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1.
Hsueh and O Brien (1971) proposed a model on coastal upwelling induced by alongshore current. Their model is two - dimensional .steady , f - plane , linear and homogeneous with constant depth , in which wind effect was not considered . In the present paper, we proposed a steady model on upwelling in a strait with alongshore boundary current and wind applied on the surface. The following conclusions have been drawn.1 . Alongshore boundary current contributes more to upwelling than wind near the right coast.2. Alongshore boundary current influence can reach to about 70 km away from the right coast.3. Upwelling in the left half of the strait is mainly produced by wind .4. Under certain conditions, the combined action of wind and alongshore boundary current can produce upwelling in the middle of the strait. 相似文献
2.
Sayyed Ahang Kowsar 《山地科学学报》2005,2(3):233-243
1 Introduction A desert is defined as a large area of barren land, waterless and treeless, often sand-covered (Oxford Advanced Learner’s Dictionary of Current English 1974). The presence of numerous, sometimes prosperous agricultural communities in the so-called deserts defies this definition. The land is not necessarily barren; leaching of nutrients that causes certain deficiencies in the soils of humid environments hardly occurs in deserts. The most apparent deficiencies for crop product… 相似文献
3.
With the use of historical data from their 1982-1985 special observation at the source area of the Taiwan Warm Current the authors conducted studies to clarify the temperature and salinity characteristics, variability, and origin of the Taiwan warm Current Water, and its influence on the expanding direction of the Changjiang Diluted Water.The main results are given below.(1)The Taiwan Warm Current Water can be divided into the "Surface Water of the Taiwan Warm Current" formed due to the mixing of the Kuroshio Surface Water flowing northward along the east coast of Taiwan with the Taiwan Strait Water, and the "Deep Water of the Taiwan Warm Current" originated from Kuroshio Subsurface Water to the east of Taiwan. It is characterized by stable low temperature and stable high salinity in summer. The maximum seasonal variation and maximum secular variation of temperature and salinity are 1.87℃, 0.26‰ and 2.96℃, 0.37‰, respectively.(2)The variation in strength of the Taiwan Warm Current is the main influe 相似文献
4.
Seagrass habitats are structurally complex ecosystems, which support high productivity and biodiversity. In temperate systems the density of seagrass may change seasonally, and this may influence the associated fish and invertebrate community. Little is known about the role of seagrass beds as possible nursery areas for fish and invertebrates in China. To study the functioning of a seagrass habitat in northern China, demersal fish and invertebrates were collected monthly using traps, from February 2009 to January 2010. The density, leaf length and biomass of the dominant seagrass Zostera marina and water temperature were also measured. The study was conducted in a Seagrass Natural Reserve(SNR) on the eastern coast of the Shandong Peninsula, China. A total of 22 fish species and five invertebrate species were recorded over the year. The dominant fish species were Synechogobius ommaturus, Sebastes schlegelii, Pholis fangi, Pagrus major and Hexagrammos otakii and these species accounted for 87% of the total number of fish. The dominant invertebrate species were Charybdis japonica and Octopus variabilis and these accounted for 98% of the total abundance of invertebrates. There was high temporal variation in species composition and abundance. The peak number of fish species occurred in August–October 2009, while the number of individual fish and biomass was highest during November 2009. Invertebrate numbers and biomass was highest in March, April, July and September 2009. Temporal changes in species abundance of fishes and invertebrates corresponded with changes in the shoot density and leaf length of the seagrass, Zostera marina. 相似文献
5.
An index of relative importance (IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche breadth and niche overlap were measured using the Feinsinger and Morisita-Horn indices, respectively, and the characteristics and seasonal variations in the niches of dominant fish were assessed via non-metric multidimensional scaling (NMDS) and cluster analysis. A total of 80 fish species, including 16 dominant species, were recorded. Only Amblychaeturichthys hexanema was dominant in all seasons. According to niche breadth values and NMDS, the 16 dominant species were grouped into the following three types: (1) wide niche breadth species, including Cynoglossus macrolepidotus, A. hexanema, and Trypauchen vagina, among others; (2) medium niche breadth species, including Setipinna taty and Johnius belangerii; and (3) narrow niche breadth species, including Atrobucca nibe and Coilia mystus. Most species with a wider niche breadth were demersal fish with a lower swimming capability and even distribution. The niche breadth of migrating fish was narrower than that of settled fish. At a given spatial scale, fish with stronger swimming capabilities had a narrower niche breadth. Niche overlap, which is associated with niche specialization, ranged from 0.000 to 0.886 and had an annual mean value of 0.314. In summer and autumn, niche overlap was relatively high within species of the Sciaenidae family and within species of the Gobiidae in autumn. Differences in thermophily, feeding habits, food organism abundance/distribution and predator-prey relationships affected the niche overlap of fish in this area. Cluster analysis revealed that species with the narrowest niche breadth and lowest niche overlap values usually displayed lower aggregation and greater distribution differences compared with other species. 相似文献
6.
On the basis of our study of the present sediments in the northern part of the continental shelf of the South China Sea, this article clarifies our views that a "three-zone pattern" is the basic feature of transgression-type sedimentation.The classification of transgression-type sedimentation of the present continental shelf is based on: the close relationships between the formation of the present continental shelf and the position of the low sea level of the Wiirrn glacial stage, the genetic types and environmental features of sedimentary zoning, the relationship between the formation of glauconite with different maturity and the migration of coastline, the speed of transgression, and the overlying speed of sedimentation. We put forward the genetic name of the "three-zone pattern" to denote:1.The inner zouu, river mouth-coastal current sedimentary area;2.The intermediate zone, coastal current-sea current scouring-sedimentary area;3.The outer zone, sea current scouring area.All these are of significance 相似文献
7.
Although the mid-late Holocene cold and dry event about 4000 years ago(the 4 ka event) has been observed almost globally, it was most prominent in terrestrial climate proxies from the lower latitudes. Here we evaluate the oceanic response to this event in terms of a Holocene sea surface temperature(SST) record reconstructed using the K'37U index for Core B3 on the continental shelf of the East China Sea. The record reveals a large temperature drop of about 5℃ from the mid-Holocene(24.7℃ at 5.6 ka) to the 4 ka event(19.2℃ at 3.8 ka). This mid-late Holocene cooling period in Core B3 correlated with(i) decreases in the East Asia summer monsoon intensity and(ii) the transition period with increased El Nino/Southern Oscillation activities in the Equatorial Pacific. Our SST record provides oceanic evidence for a more global nature of the mid-late Holocene climate change, which was most likely caused by a southward migration of the Intertropical Converge Zone in response to the decreasing summer solar insolation in the Northern Hemisphere. However, the large SST drop around Core B3 indicates that the mid-late Holocene cooling was regionally amplified by the initiation/strengthening of eddy circulation/cold front which caused upwelling and resulted in additional SST decrease. Upwelling during the mid-late Holocene also enhanced with surface productivity in the East China Sea as reflected by higher alkenone content around Core B3. 相似文献
8.
The spatial distribution of siliceous microfossils (diatoms and silicoflagellates) in the surface sediments was mapped at 113 sites in the Yellow Sea and sea areas adjacent to the Changjiang (Yangtze) River, China. In total, 267 diatom taxa and two silicoflagellate species were identified from the sediments. The spatial variations in abundance and diversity were classified into three distinct geographic patterns using Q mode clustering: a south-north geographic pattern, a coastal-offshore pattern and a unique pattern in the Changjiang River mouth. The south-north geographic pattern was related to the spatial variations in sea temperature. Coscinodiscus oculatus, a warm-water species, indicated these variations by a gradual decrease in abundance from the south to the north. The coastal-offshore pattern was in response to the spatial variations in salinity. Cyclotella stylorum, Actinocyclus ehrenbergii and Dictyocha messanensis, the dominant brackish species in coastal waters, significantly decreased at the isobaths of approximately 30 m, where the salinity was higher than 31. Paralia sulcata and Podosira stelliger indicated the impact of the Yellow Sea Warm Current in the central Yellow Sea. The unique pattern in the Changjiang River mouth showed the highest species diversity but lower abundance, apparently because: freshwater input can significantly increase the proportion of brackish species; nutrients can supply the growth of phytoplankton; and high sedimentation rates can dilute the microfossil abundance in the sediments. Our results show that an integration of environmental factors (e.g., nutrient levels, sedimentation rate, sea temperature, salinity and water depth) determined the spatial characteristics of the siliceous microfossils in the surface sediments. 相似文献
9.
Study of the distribution and migration of the common squid,Todarodes pacificus Steenstrup,basedon the index of important fishing ground(P) and fisheries statistics on the Yellow Sea and northern EastChina Sea during 1980—1991 showed that:1.Its catch in the fishing period(June to November) is 91.77% of the annual yield.The fishingground distributes over the northem and middle Yel1ow Sea and adjacent area of the Changjiang Estuary.2. It over-winters in the northem East China Sea and waters adjacent to Goto Island from De-cember to February and spawns in waters near Haijiao Is1and and west of Kyushu. The main stock mi-grates along 123°30′E to the ChangJiang Estuary, Haizhou Bay. offsea from Shidao to Qingdao,mideastern Yellow Sea, and offsea Weihai and Haiyang Island succesively for feeding after April. The sur-plus stock migrates again to the wintering ground in December.3.The favorable feeding temperature is 6-23℃(optimum of l3-20℃ in the Changjiang Estua-ry and 7-13℃ in the northern and middle Yel 相似文献
10.
The status of fishery stocks in the coastal waters of China is far from ideal, mainly due to climate change and the impacts
of human activities (e.g., pollution and overfishing). Thus, the restoration and protection of fishery resources have become
critical and complex. The stability and balanced structure of the fish community is a basic foundation for the protection
of fishery resources. Based on data collected from bottom trawls by the R/V Beidou in continental shelf of the East China Sea in November 2006 and February 2007, changes in the composition and diversity of
fish species and functional groups were analyzed. The research area was divided into offshore waters and inshore waters by
the two-way indicator species analysis (TWIA). The results showed that the dominant species were different between offshore
waters and inshore waters and also varied with the survey time. The most abundant family was Sciaenidae and Teraponidae in
November 2006, Sciaenidae, Engraulidae and Triglidae were most abundant in February 2007. The species belonged mainly to mobile
piscivores (G6), benthivores/piscivores (G4), benthivores (G3) and planktivores (G1), and the dominant species in November
2006 were commercial species (e.g. Larimichthys polyactis and Trichiurus japonicus), but small-sized species were dominant in February 2007 (e.g., Harpadon nehereus, Benthosema pterotum, Champsodon capensis, and Acropoma japonicum). The species diversity showed a similar trend as the functional group diversity. Stations with higher diversity were mainly
distributed in inshore waters in February 2007, whereas higher diversity was found in offshore waters in November 2006. The
highest biomass and species number were found in G6 group, followed by the G4, G5 and G1 groups. The distribution of the number
of individuals of each functional group showed the opposite trend as that of the biomass distribution. In addition, the size
spectra were mainly concentrated around 3–29 cm, and the individual number of fish species gradually decreased with the increase
in body size, but the relative biomass showed a moderate fluctuation in each size class. These changes showed that species
with faster growth rate and earlier maturity age became dominant in continental shelf of the East China Sea. So the variations
in biological characteristics of fish should be fully considered in maintaining sustainable utilization of fishery resource. 相似文献
11.
Cadmium(Cd) mainly derived from anthropogenic emissions can be transported through atmospheric pathway to marine ecosystem,affecting the phytoplankton community and primary productivity.In this study,we identified the toxicity threshold of Cd for phytoplankton under seawater conditions of the coastal East China Sea(ECS) through both laboratory and in situ mesocosm incubation experiments.The mesocosm experiment showed that Cd in low concentration(0.003 μg per μg chl a) was conducive to the growth of natural community and increased chl a productivity.In high concentration(0.03 μg per μg chl a) Cd acted as an inhibiting factor which decreased the total chl a productivity.The diatom community was found to be more sensitive to Cd toxicity than dinoflagellate,as the low concentration Cd showed toxicity to diatom but enhanced dinoflagellate growth.We noticed that the soluble Cd estimated from atmosphere deposition to the coastal ECS was below the toxicity threshold and the Cd deposition might promote phytoplankton growth in this region.In our laboratory experiments,adding Cd,similar to aerosol deposition,stimulated the growth of both dominant algal species Prorocentrum donghaiense Lu(dinoflagellate) and Skeletonema costatum(diatom).Adding Cd on a higher level inhibited the growth of both the species,but Skeletonema costatum seemed obviously more sensitive to toxicity.This indicates the potential impact of atmospheric deposition Cd on phytoplankton community succession in the ECS. 相似文献
12.
东海中部夏季鱼类群落结构及其多样性分析 总被引：2，自引：0，他引：2
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。 相似文献
13.
The annual bloom of the green macroalgal Ulva prolifera from May through July since 2008 and another of giant jellyfish Nemopilema nomurai from June through September have been frequent events in the Yellow Sea. However, the patterns of benthic ciliate communities during and after the blooms are still not known. In combination with analyses of benthic environmental factors, we investigated the distribution and community composition of benthic ciliates in the Yellow Sea in July and November 2011. In July, ciliates had high standing crops and diversity in the northern Yellow Sea, and in the inshore area off the southern Shandong Peninsula, where large numbers of green macroalgae accumulated. In November, the abundance, biomass and diversity of ciliates were high in the sea areas off the Shandong Peninsula and Changjiang estuary, where a large quantity of jellyfish occurred in August. Neither the abundance nor the biomass had significant difference between seasons, or between different compartments of the Yellow Sea. The species number, and both Margalef and Shannon-Wiener indices of ciliates were all significantly higher in November than in July. In both seasons, prostomateans and karyorelicteans consistently constituted the first and second most important ciliate groups in biomass; and carnivorous ciliates constituted the primary feeding type in terms of biomass as well as species richness, followed by bacterivores, algivores and omnivores. Compared with that in June 2007 when no macroalgae occurred, the percentage of small-sized bacterivores (e.g. Metacystis spp., Euplotes spp. and scuticociliates) increased in July 2011. The proportion of carnivorous ciliates increased in November, and this increased dominance of carnivorous ciliates may be a response to the increase in predominance of heterotrophic nanoflagellates, which might in turn be ascribed to an effect of green macroalgal and giant jellyfish blooms in the Yellow Sea. 相似文献
14.
Lei Xing Yiqing Jiang Zineng Yuan Hailong Zhang Li Li Liping Zhou Meixun Zhao 《中国海洋大学学报(英文版)》2013,12(4):599-604
As an important marginal sea under the influences of both the Changjiang River and the Kuroshio, the East China Sea (ECS) environment is sensitive to both continental and oceanic forcing. Paleoenvironmental records are essential for understanding the long-term environmental evolution of the ECS and adjacent areas. However, paleo-temperature records from the ECS shelf are currently very limited. In this study, the U 37 K′ and TEX86 paleothermometers were used to reconstruct surface and subsurface temperature changes of the mud area southwest of the Cheju Island (Site F10B) in the ECS during the Holocene. The results indicate that temperature changes of F10B during the early Holocene (11.6–6.2 kyr) are associated with global climate change. During the period of 6.2–2.5 kyr, the similar variability trends of smoothing average of ΔT (the difference between surface and subsurface temperature) of Site F10B and the strength of the Kuroshio suggest that the Kuroshio influence on the site started around 6.2 kyr when the Kuroshio entered the Yellow Sea and continued to 2.5 kyr. During the late Holocene (2.5–1.45 kyr), apparent decreases of U 37 K′ sea surface temperature (SST) and ΔT imply that the direct influence of the Kuroshio was reduced while cold eddy induced by the Kuroshio gradually controlled hydrological conditions of this region around 2.5 kyr. 相似文献
15.
This study investigates the migration and distribution of the warm-temperate fish Nibea albiflora. Their spawning migration and wintering migratory routes within in the Yellow Sea are described in detail. Considering the main physical features and environment of the Yellow Sea, it appears to be have one wintering ground and three migratory routes from the wintering ground to the spawning grounds. The fish begin to migrate from the wintering ground to the spawning grounds in the northwest region of the Yellow Sea in late March. The Yellow Sea has three spawning grounds. The first is located near the Yalu River on the Liaodong Peninsula and the second one is located in Rushan Bay of Shandong Peninsula. The third spawning ground is located in Haizhou Bay in the southern region of the Yellow Sea. This study found that the temperature of the Yellow Sea influences the migration of N. albiflora, and that the migratory routes coincide with the thermal fronts in the sea. Nutrients for juvenile fish are taken from the coastal upwelling area. Chlorophyll is a good environmental indicator of phytoplankton biomass and thereby provides the status of biological resources. Different types of sediment in near-shore zones are also of practical significance for the growth of fish. The study of the effects of marine environments on the migration of various fishes is not only significant to the fishing industry, but can also provide a scientific basis for the understanding of the ecological implications of the relevant physical processes. 相似文献
16.
Status of two <Emphasis Type="Italic">Coreius</Emphasis> species in the Three Gorges Reservoir,China
Dam construction alters natural flow regimes which, in turn, cause significant changes in fish communities during and after impoundment. The construction of the Three Gorges Reservoir, from impoundment of the Changjiang (Yangtze) River, China, may have affected native fish species. Thus, the status of two lotic freshwater fish species, Coreius heterodon and C. guichenoti, were monitored in the Three Gorges Reservoir, including fish abundance, individual composition, growth, condition, and mortality. Data on both species were gathered from upstream, midstream and downstream areas of the reservoir and, where available, from studies published before and after dam construction. Lower abundance, slower growth, a less diversified age structure, poorer fish condition (indicated by hepatosomatic index) and higher mortalities were recorded in sites nearest the dam compared with upstream areas. Furthermore, after final impoundment, individual Coreius species inhabiting the area changed, with young individuals becoming more abundant, while upstream of the reservoir the two Coreius species became smaller at a given age. The results show that the status of the two Coreius species was subject to dramatic changes after impoundment. 相似文献
17.
Xu Fengshan 《中国海洋湖沼学报》1990,8(4):374-377
The present paper dealing with two new species and one new genus of the Polyplacophora, is the first of a series of reports
of systematic study on the deep sea mollusca collected by the research vesselsJINXING andKEXUE I of the Academia Sinica, Institute of Oceanology, during 1978 and 1981 from the continental margin to the bathyal zone of
the East China Sea.
Contribution No. 1647 from the Institute of Oceanology, Academia Sinica. 相似文献
18.
Studies on the community structures of meiofauna and marine nematode at six stations in the Southern Yellow Sea,China 总被引：6，自引：1，他引：5
HUANG Yong ) ZHANG Zhinan) and LIU Xiaoshou) ) College of Marine Life Sciences Ocean University of China Qngdao P.R.China ) Agricultural College Liaocheng University Liaocheng Shandong P.R.China 《中国海洋大学学报(英文版)》2005,4(1):34-42
1Introduction As part of a comprehensive investigation of ecosys-tem dynamics in the Yellow Sea and East China Sea,astudy has been made of meiofauna,defined here asmetazoans passing a0.5mm sieve but retained by a0.031mm sieve.Meiofauna is an important energeticgroup in benthic small food web due to their smallsize,high abundance and fast turnover rates.Theproduction of meiofauna is equal to or higher than thatof macrofauna in estuaries,shallow waters and deepseas(Gerlach,1971;Platt and Warw… 相似文献
19.
The South China Sea (SCS), which is the largest marginal sea in the western tropical Pacific, plays an important role in regional climate change. However, the research on the phytoplankton community structure (PCS) response to the upwelling remains inadequate. In January 2014, the upwelling simulation experiment was performed in the western SCS. Results indicate that the nutrient-rich bottom water not only increased the total Chlorophyll a (Chl a) concentrations, but would potentially altered the PCS. Due to new nutrients added, microphytoplankton had more sensitivity response to nutrient uptake than other phytoplankton groups. The variation of nutrients induced by formation, weakening and disappearance of upwelling resulted in phytoplankton species succession from cyanophyta to bacillariophyta. It may be the leading factor of the changes in PCS and size-fractionated Chl a. The initial concentration of DIP less than 0.1 μmolL?1 could not sustain the phytoplankton growth. This indicates that phosphorus may be the limiting factor in the western SCS. 相似文献
20.
Oplegnathus fasciatus (rock bream) is a commercial rocky reef fish species in East Asia that has been considered for aquaculture. We estimated the population genetic diversity and population structure of the species along the coastal waters of China using fluorescent-amplified fragment length polymorphisms technology. Using 53 individuals from three populations and four pairs of selective primers, we amplified 1 264 bands, 98.73% of which were polymorphic. The Zhoushan population showed the highest Nei’s genetic diversity and Shannon genetic diversity. The results of analysis of molecular variance (AMOVA) showed that 59.55% of genetic variation existed among populations and 40.45% occurred within populations, which indicated that a significant population genetic structure existed in the species. The pairwise fixation index F st ranged from 0.20 to 0.63 and were significant after sequential Bonferroni correction. The topology of an unweighted pair group method with arithmetic mean tree showed two significant genealogical branches corresponding to the sampling locations of North and South China. The AMOVA and STRUCTURE analyses suggested that the O. fasciatus populations examined should comprise two stocks. 相似文献