夏季黄东海中华哲水蚤种群分布、脂类含量和利用策略

Chinese National Programs for Fundamental Research and Development(973 program) [2005CB422300]

The seasonal variations of several main water masses in the southern Yellow Sea (SYS) and East China Sea (ECS) in 2011 were analyzed using the in-situ data collected on four cruises. There was something special in the observations for the Yellow Sea Warm Current (YSWC), the Yellow Sea Cold Water Mass (YSCWM) and the Changjiang Diluted Water (CDW) during that year. The YSWC was confirmed to be a seasonal current and its source was closely associated with the Kuroshio onshore intrusion and the northerly wind. It was also found that the YSCWM in the summer of 2011 occupied a more extensive area in comparison with the climatologically-mean case due to the abnormally powerful wind prevailing in the winter of 2010 and decaying gradually thereafter. Resulting from the reduced Changjiang River discharge, the CDW spreading toward the Cheju Island in the summer of 2011 was weaker than the long-term mean and was confined to flow southward in the other seasons. The other water masses seemed normal without noticeable anomalies in 2011. The Yellow Sea Coastal Current (YSCC) water, driven by the northerly wind, flowed southeastward as a whole except for its northeastward surface layer in summer. The Taiwan Warm Current (TWC) was the strongest in summer and the weakest in winter in its northward movement. The Kuroshio water with an enhanced onshore intrusion in autumn was stable in hydrographic features apart from the seasonal variation of its surface layer.

Viral dynamics are the result of the balance between the rates of viral production and decay. Here, we have carried out independent measurements of viral production and decay rates in different depths of the southern East China Sea in summer (August and October 2021). In this study, the prevalence of viral abundance at the surface waters (14.2~27.6 × 105 viruses mL−1) was significantly higher than the bottom of the euphotic zone (2.9~12.6 × 105 viruses mL−1). As for viruses to bacteria ratio (VBR) values, we found a wide variability both at the surface (1.4 to 3.2) and bottom of the euphotic zone (2.1 to 16.2). The results of our study showed that at all stations examined, in the southern East China Sea, the values of gross viral production (GVP) were significantly higher in the sunlit surfaces compared to the bottom of the euphotic zone. In particular, our analysis indicates that no significant viral decay rates (VD) were observed in some regions at the bottom of the euphotic zone. Here, we also provide a budget for viral abundance and net viral production in different regions in the southern East China Sea. The GVP or VD is not applicable in our case to explain VBR is high at bottom of the euphotic zone. The mechanisms underlying VBR uncoupling, viral production, and viral loss in marine systems are still being investigated.

Progress on circulation dynamics in the East China Sea and southern Yellow Sea: Origination, pathways, and destinations of shelf currents

The East Asian marginal seas (EAMS) are one of the fastest‐warming ocean regions globally. This study presents the long‐term trends (1982–2020) of extreme ocean warming events called “marine heatwaves” over the EAMS and examines the relationships between marine heatwave trends and mean SST warming trends. We focus on five subregions with different influences from atmospheric perturbation and ocean currents: the northern East Sea (N‐ES), southern East Sea, Yellow Sea, Korea Strait (KS), and East China Sea (ECS). During the past four decades, marine heatwave duration and intensity in the EAMS have increased to approximately +4 days and +0.3°C per decade on average, respectively. In summer, the positive trend of marine heatwaves is the highest in the ECS, primarily due to the rapidly increasing mean sea surface temperature (SST). In winter, the N‐ES reveals remarkably rapid increases in marine heatwave properties in the last two decades, with increasing rates of approximately 6.2 (4.9) times longer total duration (stronger intensity) than the global average changes. Beyond the impact of the rapid increase in mean SST, the N‐ES marine heatwaves can be further extended due to the northward shift of the East Korea Warm Current. In general, mean SST changes are critical to the increasing trend in marine heatwave duration and intensity. This study further emphasizes that the changes in ocean circulation may expedite more rapid changes in extreme ocean events, which can produce more vulnerability in some places, such as the N‐ES, to marine heatwaves under continued global warming.

Carbonate chemistry variability in the southern Yellow Sea and East China Sea during spring of 2017 and summer of 2018

The progress on the studies of marine macrobenthic biodiversity from Chinese waters with a focus on the Yellow Sea is summarized in the present paper, with discussions of achievements in the fields of species composition, individual consistency, biomass, biodiversity, secondary productivity, macrobenthic community energy levels, and the introductions of research methods, impacts of environmental change and pollution. To date, Jiaozhou Bay, Changjiang Estuary, and the Fujian and Zhejiang coastal zones are the most intensively studied regions. The seminal research projects on macrobenthic ecology and biodiversity within the 第 6期 李新正: 我国海洋大型底栖生物群落多样性研究及展望: 以黄海为例 677 study region are also listed. In conclusion of the studies of macrobenthic ecology and biodiversity in China seas, the macrobenthic fauna from the Bohai Bay is the most simple. A total of 413 macrobenthic species have been found in this gulf, the common or dominant species are usually the hypothermal, euryhalinous warm water species; the annual mean biomass is 19.83 g/m, the Mollusca is the main contributing group to the biomass; the annual mean density is 474 inds./m, the Polychaeta and Mollusca are the two main contributing groups to the density. In the Yellow Sea, 853 macrobenthic species have been found. The common or dominant species are stenohaline warm water species; the annual mean biomass from the northern Yellow Sea is 99.66 g/m, the Echinodermata is the main contributing group to the biomass, the annual mean biomass from the southern Yellow Sea is 27.69 g/m, which is much lower than that from the northern Yellow Sea, the Polychaeta is the main contributor; the annual mean density from the northern Yellow Sea is 2,017.40 inds./m, that from the southern Yellow Sea is only 88.67 inds./m. In fact, the mean density and biomass from the northern Yellow Sea is much higher than those from other areas in China seas; the annual mean secondary productivity from the southern Yellow Sea is 4.98 g(AFDW)/m, the two high areas of secondary productivity are located in the two sides of the Yellow Sea Cold Water Mass. In the East China Sea, there have been found 1,300 macrobenthic species, in which, 45 are common or dominant ones; the differences among the seasonal mean biomasses are indistinct, usually spring>winter>summer>autumn; the annual mean biomasses from area off Zhejiang Province(28.22 g/m)>Changjiang Estuary area (15.55 g/m) >Taiwan Strait (8.98 g/m), the annual mean density from the East China Sea is 164 inds./m, the trend of the density is higher and higher from north to south areas. In the South China Sea, 1,661 macrobenthic species, distinctly more than those from the Bohai Gulf, Yellow Sea and East China Sea, part of dominant species are the same as those from the East China Sea, very different from those from the Bohai Gulf and the Yellow Sea; the annual mean biomass is 20.06 g/m, usually the seasonal biomasses are spring>winter>autumn> summer, the Mollusca and Echinodermata are the two main contributing groups to the biomass; the annual mean density is 198 ind./m, usually the seasonal densities are summer>spring>winter>autumn, the Polychaeta is the main contributor to the density. The main themes of this research are ever-increasing impacts from human activities and global climate change, and the pressing need for conservation of marine biological resources. The conservation and sustained utilization of marine biological resources need the understanding of the changing mechanisms of marine macrobenthic biodiversity based on the approach of long-term change of marine environment.

Distinct variations and mechanisms for terrestrial OC 14C-ages in the Eastern China marginal sea sediments since the last deglaciation

Sediment settling velocity (w s) patterns are well established at the Huanghe and Changjiang river mouths, but no w s results have been reported for the Yellow Sea and the East China Sea (YSECS) shelves due to the labor-intensive and time-consuming aspect of traditional w s measurement approaches (e.g., settling column method). This disadvantage can be overcome by the acoustic Doppler velocimeter (ADV). In this study, ten ADV-based field campaigns were conducted over various seasons of the years 2011 and 2013 at six YSECS sites, five on the East China Sea shelf (28 to 87 m depth) and one on the Yellow Sea shelf (74 m depth). The results demonstrate that ADV backscatter was a reliable proxy of suspended sediment concentration over a measurement range of 1 to 1,000 mg/L. The ADV-estimated w s was highest (1.43–1.88 mm/s) in summer in the southern East China Sea, and lowest (0.07 mm/s) in spring in the northern Yellow Sea. This can plausibly be explained by the hydrodynamic environment and bottom sediment type at the campaign sites. More importantly, the data reveal evidence of marked seasonal variations of w s in the middle sector of the East China Sea, as well as intra-tidal variations at all campaign sites. However, these variations of w s are not directly regulated by current velocity or suspended sediment concentration. This aspect represents a major challenge in future research in this shelf region and, for that matter, in similar settings worldwide. Evidently, expanding on the well-resolved continuous time series provided by the ADV approach is a key step in this direction.

Abstract. This paper describes the distribution of living coccolithophores (LCs) in the Yellow Sea and the East China Sea in summer and winter, and its relationship with environmental factors by canonical correspondence analysis (CCA). We carried out a series of investigations on LCs distribution in the Yellow Sea and the East China Sea in July and December 2011. 210 samples from different depths were collected from 44 stations in summer and 217 samples were collected from 45 stations in winter. Totally 20 taxa belonging to coccolithophyceae were identified using a polarized microscope at the 1000 × magnification. The dominant species of the two seasons were Gephyrocapsa oceanica, Emiliania huxleyi, Helicosphaera carteri, and Algirosphaera robusta. In summer the abundance of coccolithophore cells and coccoliths ranged 0–176.40 cells mL−1, and 0–2144.98 coccoliths mL−1, with the average values of 8.45 cells mL−1, and 265.42 coccoliths mL−1, respectively. And in winter the abundance of cells and coccoliths ranged 0–71.66 cells mL−1, and 0–4698.99 coccoliths mL−1, with the average values of 13.91 cells mL−1 and 872.56 coccoliths mL−1, respectively. In summer, the LCs in surface layer were mainly observed on the coastal belt and southern part of the survey area. In winter, the LCs in surface layer had high value in the continental shelf area of section P. The comparison among section A, section F, section P and section E indicated lower species diversity and less abundance in the Yellow Sea than those in the East China Sea in both seasons. Temperature and the nitrate concentration may be the major environmental factors controlling the distribution and species composition of LCs in the studying area based on CCA. Abbreviations: LCs: Living Coccolithophores; CCA: canonical correspondence analysis; DCM: Deep Chlorophyll Maximum

Fluctuations in distribution and relative abundance of Japanese Spanish mackerel, Scomberomorus niphonius, in the Yellow Sea, East China Sea and Sea of Japan

PDF HTML阅读 XML下载 导出引用 引用提醒 长江口及东海春季底栖硅藻、原生动物和小型底栖生物的生态特点 DOI: 10.5846/stxb201207090964 作者: 作者单位: 中国科学院海洋研究所,中国科学院海洋研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点基础研究发展计划（973）项目（2011CB403604）；中国科学院知识创新工程重要方向项目（KZCX2-EW-Z-5）；中国科学院海洋研究所"一三五"专项资助项目（2012IO060104） Ecological characteristics of benthic diatoms, protozoa and meiobenthos in the sediments of the Changjiang Estuary and East China Sea in spring Author: Affiliation: Institute of Oceanology,Chinese Academy of Sciences,Institute of Oceanology,Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:利用Ludox-QPS方法并结合沉积环境因子的综合分析，研究了2011年4月采自长江口及东海10个站位以底栖硅藻、纤毛虫和异养小鞭毛虫为代表的微型底栖生物及小型底栖生物的组成、丰度和生物量、分布及生态特点。结果表明，底栖硅藻的丰度（5.92×104 个/10 cm2）和生物量（83.29 μg C/10 cm2）远高于纤毛虫（丰度为1036 个/10 cm2，生物量为3.33 μg C/10 cm2）、异养小鞭毛虫（丰度为4451 个/10 cm2，生物量为2.51 μg C/10 cm2）和小型底栖生物（丰度为（1947±849）个/10 cm2，生物量为（49.01±22.05）μg C/10 cm2）。在鉴定出的11个小型底栖生物类群中，线虫占小型底栖生物总丰度的90%和总生物量的37%。底栖硅藻生物量在长江口及东海海域呈由近岸向外海逐渐降低的分布特点，而底栖纤毛虫、异养小鞭毛虫及小型底栖生物的分布则正相反。在垂直分布上，76%的硅藻和80%的线虫分布在0-2 cm沉积物表层，仅1%的硅藻和6%的线虫分布在5-8 cm分层。统计分析表明，底栖硅藻的现存量与沉积物中叶绿素a含量呈极显著的正相关，与底层水温度呈弱的正相关;该海域底栖原生动物和小型底栖生物的分布受多个因子而非单一环境因子的共同作用。对比分析表明，长江口及东海单位体积沉积物中的硅藻丰度较水体中的硅藻丰度高2个数量级，沉积物中相当部分的叶绿素a含量可能系底栖硅藻所贡献；表层8 cm沉积物中纤毛虫的丰度约是上层30 m水柱中纤毛虫丰度的30倍，生物量约是后者的40倍。尽管纤毛虫在生物量上远小于小型底栖生物，但其估算的生产力约是后者的3倍；而异养小鞭毛虫由于个体更小，其周转率可能较纤毛虫更高。长江口及东海陆架区原生动物和小型底栖生物的高现存量及生产力预示着其在该海域生态系统中的重要作用。 Abstract:Using the newly developed Ludox-QPS method, we investigated the community composition, abundance and biomass, and distribution of benthic diatoms, ciliates and heterotrophic microflagellates (HMF) and meiobenthos in combination with the analysis of benthic environmental variables at ten stations in the Changjiang (Yangtze) Estuary and East China Sea in April 2011. The benthic diatoms were dominant both in the abundance (5.92×104 ind/10 cm2) and biomass (83.29 μg C/10 cm2), followed by benthic ciliates (abundance: 1036 ind/10 cm2, biomass: 3.33 μg C/10 cm2) and HMF (4451 ind/10 cm2, 2.51 μg C/10 cm2). The abundance of meiobenthos in the upper 8 cm of sediments was (1947±849) ind/10 cm2 and the biomass was (49.01±22.05) μg C/10 cm2. Among the 11 meiobenthos groups identified, nematodes accounted for 90% of the total abundance and 37% of the total biomass. The biomass of benthic diatoms was distinctly higher in the coastal region than that in the offshore area, while the distribution pattern of benthic ciliates, HMF and meiobenthos was exactly opposite. On average 76% of diatoms and 80% of nematodes were distributed in the 0-2 cm sediment layers, while the respective proportions were only 1% and 6% in the 5-8 cm layers. Statistical analyses showed that the standing crops of benthic diatoms had significantly positive correlation with sediment chlorophyll-a contents and weak positive correlation with bottom water temperature, and benthic protozoa and meiobenthos might be structured by the interaction of multiple rather than single environmental variables. Our data indicate that the density of benthic diatoms in the sediments was very high, about two orders magnitude higher per unit volume than that in the water column of the Changjiang Estuary and East China Sea, where a great proportion of sediment chlorophyll a was contributed by benthic diatoms. The benthic ciliate abundance in the upper 8 cm of sediments were 30 times higher and the biomass was 40 times higher than those in the water column of upper 30 m of the Changjiang Estuary and East China Sea. Although the biomass of ciliates was lower than that of meiobenthos, their production was up to 3 times higher than that of meiobenthos. The relative turnover rate of heterotrophic microflagellates might even be much higher due to their small size. The high standing crops and production of benthic protozoa and meiobenthos indicate their important role in the ecosystem structure and function of the Changjiang Estuary and East China Sea. 参考文献 相似文献 引证文献

This study investigates the effects of surface vegetation density on the East Asian summer monsoon (EASM). The analysis using observation and reanalysis data reveals that the increase of vegetation drives a dipole pattern in the precipitation anomalies where the precipitation in Northeast Asia tends to increase, whereas the precipitation in southern China and East China Sea tends to decrease. The model sensitivity experiments confirm the mechanism of regional monsoon circulation changed by changes in surface vegetation density, in which enhanced vegetation leads to an increase of surface evapotranspiration and a decrease of surface temperature over land. The decrease in precipitation over southern China and East China Sea is attributed to the slow‐down of EASM circulation due to the reduction in thermal contrast between the continent and the ocean. The results suggest that the surface vegetation can change the local thermal conditions and induce the dynamical process in broader scale to change the precipitation response.

Effect of uv-b on lipid content of three antarctic marine phytoplankton

Bottom water at the center of the north East China Sea in summer: Remnant winter water