Formation and evolution of the modem warm current system in the East China Sea and the Yellow Sea since the last deglaciation

To reconstruct the formation and evolution process of the warm current system within the East China Sea (ECS) and the Yellow Sea (YS) since the last deglaciation, the paleoceangraphic records in core DGKS9603, core CSH1 and core YSDPI02, which were retrieved from the mainstream of the Kuroshio Current (KC), the edge of the modem Tsushima Warm Current (TWC) and muddy region under cold waters accreted with the Yellow Sea Warm Current (YSWC) respectively, were synthetically analyzed. The results indicate that the formation and evolution of the modem warm current system in the ECS and the YS has been accompanied by the development of the KC and impulse rising of the sea level since the last deglaciation. The influence of the KC on the Okinawa Trough had enhanced since 16 cal kyr BE and synchronously the modem TWC began to develop with the rising of sea level and finally formed at about 8.5 cal kyr BP. The KC had experienced two weakening process during the Heinrich event 1 and the Younger Drays event from 16 to 8.5 cal kyr BP. The period of 7-6 cal kyr BP was the strongest stage of the KC and the TWC since the last deglaciation. The YSWC has appeared at about 6.4 cal kyr BP. Thus,the warm current system of the ECS and the YS has ultimately formed. The weakness of the KC,indicated by the occurrence of Pulleniatina minimum event (PME) during the period from 5.3 to 2.8 cal kyr BE caused the main stream of the TWC to shift eastward to the Pacific Ocean around about 3 cal kyr BP. The process resulted in the intruding of continent shelf cold water mass with rich nutrients. Synchronously, the strength of the YSWC was relatively weak and the related cold water body was active at the early-mid stage of its appearance against the PME background, which resulted in the quick formation of muddy deposit system in the southeastern YS. The strength of the warm current system in the ECS and the YS has enhanced evidently, and approached to the modern condition gradually since 3 cal kyr BP.     

Macrobenthic community structure and species composition in the Yellow Sea and East China Sea in jellyfish bloom

To understand the characteristics of macrobenthic structures and the relationship between environment and benthic assemblages in jellyfish bloom, we studied the macrobenthos and related environmental factors in the coastal waters of the Yellow Sea and East China Sea. Data were collected during two seasonal cruises in April and August of 2011, and analyzed with multivariate statistical methods. Up to 306 macrobenthic species were registered from the research areas, including 115 species of Polychaeta, 78 of Crustacea, 61 of Mollusca, 30 of Echinodermata, and 22 of other groups. Nine polychaete species occurred at frequencies higher than 25% from the sampling stations： Lumbrineris longifolia, Notomastus latericeus, Nin6e palmata, Ophelina acuminata, Nephtys oligobranchia, Onuphis geophiliformis, Glycera chirori, Terebellides stroemii, and Aricidea fragilis. Both the average biomass and abundance of macrobenthos are higher in August （23.8 g/m^2 and 237.7 ind./m^2） than those in April （11.3 g/m^2 and 128 ind./m^2）; the dissimilarity ofmacrobenthic structures among stations is as high as 70%. In terms of the dissimilarity values, we divided the stations into four clusters in spring and eight in summer. The ABC curve shows that the macrofauna communities in high jellyfish abundance were not changed. Canonical correspondence analysis showed that depth, temperature, median grain size, total organic carbon of sediment and total nitrogen in sediment were important factors affecting the macrozoobenthic community in the study area.     

Numerical Study of Water and Suspended Matter Exchange Between the Yellow Sea and the East China Sea

INTRODUCTIONTheYellowSeaandtheEastChinaSea (ECS)aremarginalseasofthenorthwestPacificandhaveexpansivecontinentalshelves .TheuniqueandstrikingfeaturesoftheYellowSeaandtheECSarethattheyhavestrongtidalcurrent;aresubjecttostrongmonsooninfluence ;andreceiveinflowfromthebiggestriverinChina ,theChangjiangRiver ;andthatthefamouswesternboundarycurrent,theKuroshio ,passesthroughtheECS ,withitsbranchesintrudingupwardintothecontinentalshelfareas.Generallyspeaking ,thewaterexchangecapacityofthe…     

Distribution of heavy metals and nutrients in rainwater in coastal regions between the southern Yellow Sea and East China Sea

Rainwater samples were collected in series in Qianliyan Island (southern Yellow Sea) and Shengsi Archipelago (East China Sea) between May 2000 and May 2002, chemical analysis for pH values,concentrations of heavy metals (Cu, Pb, Zn and Cd) and nutrients (NH4^-, NO3^-, PO43^-, SiO32^-) were performed.Results indicate that concentrations of most of the heavy metals and nutrients in rainwater show clear seasonal variation, i.e. high level in winter and low level in summer. Regionally, concentrations are higher in the southern Yellow Sea than in the East China Sea, but the annual input of heavy metals into oceans by wet deposition is similar in both stations. However, the input of nutrients by wet deposition in the East China Sea is 2-3 times higher than that in the southern Yellow Sea. In individual, Pb and PO4^3- are input to the sea mainly by dry deposition; whereas Cu, Zn, Cd and N compounds are input dominantly by wet deposition, the N/P ratios in the rainwater from two stations are much higher than those in seawater, showing a significant impact of atmospheric wet deposition on marine production and biogeochemical circulation of nutrients in these sea regions.     

Distribution of dissolved inorganic nitrogen over the continental slope of the Yellow Sea and East China Sea

Based on survey data from April to May 2009, distribution and its influential factors of dissolved inorganic nitrogen (DIN) over the continental slopes of the Yellow Sea (YS) and East China Sea (ECS) are discussed. Influenced by the Changjiang (Yangtze) River water, alongshore currents, and the Kuroshio current off the coast, DIN concentrations were higher in the Changjiang River estuary, but lower (<1 μmol/L) in the northern and eastern YS and outer continental shelf area of the ECS. In the YS, the thermocline formed in spring, and a cold-water mass with higher DIN concentration (about 11 μmol/L) formed in benthonic water around 123.2°E. In Changjiang estuary (around 123°E, 32°N), DIN concentration was higher in the 10 m layer; however, the bottom DIN concentration was lower, possibly influenced by mixing of the Taiwan Warm Current and offshore currents.     

A THREE-DIMENSIONAL THERMOCLINE MODEL FOR THE YELLOW SEA AND NORTHERN EAST CHINA SEA

A time-dependent, three-dimensional finite difference model is presented for simulating the stratifiedYellow Sea and northem East China Sea. The mode is forced by time-dependent observed wind, surfaceflux of heat, and tidal turbulence. With this model, momentum and temperature distribution can be computed,and an approximation for the sub-grid scale effects is introduced by the use of mass and momentumexchange coefficients. The vertical exchanges are quite dependent on these assumed coefficents, whichare complicated functions of the turbulence energy of tide and wind, of the stratified strength and otherfactors. This model was applied to describe the mechanics of the variations in strength and thickness ofthe thermocline covering almost the whole Yellow Sea and northern East Chna Sea in summer. Comparisonsof the computed output with obtained survey data led to some important conclusions.     

The distribution of dissolved aluminum in the Yellow and East China Seas

Water samples containing dissolved aluminum were collected from the Yellow and East China Seas in October-November 2000. The average concentrations of dissolved AI in the Yellow Sea （YS） and East China Sea （ECS） were 0.042 and 0.056 μ molL^-1, respectively. The concentration of dissolved aluminum decreased gradually across the continental shelf. The lower concentrations appeared in the YS cold water center and in the bottom layer at the shelf edge of the ECS, where they were 0.016 and 0.011 μmolL^-1, respectively. The distribution of dissolved Al was controlled by physical mixing processes rather than biological uptake processes. The impact of different water masses along the PN transect was calculated based on the mass balance model. The results show that the impact of the Changjiang River was mainly concentrated on the coastal area and the top thermocline water on the ECS shelf, where the impact percentage decreased from 12.6% to 1.1% in the surface water, while the contribution of the Kuroshio water was dominant on the ECS shelf in this survey, increasing from 77.6% to 97,8% along the PN transect from the Changjiang River Estuary to the Ryukyu Islands. It is concluded that aluminum can serve as a proper tracer for studying the impact of Changjiang terrestrial matter on the ECS shelf water.     

Formation and evolution of the modern warm current system in the East China Sea and the Yellow Sea since the last deglaciation

To reconstruct the formation and evolution process of the warm current system within the East China Sea (ECS) and the Yellow Sea (YS) since the last deglaciation, the paleoceangraphic records in core DGKS9603, core CSH1 and core YSDP102, which were retrieved from the mainstream of the Kuroshio Current (KC), the edge of the modern Tsushima Warm Current (TWC) and muddy region under cold waters accreted with the Yellow Sea Warm Current (YSWC) respectively, were synthetically analyzed. The results indicate that the formation and evolution of the modern warm current system in the ECS and the YS has been accompanied by the development of the KC and impulse rising of the sea level since the last deglaciation. The influence of the KC on the Okinawa Trough had enhanced since 16 cal kyr BP, and synchronously the modern TWC began to develop with the rising of sea level and finally formed at about 8.5 cal kyr BP. The KC had experienced two weakening process during the Heinrich event 1 and the Younger Drays event from 16 to 8.5 cal kyr BP. The period of 7–6 cal kyr BP was the strongest stage of the KC and the TWC since the last deglaciation. The YSWC has appeared at about 6.4 cal kyr BP. Thus, the warm current system of the ECS and the YS has ultimately formed. The weakness of the KC, indicated by the occurrence of Pulleniatina minimum event (PME) during the period from 5.3 to 2.8 cal kyr BP, caused the main stream of the TWC to shift eastward to the Pacific Ocean around about 3 cal kyr BP. The process resulted in the intruding of continent shelf cold water mass with rich nutrients. Synchronously, the strength of the YSWC was relatively weak and the related cold water body was active at the early-mid stage of its appearance against the PME background, which resulted in the quick formation of muddy deposit system in the southeastern YS. The strength of the warm current system in the ECS and the YS has enhanced evidently, and approached to the modern condition gradually since 3 cal kyr BP. Supported by the National Natural Science Foundation of China (Nos. 90411014 and 40506015), the National major Fundamental Research and Development Project (No. 2007CB815903) and the CAS Pilot Project of the National Knowledge Innovation Program (No. KZCFX3-SW-233)     

Concentration and Characterization of Colored Dissolved Organic Matter in the Surface Microlayer and Subsurface Water of the Yellow Sea and the East China Sea

The distribution and chemical properties of colored dissolved organic matter(CDOM) in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated. The input of freshwater and biological activities had an evident influence on the CDOM levels(characterized by the light absorption coefficient at the wavelength of 355 nm a₃₅₅) in the study area. The spatial distribution of CDOM levels displayed a gradually decreasing trend from the coastal waters(0.37 m^-1) to the open sea(0.18 m^-1). The spectral slope ratio(the slope ratio S_R defined as S_275-295:S_350-400) during the cruise was correlated with salinity, and exhibited a large variation from inshore(average of 2.515) to offshore sites(average of 5.327) compared with the distribution of a₃₅₅. The values of S_R were related to CDOM molecular weight(MW). The a₃₅₅, S_R, and chlorophyll a in 37 samples collected from the surface microlayer were significantly correlated with those in the corresponding subsurface water samples, implying a strong exchange action between the microlayer and bulk water. The a₃₅₅ and S_R of CDOM exhibited significant microlayer enrichment, with mean enrichment factors(EFs) of 1.72 and 1.62, respectively.     

东海中南部海域锈斑蟳渔业生物学和数量分布

研究了1998—1999年东海区虾蟹类调查所获的部分锈斑蟳样品与1998~2004年在东海拖虾作业与蟹笼作业等周年逐月渔获物中采集的锈斑蟳样品的生物学特性,结果表明:东海锈斑蟳渔获群体的甲长范围为26~105mm,甲宽范围为36~165 mm,体重范围为5~610 g,雄性个体平均要略大于雌性个体;周年雌蟹略多于雄蟹,性比为1∶0.94,繁殖期为7~12月,繁殖高峰期为8~10月,不同个体怀卵量在113 867~1 594 167粒之间;调查海区10月开始出现幼蟹,5月生长加速,最小抱卵个体的甲长为60 mm,甲宽为85 mm,体重为110 g。另根据1998~1999年调查资料分析得知:锈斑蟳主要分布在长江口渔场以南水深60 m以内海域,中心区分布在闽东渔场,渔期为11月~翌年2月,是舟山、长江口渔场三疣梭子蟹汛期结束后,蟹笼、流刺网作业的又一主捕对象。     

东、黄海鲐鱼群体遗传差异的RAPD分析

利用随机扩增多态DNA(RAPD)技术分别分析了五岛西部日本鲐、东海西部日本鲐和澳洲鲐三群体的样本,共产生226个分子标记,其中143个为多态性标记,多态百分率达到63.3%,每条引物产生的平均标记数为7.29。五岛西部日本鲐、东海西部日本鲐和澳洲鲐群体内遗传相似度分别为0.949、0.877和0.936,而群体间遗传距离依次为:五岛西部日本鲐-东海西部日本鲐(0.2357)<东海西部日本鲐-澳洲鲐(0.3030)<五岛西部日本鲐-澳洲鲐(0.3528),五岛西部日本鲐与东海西部日本鲐个体在UPGMA系统树独立聚类为两个类群,初步支持东、黄海的日本鲐存在东海西部和五岛西部的两个种群的观点。Shannon多样性指数表明,其遗传多样性大小依次为东海西部日本鲐、澳洲鲐、五岛西部日本鲐。     

HETEROTROPHIC BACTERIOPLANKTON PRODUCTION IN THE EAST CHINA SEA

ＩＮＴＲＯＤＵＣＴＩＯＮＭｏｒｅｔｈａｎａｄｅｃａｄｅｈａｓｐａｓｓｅｄｓｉｎｃｅｂａｃｔｅｒｉａｗａｓｒｅｃｏｇｎｉｚｅｄａｓｑｕａｎｔｉｔａｔｉｖｅｌｙｉｍｐｏｒｔａｎｔｃｏｎ ｓｕｍｅｒｓｏｆｏｒｇａｎｉｃｃａｒｂｏｎｉｎｍａｒｉｎｅｆｏｏｄｗｅｂｓａｎｄｍａｒｉｎｅｅｃｏｓｙｓｔｅｍｓ (Ｆｕｈｒｍａｎ ,1 992 ) .ＴｈｅｂａｓｉｃｉｎｆｏｒｍａｔｉｏｎｏｎｔｈｅｓｉｇｎｉｆｉｃａｎｃｅｏｆｔｈｅｍｉｃｒｏｂｉａｌｆｏｏｄｗｅｂｗａｓｐｒｅｓｅｎｔｅｄｂｙＰｏｍｅｒｏｙ ( 1 974 ) ,ｗｈｏｐｉｅ…     

DISSOLVED ORGANIC CARBON IN THE EAST CHINA SEA IN AUTUMN

ImODUcrIONThepoolofdissolvedorganicrnatter,eva1uatalasdissolvedorganiccarbonpoC),hasbostudndforrnanyycars(Med,l964,SkopintSevCtal.,l966).Continentalmar-ginshavedrihypotheSedtobeasirnPortanttothemarinecarbonbiogeochdricalCy-desasthedeepsea(Walsh,l99l),butinmostdiscussions,onlyexportofparticulateorganieswasconsidetal.HighconcentIationofDOCincoastalwatershasaspedlroleinexportingcarbonfromcontinentalmarginstotheopenocean.UndelstandingtheroleoftheoceanmarginsintheglobalcarbonCycAsdependsla…     

Chemical hydrography of coastal upwelling in the East China Sea

Based on the field data obtained during cruises on the shelf of the East China Sea from 1997 to 1999, seasonal variations of coastal upwelling on the inner shelf are discussed by using cross-shelf transect profiles and horizontal distributions of chemical and hydrographic variables. Results show that the coastal upwelling was year-round, but the areas and intensities of the upwelling were quite different in season. The coastal upwelling occurred in all of the coastal areas of the region in spring and summer, but in autumn only in the area off Zhejiang Province, and in winter in the area off Fujian Prov- ince. It was the strongest in summer and the weakest in winter. Geographically, it was the strongest in the area off Zhejiang Province and the weakest in the southmost or northmost parts of the East China Sea. The estimated nutrient fluxes upward into euphotic zone through coastal upwelling were quite large, es- pecially for phosphate, which contributed significantly to primary production and improved the nutrient structure of the coastal ecosystem in the East China Sea.     

中日东海划界之中间线方案:问题与评析

中日东海划界历经旷日持久而未能解决,中国主张尊重《联合国海洋法公约》(以下简称《公约》)中大陆架之自然延伸原则,采取不同于专属经济区的方法对大陆架进行划界,而日本则始终坚持采用中间线对中日东海大陆架和经济专属区作一揽子划界。无论从逻辑角度还是法理视角,日本主张在中日东海划界中适用中间线将混淆《公约》中专属经济区与大陆架两种制度。基于中日东海大陆架的地质与地貌特点以及公约对上述两种权利的不同规定,中日难以通过中间线对东海的海洋权益作出公平划分。中日两国应以《公约》为依据,分别对专属经济区和大陆架的划界作出安排,同时兼顾处理钓鱼岛群岛的主权归属问题,使中日东海划界问题得到妥善解决。     

A probe heat flow value of the East China Sea shelf

Bottom temperature variation (BTV) is a serious problem in determining the thermal gradient and heart flow of the sediments in shallow seas. The water depth of the East China Sea shelf is mostly below 150m, and the heat flow measurement is strongly affected by BTV. Following a statistical algorithm, we rechecked the temperature and thermal conductivity data of the cruises KX90-1 and KX91-1, carried out by a cooperation program of China and Japan, and calculate the heat flow in a site without long-term temperature record. The calculated heat flow in the site was 58.6±3.6 mW/m², being just within the range of the drill heat flow value of East China Sea shelf. The inversed amplitude spectrum of BTV has a peak in frequency of 1/10 per year, and the annual component is also an important part. Comparison with two lakes of Lake Greifensee and Lac Leman (i.e. Lake Geneva), which are in different water depth, revealed that with increasing water depth, the peak of amplitude spectrum moved towards low frequency components. The heat flow values calculated in this paper and from petroleum bore hole in East China Sea shelf are much more close to that in southeast China than in Okinawa Trough. Supported by the National High Technology R&D Program of China (2004 AA616060)     

东海中部夏季鱼类群落结构及其多样性分析

根据2008年8月东海区主要渔场重要渔业资源调查资料,分析东海中部鱼类的种类组成、区系特征、多样性等群落结构特征。结果表明:共调查捕获鱼类88种,其中暖水种59种,占67.0%;暖温种29种,占33.0%。相对重要性指数(IRI)值大于500的优势种鱼类共有5种,分别为带鱼、刺鲳、小黄鱼、六斑刺鲀和鳄齿鱼;种类丰富度指数变动范围为0.10～2.31,平均为0.88;Shannon-Wiener多样度指数变动范围为0.01～1.86,平均为0.87;种类均匀度指数变动范围为0.01～0.92,平均为0.41;东海中部夏季鱼类多样性指数与往年相比有下降的趋势。     

Phytoplankton distribution and community structure in the East China Sea (ECS) continental shelf

ＩＮＴＲＯＤＵＣＴＩＯＮＰｈｙｔｏｐｌａｋｔｏｎｈａｓａｋｅｙｒｏｌｅｉｎｔｈｅｍａｒｉｎｅｅｃｏｓｙｓｔｅｍａｓｔｈｅｂａｓｉｃｐａｒｔｉｎｔｈｅｆｏｏｄｃｈａｉｎ ,ｗｈｉｃｈｉｓｉｍｐｏｒｔａｎｔｉｎｆｏｒｍａｔｉｏｎｆｏｒａｓｓｅｓｓｉｎｇｐｒｏｄｕｃｔｉｖｉｔｙｐｏｔｅｎｔｉａｌａｎｄｆｉｓｈｅｒｙｒｅｓｏｕｒｃｅｓ.Ｐｈｙｔｏｐｌａｎｋｔｏｎａｌｓｏｈａｓａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｔｈｅｃａｒｂｏｎｂｉｏｇｅｏｃｈｅｍｉｃａｌｃｙｃｌｅ,ｂｅｃａｕｓｅｉｔｃａｎａｂｓｏｒｂａｌａ…     

STUDY OF WATER—TRANSPORT THROUGH SOME MAIN STRAITS IN THE EAST CHINA SEA AND SOUTH CHINA SEA

OCCAM global ocean model results were applied to calculate the monthly water transport through 7 straits around the East China Sea(ECS)and the South china Sea(SCS).Analysis of the features of velocity profiles and their variations in the Togara Strait,Luzon Strait and Eastern Taiwan Strait showed that;1)the velocity profiles had striped pattern in the Eastern Taiwan Strait,where monthly flux varied from 22.4 to 28.1 Sv and annual mean was about 25.8 Sv;2)the profiles of velocity in the Togara Strait were characterized by core structure,and monthly flux varied from 23.3 to 31.4 Sv,with annual mean of about 27.9 Sv;3)water flowed from the SCS to the ECS in the Taiwan Strait,with maximum flux of 3.1 Sv in July and minimum of 0.9 Sv in November;4)the flux in the Tsushima Strait varied by only about 0.4 Sv by season and its annual mean was about 2.3 Sv;5)Kuroshio water flowed into the SCS in the Luzon Strait throughout the year and the velocity profiles were characterized by multi-core structure.The flux in the Luzon Strait was minimun in June(about 2.4 Sv)and maximum in February(about 9.0 Sv),and its annual mean was 4.8 Sv;6)the monthly flux in the Mindoro Strait was maximum in December(3.0 Sv)and minimum in June(Only 0.1 Sv),and its annual mean was 1.3 Sv;7)Karimata Strait water flowed into the SCS from May to August,with maximum in-flow flux of about 0.75 Sv in June and flowed out from September to April at maximum outflow flux of 3.9 Sv in January.The annual mean flux was about 1.35 Sv.     

Simple ecosystem model of the central part of the East China Sea in spring

ImODUrnONTheobjeCtiveoftheJointGobaldrinFluxStudy(JGoFS)istogainunder-standingoftheglobalbiogeochdricalCycling(ofcarbonandotherbiogenicelemetS)whichplaysaTnaorroleininIlUencintheworkldrite.OnofitSessentinlcomPonentSistocharaCtedrithernarineprharybiomassproductionandthefixationofCO=bytheocan.AmngtheproassesaffedgVCrthalfluxofcarbontotheinterioroftheoean,thebiologhalproass,thesocalled"biologhalpUmP,',isthemostirnPortantone.bologicalmodellingisamehodtorelateleVeIs,distributionandfluC…