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Abstract. The brown alga Scytosiphon lomentaria is discussed as a possible indicator of heavy-metal contamination of marine coastal waters. A comparison with other brown algae shows that a strong development of the specific surface of S. lomentaria thallus increases the ability of accumulating suspended iron and lead from ambient waters. The paper presents the results obtained from several localities in the Sea of Japan. Scytosiphon has an advantage over other indicator species used in the monitoring of sea heavy-metal contamination due to its virtually "cosmopolitic" distribution. 相似文献
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Contamination patterns and molluscan and polychaete assemblages in two Persian (Arabian) Gulf oilfields 
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下载免费PDF全文 Paolo G. Albano Nadezhda Filippova Jan Steger Hannah Schmidbaur Adam Tomašových Michael Stachowitsch Martin Zuschin 《Marine Ecology》2016,37(4):907-919
This study examined two shallow‐water, offshore oil facilities and their surroundings in the Umm Al Dalkh and Zakum oilfields [United Arab Emirates, Persian (Arabian) Gulf]. The focus was on sediment contamination levels and the detection of disturbance based on two representative invertebrate components of the benthos: molluscs and polychaetes. We tested the hypothesis that significant disturbance to the community has occurred, by examining whether distance from the platform or variation in contaminants explains among‐site variation in the composition of benthic communities. Moreover, we also tested the hypothesis that organic enrichment because of oil input has modified the feeding guild structure by examining whether the relative abundances of filter‐feeders, deposit‐feeders and omnivores are correlated with distance from the platform or with contamination by hydrocarbons. The contamination levels and their spatial distribution in the sediments differed significantly between the two fields, as did their mollusc and polychaete communities. The within‐field variability, however, was much lower: no clear structuring of contamination values and species composition and abundance was detectable in relation to distance from the oil platform. Contamination levels were low, often below detection levels or international guideline values. Variation in contaminant concentrations did not explain variation in taxonomic composition and abundance. The relative abundance of the above‐mentioned feeding guilds did not correlate with either distance from the platform or with contaminant concentrations. These patterns may reflect the long time that has elapsed since drilling (15–20 years), which appears to have allowed contaminants to disperse and degrade and assemblages to recover from the impact, if indeed such a disturbance ever occurred. In contrast to low values of barium and total petroleum hydrocarbons, associated with well drilling, some metals were at their highest concentrations beneath the central platforms. This suggests that production‐related activities (including platform cleaning and maintenance) are currently a more relevant contamination source. 相似文献
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Vsevolod Prokofiev Ivan Baksheev Lidiya Zorin Boris Belyatsky Vladimir Ustinov Nadezhda Krivitskaya 《地学前缘(英文版)》2012,3(1):59-71
Zoned tourmaline（schorl-dravite） in the matrix of hydrothermal explosive breccia and ore veins in gold deposits,Chita region.Eastern Transbaikalia.Russia,are associated with Na- and K-rich porphyry-type subvolcanic intrusives.δ18O values of tourmaline from three gold deposits（Darasun. Talatui,Teremkinskoye） are +8.3‰,+7.6‰,and +6.0‰and calculatedδ18O values of fluids responsible for the tourmalinization are +7.3‰,+7.7‰,and +4.2‰,respectively.These data imply an igneous fluid source,except at the Teremkin deposit where mixing with meteoric water is indicated.Wide ranges of Fe3+/Fetot,and the presence of vacancies characterize the Darasun deposit tourmaline indicating wide ranges of f（O2） and pH of mineralizing fluids.Initial stage tourmalines from the gold deposits of the Darasun ore district are dravite or high mg schorl.Second stage tourmaline is characterized by oscillatory zoning but with Fe generally increasing towards crystal rims indicating decreasing temperature.Third stage tourmaline formed unzoned crystals with xMg（mole fraction of Mg） close to that of the hrst stage tourmaline,due to a close association with pyrite and arsenopyrite.From Fe3+/Fetot values,chemical composition and crystallization temperatures.logf（O2） of mineralizing fluids ranged from ca.—25 to—20. much higher than for the gold-bearing beresite—listvenite association,indicating that tourmalinization was not related to gold mineralization. 相似文献
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Inna S. Lykova Nikita V. Chukanov Anatoliy I. Kazakov Viktor P. Tarasov Igor V. Pekov Vasiliy O. Yapaskurt Nadezhda A. Chervonnaya 《Physics and Chemistry of Minerals》2013,40(8):625-633
Products and kinetics of ion exchange of heterophyllosilicate minerals lomonosovite and murmanite with aqueous AgNO3 solutions under low-temperature conditions have been studied using scanning electron microscopy, electron microprobe analysis, single-crystal X-ray diffraction, infrared spectroscopy, 23Na nuclear magnetic resonance spectroscopy and dynamic calorimetry. Both minerals show strong affinity for silver in cation exchange. Simplified formulae of Ag-exchanged forms of murmanite and lomonosovite are (Ag3.0Ca0.5Na0.5) (Ti,Nb,Mn,Fe)3.7?4 (Si2O7)2O4·4(H2O,OH) and (Ag8.2Na1.2Ca0.3) (Ti,Nb,Mn,Fe)3.9?4 (Si2O7)2 (PO4)1.9O4·xH2O, respectively. The reaction of ion exchange for murmanite follows the first-order kinetic model up to ca. 70–80 % conversion. The rate of the process is described by the equation k(h?1) = 107.64±0.60 exp[?(12.2 ± 0.9)·103/RT]. The average heat release value in the temperature range 39.4–72 °C is 230 J g?1. The cation exchange is limited by processes in solid state, most probably binding of silver. 相似文献
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Manifestation of the 2011 Great Tohoku Tsunami on the Coast of the Kuril Islands: A Tsunami with Ice
Victor Kaistrenko Nadezhda Razjigaeva Andrey Kharlamov Alexander Shishkin 《Pure and Applied Geophysics》2013,170(6-8):1103-1114
The tsunami generated by the 2011 Tohoku Earthquake (M w = 9.0) reached maximum heights of about 5 m along the coast of the Kuril Islands. The most essential feature of this event was sea ice about 0.5 m thick moved by the ocean water. The tsunami did not cause any essential damage on the Kuril Islands, but significantly affected coastal zones and produced interesting effects. The problem of a tsunami accompanied by marine ice is discussed and illustrated with photos. 相似文献
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Influence of agricultural development and climate changes on the drainage valley density of the southern half of the Russian Plain 总被引：1，自引：1，他引：0
The southern half of the Russian Plain is characterized by a relatively short history of intensively ploughed lands.The duration varies from approximately three centuries in the southern part of the forest zone to less than one century in some parts of the steppe zone.It was found that after cultivation,on more than 40％ of lands in river basins the drainage valley density (Ddv) decreased by 15-58％ in all landscape zones.In the first stage,the Ddv decrease was mostly associated with increasing surface runoff coefficient after cultivation of virgin lands with proportional decreases in groundwater runoff.In the second stage,usually after reaching areas of arable lands in river basins ＞ 60％,the volume of eroded sediments entering small fiver channels exceeded the transport capacities of the permanent water-courses.As a result,the river channels completely silted.In later stages,the sediment redistribution cascade within the small river basins of the Russian Plain stabilized because of the increasing proportion of sediment eroded from the basin areas and re-deposited before entering the river channels because of the increasing area of sediment sinks due to the increase in dry valley lengths and total areas.The morphological parameters of small valleys and groundwater discharges are the key parameters that affect the intensity of small river aggradation on the regional scale. 相似文献
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Nina N. Belcheva Maxim V. Zakhartsev Nadezhda V. Dovzhenko Avianna F. Zhukovskaya Victor Ya. Kavun Victor P. Chelomin 《Ocean Science Journal》2011,46(2):85-94
The digestive gland and gills of the mussel Crenomytilus grayanus extracted from three locations — (i) sampled from a clean and (ii) polluted site and (iii) transplanted from the nonpolluted
to polluted site - were analysed for antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase), total oxyradical
scavenging capacity and levels of lipid peroxidation products (malondialdehyde, conjugated dienes and lipofuscin). Perturbation
of redox status was found in both digestive gland and gill tissues of mussels living in the polluted area. As the activities
of superoxide dismutase and catalase were 1.2–3 times higher, the total oxyradical scavenging capacity was lower by 20–35%
and the levels of lipid peroxidation products were 2–7 times higher compared to mussels from the reference site. In transplanted
mussels, the lipid peroxidation process in both tissues was significantly stimulated (the level of conjugated dienes was increased
1.7–2.5-fold; malondialdehyde and lipofuscin contents were increased 3.5–5-fold) and the total oxyradical scavenging capacity
fell by 50–70%. In addition, the transplantation generally resulted in transient and variable responses of antioxidant enzymes
for both tissues. Complex response-behaviour of the antioxidant enzymes strongly points to the necessity of employing a combined
approach that takes into account activities of antioxidant enzymes and the total oxyradical scavenging capacity, as well as
measurement of oxidative damage (e.g., lipid peroxidation) to evaluate the physiological health of molluscs. 相似文献
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Marine sediment contamination of an industrial site at Port of Bagnoli, Gulf of Naples, Southern Italy 总被引：1，自引：0，他引：1
Romano E Ausili A Zharova N Celia Magno M Pavoni B Gabellini M 《Marine pollution bulletin》2004,49(5-6):487-495
For almost one century an important steel plant has been active at the Bagnoli industrial area (Naples, Southern Italy). The environmental survey of near shore and offshore sediments has been carried out as fundamental part of a clean up project. The characteristics of the area, supposed type of pollution, national and international protocols in force were taken into consideration in designing sampling schemes and selecting analytical parameters. For this work, sediment grain size, PAHs, PCBs, trace elements, total hydrocarbons and organic matter were considered. Factor analysis evidenced two main types of pollution in the proximity of the industrial plant, both probably attributable to the activity of the industrial site. The first one, due to Cd, Pb, Zn and Mn seems determined by localised activities at the southern part of the plant. The second one, due to Fe and Mn, appears directly linked to the whole contaminated area. 相似文献
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Tatyana A. Zotina Alexander P. Tolomeyev Nadezhda N. Degermendzhy 《International Journal of Salt Lake Research》1999,8(3):211-232
The specific composition, vertical distribution and daily migration of plankton in a meromictic salt lake, Lake Shira, have been investigated. The main structural components of the ecosystem are bacteria, algae and crustaceans. Since the late 1970s, blue-green algae are reported as dominant. Nowadays the phytoplankton is dominated by Lyngbya contorta, Microcystis ichtyoblabe (Cyanophyta), Cyclotella tuberculata (Bacillariophyta) and Dictyosphaerium tetrachotomum (Chlorophyta). The zooplankton of Lake Shira comprises Arctodiaptomus salinus (Copepoda), Brachionus plicatilis and Hexarthra oxiuris (Rotatoria). Investigation revealed a stratified vertical distribution of all dominant species except Cyclotella with a maximum at a depth of 12--15 m during the summer growth period. Zooplanktons differ in the pattern of distribution and daily migration, but most zooplankton tend to concentrate near the surface. The possible reasons for the vertical distribution of the plankton are discussed. 相似文献