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1.
Data on the contents and compositions of the hydrocarbons (HCs)—aliphatic (AHCs) and polycyclic aromatic (PAHs)—are provided in comparison with the contents of the total organic carbon (Corg), the lipids in the particulates, and the Corg in bottom sediments. Particular attention has been paid to the distribution of the HCs in the water area of the Kravtsov oil field. It has been established that the concentrations of AHCs in the water are governed by the content of particulates, and the elevated AHC concentrations are confined to the coastal areas. In the water area of platform D-6, the sandy bottom sediments were notable for the great variability of the HC concentrations, both laterally and from year to year. In the summer of 2010, the content of AHCs averaged 40 μg/g (19% in the Corg), and that of PAHs, 23 ng/g. Natural seepage from the sediment mass is considered to be a source of HCs along with oil contamination.  相似文献   

2.
Kh. M. Saidova 《Oceanology》2014,54(3):319-326
A total of 15 communities of ostracods have been recorded based on the dominant species in the bottom sediments sampled at 204 stations in the Caspian Sea. The distribution of the communities is determined by the bathymetric zonality of the sea, the currents, the topography of the water mass boundaries, the hydrochemical parameters of the water, the continental runoff, and the concentrations of O2 and Corg in the water and sediments.  相似文献   

3.
This study examined the fate of Prudhoe Bay crude oil in nearshore sediments of the Beaufort Sea, in situ, with emphasis on the rôle of microorganisms in the weathering process. The results indicate that oil is degraded in Arctic sediments very slowly; only after 1 year's exposure was biodegradation evident. Several factors probably contributed to the slow rate of microbial weathering, including: limited populations of hydrocarbon utilising microorganisms; localised high oil concentrations; low temperatures; limiting nutrient concentrations (unfavourable C:N and C:P ratios); low oxygen tensions and limited circulation of interstitial waters in fine-grained sediments. Abiotic weathering of the oil was also slow, with limited loss of low molecular weight aliphatic and aromatic hydrocarbons during 2 years' exposure. Significant features of the overall weathering process were: lack of initial loss of low molecular weight compounds; aliphatic compounds were not preferentially degraded over aromatic compounds and C17, and lower molecular weight normal alkanes were preferentially degraded over higher molecular weight alkanes. The results of this study indicate that hydrocarbons will persist relatively unaltered for several years if Beaufort Sea sediments are contaminated with petroleum.  相似文献   

4.
Data are presented on the content of aliphatic and polycyclic aromatic hydrocarbons (AHC and PAH, respectively) in the interstitial waters and bottom sediments of the Kara Sea compared to the distribution of the particulate matter and organic carbon. It was found that the AHC concentrations within the water mass (16 μg/l on average) are mainly formed by natural processes. The AHC distribution represents the variability of the hydrological and sedimentation processes in different regions of the sea. The widest ranges of the concentrations were registered in the Ob Bay-Kara Sea section: in the water (10–310 μg/l for the AHC and 0.4–7.2 ng/l for the PAH) and in the surface layer of the bottom sediments (8–42 μg/l for the AHC and 9–94 ng/g for the PAH). The differentiation of the hydrocarbons (HC) in the different media follows the marginal filter’s regularities; therefore, no oil and pyrogenic compounds are supplied to the open parts of the sea. In the sediment mass, the HC content is determined by the variations in the oxidative conditions in the sediment and its material’s composition.  相似文献   

5.
Hydrocarbons have been investigated in the sediments of Port Valdez, Alaska after three to five years of oil terminal operation with a routine daily discharge of 170 kg of petroleum residue in an otherwise undeveloped area. Surficial benthic sediments (0–5 cm) and core segments down to 30 cm have been analyzed. Information about total hydrocarbons, unresolved complex mixture, normal alkanes, pristane, phytane, hopanes and polycyclic aromatic hydrocarbons indicates that petroleum, biogenic hydrocarbons, and combustion-derived aromatic hydrocarbons are present in sediments around the terminal at concentrations up to 218 μg g?1 dry sediment. The vertical, horizontal and temporal distributions of anthropogenic hydrocarbons indicate that most of the sedimentary hydrocarbon accumulation has occurred within 1 km of the terminal. A simple calculation suggests that less than 3% of the total oil discharged during routine operations of the terminal has entered the sediments of Port Valdez. For comparison sediment hydrocarbon accumulation associated with a nearby small boat harbor was also examined.  相似文献   

6.
The occurrence of widely distributed acyclic isoprenoid hydrocarbons (C2O, C25 and C30) with highly branched structures, in sediments and biota is reviewed. The compounds occur as alkanes and alkenes with from one to at least four double bonds in young aquatic (both marine and lacustrine) sediments from many parts of the globe (e.g. Peru, Antarctica, Gulf of Suez, North Sea, Atlantic) sometimes in high concentrations (e.g. 40 μg g−1 sediment) relative to other hydrocarbons. However, the compounds rapidly disappear in older sediments, possibly due to biodegradation and reaction with sedimentary sulphur. These and other factors are discussed.The sources of this fascinating group of hydrocarbons remain largely unknown, though evidence points to algae (possibly diatoms) as one possibility. The recent identification of related sulphur-containing compounds in a crude oil promises to extend the number of reports of these compounds still further, and to increase their importance as environmental biological markers.  相似文献   

7.
Data are presented on the content and composition of hydrocarbons (HC) (aliphatic, AHC and polyaromatic, PAH) in the filtered particulate matter and in the surface layer of the bottom sediments on the northern shelf of the Caspian Sea and related to the data on their content in the Volga River estuary. Because of the transformation and precipitation of anthropogenic and natural compounds, the HC composition in the particulate matter and bottom sediments undergoes transformations caused by the mixing of fresh and saline waters (in the bottom sediments, within the concentration ranges 70.4–4557.9 μ g/g for AHC and 3.8–4800 ng/g for PAH). It was found that the greatest concentrating of HC proceeds in the region of the avalanche sedimentation, and their content is independent of the grain-size type of the sediments. The anthropogenic HC (oil and pyrogenous) do not get over the marginal filter of the Volga River and do not pass to the open part of the sea.  相似文献   

8.
A study on the bulk distributions and molecular structures of n-alkanes and polycyclic aromatic hydrocarbons (PAH) in organic matter of the sediments from the Bay of Bengal and the Eastern and Central Indian Basins was undertaken. The former two regions represent areas characterised by “normal” sedimentation while the third one mainly represents a region of “active tectonism”. Content of the hydrocarbons in the sediments of “normal” sedimentation ranges between 4.6 and 10.5 μg/g and aromatic hydrocarbons ranges between 0 and 0.38 μg/g. n-Alkanes in the sediments of the northern deep part of the Bay of Bengal consist mostly of long-chain structures (total C25–C33 up to 70%) with a high carbon preference index (CPI=3.01–3.43), indicating a large contribution of organic matter from terrigenous sources. The sediments from the Eastern Indian Basin have n-alkane distributions in which the long-chain components did not exceed 52.5% and the CPI was 1.7–1.90, indicating that the hydrocarbons are mostly derived from marine sources. Sharp increases of hydrocarbons are found in the vicinity of the tectonically active region of the Central Indian Basin, particularly in the sediments collected from the fracture zone. The total concentration of hydrocarbons increase to 170 μg/g and the aromatic hydrocarbons fraction to 156.3 μg/g. The proportion of short-chain n-alkanes increases up to 70%, CPI decreases to 0.76–1.12, and high concentrations of n-C16 (16–40%) occur, all of which are absent in the other samples. The molecular content of PAH includes the unsubstituted individual structures: biphenyl, fluorene, pyrene, perylene, benzo(ghi)perylene, and the groups of homologues of naphthalene, benzofluorene, phenanthrene and chrysene. The association of the PAH and composition of paraffin hydrocarbons in the surficial sediments of deformation zone indicate that these are the resultant products of hydrothermal processes. It is, therefore, suggested that the association and composition of the hydrocarbons in sediments can be utilised as a paleoceanographic parameter to decipher the history of tectonism of an area.  相似文献   

9.
The sources and distributions of polycyclic aromatic hydrocarbons (PAH) and aliphatic hydrocarbons are characterized in seventeen sediments from a highly river-influenced sedimentary environment off the southwestern coast of Washington. The major hydrocarbons are land-derived, introduced as preformed compounds and display long-term stability in sediment cores. A series of PAH of anthropogenic origin and two naturally derived compounds, retene and perylene, dominate the PAH composition in these sediments. Plantwax n-alkanes are the major aliphatic hydrocarbon constituents. Aliphatic hydrocarbons of marine origin, pristane and a series of four acyclic, multibranched C25 polyolefins, are also observed in many sediments. The concentrations of these marine-derived hydrocarbons decrease to negligible levels rapidly with sediment depth from the sea-sediment interface, suggesting degradation.In general, the major land-derived hydrocarbons are concentrated in the midshelf silt deposit which extends northwestward along the continental shelf from the Columbia River mouth. A quantitatively more minor, natural series of phenanthrene homologs, also of terrestrial origin, is preferentially advected further offshore and deposited in continental slope sediments. These distributions are consistent with recognized particle associations for these compounds and sediment dispersal processes in this coastal environment. Sediment core records suggest the present pattern of dispersal has persisted for at least the past century and possibly since the Late Pleistocene.  相似文献   

10.
Nemirovskaya  I. A. 《Oceanology》2021,61(2):183-192

The paper summarizes results on the content and composition of aliphatic hydrocarbons (HCs) in suspended particulate matter (SPM) and bottom sediments in the Kara, Laptev, and East Siberian seas obtained in 2015–2018. It was established that the “losses” in HC concentrations in surface waters in the river (Ob, Yenisei, Lena, Khatanga, Indigirka, Kolyma) and seawater mixing zone in some cases exceeded their river removal by 90%. The composition of HCs in surface waters depends on the characteristics of the river catchment area, sampling season. and time of day (high/low tide) and basically coincides with the SPM distribution. In the pelagic zone of the seas, the HC content is close to the background (2–7 μg/L). The influence of anthropogenic input was established only in the Gulf of Ob, where the composition of alkanes is close to oil with a HC content of 86 μg/mg SPM. In bottom sediments, the particle size distribution determines the HCs, and terrigenous n-alkanes play the dominant role in the molecular composition.

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11.
In three sections in the Kara Sea, the contents of the dissolved and particulate organic carbon (the DOC and POC, respectively), as well as of the organic carbon of the bottom sediments (Corg) were determined. The contents of varied from 6.3 to 2400 μg/l for the DOC and from 0.84 to 12.2 mg of C/l for the POC. The average concentrations for all the samples tested amounted to 200 μg/l for the DOC (n = 78, σ = 368) and 2.7 mg/l for the POC (n = 92, σ = 2.7). The concentrations of Corg in the samples of the upper layer of the bottom sediments of the area treated varied from 0.13 to 2.10% of the dry substance at an average value of 0.9% (n = 21, σ= 0.49%). It is shown that the distribution of the different forms of organic matter (OM) is an indicator of the supply and spreading of the particulate matter in the Kara Sea and that the DOC and POC of the Kara Sea are formed under the impact of the runoff of the Ob and Yenisei river waters. It is found that the distribution of the OM of the bottom sediments in the surveyed area of the Kara Sea is closely related to their grain-size composition and to the structure of the currents in the area studied. The variations in the Corg content in the bottom sediment cores from the zone of riverine and marine water mixing represent the variability of the OM burial.  相似文献   

12.
南海沉积物中的正构烷烃和多环芳烃的分布及来源(英文)   总被引:1,自引:0,他引:1  
重点研究南海沉积物中烃类化合物的有机地球化学特征,讨论了南海沉积物中有机物质的分布和来源。其中正构烷烃分布在C16-C33奇偶优势不明显,结合其轻重比值,显示有机质的输入在大部分站位以海洋源为主,在一些站位陆源输入的贡献也比较明显,海源输入中又以藻类等有机碎屑的贡献最大。在南海沉积物中共检出60余种环芳烃,高环化合物(四环和五环)的总含量明显高于其他组分。一些陆源特征标志物如惹烯、烷基屈等化合物被检出,在大多数样品中都发现有的存在,推测其可能来源应是燃烧产物,而非陆源输入。  相似文献   

13.
In the summer 2006, integrated geological, geochemical, hydrological, and hydrochemical studies were performed on the relict anoxic Lake Mogil’noe (down to 16 m depths) located on Kil’din Island in the Barents Sea. The chemical and grain-size composition of the bottom sediments were compared for the lake (a permanently anoxic basin) and the Baltic Sea Deeps (periodically anoxic basins). The vertical location of the hydrogen sulfide layer boundary in the lake (9–11 m depths) was practically the same from 1974 up to now. The concentrations of suspended particulate matter in the lake in June and July 2006 appeared to be close to its summer concentrations in the seawaters of the open part of the Baltic Sea. The mud from Lake Mogil’noe compared to those of the Baltic Sea Deeps are characterized by fluid and flake consistency and by pronounced admixtures of sandy and silty fractions probably of eolic origin. The lacustrine mud contain much plant remains; iron sulfides and vivanite were also found in ooze. The concentrations of 22 elements determined in the lacustrine bottom sediments were of the same levels as those found here 33 years ago. The concentrations also appeared to be close to those in the corresponding grain-size types of the bottom sediments in the Baltic Sea. The low Corg/N value (5% on average) in the mud of Mogil’noe Lake compared to the values for the mud of the Baltic Sea Deeps (10% on average) points to the considerable planktogenic component in the organic matter composition of the lacustrine mud. No indications were reveled for anthropogenic contaminations of the lacustrine bottom sediments with toxic metals.  相似文献   

14.
The areas that we studied in the North Atlantic (53 and 60°N) and in the Labrador Sea in the summer were characterized by a wide variability of the concentrations of dissolved and particulate organic matter and its elemental composition both in the surface and in the deep waters. The concentrations of dissolved and particulate Corg varied within 69–360 μM and 0.7–25.6 μM, respectively; the Norg and Porg contents varied within 1.4–22.2 μM and 0.02–0.86 μM, respectively. The maximal concentrations were registered in the photic layer and in the zones of mixing between the waters of different genesis. The particulate matter contribution to the total organic matter (OM) content varied from 0.5 to 15.4%. The waters of the photic layer contained more particulate Corg than those of the near-bottom layer. The values of the C/N molar ratios from the surface to the bottom over the entire aquatic area surveyed varied 5-to 6-fold; at that, the values of the C/P molar ratios varied more than tenfold. In the most productive waters, the values of the C/N ratios were close to the Redfield ratios (6–10). The values of the C/P molar ratios varied from 160 in the photic layer to 4831 in the deep waters. The pronounced non-uniformity in the spatial distribution of the OM and its elemental composition is caused not only by the penetration of the waters of different origins but also by the changes in the microplankton metabolism under mixing of these waters.  相似文献   

15.
The mineral composition of heavy and light subfractions of the modern bottom sediments of the Caspian Sea is studied. The concentration of the minerals in the Caspian Sea made it possible to identify nine terrigeneous mineralogical provinces in its area. Based on the mineral composition of the heavy subfraction of the bottom sediments, the main sources of the fragmentary material supply are established. The distribution of the terrigeneous minerals over the bottom area in the modern bottom sediments of the Caspian Sea depends on the sources of the fragmentary material; the stability and flotation properties of minerals; the morphology of the bottom; and the hydrodynamic conditions.  相似文献   

16.
Surface sediments from the Saronikos Gulf were analyzed for their aliphatic hydrocarbon (AHC) and polycyclic aromatic hydrocarbon (PAH) content by gas chromatography – mass spectrometry (GC/MS). The concentrations of Fe, Cr, As, Sb, Co and Sc were also determined by neutron activation analysis (NAA). The survey was performed at the beginning of the operation of Athens’ sewage primary treatment unit and the results can be used to monitor the unit's long-term effects in the area. The composition of aliphatic hydrocarbons indicated a chronic oil-pollution in the Saronikos Gulf sediments. The industrially impacted Elefsis Bay sediments suffered from heavy petroleum pollution, while the sediments near the sewage outfall had a moderate degree of pollution. Mixed source patterns of polycyclic aromatic hydrocarbons with dominant pyrolytic inputs have been identified in the sediments. Total concentrations of Fe, As and Sb along with their Sc normalized values presented elevated values in Elefsis Bay sediments. Chromium was found enriched in the sediments near the Athens sewage outfall. Factor analysis results showed that a part of As and Sb in Elefsis Bay sediments could be associated with organic or sulphidic phases. In addition, the lithogenic fraction of the sediments and the Fe oxides/hydroxides were important trace element carriers. Chromium and PAH inputs from the sewage outfall were also detected. Comparison of PAH and trace element concentrations with internationally-used sediment quality guidelines (SQG) revealed that Elefsis Bay sediments had the greatest potential of causing adverse effects in benthic organisms.  相似文献   

17.
Using the authors’ data obtained during expeditions to the Sea of Okhotsk during the last decade, the primary phytoplankton production and the distribution of organic carbon and chlorophyll a degradation products (chlorin) in the bottom sediments were studied. Using the authors’ and published data, the spatial distribution of the production and paleoproduction indicators was plotted. The ratios of the chlorin and Corg content in the sediments was considered, and the correlation between these parameters was revealed. It was shown that the average annual primary production of phytoplankton and the paleoproduction indices were maximum in the coastal and upwelling zones and decreased towards the sea’s center. A quantitative correlation was found between the distribution of the present primary production in the photic layer and that of the rates of the accumulation of organic matter buried within the surface sediments. As a result, it was shown that the content of chlorin and Corg in the marine bottom sediments may be used to reconstruct the paleoproduction variability of the past.  相似文献   

18.
Data on the distribution of the zoobenthos in Kemskaya Bay (the Kem’ River estuary and the White Sea), which is subject to the strong influence of the river discharge, are presented. The number of species at the sampling stations varied from 4 to 65. The density of the communities and the zoobenthos biomass ranged from 342 ± 68 to 4293 ± 96 ind./m2 and from 0.418 ± 0.081 to 1975.22 ± 494.36 g/m2, respectively. The Shannon index values varied between 1.19 to 4.7 bit/ind. At the upper part of the estuary, detritivores dominated, while, in the central part and at outlets, sestonophages prevailed. The changes in the quantitative indices of the zoobenthos along the gradient of the water salinity were traced, and the relations of these indices with seven more environmental factors were revealed. It was found that the species composition, the biodiversity, and the trophic structure of the zoobenthos significantly correlate with some of the above mentioned parameters. Multiple regression analysis was used to assess the combined effect of the factors, and it revealed which of them play a determining role in Kemskaya Bay: for the species composition, these are the depth, the water color, and the content of total suspended matter; for the number, these are the contents of pelite and Corg in the bottom sediments. The biomass depends on the water salinity, the water chromaticity, and the Corg contents in the sediments and suspended matter. The Shannon index value is determined by the water color, the Corg contents in the sediments, and the pelite content. The calculations of the ecological stress values revealed two zones with an unstable state of the zoobenthos.  相似文献   

19.
Data are presented on the content of hydrocarbons (HC) relative to the concentrations of particulate matter, lipids, Corg, and chlorophyll a in the surface waters and snow-ice cover of the East Antarctic coastal areas. It was shown that the growth of the concentrations of aliphatic HC (AHC) to 30 μg/l in the surface waters takes place in the frontal zones and under the young ice formation. The AHC content in the snow increases with the growth of the aerosol content in the atmosphere. In the lower part of the ice at the boundary with the seawater, despite the low temperatures, the autochthonous processes may provide high AHC concentrations (up to 289 μg/l). Within the snow-ice cover on fast ice, synchronous content variations of all the compounds considered take place.  相似文献   

20.
As part of a lipid biogeochemical study, aliphatic and polyaromatic hydrocarbons were determined in surficial sediments from the Cretan Sea (South Aegean Sea) in the Eastern Mediterranean. Total concentrations of both aliphatic (AHC) and polyaromatic (PAH) hydrocarbons were low (562–5697 and 14.6–158.5 ng/g, respectively) with respect to other coastal sediments worldwide and compare with concentrations found in open sea areas. The composition of AHC was dominated by unresolved complex mixture (UCM) indicating the presence of petroleum-related hydrocarbon inputs as confirmed by the detection of specific α,β-hopanes. PAH consisted mainly of pyrolytic four- to five-ring compounds. UCM and PAH amounts revealed that Cretan Sea receives low supply of anthropogenic material compared to NW Mediterranean. The spatial distributions of AHC and PAH indicated that urban run-off and transport from the continental self are the major input pathway of anthropogenic and biogenic hydrocarbons from terrestrial sources in the near shore area, whereas atmospheric transport might be the significant source of hydrocarbons in the deep area.  相似文献   

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