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1.
The first data on ecology and trace metal (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb) bioaccumulation by macrozoobenthic organisms in area along the 130°E meridional transect from shallow water near the Lena River’s delta till the 78°N are presented. At the newly discovered methane seeps in the shallow Laptev Sea areas (72 m depth), a higher total abundance and biomass compared with background stations were recorded. In carbonate shells and soft tissues of Bivalvia Portlandia arctica and Astarte borealis, the high concentrations of Mn, Fe, Pb, Ni and Co were detected that varied in dependence from sampling site. In the dominating taxa of brittle stars (Ophiuroidea), there were found no significant differences between majority of trace metal content in organisms inhabiting the seeps area and background ones. An elevated content of some metals was detected in the Asteroidea bodies that may be attributed to its trophic behavior (deposit feeder). 相似文献
2.
The structure of the assemblages associated with the mussel aggregations of Bathymodiolus azoricus was investigated. The mussel beds were found on the hydrothermal vent fields on the Mid-Atlantic Ridge (the Menez Gwen, Lucky
Strike, and Rainbow areas) at the depths of 850–2400 m. The community structure of the mussel bed assemblages varied between
the studied areas. Large number of species was unique to Menez Gwen mussel beds; the most observed taxa were not specialized
hydrothermal species. All the other, nonunique species were found for the Lucky Strike region. The lowest mussel assemblage
structure evenness was observed in the shallowest area, the Menez Gwen area (850 m depth). We assume that two types of mussel
assemblages—nematode-dominated and copepod-dominated ones—exist in the Lucky Strike field. The assemblages of B. azoricus differ significantly from the assemblages of B. thermophilus inhabiting the Pacific hydrothermal vents. 相似文献
3.
A series of samples of inhabitants of hydrothermal vents were collected during the 12th cruise of R/V Akademik Mstislav Keldysh in Guaymas Basin (the Gulf of California) and the Axial Seamount area (Juan de Fuca Ridge). The concentrations of trace and heavy metals in the tissues of Ridgeia piscesae, Riftia pachyptila, and Paralvinella palmiformis were analyzed. The neutron-activation analysis revealed significantly higher concentrations of uranium in the tissues of Paralvinella palmiformis as compared to the ambient seawater. The possible reasons for such phenomenon are discussed. The data obtained by the neutron-activation method are compared with those obtained by the atomic-absorption method for the same tissues analyzed. 相似文献
4.
E. V. Ruban G. A. Alekseeva A. A. Arkharov E. I. Hagen-Thorn V. D. Galkin I. N. Nikanorova V. V. Novikov V. P. Pakhomov T. Yu. Puzakova 《Astronomy Letters》2006,32(9):604-607
We present the results of our visual and near-infrared spectrophotometric observations for 77 variable stars obtained during 1971–1991 in Chile, Armenia, and Bolivia. The quasi-monochromatic, extraatmospheric fluxes from the stars are given in absolute energy units (W m?2 m?1) at all wavelengths of the spectral range at 2.5-nm intervals. 相似文献
5.
Oceanology - The article reports results of benthic research carried out in the Northwest Pacific in the Bering Sea using the remotely operated vehicle Comanche. The study concerns the distribution... 相似文献
6.
Oceanology - During the 39th cruise of RV Professor Logachev, ecological studies of the Russian exploration area in the central part of the Northern Mid-Atlantic Ridge were conducted. New data on... 相似文献
7.
S. V. Galkin N. V. Kucheruk K. V. Minin A. K. Rayskiy E. I. Goroslavskaya 《Oceanology》2010,50(5):793-797
The composition and distribution of the macrobenthic communities in the Ob estuary and the adjacent Kara Sea shelf were studied
during the 54th cruise of the R/V Akademik Mstislav Keldysh. With the transition from the Ob River’s mouth to the open parts of the sea, the gradual changes of the bottom biocenoses
included changes in the leading taxa. Along with the increase in the salinity, the freshwater and brackish water taxa are
replaced by related forms adapted to dwelling in seawater. The comparison of the original data with the results of the previous
investigations revealed considerable spatial and temporal variations of the bottom communities in the studied area. The main
environmental factors determining the fauna distribution in the estuarine zone are discussed. The extensive biocenosis dominated
by Portlandia aestuariorum in the Ob estuary was found for the first time. 相似文献
8.
Bottom fauna associated with mussel beds and alvinellid communities in the hydrothermal field at 9° N of the East Pacific Rise 总被引:1,自引:0,他引:1
Samples from mytilid mollusk and alvinellid polychaet communities and associated fauna were collected during cruise 49 of R/V Akademik Mstislav Keldysh at 9° N of the East Pacific Rise. The mytilids Bathymodiolus thermophylus occupied zones of diffuse releases of hydrothermal solutions with temperature anomalies a few degrees in amplitude. The alvinellid assemblages were located in the hottest parts of hydrothermal vents (~ 40°C) over sulfide mounds. The taxonomic compositions of these kinds of assemblages are different. The taxonomic richness of mytilid communities is almost twice higher. A comparison of the samples using Jaccard’s index showed a greater similarity among the alvinellid samples than that between the mytilid ones. With respect to the species number, polychaets formed the most diverse group, while gastropods were the second most diverse. The dominant species had greater proportions in alvinellid communities than in mytilid ones. This study showed great differences between the mytilid and alvinellid associations in their species composition and community structure. 相似文献
9.
The Barrell and Sears and Edlen formulae use the Sellmeier form away from resonances, which gives a “smooth” dependence within
the visible and near-infrared spectra. All known atlases indicate numerous resonances in these regions, which cause local
disturbance of the dispersion curve. Anomalous dispersion may be estimated from an absorption by the Kramer-Kronig ratios.
It gives a change of phase refractive index of air in a range from several ppt to 1 ppb within narrow optical regions, causing
large local dispersions. Computation of the group refractive index with the use of Rayleigh's ratio shows that the influence
of resonance effects may be more than several ppm. For example, the error of the group refractive index for high-precision
EDM using HeNe lasers (633 nm) varies between 0.2 and 0.7 ppm, depending on the laser stability.
Received: 17 July 1996 / Accepted: 27 March 1997 相似文献
10.
Thermal expansion of ZnSiO3 high-pressure clinopyroxene and ilmenite phases was measured in the temperature range 100–620 K by the X-ray powder diffraction
method. Interpolation and extrapolation of experimental data were performed by the procedure based on the Debye-Mie-Gruneisen
theory in the range from 50 to 1,500 K. Temperature dependencies of molar volumes and coefficients of bulk thermal expansion
of ZnSiO3 phases were determined. 相似文献