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Paleoenvironmental implications of Holocene long-chain n-alkanes on the northern Bering Sea Slope

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Acta Oceanologica Sinica 2017年第8期36卷 137-145页

作者： ZHANG Haifeng WANG Rujian XIAO Wenshen laboratory of marine ecosystem and biogeochemistry State Oceanic Administration State key laboratory of marine Geology Tongji University

The records of high-resolution terrestrial biological markers （biomarkers） from Core B2-9 from the northern Bering Sea Slope over the last 9.6 ka BP were presented in the study. Variations in input of terrestrial long-chain n-alkanes （referred to as n-alkanes） and vegetation structure in their source regions were investigated. The results show that the nCz7 is the main carbon peak and has the greatest contribution rate of the total n-alkane content; this might be related to the abundance of woody plants and their spatial distribution in the source region, nC23 is another n-alkane having a relatively high content; this was mainly derived from submerged plants widespread along the coastal areas in the northern hemisphere. Total n-alkane content dropped quickly at ca. 7.8 ka BP, ca. 6.7 ka BP and ca. 5.4 ka BP, and was followed by four relatively stable stages mostly controlled by sea-level rise, climate change and vegetation distribution in the source region. Variation in carbon preference index （CPI） indicates that the n-alkanes primarily originated from higher land plants, and the average chain length （ACL） and nCa1/nC27 ratio reveal the relatively stable presence of woody/herbaceous plants during the Holocene, and dominate woody plants in most of the time. Simultaneous variation in total n-alkane content, nC27 content and its contribution, CPI, ACL and nC31/nC27 ratio over several short periods suggest that the growth rate of the woody plant n-alkane contribution was lower than that of herbaceous plants and fossil n-alkanes under the particular climatic conditions of the source region.

关键词： Bering Sea terrestrial input long-chain n-alkanes vegetation structure Holocene

Seasonal distribution of macrobenthos and its relationship with environmental factors in Yellow Sea and East China Sea

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Journal of Oceanology and Limnology 2018年第3期36卷 772-782页

作者：寿鹿廖一波汤雁滨陈建芳江志兵高爱根陈全震 Key Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyState Oceanic Administration key laboratory of Applied marine Biotechnology Ministry of Education Marine College of Ningbo University

Macrobenthos samples were collected from the Yellow and East China Seas in four seasons during 2011 to 2012. The seasonal distribution of macrobenthos and its relationship with environmental factors were analyzed. A total of 562 macrobenthic species were identified, with polychaetes and mollusks accounting for 67% of the total number of species. A similarity percentage(SIMPER) analysis showed that the dominant species were bivalve mollusks in the Yellow Sea and small-sized polychaetes in the East China Sea. A two-factor analysis of variance showed significant seasonal variations in species number, density and diversity index, and significant regional differences of biomass and density. Two-factor community similarity analysis also showed significant seasonal and regional differences in macrobenthic communities. Canonical correspondence analysis indicated that the main environmental factors af fecting the macrobenthic communities were water depth, temperature, dissolved oxygen, and inorganic nitrogen. The results demonstrate significant regional differences and seasonal variations in macrobenthos in the two seas. Sediment properties and water mass characteristics are speculated to be the causes of regional differences.

关键词：季节性环境因素理论研究湖泊

Macrobenthic assemblages of the Changjiang River estuary (Yangtze River, China) and adjacent continental shelf relative to mild summer hypoxia

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Chinese Journal of Oceanology and Limnology 2017年第3期35卷 481-488页

作者：廖一波寿鹿汤雁滨曾江宁高爱根陈全震严小军 Key Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyState Oceanic Administration key laboratory of Applied marine Biotechnology Ministry of Education Marine College of Ningbo University

To assess the effects of hypoxia, macrobenthic communities along an estuarine gradient of the Changjiang estuary and adjacent continental shelf were analyzed. This revealed spatial variations in the communities and relationships with environmental variables during periods of reduced dissolved oxygen(DO) concentration in summer. Statistical analyses revealed significant differences in macrobenthic community composition among the three zones: estuarine zone(EZ), mildly hypoxic zone(MHZ) in the continental shelf, and normoxic zone(NZ) in the continental shelf(Global R =0.206, P =0.002). Pairwise tests showed that the macrobenthic community composition of the EZ was significantly different from the MHZ(pairwise test R =0.305, P =0.001) and the NZ(pairwise test R =0.259, P =0.001). There was no significant difference in macrobenthic communities between the MHZ and the NZ(pairwise test R =0.062, P =0.114). The taxa included small and typically opportunistic polychaetes, which made the greatest contribution to the dissimilarity between the zones. The effects of mild hypoxia on the macrobenthic communities are a result not only of reduced DO concentration but also of differences in environmental variables such as temperature, salinity, and nutrient concentrations caused by stratification.

关键词：大型底栖动物群落大陆架缺氧区长江口夏季邻近扬子江成对测试

A new record of Candacia varicans Giesbrecht, 1892 (male)(Crustacea: Copepoda: Candaciidae) from the South China Sea

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Acta Oceanologica Sinica 2018年第10期37卷 202-204页

作者： LIU Zhensheng SUN Dong LI Xiaohui Second Institute of Oceanography State Oceanic Administration Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration

The male of Candacia varicans Giesbrecht, 1892 from the South China Sea was recorded and described. In general, the male of C. varicans is morphologically similar to those of C. arrnata and C. curta. However, it is distinguished with them by below several morphological characters：（1） posterolateral corners of the fifth thoracic segment prominently sharp and symmetrical; （2） right side of posterior edge of genital segment with a small backward protuberance; and （3） the dorsal surface of the third segment of the fifth pereiopod with a squamashaped protuberance.

关键词： copepods new record Candacia varicans the South China Sea

The first record of Porcellanaster ceruleus (Echinodermata:Porcellanasteridae) in the South China Sea

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Acta Oceanologica Sinica 2018年第10期37卷 185-189页

作者： ZHANG Ruiyan WANG Xiaogu ZHOU Yadong LU Bo WANG Chunsheng Key Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China

Porcellanasteridae is a group of starfish that live in the deep ocean around the world. The type species of this family, Porcellanaster ceruleus Wyville Thomson, 1878, is cosmopolitan as well as polymorphic. The first record of its occurrence in the South China Sea is reported in this paper. One specimen was caught in the South China Sea on June 6, 2015 by trawl and identified to be a P. ceruleus. The morphological characteristics of this specimen are described and detailed pictures are provided. The discovery of this specimen further expands the distribution of P. ceruleus in the Pacific Ocean. The world distribution records of P. ceruleus and its synonymic species are reviewed in this paper.

关键词： Porcellanasteridae PorceUanaster ceruleus new record South China Sea

Characteristics of particle fluxes in the Prydz Bay polynya, Eastern Antarctica

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Science China Earth Sciences 2019年第4期62卷 657-670页

作者： Zhengbing HAN Chuanyu HU Weiping SUN Jun ZHAO Jianming PAN Gaojing FAN Haisheng ZHANG Second Institute of Oceanography Ministry of Natural Resources Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration China University of Geosciences

The settling of particulate carbon in seawater is a key component of the ocean carbon cycle. We deployed a set of sediment trap in the polynya of Prydz Bay from December 2010 to December 2011 to investigate the seasonal variations in particle fluxes. There was a clear seasonal variation in the particle fluxes, with maximum and minimum fluxes recorded during the summer and winter, respectively. The average total flux over the sampling period was 193.58 mg m^(-2)d^(-1), and the average fluxes of organic carbon(C_(org)), inorganic carbon(C_(inorg)), and biogenic silica(Si_(bio)) were 721.78, 28.67, and 2382.80 μmol m^(-2) d^(-1), respectively. Si_(bio)was the main contributor to the total mass flux, and strongly correlated with C_(org). The high Si_(bio)/C_(org)molar ratios(>1) suggest that C_(org)was transported to deep sea in association with Si_(bio). By comparing remote sensing data of sea ice and chlorophyll in the upper water column, we found that the dynamics of carbon fluxes were closely related to changes in sea ice. Algae in sea ice may have a key role in biological pump processes in early summer. Apart from the ice algae bloom period, variations in carbon fluxes generally corresponded with phytoplankton blooms in the upper water. The ballast effect controlled the particle settling velocity and the efficiency of the biological pump. Sea ice rafts initiated the first particle export event and enhanced the particle settling efficiency during melting period. As diatoms might become less dominant in the ice-free area, sea ice loss may cause the efficiency of the biological pump efficiency to decrease over the long term.

关键词： Prydz Bay Particle fluxes Polynya Ballast effect Biological pump efficiency

Calcareous Nannofossils and Molecular Fossils in Cobalt-rich Crusts and their Response to the P/E Global Event

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Acta Geologica Sinica(English Edition) 2013年第5期87卷 1264-1274页

作者： ZHANG Haisheng ZHAO Jun HAN Zhengbing LU Bing WU Guanghai PULYAEVA I.A. Key Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyState Oceanic Administration State Scientific Centre Yuzhmorgeologia

A biostratigraphic study on calcareous nannofossils from the CM3D06 Co-rich ferromanganese crust from the Magellan seamounts in the northwestern Pacific enabled estimation of depositional age. The bio-imprinting of calcareous nannofossils and other fossil species suggests six age ranges for the nannofossils： late Cretaceous, late Paleocene, （early, middle, late） Eocene, middle Miocene, late Pliocene, and Pleistocene. Gas chromatography （GC） and gas chromatography-mass spectrometry （GC-MS） were used to test the Co-rich crusts, and a variety of molecular fossils were detected, such as chloroform bituminous ＂A＂ , n-alkane, isoprenoid and sterol. Peak carbon and molecular indices （such as C23-/C24＋, CPI, Pr/Ph, Pr/nC17, Ph/nCxs and j13C） indicate that the parent organic matter is dominated by marine phytoplankton and thallogen whereas there is little input of terrestrial organic matter. Researches on calcareous nannofossils, molecular fossils and molecular organic geochemistry data reveal that the Paleocene/Eocene （P/E） global event is recorded in the cobalt- rich crusts from the northwestern Pacific Ocean. A succession of biomes can be observed near the 85 mm boundary （about 55 Ma）, i.e., the disappearance of the late Cretaceous Watznaueria barnesae and Zigodicus spiralis, and Broisonia parka microbiotas above the P/E boundary, and the bloom of Coccolithus formosus, Discoaster multiradiatus, Discoaster mohleri and Discoaster sp. below the boundary. Typical parameters of molecular fossils, such as saturated hydrocarbon components and carbon-number maxima, Pr/Ph, Pr/C17, Ph/C18, distribution types of sterols, Ts/Tm ratios and bacterial hopane, also exhibit dramatic changes near the P/E boundary. These integrated results illustrate that the biome succession of calcareous nannofossils, relative content of molecular fossils and molecular indices in the cobalt-rich crusts near the 85 mm boundary faithfully record the P/E global event.

关键词： Late Cretaceous cobalt-rich crust calcareous nannofossils molecular fossils Paleocene-Eocene boundary PETM

Variations of calcareous nannofossils of cobalt-rich crusts and geological records at the Eocene-OIigocene transition in western Pacific seamounts

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Science China Earth Sciences 2015年第4期58卷 784-794页

作者： ZHANG HaiSheng HU Ji ZHAO Jun HAN ZhengBing YU PeiSong WU GuangHai LEI Ji Jiang LU Bing Irina A PULYAEVA Second Institute of Oceanography State Oceanic Administration Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration State Scientific Centre Yuzhmorgeologia

Two records of the crust laminae from the Marcus-Wake Seamounts and the Magellan Seamount were biostratigraphically studied. Based on biological imprints of the calcareous nannofossils, the geological ages of the two records were determined, with CM1D03 from the Marcus-Wake Seamounts being of late Paleocene to Pleistocene and CM3D06 from the Magellan Seamount of Late Cretaceous(more than 70.0 Ma). There are the obvious temporal-spatial differences in the initial formation period and enrichment characteristics of the cobalt-rich crusts of the two seamount chains and differences in the combination and distribution of microfossils in the inner crust layers between the seamounts. These differences are due to the adaptabilities of oceanic species in different environments. Ecological research was carried out in terms of population size of the calcareous nannofossils preserved in the crustal layers to discern the relation of the geological events at the Eocene-Oligocene(E/O) transition. The results show the transitions and recombination of species in the biotic community during the E/O transition obviously corresponded to 25 mm depth in the CM1D03 crust and 58 mm depth in the CM3D06 crust. The changes in biological species and the formation of particular ecological structures indicate the adaptive response of the paleo-biological community in the western Pacific Ocean to the global cold-climate events and the close correlation between the formation of the crust and the global climate change.

关键词：钙质超微化石麦哲伦海山富钴结壳西太平洋始新世渐新世地质记录适应性反应

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The size-fractionated chlorophyll a and primary productivity in the Bering Sea during the summer of 2003

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Acta Oceanologica Sinica 2005年第6期24卷 127-134页

作者： LIU Zilin CHEN Jianfang CHEN Zhongyuan ZHANG Tao ZHANG Haisheng Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration Hangzhou 310012 China Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration Hangzhou 310012 China Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration Hangzhou 310012 China Key Laboratory of Ocean Dynamic Processes and Satellite Oceanography State Oceanic Administration Hangzhou 310012 China Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic Administration Hangzhou 310012 China

Investigations of chlorophyll a and primary productivity were carried out inthe Bering Sea along the BR line and the BS line during the Second Chinese National Arctic ResearchExpedition in the summer of 2003. The results showed that the surface chlorophyll a concentrationswere 0.199～1.170 μg/dm^3, and the average value was 0.723 μg/dm^3 on the BR line. For the BSline, the surface chlorophyll a concentrations were 0.519～4.644 μg/dm^3 (average 1.605 μg/dm^3)and 0.568～14.968 μg/dm^3 (average 5.311 μg/dm^3) during the early and late summer, respectively.The average value in the late summer was much higher than that in the early summer. The high values(more than 4.0 μg/dm^3) occurred at stations of the BS line in the southern Bering Strait. Thechlorophyll a concentrations in the subsurface layer were higher than those in the surface layer.The results of the size-fractionated chlorophyll a showed that the contribution of the picoplanktonto total chlorophyll a was the predominance at the early summer and the contribution of thenetplankton was the predominance at the late summer. The carbon potential primary productivitiesvaried between 0.471 and 1.147 mg/(m^3·h) on the BR line, with average rates of 0.728 mg/(m^3·h).The primary productivities on the BS line were much higher than those of the BR line, ranging from1.227 mg/(m^3·h) at the early summer to 19.046 mg/(m^3·h) at the late summer. The results of thesize-fractionated primary productivity showed that the contribution of the nanoplankton to totalproductivity was the predominance at the early summer and the contribution of the netplankton waspredominance at the late summer. The assimilation number of photosynthesis was 0.45～2.80 mg/(mg·h)in the surveyed stations.

关键词： chlorophyll a primary productivity the size-fractionated bering sea