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1.
The life history ofEuphausia similis G.O. Sars in Sagami Bay, central Japan, has been studied by examining the abundance, size distribution, and occurrence of each growing stage from egg to adult. Three cohorts were laid within the period from July 1979 to July 1980. Individuals of cohort I of 1980 were laid in November and December 1979, and matured and spawned in March and April of the following year. Those of cohort II of 1980 laid in January and February 1980 should mature in November and spawn after December, by analogy with cohort II of 1979. Cohort III of 1980 was laid in April 1980, but decreased in number in July. Cohort II was the dominant cohort in Sagami Bay throughout the period studied. From December 1979 to April 1980 when the mixing layer was present, many eggs ofE. similis were in the epipelagic zone. It is suggested that the spawning season ofE. similis roughly coincided with the season of active feeding, indicated by high fullness of stomachs in individuals. The production of juveniles and adults was about 1.33 mg C m–2 day–1, and the production to bio mass (P/B) ratio was estimated to be 4.78 between July 1979 and July 1980. 相似文献
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Katsumi Marumo Tetsuro Urabe Akiko Goto Yoshinori Takano Miwako Nakaseama 《Resource Geology》2008,58(3):220-248
This report presents mineralogical, geochemical and isotopic data on samples obtained using the Benthic Multi‐coring System (BMS) to drill a submarine hydrothermal deposit developed in a caldera on the summit of the Suiyo Seamount in the Izu–Bonin Island Arc, south of Japan. This deposit is regarded as the first example of Kuroko‐type sulfide mineralization on a volcano at the volcanic front of an island arc. The mineralization and hydrothermal alteration below the 300 × 150‐m area of active venting was investigated to depths of 2–9 m below the sea floor. Drilling beneath the area of active venting recovered a sequence of altered volcanic rocks (dacite lavas, pyroclastic rocks of dacite–rhyolite compositions and pumice) associated with sulfide veining and patches/veins of anhydrite. No massive sulfide was found, however, and the subsea‐floor mineralization to 10 m depth is dominated by anhydrite and clay minerals with some sulfides. Sulfide‐bearing samples contained high Au (up to 42 ppm), Ag (up to 263 ppm), As (up to 1550 ppm), Hg (up to 55 ppm), Sb (up to 772 ppm), and Se (up to 24 ppm). Electron probe microanalyzer indicated that realgar, orpiment, and mimetite were major As‐bearing minerals. The sulfides were also characterized by high Zn (>10%) compared to Cu (<6.3%) and Pb (<0.6%). The δ202Hg/198Hg, δ202Hg/199Hg and δ202Hg/200Hg of the sulfide‐bearing dacite samples and a sulfide chimney decreased with increasing Hg/Zn concentration ratio. The variation of the δ202Hg/198Hg ranged from ?2.8 to +0.5‰ to relative to S‐HG02027. The large range of these δ202Hg/198Hg was greater than might be expected for such a heavy element and may be due to a predominance of kinetic effects. The variation of δ202Hg/198Hg of sulfide‐bearing dacite samples suggested that light Hg isotope in the vapor mixed with oxygenated seawater near sea floor during mineralization. Lead isotope ratios of the sulfide were very similar to those of the dacite lava, suggesting that lead is of magmatic origin. The 87Sr/86Sr ratio (0.70872) of anhydrite was different from that of the dacite lava, and suggests an Sr derivation predominantly from seawater. Hydrothermal alteration of the dacite in the Suiyo hydrothermal field was characterized by Fe‐sulfides, anhydrite, barite, montmorillonite, chlorite/montmorillonite mixed‐layer minerals, mica, and chlorite with little or no feldspar or cristobalite. Hydrothermal clay minerals changed with depth from montmorillonite to chlorite/montmorillonite mixed‐layer minerals to chlorite and mica. Hydrogen isotope ratios of chlorite/montmorillonite and mixed‐layer, mica‐chlorite composites obtained below the active venting sites ranged from ?49 to ?24‰, suggesting seawater as the dominant fluid causing alteration. Oxygen isotope ratios of anhydrite ranged from 9.2 to 10.4‰ and anhydrite formation temperatures were calculated to be 188–207°C. Oxygen isotope ratios ranged from +5.2 to +9.2‰ for montmorillonite, +3.2 to +4.5‰ for chlorite/montmorillonite mixed‐layer minerals, and +2.8 to +3.8‰ in mixtures of chlorite and mica. The formation temperatures of montmorillonite and of the chlorite–mica mixture were 160–250°C and 230–270°C, respectively. The isotope temperatures for clay minerals (220–270°C) and anhydrite (188°C) were significantly lower than the borehole temperature (308.3°C) measured just after the drilling, suggesting that temperature at this site is now higher than when clay minerals and anhydrite were formed. 相似文献
3.
The larvae ofEuphausia similis G. O. Sars in Sagami Bay, Central Japan, are described. Nauplius, metanauplius, calyptopis and furcilia stages are included. In the furcilia stage, six forms are identified on the basis of the form of the pleopods and the number of terminal telson spines. Furcilia I: a pair of non-setose pleopods and seven terminal telson spines. Furcilia II: a pair of setose and three pairs of non-setose pleopods and seven terminal spines. Furcilia III: four pairs of setose and a pair of non-setose pleopods and seven terminal spines. Furcilia IV: five pairs of setose pleopods and five terminal telson spines. Furcilia V: five pairs of setose pleopods and three terminal telson spines. Furcilia VI: five pairs of setose pleopods and one terminal telson spine. On the basis of the developmental pathway of the larvae,E. similis is suggested to be related toE. spinifera, E. longirostris, E. hanseni and theE. gibboides group species. The size ofE. similis larvae, expressed as total length, in Sagami Bay varied according to month. The sizes of calyptopis III and furcilia I–V stages were smallest in November and March and largest in May. 相似文献
4.
Biogenic amino acids, taken as representative of organic matter, were analyzed to determine the apparent degradation rate constant in boreal terrestrial sediment. Age determination using 14C dating gave two rate constants: the initial degradation rate constant for glycine (kGLY 1), the simplest amino acid, was 1.5 × 10−3 yr−1 (r = 0.97) until about 2200 yr BP. After the inflection point, the rate constant kGLY 2 was 9.1 × 10−5 yr−1 (r = 0.73). The degradation of amino acids in the labile organic matter in the sediment was markedly affected by rapid processes. After the inflection point, the rate constant profiles for sub-surface amino acids were shown to have discontinuous relationships with sediment age. One pattern which emerged in the vertical distribution is that the biogenic amino acid degradation rate constant k was far greater in the labile organic matter phase than that in the refractory organic matter over the past 10,000 years. 相似文献
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R. V. P. Ferreira E. A. Silva R. L. S. Canevesi E. G. A. Ferreira M. H. T. Taddei M. C. Palmieri F. R. O. Silva J. T. Marumo 《International Journal of Environmental Science and Technology》2018,15(8):1629-1640
The treatment of radioactive liquid waste containing organic compounds was always a cause for concern to radioactive waste management facilities because the processes available are expensive and difficult to manage. Biosorption has been studied as a new process in simulated wastes as an alternative to treating them. Among the potential biomass, the coconut fiber has very attractive features that allow the removal of radionuclides using a low-cost biosorbent. The aim of this study was to evaluate the capacity of coconut fiber to remove uranium, americium, and cesium from real radioactive liquid organic waste. Experiments with the biosorption of these radionuclides in coconut fiber were made including (1) preparation, activation, and characterization of biomass and (2) biosorption assays. The biomass was tested in raw and activated form. Biosorption assays were performed, adding the biomass to real waste solutions. The solutions contain natural uranium, americium-241, and cesium-137. The contact times and the concentrations range were varied. The radioisotopes remaining concentration in the solutions was determined by inductively coupled plasma optical emission spectrometry and gamma spectrometry. The results were evaluated by maximum experimental sorption capacity and isotherm and kinetics ternary models. The highest sorption capacity was observed with the activated coconut fiber, with values of 2 mg/g of U (total), 70E?06 mg/g of Am-241 and 40E?09 mg/g of Cs-137. These results suggest that biosorption with activated coconut fiber can be applied in the treatment of radioactive liquid organic wastes containing uranium, americium-241, and cesium-137. 相似文献
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Ryuzo Marumo 《Journal of Oceanography》1980,36(2):126-133
Over the past 30 years, I have carried out research on the distribution and ecology of marine plankton using research vessels
of the Japan Meteorological Agency and the Ocean Research Institute mainly in the Kuroshio and Oyashio areas as well as in
Sagami Bay. In this report, some results obtained on the ecological features of blue-green algae, diatoms, chaetognaths etc.
in relation to water masses and currents are shown. 相似文献
9.
The distribution of pelagic blue-green algae, especially ofTrichodesmium thiebautii, was investigated on the basis of the collection of theHakuhō Maru Cruise KH-69-4 along 155°W (50°N-15°S) in the North Pacific Ocean from September to November 1969.
- Five species were identified:Trichodesmium thiebautii (most predominant),T. erythraeum, Oscillatoria sp.,Katagnymene spiralis andRichelia intracellularis.
- T. thiebautii was most abundant in the western North Pacific central water and abundant next to it in the equatorial water, but it did not occur in the subarctic water.
- T. thiebautii was ubiquitously distributed in the lower layer of 100–200 m in the equatorial water, though not in a large quantity.
- T. thiebautii inhabited only the water warmer than 20°C. In its main habitat, nitrate and nitrite were almost zero, but ammonia and phosphate were present. There was not found any correlation between its occurrence and the salinity.
- Blue-green algae were generally thinly populated in the water rich in diatoms.
10.
The feeding ofSagitta nagae was analyzed in connection with food chains in the pelagic and near-bottom communities of Suruga Bay. The following results are obtained: (1)S. nagae feeds on dominant copepod species both in the free water (upper water layers) and the near-bottom habitats; (2)S. nagae did not show any food-size selection in the range of 0.2 to 1.2 mm in cephalothorax width and height of copepods; (3) Feeding activity ofS. nagae in the free water is highest at night, while in the near-bottom habitat the species feeds more actively during the day than at night; and (4)S. nagae migrates between the bottom and free water and plays an important role in shallow water by connecting the near-bottom community with the pelagic community. 相似文献