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《Deep Sea Research Part I: Oceanographic Research Papers》2006,53(6):1044-1060
Zooplankton and nekton at 2000 m depth in the axial valley of Endeavour Segment, Juan de Fuca Ridge, show marked variability in abundances in a plane at 20 m above bottom. A remotely operated vehicle flew a gridded rectangle 3.2×0.5 km that included two large high-temperature and two small low-temperature vent fields. Numbers of zooplankton, jellyfish, shrimp and fish were recorded with a video camera, and the abundance patterns were examined with the program SADIE©. Each organism group displayed a distinctive distribution pattern. Abundance gaps over the high-temperature fields were significant and, for the more abundant copepods, were related to the locations of individual smokers. Pelagic shrimp and macrourid fish abundances were correlated and concentrated around the northern high temperature field. Distinct aggregations of zooplankton and nekton were correlated with the fluid indicators from both the low temperature diffuse effluent and the focused high temperature vents. Patterns were likely established by organism choice that forms aggregations and gaps, and by physical processes that entrain passive particles near vigorous smoker plumes. While enhanced plankton and nekton numbers were not observed over the vent fields, overall abundances in the axial valley may be sustained by production transported from the vent fields on the seafloor. 相似文献
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Meiobenthos densities and higher taxon composition were studied in an active gas seepage area at depths from 182 to 252 m in the submarine Dnieper Canyon located in the northwestern part of the Black Sea. The meiobenthos was represented by Ciliata, Foraminifera, Nematoda, Polychaeta, Bivalvia, Gastropoda, Amphipoda, and Acarina. Also present in the sediment samples were juvenile stages of Copepoda and Cladocera which may be of planktonic origin. Nematoda and Foraminifera were the dominant groups. The abundance of the meiobenthos varied between 2397 and 52,593 ind.·m−2. Maximum densities of Nematoda and Foraminifera were recorded in the upper sediment layer of a permanent H2S zone at depths from 220 to 250 m. This dense concentration of meiobenthos was found in an area where intense methane seeps were covered by methane‐oxidizing microbial mats. Results suggest that methane and its microbial oxidation products are the factors responsible for the presence of a highly sulfidic and biologically productive zone characterized by specially adapted benthic groups. At the same time, an inverse correlation was found between meiofauna densities and methane concentrations in the uppermost sediment layers. The hypothesis is that the concentration of Nematoda and Foraminifera within the areas enriched with methane is an ecological compromise between the food requirements of these organisms and their adaptations to the toxic H2S. 相似文献
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Kazunari Ogawa 《Journal of Oceanography》1973,29(5):203-208
Distribution of coliform bacteria was surveyed monthly during July-1968 through December-1969 in Shimizu Harbor and Orido Bay. Among three significant rivers flowing into the coastal region, the water of Tomoe River was most microbiologically polluted. Throughout the period of investigation horizontal distribution of the bacterial density was highest at the estuary of the Tomoe River, and its density decreased toward Shimizu Harbor and Orido Bay.It was shown that the bacterial density decreased from surface to deeper layer. High density of bacteria was observed in bottom deposits at winter. The bacterial distribution might be disturbed by current caused by geographical features.Various types of coliform group were isolated in the surveyed areas. All types ofE. coli, E. freundii, A. aerogenes and Irregular appeared in the area of estuaries, and only limited types occurred in offshore.Bacterial number increased from upper stream toward the mouth of each river. The bacterial density differed from river to river. In the rivers flowing through the city the bacterial density changed with water temperature, whereas in the river running through agricultual district it might be affected with the rainfall. 相似文献
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Microbes are believed to play important roles in ecosystem function in many environments. The hot springs of Xiamen Island are close to the Xiamen Sea, and may have some characteristics different from those of inland hot springs. Microbes living in the hot springs of Xiamen may have new characteristics. However, little is known about microbial communities of hot springs close to the Xiamen Sea. A cuhure-dependent survey of microbial population in the Xiamen hot springs was pcrformed by using an approach combining total cellular protein profile identification and 16S rRNA gene sequencing. A total of 328 isolates of bacteria were obtained from liquid and sediment samples from the Xiamen hot springs, including neutrophilie thermophilic bacteria and moderately thermophilic acidophiles. Neutrophilic thermophilic bacteria, which grow at a temperature range of 55-90℃ including Rhodothermus marinus (Strain 1) , Thermus thermophilus (Strain 2), Thermus thiopara (Strain 3) , Geobacillus stearothermophilus(Strain 4) , Geobacillus thermoleovorans (Strain 5) , and Pseudomonas pseudoal-caligenes (Strain 6), were recovered by 2216E plates. Moderately thermophilic acidophiles, which can grow at temperatures above 50℃ and a pH range of 1. 8-3.5 such as Alicyclobacillus acidoterrestris (Strain 8) , Sul-fobacillus acidophilus (Strain 9), and Sulfobacillus thermosulfidooxidans (Strain 10), were isolated on selective solid medium containing sulfur and Fe2+. Among these strains, Rhodothermus marinus, Thermus thermophilus and Geobacillus stearothermophilus are not only thermophilcs, but also halophiles. One bacterium strain (Strain 6) shared 99% nucleotide sequence homology with Pseudomonas pseudoalcaligenes on the 16S rRNA gene se-quence, but was quite different from Pseudomonas pseudoalcaligenes in biological characteristics, suggesting that it may represent a novel thermophilic species. Results indicated that various species of neutrophilic thermophiles and moderately thermophilic acidophiles were widely distributed in the Xiamen hot springs and that Rhodother-mus marinus and Thermus thermophilus dominated the cultivable microbial community. 相似文献
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Microbes are believed to play important roles in ecosystem function in many environments. The hot springs of Xiamen Island are close to the Xiamen Sea, and may have some characteristics different from those of inland hot springs. Microbes living in the hot springs of Xiamen may have new characteristics. However, little is known about microbial communities of hot springs close to the Xiamen Sea. A culturedependent survey of microbial population in the Xiamen hot springs was performed by using an approach combining total cellular protein profile identification and 16S rRNA gene sequencing. A total of 328 isolates of bacteria were obtained from liquid and sediment samples from the Xiamen hot springs, including neutrophilic thermophilic bacteria and moderately thermophilic acidophiles. Neutrophilic thermophilic bacteria, which grow at a temperature range of 55—90℃ including Rhodothermus marinus (Strain 1), Thermus thermophilus (Strain 2), Thermus thiopara (Strain 3), Geobacillus stearothermophilus (Strain 4), Geobacillus thermoleovorans (Strain 5), and Pseudomonas pseudoalcaligenes (Strain 6), were recovered by 2216E plates. Moderately thermophilic acidophiles, which can grow at temperatures above 50℃ and a pH range of 1.8—3.5 such as Alicyclobacillus acidoterrestris (Strain 8), Sulfobacillus acidophilus (Strain 9), and Sulfobacillus thermosulfidooxidans (Strain 10), were isolated on selective solid medium containing sulfur and Fe2+. Among these strains, Rhodothermus marinus, Thermus thermophilus and Geobacillus stearothermophilus are not only thermophiles, but also halophiles. One bacterium strain (Strain 6) shared 99% nucleotide sequence homology with Pseudomonas pseudoalcaligenes on the 16S rRNA gene sequence, but was quite different from Pseudomonas pseudoalcaligenes in biological characteristics, suggesting that it may represent a novel thermophilic species. Results indicated that various species of neutrophilic thermophiles and moderately thermophilic acidophiles were widely distributed in the Xiamen hot springs and that Rhodothermus marinus and Thermus thermophilus dominated the cultivable microbial community. 相似文献
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为了了解某核电厂周边海域的生态环境状况,筛选潜在威胁核电厂冷源安全的致灾生物,分析影响致灾生物时空分布的主要环境因素,本研究于2018年进行了4个季节的生态调查。结果表明,研究海域浮游植物密度秋季最高,春季优势种为东海原甲藻(Prorocentrumdonghaiense),其他季节优势种为中肋骨条藻(Skeletonema costatum)等硅藻。浮游动物密度夏季最高,以桡足类为主,春、夏季优势种还包括球型侧腕水母(Pleurobrachiaglobosa)和薮枝螅水母(Obeliasp.)。底栖动物的密度和生物量在秋季最高,优势种主要为豆形短眼蟹(Xenophthalmus pinnotheroides)、长吻沙蚕(Glycera chirori)和丝异须虫(Heteromastusfiliforms)。浮游植物、浮游动物和底栖动物群落均在夏季最为稳定,群落多样性水平和物种丰度较高,且分布较为均匀。浮游植物群落的细胞丰度与悬浮物和磷酸盐的浓度正相关性最高。浮游动物的密度受温度和盐度的影响较大。底栖动物的群落分布主要受悬浮物和无机营养盐的浓度影响。本研究共筛选出17种威胁该核电厂冷... 相似文献
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Extensive surveys were made to establish the concentrations of several metals (Zn, Cd, Pb, Cu and Hg) in various marine organisms from different parts of the Adriatic Sea in the period from 1979 to 1985. The results obtained are based on analyses which were performed in conjunction with carefully tested procedures. Proper sampling, sample storage, treatment of samples and final analytical determination has excluded artefacts which would influence the accuracy, or cause contamination and/or trace metal losses.The metal concentrations in shellfish from the coastal areas of the Adriatic Sea are in the range of the lowest values obtained for similar organisms from other localities throughout the Mediterranean Sea. Special attention has been paid to the anthropogenic influence on trace metal concentrations in organisms living in the vicinity of domestic sewage and/or industrial waste-water outflows. 相似文献
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Photosynthetic pigment system of picophytoplankton of cyanophytes was examined with five strains isolated from the Kuroshio
water at the depth of 70 m. Examination was made for the absorption spectra of intact cells of each strain. Analysis of pigment
composition was also made withSynechococcus NIBB 1059 and 1071, which were isolated from surface waters of the Gulf Stream and Kuroshio area, respectively. Results indicated
that (1) all strains contain phycoerythrin with a very high concentration, and (2) the phycoerythrin in these strains contains
two chromophores, phycoerythrobilin and phycourobilin, and (3) a large abundance of phycoerythrin and phycourobilin in the
phycoerythrin enablesSynechococcus picophytoplankton to absorb effectively the light in the blue-green region at the subsurface depth. These characteristics
suggest that cyanophytes in the subsurface water can collectt the blue-green light and perform actively photosynthesis even
at the bottom of euphotic layer. 相似文献
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Yuzo Komaki 《Journal of Oceanography》1970,26(5):283-295
A considerable number ofEuphausia similis
G. O. Sars were found to be infected with a parasite in the samples collected in the summer of 1969 in Suruga Bay. The same species
was also parasitized by an ellobiopsid,Thalassomyces fagei (Boschma), but it was rare in occurrence. The former parasite is slightly oval in shape with the longer diameter ranging between 1.0
and 1.5 mm, average diameter 1.35 mm. It infests cardiac region, rarely gastric region, of the host. It has been preliminarily
identified by Drs.T. Oshima andT. Shimazu of the Shinshu University as the progenetic metacercaria of a trematode species very closely related toPseudopecoelus japonicus; its adult was originally reported to infest several bathypelagic fishes and the encysted stage was also found in jack mackerel
from Suruga Bay byYamaguti (1938). The occurrence of the metacercaria inE. similis from the area may be new to science, althoughG. O. Sars (1885) has reported the immature forms ofDistomum filiferum
G. O. Sars inNematoscelis megalops
G. O. Sars andThysanoessa gregaria
G. O. Sars and the crustaceans of wide variety have been proved to serve as the second intermediate host of various trematodes. The
euphausiids infected with the metacercaria were concentrated in the innermost part of the bay. This might suggest the presence
of the euphausiid population which is confined to the geographical area for some period. The metacercaria may be used as a
“biological tag” to trace the migratory range of the host when the life history of the parasite is elucidated. The finding
ofT. fagei in the area may be the first record of occurrence of the species in the western North Pacific, andE. similis is now recorded as the fourteenth known host euphausiid of the ellobiopsid. 相似文献
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Influence of moonlight on the vertical migrations of benthopelagic organisms in the near-shore area of the Black Sea 总被引:1,自引:0,他引:1
L. L. Anokhina 《Oceanology》2006,46(3):385-395
From October 1999 to September 2000, six daily stations have been carried out to study the influence of the phases of the moon on the intensity of the vertical migrations of benthopelagic plankton in Golubaya Bay (near Gelendzhik). It was found that, at the full moon, the density and species diversity of the species of benthopelagic organisms are less than those in the first or the last quarters of the moon. The maximum abundance and diversity of benthopelagic organisms at the full moon occur at the beginning of the dark period. During the other phases of the moon, a gradual increase in the animal density is observed, whose maximum, as a rule, occurs in the middle of the night. At the full moon, benthopelagic animals are basically represented by juvenile individuals; all the adult individuals are males. 相似文献
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为了了解XX核电厂周边海域的生态环境状况,筛选潜在威胁核电厂冷源安全的致灾生物,分析影响致灾生物时空分布的主要环境因素,本研究于2018年进行了四个季节的生态调查。结果表明,研究海域浮游植物密度秋季最高,春季优势种为东海原甲藻,其他季节优势种为中肋骨条藻等硅藻。浮游动物密度夏季最高,以桡足类为主,春、夏季优势种还包括球型侧腕水母和薮枝螅水母。底栖动物的密度和生物量在秋季最高,优势种主要为豆形短眼蟹、长吻沙蚕和丝异须虫。浮游植物、浮游动物和底栖动物群落均在夏季最为稳定,群落多样性水平和物种丰度较高,且分布较为均匀。浮游植物群落的细胞丰度与悬浮物和磷酸盐的浓度正相关性最高。浮游动物的密度受温度和盐度的影响较大。底栖动物的群落分布主要受悬浮物和无机营养盐的浓度影响。本研究共筛选出17种威胁XX核电厂冷源安全的潜在致灾生物。海地瓜、棘刺锚参、海葵和球型侧腕水母的风险等级较高,其分布主要受温度和盐度的影响。后续工作中,XX核电厂应根据潜在致灾生物与环境因子的关系加强暴发机制研究、提升监测预警能力,并优化驱赶消杀技术和干扰体系,为核电厂冷源安全提供理论和技术保障。 相似文献
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Batches of mussels, Mytilus edulis, obtained from a sewage-free shore were introduced into the water column at a sewage polluted site and the changed content (Escherichia coli, faecal streptococci) was assessed after immersion periods of 2 to 40 h. Rapid bacterial uptake was demonstrated; changes were analysed with respect to immersion period, revealing that 2h was satisfactory. The numbers of bacteria varied with height in the water column; mussels from the sea bed contained higher numbers of E. coli than mussels immersed just below the surface except for mussels withdrawn at, and for about 3h after, low water (LW). These observations were shown to be related to the characteristics of the e effluent and tidal systems operative at the site. 相似文献
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Pelagic organisms from the central and eastern basins of the Mediterranean Sea were surveyed for chlorinated hydrocarbon residues. Levels in selected macrozooplankton and nekton, as well as mixed microplankton, were compared with those in similar species from other oceanic areas. Although data are sparse, PCBs in macrozooplankton and nekton do not appear to differ significantly from concentrations in similar species measured elsewhere. In the case of mixed microplankton, there was a trend towards slightly lower values in the Mediterranean samples. Differences between our results and those reported previously for other oceanic regions are discussed. 相似文献
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It is well established that the modulational instability enhances the probability of occurrence for extreme events in long crested wave fields. Recent studies, however, have shown that the coexistence of directional wave components can reduce the effects related to the modulational instability. Here, numerical simulations of the Euler equations are used to investigate whether the modulational instability may produce significant deviations from second-order statistical properties of surface gravity waves when short crestness (i.e., directionality) is accounted for. The case of a broad-banded directional wave field (i.e. wind sea) is investigated. The analysis is concentrated on the wave crest and trough distribution. For completeness a comparison with a unidirectional wave field is presented also. Results will show that the distributions based on second-order theory provide a good estimate for the simulated crest and trough height also at low probability levels. 相似文献