of sea lice(C. elongatus) infestation of farmed salmon in northern Norway, Faroese Islands and Iceland and the urgent need to determine if common lumpfish can be used to reduce the number on farmed Atlantic salmon by actively grazing on sea lice. Available data from Norway clearly indicate that lumpfish grazes on C. elongatus, and it is possible to enhance this grazing with the assistances of livefeed conditioning prior to sea pen transfer and selective breeding. Observations from Iceland, Faroese Islands and Scotland also indicate that lumpfish can effectively lower infestations of C. elongatus on salmon. Overall, this mini review expresses that lumpfish can actively lower the number of C. elongatus on farmed Atlantic salmon.

    2020年05期 v.19 1133-1139页 [查看摘要][在线阅读][下载 395K]
  • Effects of Liaoning Hongyanhe Nuclear Power Plant on the Zooplankton Community in Summer of 2017

    WANG Junjian;TAO Zhencheng;WANG Yantao;WEI Hao;LIU Xin;LI Chaolun;

    To evaluate the effects of the Hongyanhe Nuclear Power Plant on the zooplankton community in the surrounding seawater during summer, multiple environmental factors and zooplankton distribution along the east coast of Liaodong Bay were investigated in the summer of 2017. In particular, the influences of seawater temperature, salinity, and chlorophyll a(Chl a) on the zooplankton community were analyzed. Zooplankton abundances and Chl a concentrations along the east coast of Liaodong Bay showed an initial increase followed by a decrease from July to September. During the three months, the zooplankton abundance was the highest(8116.70 ind m~(-3)) in August. The Shannon-Wiener index showed a downtrend from July to September, with the average value falling from 1.65 in July to 1.50 in September. Calanus sinicus, Paracalanus parvus, copepodid, and bivalve larvae were the dominant species/groups in the three months. The effects of the nuclear power plant's outlet on the environment factors were mainly reflected in the increased seawater temperature. Redundancy analysis showed that the zooplankton community was jointly affected by seawater temperature, salinity and Chl a concentration, and the degree of this impact varied monthly. The impact of seawater temperature on the zooplankton community was stronger than that of salinity. The primary impact of the Hongyanhe Nuclear Power Plant on the structure and distribution of the zooplankton community in the surrounding seawater during the summer was increased seawater temperature, which caused a reduction in the abundance of dominant species/groups.

    2020年05期 v.19 1140-1152页 [查看摘要][在线阅读][下载 915K]
  • Establishment and Characterization of Four Long-Term Cultures of Neural Stem/Progenitor Cell Lines from the Japanese Flounder Paralichthys olivaceus

    GAO Chen;SONG Huayu;WANG Mengxun;LIU Xiumei;ZHAO Jun;WANG Xubo;ZHANG Quanqi;

    Neurogenesis is an important progress wherein the neural stem cells(NSCs) differentiate into functional neurons under conductive conditions. Neurogenesis occurs continuously in different areas of the central neural system in adult teleosts compared with adult mammals. Therefore, NSC cell lines must be established to offer a valuable in vitro system for studies on neurogenesis and other related functions. In this study, four cell lines designated as PoB1, PoB2, PoBf and PoBh were established from the brain of the Japanese flounder Paralichthys olivaceus. The cell lines were sub-cultured over 150 times and still grew well in DMEM/F12 medium at 24℃. PoB1, PoB2, PoBf and PoBh were identified as neural stem/progenitor cell lines on the basis of the mRNA expression of nestin and/or aldh111 or slc6 a4 and the formation of neurospheres. The cells transfected with the pEGFP-C1 plasmid showed fluorescent signals with distinct reagent dependencies. The established cell lines from the brain of P. olivaceus offer a valuable system in vitro for the study of neurogenesis, fish neural regulation and endocrinology-related functions.

    2020年05期 v.19 1153-1162页 [查看摘要][在线阅读][下载 1075K]
  • Annual Occurrence of Calanus sinicus Carcasses in the Jiaozhou Bay and the Adjacent Waters

    WANG Shiwei;WAN Aiyong;ZHANG Guangtao;SUN Song;

    The dead proportion of a calanoid copepod Calanus sinicus population was investigated monthly with neutral red staining method at 12 stations in the Jiaozhou Bay and the adjacent waters from December 2008 to November 2009. C. sinicus could be observed through the whole year, with an evident numerical peak from February to April and an extremely low abundance in summer. Annual variation of the dead proportion differed greatly between adult females and copepodites. Dead females were observed only in the southern part and outside the bay sporadically in five months, when the egg production was the most active. Dead proportion of females was usually less than 5%. Dead copepodites could be observed in all but three months in summer in the whole study area, and the proportion varied between 3.8% – 18.2%. Death percentage of copepodites increased significantly in the northern part in January and June, when water temperature exceeded it's favorable limits; however, the fluctuated salinity had no significant effect on the survival of both females and copepodites. Thus the dead proportion of C. sinicus was relatively low in the Jiaozhou Bay, while difference could be observed between females and copepodites. Dead copepodites were common in all samples, but dead females were presented mainly as ‘reproduction cost' during generation alternation.

    2020年05期 v.19 1163-1168页 [查看摘要][在线阅读][下载 276K]
  • Carbon Sources of Sediment and Epifaunal Food Sources in a Tropical Mangrove Forest in North Sulawesi, Indonesia

    WU Zhiqiang;XIE Limei;CHEN Bin;DHAMAWAN I Wayan Eka;SASTROSUWONDO Pramudji;CHEN Shunyang;RIANTA Pratiwi;ERNAWATI Widyastuti;CHEN Guangcheng;

    The stable isotope ratios of nitrogen(δ~(15)N) and carbon(δ~(13)C) were applied in this study to analyze sediment carbon sources and primary food sources of epifauna in an oceanic mangrove forest in tropical North Sulawesi, Indonesia. Proportional contribution of mangrove-derived carbon to the food sources was compared among epifauna belonging to different feeding guilds. The sediment in the mangrove site with a depleted δ~(13)C signature(-28.02‰± 0.24‰) mainly consists of mangrove-derived carbon. Analysis using Bayesian stable isotope mixing model in the R program shows that mangrove-derived carbon can dominate the food sources of a majority of the epifauna(11 out of the total 18 species), especially 2 sesarmid crabs Parasesarma semperi and Sesarma sp., crab Epixanthus dentatus, and snails Terebralia sulcata and Optediceros breviculum, which belong to various feeding guilds. Mangrove-derived carbon has a proportional contribution to the food sources of fiddle crab Tubuca coarctata and 3 littorinid snails(Littoraria spp.) close to that of suspended particulate organic matter. Three planktophagous bivalve species(Anadara antiquata, Anadara sp. and Callista erycina) were found to mainly feed on seagrass-derived materials. Mean proportional contributions of mangrove-derived carbon to the food sources were 50.15%, 59.60%, 46.20% and 27.58% for the carnivorous, omnivorous, phytophagous and planktophagous groups, respectively. The results suggest that mangrove-derived carbon can directly(via grazing plant tissues) or indirectly(via deposit feedings) make an important contribution to the food sources of epifauna in the oceanic mangrove forest where the allochthonous input of organic carbon is low.

    2020年05期 v.19 1169-1176页 [查看摘要][在线阅读][下载 384K]
  • Simultaneous Quantification of κ-Carrageenan Oligosaccharides of DP 3, 5 and 7 by LC-MS/MS: Application to an in vitro Absorption Study

    YANG Yali;ZHANG Pengpeng;LIU Guilin;YANG Shuang;WANG Yuanhong;JIANG Tingfu;LV Zhihua;YU Mingming;

    Carrageenans are widely utilized in many commercial applications such as the food and pharmaceutical industry, due to their excellent functional properties. In this study, a sensitive LC-MS/MS method was developed to determine κ-3, κ-5, and κ-7 carrageenan oligosaccharides simultaneously. Optimum MRM transitions for κ-3, κ-5, and κ-7 carrageenan oligosaccharides were(645.079→565.111, [M-H]-),(515.137→474.946, [M-2H]~(2-)), and(471.484→445, [M-3H]~(3-)), respectively. Chromatographic separation was performed on an Amide column coupled with a guard column operated at 60℃ under stepwise gradient elution. The linearity of the LC-MS/MS method for κ-3, κ-5, and κ-7 carrageenan oligosaccharides, evaluated over the concentration range of 0.10- 20.0 μmol L~(-1), was excellent. The precisions of the method for κ-3, κ-5, and κ-7 carrageenan oligosaccharides were from 0.91% to 9.66%, and the inter-day precisions were from 0.92% to 10.5%. Validation of the LC-MS/MS method indicated that the method was precise and in line with the CFDA guidance. This method has been successfully applied to an in vitro absorption study.

    2020年05期 v.19 1177-1182页 [查看摘要][在线阅读][下载 507K]
  • Effect of pH, Temperature, and CO_2 Concentration on Growth and Lipid Accumulation of Nannochloropsis sp. MASCC 11

    PENG Xiaoling;MENG Fanping;WANG Yuejie;YI Xiaoyan;CUI Hongwu;

    This study determined growth and lipid accumulation in Nannochloropsis sp. MASCC 11 cultivated at different p H, temperatures, and CO_2 concentrations in 10-day period. The suitability for biodiesel production was also evaluated based on the fatty acid profiles of microalgae lipid. Nannochloropsis sp. MASCC 11 showed an excellent tolerance to acidic p H(as low as 4.0), high temperatures(at least 40℃), and high CO_2 concentrations(5%-15%), which are major stressed conditions in flue gas. The highest algal biomass was acquired at p H of 9.0(0.44 g L~(–1)), a temperature of 35℃(0.63 g L~(–1)), and a CO_2 concentration of 5%(2.27 g L~(–1)). Maximum lipid production was obtained at p H of 6.0(108.2 mg L~(–1)), a temperature of 35℃(134.6 mg L~(–1)), and a CO_2 concentration of 5%(782.7 mg L~(–1)). Synthesis of polyunsaturated fatty acids(PUFAs) in biomass was stimulated under high CO_2 concentrations, remaining above 80% of total fatty acids, mainly composed of C16:3, C18:2, and C18:3. This led to the algae-based biodiesel having a lower oxidation stability, better cold flow properties, and other parameters such as its kinematic viscosity, cetane number, and specific gravity complied with ASTM or EN 14214 biodiesel specifications. Therefore, the improvement of oxidative stability needs to be considered before Nannochloropsis sp. MASCC 11 lipid can be used for biodiesel production, even if this species can grow well under stressful conditions.

    2020年05期 v.19 1183-1192页 [查看摘要][在线阅读][下载 316K]
  • ~1H NMR Quantification of DHA and EPA in Fish Oil

    LV Jinxiao;WANG Cong;ZHANG Xiuli;LV Zhihua;YU Mingming;

    Fish oil is a popular nutritional product consumed in China. The beneficial effects of fish oil have been attributed to docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA). Hence, it is crucial to develop a rapid and precise method to determine the contents of EPA and DHA in fish oil. In this study, a rapid and accurate proton nuclear magnetic resonance method for the quantification of DHA and EPA was developed. Dimethyl terephthalate was selected as an internal standard, and the signals at 2.391 ppm for DHA and at 1.697 ppm for EPA were chosen for the quantification. Validation of the method was performed in terms of specificity, precision, and stability. The results indicated that the method was precise and in line with the China Food and Drug Administration guidance. The method has been successfully applied to characterize fish oil capsules obtained from four pharmaceutical companies. This study indicated that the rapid ~1H NMR method is suitable for the quality control of fish oil.

    2020年05期 v.19 1193-1197页 [查看摘要][在线阅读][下载 266K]
  • Characterization of the Complete Mitochondrial Genome of Arius dispar(Siluriformes: Ariidae) and Phylogenetic Analysis Among Sea Catfishes

    CUI Lei;DONG Yuelei;CAO Rongbo;ZHOU Xiaoyu;LU Songhui;

    The mitochondrial genome(mitogenome) was 16792 bp in length, containing 13 protein coding genes(PCGs), two rRNA genes(12 S rRNA and 16 S rRNA), 22 tRNA genes, and two main non-coding regions. Among these 37 genes, 28 genes were encoded on the heavy strand, while 9 genes were transcribed on the light strand. The non-coding regions of A. dispar included a control region, a light strand replication and another 11 intergenic spacers. The CR of A. dispar contained 8 conserved sequence blocks(CSBs), a termination-associated sequence(TAS) and a pyrimidine tract. Phylogenetic analysis based on 12 PCGs revealed that A. dispar was genetically closest to Arius arius. The families Schilbeidae, Claroteidae, Mochokidae, and Ariidae formed a closely evolved clade. Molecular information from this research introduces mitogenomice data of A. dispar and suggests the phylogenetic relationships among Siluriformes.

    2020年05期 v.19 1198-1206页 [查看摘要][在线阅读][下载 986K]
  • Phaeocystis globosa Bloom Monitoring: Based on P. globosa Induced Seawater Viscosity Modification Adjacent to a Nuclear Power Plant in Qinzhou Bay, China

    KANG Zhenjun;YANG Bin;LAI Junxiang;NING Yi;ZHONG Qiuping;LU Dongliang;LIAO Riquan;WANG Pei;Solomon Felix Dan;SHE Zhicai;JIA Zhen;LAO Yanling;LI Nan;

    The mucus produced by the outbreak of Phaeocystis globosa in the adjacent waters of the Fangchenggang Nuclear Power Plant(FCGNPP) in China has blocked the entrance of the cooling water filtration system of the FCGNPP, and posed a threat to the safe operation of the FCGNPP. At present, there is no related research on whether the changes in seawater viscosity could be used as a new method for monitoring and providing early warning of P. globosa tide. During a complete red tide cycle, the temporal and spatial changes in the hydrological conditions(temperature, salinity, dissolved oxygen), chlorophyll-a(Chl-a), composition and abundance of phytoplankton, number and size of P. globose colonies, concentration of transparent exopolymer particles(TEP) and the seawater viscosity were measured in this study. The results indicate that there was an extremely significant negative correlation between the physical seawater viscosity η_(T,S) and temperature, and the correlation coefficient reached-0.998. The biological seawater viscosity η_(Bio) was positively correlated with the number of P. globosa colonies, and the correlation coefficients is 0.747. Because the increase in phytoplankton abundance, especially during the outbreak of P. globosa and a large amount of mucus produced by the colonies could significantly increase seawater viscosity, we suggest that biological factors were the main reasons for the increase in seawater viscosity. The η_(Bio) was completely consistent with the occurrence process of P. globosa bloom and could be used as a valuable index for P. globosa bloom monitoring.

    2020年05期 v.19 1207-1220页 [查看摘要][在线阅读][下载 1194K]