Plate culture counting and strain isolation methods were utilized to assess the species richness and abundance of planktonic and attached bacteria on glass plates in the surface and bottom seawater of Qingdao Middle H...Plate culture counting and strain isolation methods were utilized to assess the species richness and abundance of planktonic and attached bacteria on glass plates in the surface and bottom seawater of Qingdao Middle Harbor over a year,with monthly and quarterly sampling.Both species richness and bacterial numbers exhibited seasonal variations.Specifically,the abundance of attached bacteria and bacterioplankton peaked in June and July,corresponding to higher water temperatures in summer and autumn,while lower abundances were noted in January and December during cooler periods.Throughout the year,the species richness of attached bacteria consistently exceeded that of planktonic bacteria in both shallow and deep waters.Pseudoalteromonas emerged as the most prevalent genus among both planktonic and attached bacteria in surface and bottom seawater samples.Furthermore,the magnitude of changes in species richness and abundance for attached bacteria(0.66×10^(5)-15.85×10^(5)CFU/cm^(2))was greater than that observed for planktonic bacteria(0.58×10^(8)-5.33×10^(8)CFU/L).We propose that the attached bacterial populations,situated in limited microenvironments within the larger seawater ecosystem,exhibit heightened sensitivity to environmental fluctuations,resulting in more rapid shifts in population dynamics and lower ecological stability.The theoretical implications and potential applications of these findings warrant further investigation.展开更多
As one of the main application directions of quantum technology,underwater quantum communication is of great research significance.In order to study the influence of marine planktonic algal particles on the communicat...As one of the main application directions of quantum technology,underwater quantum communication is of great research significance.In order to study the influence of marine planktonic algal particles on the communication performance of underwater quantum links,based on the extinction characteristics of marine planktonic algal particles,the influence of changes in the chlorophyll concentration and particle number density of planktonic algal particles on the attenuation of underwater links is explored respectively,the influence of marine planktonic algal particles on the fidelity of underwater quantum links,the generation rate of the security key,and the utilization rate of the channel is analyzed,and simulation experiments are carried out.The results show that with the increase in chlorophyll concentration and particle density of aquatic planktonic algal particles,quantum communication channel link attenuation shows a gradually increasing trend.In addition,the security key generation rate,channel fidelity and utilization rate are gradually decreasing.Therefore,the performance of underwater quantum communication channel will be interfered by marine planktonic algal particles,and it is necessary to adjust the relevant parameter values in the quantum communication system according to different marine planktonic algal particle number density and chlorophyll concentration to improve the performance of quantum communication.展开更多
Based on 4 cruise surveys from July 2006 to October 2007 in the Taiwan Strait, the species composition, community structure and spatio-temporal distribution of dinoflagellate were studied. A total of 131 dinoflagellat...Based on 4 cruise surveys from July 2006 to October 2007 in the Taiwan Strait, the species composition, community structure and spatio-temporal distribution of dinoflagellate were studied. A total of 131 dinoflagellates belonging to 18 genera were identified. The population was dominated by hyperthermal and hyperhaline species accounting for 72.52% of the total species. Eurythermal and euryhaline species were the second most common one accounting for 25.19% of the total species. It was only 2.29% for neritic species. The maximum species number occurred in summer, while the maximum cell density appeared in spring. The average dinoflagellate cell density was 404.96x104 cells/m3. It showed that the dinof]agellate cell density increased from the nearshore waters to the open sea and from the north to the south. Compared with the results during 1984-1985, the horizontal distribution pattern and seaeonal variation of the dinofiagellate have not changed significantly, but the dinoflagellate cell density increased by 3.01 times. Further analysis of the dinoflagellate abundance variations both in the spatial and temporal aspects, indicated that the abundance of dinoflagellate increased more significantly in cold seasons, and there was a larger increase in the north of the Taiwan Strait. Besides, the dinoflagellate community structure changed notably. It showed that the diversity and evenness index were relatively high, and the proportion of dinoflageliate cell density to the total phytoplankton increased.展开更多
Ciliates are important components in planktonic food webs,but our understanding of their community structures in different oceanic water masses is limited.We report pelagic ciliate community characteristics in three s...Ciliates are important components in planktonic food webs,but our understanding of their community structures in different oceanic water masses is limited.We report pelagic ciliate community characteristics in three seas:the tropical West Pacific,the Bering Sea and the Arctic Ocean.Planktonic ciliate abundance had"bimodal-peak","surface-peak"and"DCM(deep chlorophyll a maximum layer)-peak"vertical distribution patterns in the tropical West Pacific,the Bering Sea and the Arctic Ocean,respectively.The abundance proportion of tintinnid to total ciliate in the Bering Sea(42.6%)was higher than both the tropical West Pacific(7.8%)and the Arctic Ocean(2.0%).The abundance proportion of small aloricate ciliates(10–20μm size-fraction)in the tropical West Pacific was highest in these three seas.The Arctic Ocean had higher abundance proportion of tintinnids in larger LOD(lorica oral diameter)size-class.Proportion of redundant species increased from the Arctic Ocean to the tropical West Pacific.Our result provided useful data to further understand ecology roles of planktonic ciliates in different marine habitats.展开更多
Horizontal and vertical distributions of δ^18 and δ^13 were investigated in shells of four planktonic foraminiferal species, Globigerinoides ruber, Globigerinoides sacculifer, Pulleniatina obliquiloculata and Neoglo...Horizontal and vertical distributions of δ^18 and δ^13 were investigated in shells of four planktonic foraminiferal species, Globigerinoides ruber, Globigerinoides sacculifer, Pulleniatina obliquiloculata and Neogloboquedrina dutertrei, from a total of 62 core-top sediment samples from the Indonesian throughflow region. Results were compared to modern hydrologic conditions in order to explore potential of proxies in reconstructing fluvial discharge and upper ocean water column characteristics in this region. Our results show that, in the Makassar Strait, both of depleted δ^18 and δ^13 of these four species were linked to freshwater input. In the Bali Sea,however, depleted δ^18 and δ^13 for these species may be due to different reasons. Depleted δ^18 was a result of freshwater input and as well influenced by along-shore currents while depleted δ^13 was more likely due to the Java-Sumatra upwelling. Comparison of shell δ^18 records and hydrographic data of World Ocean Atlas 2005 suggests that G. ruber and G. sacculifer calcify within the mixed-layer, respectively at 0–50 m and 20–75 m water depth, and P. obliquiloculata and N. dutertrei within the upper thermocline, both at 75–125 m water depth. N.dutertrei calcifies at slightly deeper water depth than P. obliquiloculata does. In general, δ^13 values of both G.ruber and G. sacculifer are larger than those of P. obliquiloculata and N. dutertrei at all sites, possibly related to depth habitats of these species and vertical distribution of nutrients in the Indonesian throughflow region.展开更多
The Paper is the succession of the study on abundance distribution of planktonic copepods in the waters north of Taiwan, and the emphasis is laid on the analysis and discussion of the constructions and features of cop...The Paper is the succession of the study on abundance distribution of planktonic copepods in the waters north of Taiwan, and the emphasis is laid on the analysis and discussion of the constructions and features of copepod community and the relationships with water environment. The results show as follows: a total of 237 species were identified and the construction of communtity was complex. The percentage of annual present species was only 32%. The mean values of diversity and homogeneity of the copepod community were 3. 714 and 0. 690 respectively, and their horizontal distribution patterns were higher in outshore area than in nearshore area. The copepods of the area could be divided into five ectotypes. Warm-water outshore high temperature and lower saline group and tropic oceanic high temperature and saline group could indicate the seasonal changes of the Taiwan Strait water and the Kuroshio surface water respectively. According to the various aspects of calculation and analysis, winter was different from other three seasons in environmental conditions. In spring, summer and autumn, Undinula valgaris was the meat dominant species and salinity was the main factor that affected the community feature values. The communities in the three seasons had the subtropic-tropic characteristics in which warm-water outshore species were dominant and tropic oceanic species accounted for also certain proportion. While in winter, the dominant species was Euchaeta manna and temperature was the main factor influencing the community feture values. The community had the tropic oceanic characteristics in which tropic oceanic species were dominant.展开更多
The identification of scallop larvae is essential to understand the population structure and community dynamics and to assess the potential environmental impacts caused by scallop larvae released or escaped. However, ...The identification of scallop larvae is essential to understand the population structure and community dynamics and to assess the potential environmental impacts caused by scallop larvae released or escaped. However, the larvae identification by morphological characteristics is notoriously difficult, mainly due to the small size （usually being less than 150 μm） and vague morphological characteristics among different scallop species. A simple and accurate molecular method was developed to identify four economically farmed scallop species, the Zhikong scallop Chlamys farreri, the noble scallop C. nobilis, the bay scallop Argopecten irradians and the Yesso scallop Mizuhopecten yessoensis. The tests used the high degree of species-specific microsatellite markers, which was specified by transferability analyses, assessed by reference individuals and evaluated by BLAST searches. The sensitivity test indicated that the species-specific microsatellites were sensitive enough for the detection of 1% -2% larvae in mixed plankton samples. Larvae collected from scallop hatcheries and their effluents and from the artificially controlled crosses were well identified to the species/hybrid level. The results demonstrated that the one-step PCR-based assay was technically simple, inexpensive and robust in identification analyses, and also less sensitive to initial quality of template DNA extracted from the ethanol-preserved samples for several years.展开更多
Test geochemistry of planktonic foraminifera is an indispensable tool in reconstructing past ocean hydrological changes. It is essential to investigate region-specific implications of test geochemistry,although those ...Test geochemistry of planktonic foraminifera is an indispensable tool in reconstructing past ocean hydrological changes. It is essential to investigate region-specific implications of test geochemistry,although those established from other regions can be broadly applied. In this study, characteristics of6180 and Mg/Ca from tests of four planktonic foraminiferal species, Globigerinoides ruber sensu stricto(s.s.), Globigerinoides sacculifer, Pulleniatina obliquiloculata and Neogloboquadrina dutertrei, from 60 coretop sediment samples retrieved from the Indonesian Throughflow(ITF) region were studied. These geochemical data were compared with modern hydrographic profiles in order to assess their relations and to investigate potential implications of test geochemical parameters in reconstructing past oceanographic change in the ITF region. Calcification depths of these four species were first estimated based on comparison between measured test δ180 and predicted calcite δ^(18)O that was calculated from modern temperature and salinity. The results indicate that G. ruber s.s. and G. sacculifer calcify within the mixedlayer at 0-50 m and 20-75 m, respectively, whereas P. obliquiloculata and N. dutertrei calcify within the thermocline at around 75 to 125 m. A combined study of excess Mg/Ca(difference between measured and predicted Mg/Ca) and salinity suggests that salinity exerts a negligible impact on test Mg/Ca of these foraminiferal species in the ITF region. Comparison of test Mg/Ca-derived temperatures with temperature profiles of the upper 200 m of the water column from the seas of the ITF region also indicate calcification depths of these species, which match well with the above estimations using test δ^(18)O. It further indicates that G. sacculifer may be more sensitive in reflecting changes in the depth of the mixedlayer, highlighting a potential use of Mg/Ca temperature difference between G. ruber s.s. and G. sacculifer in reconstructing the depth of the mixed-layer in the ITF region.展开更多
1 Introduction The collision evolution between the Indian plate and the Eurasian plate is one of the significant geological events since the Mesozoic.It has profoundly influenced the global tectonic framework and led ...1 Introduction The collision evolution between the Indian plate and the Eurasian plate is one of the significant geological events since the Mesozoic.It has profoundly influenced the global tectonic framework and led to the formation of the Qinghai-Tibet Plateau,which has attracted extensive attention of global geologists and become a research hotspot(Butler,1995;Li and Wan,2003a and b;Wang et al.,2003;Aitchison et al.,2007).展开更多
On the basis of the investigation materials of 6 cruise in the waters north of Taiwan from 1987~1990, the distribution characteristics of planktonic copepods are discussed in the study from three aspects of abundance ...On the basis of the investigation materials of 6 cruise in the waters north of Taiwan from 1987~1990, the distribution characteristics of planktonic copepods are discussed in the study from three aspects of abundance distribution, community feature and indicative species. The paper is the first part of the study. The results show as follows: the highest abundance of copepods occurred in spring and the lowest one in winter, while the abundance in summer and autumn was between the above two seasons. The copepod abundance in the west of the Kuroshio front was higher than that in the east of the front. There was a distribution tendency that higher abundance occurred in outshore area in summer and in nearshore area in winter, which corresponded with the trend of seasonal swings of the Kuroshio front. The higher copepod abundance appeared generally in the mixed areas of various water masses, especially in nearshore side of upwelling of the Kuroshio sub-surface water. However, in the Kuroshio subsurface main water, the abundance was low because of some factors such as low concentration of dissolved oxy gen and so on. The vertical distribution trend was that the copepopd abundance decreased with the in crease of depth, and the diurnal vertical migration regularities of some species were probably the one of reasons that caused the abnormal distributions in some local waters.展开更多
In this study, the Maastrichtian-Danian boundary was measured and sampled in two stratigraphic sections, the north and south flanks of the Dehnow anticline in Coastal Fars, Southern Iran. This boundary was also invest...In this study, the Maastrichtian-Danian boundary was measured and sampled in two stratigraphic sections, the north and south flanks of the Dehnow anticline in Coastal Fars, Southern Iran. This boundary was also investigated in the drilled exploratory well-1 in the same region. The lithology of the Maastrichtian-Danian deposits consists of glauconitic, phosphatic argillaceous limestones and marlstones. 30 genera and 77 species of planktonic foraminifera have been determined. The recognized biozones are the Gansserina gansseri Interval Zone, and the Contusotruncana contusa Interval Zone, which indicates latest Campanian to middle Maastrichtian age for the upper part of the Gurpi Formation. In addition, the Eoglobigerina edita(P1) Partial Range Zone, Praemurica uncinata(P2) Lowest Occurrence Zone, Morozovella angulata(P3) Lowest Occurrence Zone and Globanomalina psudomenardii(P4) Taxon Range Zone represent a Danian to Thanetian age for the lower part of the Pabdeh Formation. From the absence of the Abathomphalus mayaroensis Interval Zone, Pseudoguembelina hariaensis Interval Zone, Pseudotextularia elegans Interval Zone, Plummerita hantkeninoides Interval Zone, Guembelitria cretacea(P0) Partial Range Zone and Parvularugoglobigerina eugubina(Pα) Total Range Zone, it can be deduced that there is a paraconformity across the Maastrichtian–Danian boundary in the studied area, this hiatus encompassing the late Maastrichtian and the earliest Danian. Danian deposits from the study area contain reworked glauconitized macrofossils, planktonic and benthic foraminifera of the Cretaceous. The obtained surface gamma-ray spectrometry logs resemble the exploratory well-1 gamma-ray wireline log.展开更多
The functional groups of planktonic protist communities and their responses to the changes of environmental conditions were investigated in a semi-enclosed shrimp-farming pond in Qingdao,Shandong Province,China,during...The functional groups of planktonic protist communities and their responses to the changes of environmental conditions were investigated in a semi-enclosed shrimp-farming pond in Qingdao,Shandong Province,China,during a six-month study period （a complete shrimp-culture cycle） from May to October 2002.The results reveal that： （1） the protist communities represented five trophic and functional groups of the species identified,about 60% were photoautotrophs,20% algivores,12% bacterivores,5% raptors and about 3% non-selectives;（2） the photoautotrophs,algivores and bacterivores were the primary contributors to the changes in the protist communities in short temporal scales,the succession of dominance typically being bacterivores→photoautotrophs→algivores,with the raptors dominating the protist communities in a single sample （early June）;（3） the photoautotrophs and non-selectives were the primary contributors to the peak of protist abundance in early October whereas the photoautotrophs,bacterivores,raptors and non-selectives mainly gave rise to two bimodal peaks of biomass in July and October respectively;（4） five functional groups of protist communities represented significant correlations with water nutrients （i.e.,NH 3-N,NO 3-N,and PO 4 ）,either alone or in combination with temperature,of which algivores and raptors were strongly correlated with phosphate and the concentration of Chl a,while bacterivores were strongly related to nitrogen and the concentration of bacteria.These findings confirm that planktonic protists are potentially useful bioindicators of water quality in the semi-enclosed mariculture system.展开更多
Trait structure is increasingly used in plankton ecology to understand diversity and biogeography.However,our knowledge of micro zooplankton(e.g.planktonic ciliates)trait structure and its variation with hydrography i...Trait structure is increasingly used in plankton ecology to understand diversity and biogeography.However,our knowledge of micro zooplankton(e.g.planktonic ciliates)trait structure and its variation with hydrography is limited.In this study,we analyzed planktonic ciliate trait structure in waters with different hydrography and deep Chlorophyll a maximum(DCM)layers over three seamounts:Yap,Mariana,and Caroline seamounts.Mariana seamount had a lower surface temperature than the Yap and Caroline seamounts.DCM layers over Mariana and Caroline seamounts were deeper than Yap seamount.There was a weak upwelling in upper 50 m around top of Mariana seamount.The ciliate distribution showed bimodal pattern(high abundance appeared in the surface and DCM layers)over three seamounts.At surface layer,the large size-fraction(>30μm)abundance proportion to aloricate ciliate over Yap seamount(44.4%)was higher than Mariana(32.8%)and Caroline(36.1%)seamounts.For tintinnid abundance proportion to total ciliate,Mariana(12.0%)and Caroline(11.5%)seamounts at about 100-m depth were higher than that of Yap seamount(6.4%).Vertically,tintinnid could be divided into 4 groups over the three seamounts.At30-m depth,group I(species occurring from surface to 100 m only)was dominant component over Yap and Caroline seamounts,while group IV(species occurring at every depth)changed into dominant component over Mariana seamount,the weak upwelling might be the reason.Salpingella faurei was the top dominant species,which corresponded to deeper DCM layers over Mariana and Caroline seamounts.Our results showed that the upwelling and the deeper DCM could influence the planktonic ciliate trait structure.展开更多
The increasing emergence of multi-drug resistant Escherichia coli(E.coli)has become a global concern,primarily due to the limitation of antimicrobial treatment options.Phage therapy has been considered as a promising ...The increasing emergence of multi-drug resistant Escherichia coli(E.coli)has become a global concern,primarily due to the limitation of antimicrobial treatment options.Phage therapy has been considered as a promising alternative for treating infections caused by multi-drug resistant E.coli.However,the application of phages as a promising antimicrobial agent is limited by their narrow host range and specificity.In this research,a recombinant T4-like phage,named WGqlae,has been obtained by changing the receptor specificity determinant region of gene 37,using a homologous recombination platform of T4-like phages established by our laboratory previously.The engineered phage WGqlae can lyse four additional hosts,comparing to its parental phages WG01 and QL01.WGqlae showed similar characteristics,including thermo and pH stability,optimal multiplicity of infection and one-step growth curve,to the donor phage QL01.In addition,sequencing results showed that gene 37 of recombinant phage WGqlae had genetically stable even after 20 generations.In planktonic test,phage WGqlae had significant antimicrobial effects on E.coli DE192 and DE205 B.The optical density at 600 nm(OD600)of E.coli in phage WGqlae treating group was significantly lower than that of the control group(P\0.01).Besides,phage WGqlae demonstrated an obvious inhibitory effect on the biofilm formation and the clearance of mature biofilms.Our study suggested that engineered phages may be promising candidates for future phage therapy applications against pathogenic E.coli in planktonic and biofilm forms.展开更多
A brief morphometric study of the recent planktonic foraminifera in the eastern Indian Ocean was provided with the taxonomic key to species, synonyms, SEM microphotographs of shells and chamber arrays. By recent class...A brief morphometric study of the recent planktonic foraminifera in the eastern Indian Ocean was provided with the taxonomic key to species, synonyms, SEM microphotographs of shells and chamber arrays. By recent classification, currently 20 species representing 13 genera and 6 families （Canderinidae, Heterohelicoidae, Hedbergellidae, Higerigerinoidae, Globigerinoidae, and Globorotaloidae） identified from the planktonic material of the eastern Indian Ocean up to a depth of 200 m. Their distribution in water （0-200 m） also reports on the new range of expansion in the eastern Indian Ocean, with Dentigloborotalia anfracta, Hastigerina pelagica, Streptochilus globigerus, Globigerinella calida, Globigerinella adamsi, Orcadia reidelii, Tenuitella parkerae, Tenuitella compressa, reported for the first time in this study area. In general, only around 50 planktonic species are valid worldwide, more specifically the species, e.g., H. pelagica, G. calida, G. adamsi, S. globigerus, O. riedeli, T. parkerae, T. compressa, which occur in the eastern Indian Ocean to fill the the paucity of the recent regional taxonomic literature and the problematic identification from the eastern Indian Ocean. This work aims to bridge this gap and help scientists, managers, educators and students to identify plankton foraminifers by using species notes and images.展开更多
Corals influence microorganisms within the surrounding seawater,yet the diversities and functions of seawater bacteria and microeukaryotes in coral-reef systems have not been well addressed.We collected 40 seawater sa...Corals influence microorganisms within the surrounding seawater,yet the diversities and functions of seawater bacteria and microeukaryotes in coral-reef systems have not been well addressed.We collected 40 seawater samples in outer coral reef flats and semi-closed inner lagoons from the surface,middle and bottom layers in the pristine coral-reef system of Xisha Islands,South China Sea.We detected the abundance,composition and distribution of bacteria and microeukaryotes using flow cytometry,qPCR and high throughput sequencing techniques,and profiled the potential ecological roles based on the information of 16S and 18S rDNA sequencing.In terms of flow cytometry,Prochlorococcus dominated the autotrophs with cell abundance ranging from 5.8×10^(2)to 5.44×10^(3)cells mL−1 seawater.Based on qPCR,the 16S rDNA copies were much higher in coral reef flats than in lagoons(P=0.003).The bacterial communities held significantly lower diversity in bottom waters compared with surface and middle waters(P<0.05),which were dominated by SAR11,Flavobacteriales,and Synechococcus.Alveolata represented most of the microeukaryotic communities with Dinophyceae and Syndiniales well represented in all samples.Neither bacterial nor microeukaryotic community exhibited distinct layer or niche pattern,however,Haptophyta and Picozoa decreased with depth and SAR 86,MAST-3 and Picozoa were enriched in lagoons(P<0.05).To adapt the nutrient-poor and organic matter-rich environment,bacterial nitrogen fixation and assimilatory/dissimilatory nitrate reduction were active in the system,and mixotrophy was the most important trophic strategy among microeukaryotes.The study highlighted the ecological adaptability of seawater microbes to the unique coral-reef environments.展开更多
Species abundance and seasonal succession of copepods in saline-alkaline ponds were studied in Zhaodian Fish Farm, Gaoqing County, Shandong Province, from 5 April 1997 to 1 September 1998. The results indicated that i...Species abundance and seasonal succession of copepods in saline-alkaline ponds were studied in Zhaodian Fish Farm, Gaoqing County, Shandong Province, from 5 April 1997 to 1 September 1998. The results indicated that in the conditions of salinity ranging from 1.36 to 20 g/L, total alkalinity changing from 2.4 to 7.2 mmol/L and pH 8–9, zooplankton in saline-alkaline ponds was composed of freshwater salt-tolerated species or halophile species, some of which are halobiont species and usually occurs in freshwater. In our study, copepods were predominant in many fish-culture ponds and all control ponds without fishes in spring, late autumn and early winter. Dominant species of copepods were Sinocalanus tenellus, Cyclops vicinus, Thermocyclops taiho- kuensis. The biomass of copepods in the control ponds without fishes was higher than that of the fish-culture ponds.展开更多
Nano- and microalgae samples were collected from 34 stations in the Prydz Bay and its adjacent Southern indian Ocean, Antarctica during a Period from December 1990 to January 1991. 122 taxa belonging to 40 genera 5 ph...Nano- and microalgae samples were collected from 34 stations in the Prydz Bay and its adjacent Southern indian Ocean, Antarctica during a Period from December 1990 to January 1991. 122 taxa belonging to 40 genera 5 phyla were identified. Among them diatom occupy 73%,dinoflagellates 20. 5%, the other species 6. 5 %. The average cell abundance of nano- and microalgae was 2551×104 cells/m3 in surface waters. The concentration of nano- and microalgae occurred in the Prydz Bay and its adjacent continental station Ⅳ 7 and northern water area between West Ice Shelf and Shackleton Ice Shelf (Stations Ⅶ 3, Ⅷ 1, Ⅷ 2, Ⅷ 3, Ⅸ 1, Ⅺ 1); and minimal abundance occurred in northwestern area of the Prydz Bay (some stations of section Ⅲ and Station Ⅳ 1-5). The average cell abundance of planktonic nano- and microalgae from net sample was 811. 62×104 cells/m3, and the concentration area occurred in the adjacent continent waters of the Prydz Bay (Stations Ⅳ 2, Ⅳ 4, Ⅳ 5, Ⅳ 7, Ⅴ 4 and Ⅴ 5) and northern area of the West Ice Shelf(Stations Ⅶ 1 and Ⅶ 3); low abundance occurred in eastern area of the Shackleton Ice Shelf (at each station of sections Ⅹ and Ⅺ ). For the vertical distribution of planktonic nano- and microalgae, the maximum value was usually found at the surface and above 50 m depth, and gradually decreased with the water depth from 100 m to 200 m. The relationship between planktonic nano-and microalgal abundance and Euphausia superba density and nutrient (nitrate,phosphate and silicate) contents were negative significance.展开更多
In order to evaluate the relationships between temporal species succession of planktonic protists and physical-chemical parameters in semi-enclosed mariculture waters, species distributions in response to environmenta...In order to evaluate the relationships between temporal species succession of planktonic protists and physical-chemical parameters in semi-enclosed mariculture waters, species distributions in response to environmental stress were investigated in a shrimp-farming pond near Qingdao, China during a complete shrimp-culture cycle （May to October 2002）. A clear temporal succession in species distribution was found over the complete farming cycle. For example, before the introduction of the shrimp larvae there was low-variability of species distribution in the protist communities whereas during the stages immediately after, there was higher variability in species composition. Multiple linear/logistic regression analyses demonstrate that 12 protist taxa （e.g., Gyrodinium spirale, Teleaulax acuta, Prorocentrum spp. and Mesodinium pupula） were related to the nutrients, in particular ammonia and phosphates, alone or in combination with water temperature. These results suggest that temporal variations in species distribution of planktonic protist communities might be used in assessing water quality of semi-enclosed mariculture waters.展开更多
基金The National Natural Science Foundation of China under contract Nos 42206126 and 42076044the Natural Science Foundation of Shandong Province under contract No.ZR2021QD099.
文摘Plate culture counting and strain isolation methods were utilized to assess the species richness and abundance of planktonic and attached bacteria on glass plates in the surface and bottom seawater of Qingdao Middle Harbor over a year,with monthly and quarterly sampling.Both species richness and bacterial numbers exhibited seasonal variations.Specifically,the abundance of attached bacteria and bacterioplankton peaked in June and July,corresponding to higher water temperatures in summer and autumn,while lower abundances were noted in January and December during cooler periods.Throughout the year,the species richness of attached bacteria consistently exceeded that of planktonic bacteria in both shallow and deep waters.Pseudoalteromonas emerged as the most prevalent genus among both planktonic and attached bacteria in surface and bottom seawater samples.Furthermore,the magnitude of changes in species richness and abundance for attached bacteria(0.66×10^(5)-15.85×10^(5)CFU/cm^(2))was greater than that observed for planktonic bacteria(0.58×10^(8)-5.33×10^(8)CFU/L).We propose that the attached bacterial populations,situated in limited microenvironments within the larger seawater ecosystem,exhibit heightened sensitivity to environmental fluctuations,resulting in more rapid shifts in population dynamics and lower ecological stability.The theoretical implications and potential applications of these findings warrant further investigation.
基金funded by Youth Fund of the National Natural Science Foundation of China,grant number 11504176,61601230.
文摘As one of the main application directions of quantum technology,underwater quantum communication is of great research significance.In order to study the influence of marine planktonic algal particles on the communication performance of underwater quantum links,based on the extinction characteristics of marine planktonic algal particles,the influence of changes in the chlorophyll concentration and particle number density of planktonic algal particles on the attenuation of underwater links is explored respectively,the influence of marine planktonic algal particles on the fidelity of underwater quantum links,the generation rate of the security key,and the utilization rate of the channel is analyzed,and simulation experiments are carried out.The results show that with the increase in chlorophyll concentration and particle density of aquatic planktonic algal particles,quantum communication channel link attenuation shows a gradually increasing trend.In addition,the security key generation rate,channel fidelity and utilization rate are gradually decreasing.Therefore,the performance of underwater quantum communication channel will be interfered by marine planktonic algal particles,and it is necessary to adjust the relevant parameter values in the quantum communication system according to different marine planktonic algal particle number density and chlorophyll concentration to improve the performance of quantum communication.
基金supported by the Marine Biological Sample Collection of the Chinese Offshore Investigation and Assessment (No. 908-ZC-II-02)the Ministry of Science and Technology for Commonweal Project of China (No. 200905009-3)
文摘Based on 4 cruise surveys from July 2006 to October 2007 in the Taiwan Strait, the species composition, community structure and spatio-temporal distribution of dinoflagellate were studied. A total of 131 dinoflagellates belonging to 18 genera were identified. The population was dominated by hyperthermal and hyperhaline species accounting for 72.52% of the total species. Eurythermal and euryhaline species were the second most common one accounting for 25.19% of the total species. It was only 2.29% for neritic species. The maximum species number occurred in summer, while the maximum cell density appeared in spring. The average dinoflagellate cell density was 404.96x104 cells/m3. It showed that the dinof]agellate cell density increased from the nearshore waters to the open sea and from the north to the south. Compared with the results during 1984-1985, the horizontal distribution pattern and seaeonal variation of the dinofiagellate have not changed significantly, but the dinoflagellate cell density increased by 3.01 times. Further analysis of the dinoflagellate abundance variations both in the spatial and temporal aspects, indicated that the abundance of dinoflagellate increased more significantly in cold seasons, and there was a larger increase in the north of the Taiwan Strait. Besides, the dinoflagellate community structure changed notably. It showed that the diversity and evenness index were relatively high, and the proportion of dinoflageliate cell density to the total phytoplankton increased.
基金The National Natural Science Foundation of China under contract No.41706192the Science&Technology Basic Resources Investigation Program of China under contract No.2017FY100803+3 种基金the National Natural Science Foundation of ChinaShandong Joint Fund for Marine Science Research Centers under contract No.U1606404the CNRS-NSFC Joint Research Projects Program under contract No.NSFC 41711530149the 2017–2019 Sino-French Cai Yuanpei Programmethe National Natural Science Foundation of China under contract No.41706217
文摘Ciliates are important components in planktonic food webs,but our understanding of their community structures in different oceanic water masses is limited.We report pelagic ciliate community characteristics in three seas:the tropical West Pacific,the Bering Sea and the Arctic Ocean.Planktonic ciliate abundance had"bimodal-peak","surface-peak"and"DCM(deep chlorophyll a maximum layer)-peak"vertical distribution patterns in the tropical West Pacific,the Bering Sea and the Arctic Ocean,respectively.The abundance proportion of tintinnid to total ciliate in the Bering Sea(42.6%)was higher than both the tropical West Pacific(7.8%)and the Arctic Ocean(2.0%).The abundance proportion of small aloricate ciliates(10–20μm size-fraction)in the tropical West Pacific was highest in these three seas.The Arctic Ocean had higher abundance proportion of tintinnids in larger LOD(lorica oral diameter)size-class.Proportion of redundant species increased from the Arctic Ocean to the tropical West Pacific.Our result provided useful data to further understand ecology roles of planktonic ciliates in different marine habitats.
基金The National Natural Science Foundation of China under contract No.41176044Shaanxi Provincial Technology Foundation for Selected Overseas Chinese Scholar under contract Shaan Renshe[2015]No.1190
文摘Horizontal and vertical distributions of δ^18 and δ^13 were investigated in shells of four planktonic foraminiferal species, Globigerinoides ruber, Globigerinoides sacculifer, Pulleniatina obliquiloculata and Neogloboquedrina dutertrei, from a total of 62 core-top sediment samples from the Indonesian throughflow region. Results were compared to modern hydrologic conditions in order to explore potential of proxies in reconstructing fluvial discharge and upper ocean water column characteristics in this region. Our results show that, in the Makassar Strait, both of depleted δ^18 and δ^13 of these four species were linked to freshwater input. In the Bali Sea,however, depleted δ^18 and δ^13 for these species may be due to different reasons. Depleted δ^18 was a result of freshwater input and as well influenced by along-shore currents while depleted δ^13 was more likely due to the Java-Sumatra upwelling. Comparison of shell δ^18 records and hydrographic data of World Ocean Atlas 2005 suggests that G. ruber and G. sacculifer calcify within the mixed-layer, respectively at 0–50 m and 20–75 m water depth, and P. obliquiloculata and N. dutertrei within the upper thermocline, both at 75–125 m water depth. N.dutertrei calcifies at slightly deeper water depth than P. obliquiloculata does. In general, δ^13 values of both G.ruber and G. sacculifer are larger than those of P. obliquiloculata and N. dutertrei at all sites, possibly related to depth habitats of these species and vertical distribution of nutrients in the Indonesian throughflow region.
基金The work was supported by the National Natural Science Foundation of China under contract !No. 49576275.
文摘The Paper is the succession of the study on abundance distribution of planktonic copepods in the waters north of Taiwan, and the emphasis is laid on the analysis and discussion of the constructions and features of copepod community and the relationships with water environment. The results show as follows: a total of 237 species were identified and the construction of communtity was complex. The percentage of annual present species was only 32%. The mean values of diversity and homogeneity of the copepod community were 3. 714 and 0. 690 respectively, and their horizontal distribution patterns were higher in outshore area than in nearshore area. The copepods of the area could be divided into five ectotypes. Warm-water outshore high temperature and lower saline group and tropic oceanic high temperature and saline group could indicate the seasonal changes of the Taiwan Strait water and the Kuroshio surface water respectively. According to the various aspects of calculation and analysis, winter was different from other three seasons in environmental conditions. In spring, summer and autumn, Undinula valgaris was the meat dominant species and salinity was the main factor that affected the community feature values. The communities in the three seasons had the subtropic-tropic characteristics in which warm-water outshore species were dominant and tropic oceanic species accounted for also certain proportion. While in winter, the dominant species was Euchaeta manna and temperature was the main factor influencing the community feture values. The community had the tropic oceanic characteristics in which tropic oceanic species were dominant.
基金The National Key Technology Research and Development Program of China under contract No. 2006BAD09A09the National Nonprofit Special Foundation of China under contract No. NYHYZX07-047the Program for New Century Excellent Talents in Universities under contract No.NCET-06-0594
文摘The identification of scallop larvae is essential to understand the population structure and community dynamics and to assess the potential environmental impacts caused by scallop larvae released or escaped. However, the larvae identification by morphological characteristics is notoriously difficult, mainly due to the small size （usually being less than 150 μm） and vague morphological characteristics among different scallop species. A simple and accurate molecular method was developed to identify four economically farmed scallop species, the Zhikong scallop Chlamys farreri, the noble scallop C. nobilis, the bay scallop Argopecten irradians and the Yesso scallop Mizuhopecten yessoensis. The tests used the high degree of species-specific microsatellite markers, which was specified by transferability analyses, assessed by reference individuals and evaluated by BLAST searches. The sensitivity test indicated that the species-specific microsatellites were sensitive enough for the detection of 1% -2% larvae in mixed plankton samples. Larvae collected from scallop hatcheries and their effluents and from the artificially controlled crosses were well identified to the species/hybrid level. The results demonstrated that the one-step PCR-based assay was technically simple, inexpensive and robust in identification analyses, and also less sensitive to initial quality of template DNA extracted from the ethanol-preserved samples for several years.
基金supported by the National Natural Science Foundation of China(Grant Nos.41176044 and 41576045)Shaanxi Provincial Technology Foundation for Selected Overseas Chinese Scholar(Grant No.Shaan Renshe[2015]No.1190)
文摘Test geochemistry of planktonic foraminifera is an indispensable tool in reconstructing past ocean hydrological changes. It is essential to investigate region-specific implications of test geochemistry,although those established from other regions can be broadly applied. In this study, characteristics of6180 and Mg/Ca from tests of four planktonic foraminiferal species, Globigerinoides ruber sensu stricto(s.s.), Globigerinoides sacculifer, Pulleniatina obliquiloculata and Neogloboquadrina dutertrei, from 60 coretop sediment samples retrieved from the Indonesian Throughflow(ITF) region were studied. These geochemical data were compared with modern hydrographic profiles in order to assess their relations and to investigate potential implications of test geochemical parameters in reconstructing past oceanographic change in the ITF region. Calcification depths of these four species were first estimated based on comparison between measured test δ180 and predicted calcite δ^(18)O that was calculated from modern temperature and salinity. The results indicate that G. ruber s.s. and G. sacculifer calcify within the mixedlayer at 0-50 m and 20-75 m, respectively, whereas P. obliquiloculata and N. dutertrei calcify within the thermocline at around 75 to 125 m. A combined study of excess Mg/Ca(difference between measured and predicted Mg/Ca) and salinity suggests that salinity exerts a negligible impact on test Mg/Ca of these foraminiferal species in the ITF region. Comparison of test Mg/Ca-derived temperatures with temperature profiles of the upper 200 m of the water column from the seas of the ITF region also indicate calcification depths of these species, which match well with the above estimations using test δ^(18)O. It further indicates that G. sacculifer may be more sensitive in reflecting changes in the depth of the mixedlayer, highlighting a potential use of Mg/Ca temperature difference between G. ruber s.s. and G. sacculifer in reconstructing the depth of the mixed-layer in the ITF region.
基金granted by the National Natural Science Foundation of China(Grant No.41272030)the IGCP 608the National Basic Research Program of China(Grant No.2012CB822001).
文摘1 Introduction The collision evolution between the Indian plate and the Eurasian plate is one of the significant geological events since the Mesozoic.It has profoundly influenced the global tectonic framework and led to the formation of the Qinghai-Tibet Plateau,which has attracted extensive attention of global geologists and become a research hotspot(Butler,1995;Li and Wan,2003a and b;Wang et al.,2003;Aitchison et al.,2007).
基金National Natural Science Foundation of China ! 49576275.
文摘On the basis of the investigation materials of 6 cruise in the waters north of Taiwan from 1987~1990, the distribution characteristics of planktonic copepods are discussed in the study from three aspects of abundance distribution, community feature and indicative species. The paper is the first part of the study. The results show as follows: the highest abundance of copepods occurred in spring and the lowest one in winter, while the abundance in summer and autumn was between the above two seasons. The copepod abundance in the west of the Kuroshio front was higher than that in the east of the front. There was a distribution tendency that higher abundance occurred in outshore area in summer and in nearshore area in winter, which corresponded with the trend of seasonal swings of the Kuroshio front. The higher copepod abundance appeared generally in the mixed areas of various water masses, especially in nearshore side of upwelling of the Kuroshio sub-surface water. However, in the Kuroshio subsurface main water, the abundance was low because of some factors such as low concentration of dissolved oxy gen and so on. The vertical distribution trend was that the copepopd abundance decreased with the in crease of depth, and the diurnal vertical migration regularities of some species were probably the one of reasons that caused the abnormal distributions in some local waters.
基金the University of Isfahan for providing financial support。
文摘In this study, the Maastrichtian-Danian boundary was measured and sampled in two stratigraphic sections, the north and south flanks of the Dehnow anticline in Coastal Fars, Southern Iran. This boundary was also investigated in the drilled exploratory well-1 in the same region. The lithology of the Maastrichtian-Danian deposits consists of glauconitic, phosphatic argillaceous limestones and marlstones. 30 genera and 77 species of planktonic foraminifera have been determined. The recognized biozones are the Gansserina gansseri Interval Zone, and the Contusotruncana contusa Interval Zone, which indicates latest Campanian to middle Maastrichtian age for the upper part of the Gurpi Formation. In addition, the Eoglobigerina edita(P1) Partial Range Zone, Praemurica uncinata(P2) Lowest Occurrence Zone, Morozovella angulata(P3) Lowest Occurrence Zone and Globanomalina psudomenardii(P4) Taxon Range Zone represent a Danian to Thanetian age for the lower part of the Pabdeh Formation. From the absence of the Abathomphalus mayaroensis Interval Zone, Pseudoguembelina hariaensis Interval Zone, Pseudotextularia elegans Interval Zone, Plummerita hantkeninoides Interval Zone, Guembelitria cretacea(P0) Partial Range Zone and Parvularugoglobigerina eugubina(Pα) Total Range Zone, it can be deduced that there is a paraconformity across the Maastrichtian–Danian boundary in the studied area, this hiatus encompassing the late Maastrichtian and the earliest Danian. Danian deposits from the study area contain reworked glauconitized macrofossils, planktonic and benthic foraminifera of the Cretaceous. The obtained surface gamma-ray spectrometry logs resemble the exploratory well-1 gamma-ray wireline log.
基金The National Natural Science Foundation of China under contract Nos 40676076 and 30700069the Darwin Initiative Programme under contract No.14-015a grant from the Center of Excellence in Biodiversity Research,King Saud University
文摘The functional groups of planktonic protist communities and their responses to the changes of environmental conditions were investigated in a semi-enclosed shrimp-farming pond in Qingdao,Shandong Province,China,during a six-month study period （a complete shrimp-culture cycle） from May to October 2002.The results reveal that： （1） the protist communities represented five trophic and functional groups of the species identified,about 60% were photoautotrophs,20% algivores,12% bacterivores,5% raptors and about 3% non-selectives;（2） the photoautotrophs,algivores and bacterivores were the primary contributors to the changes in the protist communities in short temporal scales,the succession of dominance typically being bacterivores→photoautotrophs→algivores,with the raptors dominating the protist communities in a single sample （early June）;（3） the photoautotrophs and non-selectives were the primary contributors to the peak of protist abundance in early October whereas the photoautotrophs,bacterivores,raptors and non-selectives mainly gave rise to two bimodal peaks of biomass in July and October respectively;（4） five functional groups of protist communities represented significant correlations with water nutrients （i.e.,NH 3-N,NO 3-N,and PO 4 ）,either alone or in combination with temperature,of which algivores and raptors were strongly correlated with phosphate and the concentration of Chl a,while bacterivores were strongly related to nitrogen and the concentration of bacteria.These findings confirm that planktonic protists are potentially useful bioindicators of water quality in the semi-enclosed mariculture system.
基金the Science&Technology Basic Resources Investigation Program of China(No.2017FY100803)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB42000000)+5 种基金the China Postdoctoral Science Foundation(No.2020M672149)the National Key Research and Development Program of China(No.2017YFA0603204)the CNRS-NSFC Joint Research Projects Program(No.NSFC 41711530149)the 2017-2019 Sino-French Cai Yuanpei Programthe International Cooperation Project-Dynamics and Function of Marine Microorganisms(No.ICP-DYF2M):Insight from Physics and Remote Sensing。
文摘Trait structure is increasingly used in plankton ecology to understand diversity and biogeography.However,our knowledge of micro zooplankton(e.g.planktonic ciliates)trait structure and its variation with hydrography is limited.In this study,we analyzed planktonic ciliate trait structure in waters with different hydrography and deep Chlorophyll a maximum(DCM)layers over three seamounts:Yap,Mariana,and Caroline seamounts.Mariana seamount had a lower surface temperature than the Yap and Caroline seamounts.DCM layers over Mariana and Caroline seamounts were deeper than Yap seamount.There was a weak upwelling in upper 50 m around top of Mariana seamount.The ciliate distribution showed bimodal pattern(high abundance appeared in the surface and DCM layers)over three seamounts.At surface layer,the large size-fraction(>30μm)abundance proportion to aloricate ciliate over Yap seamount(44.4%)was higher than Mariana(32.8%)and Caroline(36.1%)seamounts.For tintinnid abundance proportion to total ciliate,Mariana(12.0%)and Caroline(11.5%)seamounts at about 100-m depth were higher than that of Yap seamount(6.4%).Vertically,tintinnid could be divided into 4 groups over the three seamounts.At30-m depth,group I(species occurring from surface to 100 m only)was dominant component over Yap and Caroline seamounts,while group IV(species occurring at every depth)changed into dominant component over Mariana seamount,the weak upwelling might be the reason.Salpingella faurei was the top dominant species,which corresponded to deeper DCM layers over Mariana and Caroline seamounts.Our results showed that the upwelling and the deeper DCM could influence the planktonic ciliate trait structure.
基金supported by Grants from the National Natural Science Foundation of China(U1803109)Key research and development plan of Jiangsu province(BE2019304)+2 种基金National Key R&D Program of China(2018YFC1602500)the Central University Basic Scientific Research Fund-Animal pathogenic bacteria(KYZ201846)Jiangsu modern agriculture(waterfowl)industrial technology system disease prevention and control innovation team(JATS[2018]222)
文摘The increasing emergence of multi-drug resistant Escherichia coli(E.coli)has become a global concern,primarily due to the limitation of antimicrobial treatment options.Phage therapy has been considered as a promising alternative for treating infections caused by multi-drug resistant E.coli.However,the application of phages as a promising antimicrobial agent is limited by their narrow host range and specificity.In this research,a recombinant T4-like phage,named WGqlae,has been obtained by changing the receptor specificity determinant region of gene 37,using a homologous recombination platform of T4-like phages established by our laboratory previously.The engineered phage WGqlae can lyse four additional hosts,comparing to its parental phages WG01 and QL01.WGqlae showed similar characteristics,including thermo and pH stability,optimal multiplicity of infection and one-step growth curve,to the donor phage QL01.In addition,sequencing results showed that gene 37 of recombinant phage WGqlae had genetically stable even after 20 generations.In planktonic test,phage WGqlae had significant antimicrobial effects on E.coli DE192 and DE205 B.The optical density at 600 nm(OD600)of E.coli in phage WGqlae treating group was significantly lower than that of the control group(P\0.01).Besides,phage WGqlae demonstrated an obvious inhibitory effect on the biofilm formation and the clearance of mature biofilms.Our study suggested that engineered phages may be promising candidates for future phage therapy applications against pathogenic E.coli in planktonic and biofilm forms.
基金The National Natural Science Foundation of China under contract Nos 41876134,41676112,41276124 and 41406155the University Innovation Team Training Program for Tianjin under contract No.TD12-5003the Changjiang Scholar Program of Chinese Ministry of Education of China to Jun Sun
文摘A brief morphometric study of the recent planktonic foraminifera in the eastern Indian Ocean was provided with the taxonomic key to species, synonyms, SEM microphotographs of shells and chamber arrays. By recent classification, currently 20 species representing 13 genera and 6 families （Canderinidae, Heterohelicoidae, Hedbergellidae, Higerigerinoidae, Globigerinoidae, and Globorotaloidae） identified from the planktonic material of the eastern Indian Ocean up to a depth of 200 m. Their distribution in water （0-200 m） also reports on the new range of expansion in the eastern Indian Ocean, with Dentigloborotalia anfracta, Hastigerina pelagica, Streptochilus globigerus, Globigerinella calida, Globigerinella adamsi, Orcadia reidelii, Tenuitella parkerae, Tenuitella compressa, reported for the first time in this study area. In general, only around 50 planktonic species are valid worldwide, more specifically the species, e.g., H. pelagica, G. calida, G. adamsi, S. globigerus, O. riedeli, T. parkerae, T. compressa, which occur in the eastern Indian Ocean to fill the the paucity of the recent regional taxonomic literature and the problematic identification from the eastern Indian Ocean. This work aims to bridge this gap and help scientists, managers, educators and students to identify plankton foraminifers by using species notes and images.
基金the National Key Research and Development Program of China(No.2018YF C1406501)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050303)+1 种基金the National Natural Science Foundation of China(Nos.41676154,41976115)the Key Research Program of Frontier Sciences of CAS(Nos.QYZDB-SSW-DQC013,QYZ DB-SSW-DQC041)。
文摘Corals influence microorganisms within the surrounding seawater,yet the diversities and functions of seawater bacteria and microeukaryotes in coral-reef systems have not been well addressed.We collected 40 seawater samples in outer coral reef flats and semi-closed inner lagoons from the surface,middle and bottom layers in the pristine coral-reef system of Xisha Islands,South China Sea.We detected the abundance,composition and distribution of bacteria and microeukaryotes using flow cytometry,qPCR and high throughput sequencing techniques,and profiled the potential ecological roles based on the information of 16S and 18S rDNA sequencing.In terms of flow cytometry,Prochlorococcus dominated the autotrophs with cell abundance ranging from 5.8×10^(2)to 5.44×10^(3)cells mL−1 seawater.Based on qPCR,the 16S rDNA copies were much higher in coral reef flats than in lagoons(P=0.003).The bacterial communities held significantly lower diversity in bottom waters compared with surface and middle waters(P<0.05),which were dominated by SAR11,Flavobacteriales,and Synechococcus.Alveolata represented most of the microeukaryotic communities with Dinophyceae and Syndiniales well represented in all samples.Neither bacterial nor microeukaryotic community exhibited distinct layer or niche pattern,however,Haptophyta and Picozoa decreased with depth and SAR 86,MAST-3 and Picozoa were enriched in lagoons(P<0.05).To adapt the nutrient-poor and organic matter-rich environment,bacterial nitrogen fixation and assimilatory/dissimilatory nitrate reduction were active in the system,and mixotrophy was the most important trophic strategy among microeukaryotes.The study highlighted the ecological adaptability of seawater microbes to the unique coral-reef environments.
基金The National Funds from Ministry of Agriculture of China (960080401) and the National Young Scientist Fund (39725023).
文摘Species abundance and seasonal succession of copepods in saline-alkaline ponds were studied in Zhaodian Fish Farm, Gaoqing County, Shandong Province, from 5 April 1997 to 1 September 1998. The results indicated that in the conditions of salinity ranging from 1.36 to 20 g/L, total alkalinity changing from 2.4 to 7.2 mmol/L and pH 8–9, zooplankton in saline-alkaline ponds was composed of freshwater salt-tolerated species or halophile species, some of which are halobiont species and usually occurs in freshwater. In our study, copepods were predominant in many fish-culture ponds and all control ponds without fishes in spring, late autumn and early winter. Dominant species of copepods were Sinocalanus tenellus, Cyclops vicinus, Thermocyclops taiho- kuensis. The biomass of copepods in the control ponds without fishes was higher than that of the fish-culture ponds.
文摘Nano- and microalgae samples were collected from 34 stations in the Prydz Bay and its adjacent Southern indian Ocean, Antarctica during a Period from December 1990 to January 1991. 122 taxa belonging to 40 genera 5 phyla were identified. Among them diatom occupy 73%,dinoflagellates 20. 5%, the other species 6. 5 %. The average cell abundance of nano- and microalgae was 2551×104 cells/m3 in surface waters. The concentration of nano- and microalgae occurred in the Prydz Bay and its adjacent continental station Ⅳ 7 and northern water area between West Ice Shelf and Shackleton Ice Shelf (Stations Ⅶ 3, Ⅷ 1, Ⅷ 2, Ⅷ 3, Ⅸ 1, Ⅺ 1); and minimal abundance occurred in northwestern area of the Prydz Bay (some stations of section Ⅲ and Station Ⅳ 1-5). The average cell abundance of planktonic nano- and microalgae from net sample was 811. 62×104 cells/m3, and the concentration area occurred in the adjacent continent waters of the Prydz Bay (Stations Ⅳ 2, Ⅳ 4, Ⅳ 5, Ⅳ 7, Ⅴ 4 and Ⅴ 5) and northern area of the West Ice Shelf(Stations Ⅶ 1 and Ⅶ 3); low abundance occurred in eastern area of the Shackleton Ice Shelf (at each station of sections Ⅹ and Ⅺ ). For the vertical distribution of planktonic nano- and microalgae, the maximum value was usually found at the surface and above 50 m depth, and gradually decreased with the water depth from 100 m to 200 m. The relationship between planktonic nano-and microalgal abundance and Euphausia superba density and nutrient (nitrate,phosphate and silicate) contents were negative significance.
基金The National Natural Science Foundation of China under contract Nos 40676076 and 700069a post-doctoral fellowship of Inha University and a grant from the Center of Excellence in Biodiversity Research, King Saud University
文摘In order to evaluate the relationships between temporal species succession of planktonic protists and physical-chemical parameters in semi-enclosed mariculture waters, species distributions in response to environmental stress were investigated in a shrimp-farming pond near Qingdao, China during a complete shrimp-culture cycle （May to October 2002）. A clear temporal succession in species distribution was found over the complete farming cycle. For example, before the introduction of the shrimp larvae there was low-variability of species distribution in the protist communities whereas during the stages immediately after, there was higher variability in species composition. Multiple linear/logistic regression analyses demonstrate that 12 protist taxa （e.g., Gyrodinium spirale, Teleaulax acuta, Prorocentrum spp. and Mesodinium pupula） were related to the nutrients, in particular ammonia and phosphates, alone or in combination with water temperature. These results suggest that temporal variations in species distribution of planktonic protist communities might be used in assessing water quality of semi-enclosed mariculture waters.
