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1.
Long-term biological data supported by physicochemical parameters were evaluated to investigate the biodiversity of the Golden Horn Estuary from the past to the present. Limited observations dating back to 60 years ago indicated the existence of a diverse community in this small estuary. Unfortunately, in parallel with the increase in unplanned settlements and industry around the Golden Horn, pollution stress increased since the 1960s. Preliminary studies in the 1990s indicated survival of only a couple of pollution-resistant species, in the relatively cleaner lower estuary. Following the intensification of rehabilitation studies in 1998 and particularly after the opening of the floating bridge at the mid estuary; a remarkable day-by-day recovery in marine life has begun with the improving water quality. Nutrient concentrations decreased markedly; while water clarity significantly increased. Fecal coliform values decreased 10(3) fold. Phytoplankton composition changed and dense blooms of eukaryotic phytoplankters frequently occurred. Hydrogen sulfide almost completely disappeared even during the warmest periods of the year and dissolved oxygen concentrations increased. All results clearly depicted that the Golden Horn ecosystem shifted to eutrophic conditions from an anoxic environment. SCUBA dives in 2002, documented the level of diversification of life in the Golden Horn. All appropriate substratums were intensely covered by macrobenthic forms until the Halic Bridge and filter feeders dominated the plankton-rich ecosystem. Achieving the diversity of 1940s is not possible since the Black and Marmara seas, influencing water quality of the Golden Horn, are also suffering from anthropogenic impacts and are far less diverse than their rich diversity in 1940s. However, the Golden Horn is a good example that even the most polluted ecosystems can recover when appropriate measures are taken. 相似文献
2.
Lake Umbozero (the second largest in the area and the deepest in Murmansk province) was studied with the aim to establish
the biogeochemical features of the distribution of chalcophile elements (Hg, Cd, Pb, As) in water, bottom sediments, and whitefish
organs and tissues. Lake Umbozero is subject to the effect of emissions and effluents of mining-and-metallurgical plants in
Murmansk province, as well as airborne anthropogenic pollution of global character. Surface and near-bed peaks were recorded
in the distribution of Pb and Cd in water mass. Those peaks can be due to phytoplankton development in surface layers and
the precipitation of dead organisms and mechanical suspension into bed layers. The mean Pb and Cd concentrations in Umbozero
water mass exceed the mean for lake water in taiga zone. Water body pollution manifests itself in an increase in concentrations
of elements, such as heavy metals, in the surface layers of bottom sediments. The largest contamination factors were recorded
for Cd and Pb. Lake pollution by highly toxic chalcophile elements also caused their accumulation in whitefish organs and
tissues: the biological accumulation coefficient is >1 for Cd in kidneys (5.8) and for Hg in kidneys, liver, and muscles (3.6,
3.3, and 2.2, respectively). 相似文献
3.
Evaluation of metal contamination in coastal sediments of the Bay of Bengal, India: geochemical and statistical approaches 总被引：11，自引：0，他引：11
Surface sediment samples collected from the inner shelf region of the Bay of Bengal, were analysed for the major elements and total and acetic acid available trace elements (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Si, Zn) to evaluate geochemical processes influencing their distribution. Major elemental analysis showed that the sediments had high concentrations of Si and relatively low concentrations of Al and Fe. Both major elemental and trace metal concentrations indicated that the sediments represent weathered products of granite and charnockite. Normalization of metals to Al indicated relatively high enrichment factors for Pb, Cd, Zn and Cr. The higher proportions of nondetrital Pb (66%), Cd (41%) and Co (28%) reveal metal contamination due to anthropogenic inputs. Factor analysis (FA) identified six possible types of sedimentological and geochemical associations. The dominant factor accounting for 26.9% of the total variance identifies an anthropogenic input and accumulation of nondetrital Cd, Co, Cr, Ni and Pb. Association of these metals with CaCO3 reveals that shell fragments in the surface sediments are likely act as a carrier phase for nondetrital metals. The results are discussed in the context of the sources and pathways of elements in the Bay of Bengal. 相似文献
4.
Mohammed A. Khairy Marit Kolb Christiane Schmidt Dieter W. Zachmann Alaa R. Mostafa Anwar A. EL‐Fiky Müfit Bahadir 《洁净——土壤、空气、水》2010,38(12):1184-1193
Sediment samples were collected from 30 different locations in Abu Qir Bay (Mediterranean Sea), East Alexandria, Egypt and analyzed for trace elements. The highest concentrations of most of the elements were observed in the nearshore stations in the vicinity of the major anthropogenic activities as industrial settlements, wastewater discharges, and agricultural drainage. In addition, mussel samples of Mactra corallina and Tapes decussata were collected corresponding to the sediment samples. Concentrations of As, Cd, Cr, Mn, and Zn in the mussel tissues were higher than concentrations in sediments, thus indicating their relatively high bioavailability. Sequential extraction procedure was performed on selected sediment samples. Significant correlations were observed between the concentrations of Cu, Mn, Pb, and Zn in the exchangeable fraction of the sediments and the corresponding tissues of M. corallina. The output of the risk assessment applied on the sediments revealed that adverse ecological effects to benthic species could occur and that a higher level of risk is expected from the exposure to Cd, Cr, Hg, and Zn. No adverse carcinogenic or non‐carcinogenic human health effects are expected from the consumption of the two mussel species from Abu Qir Bay. 相似文献
5.
Mohammed A. Khairy Marit Kolb Christiane Schmidt Dieter W. Zachmann Alaa R. Mostafa Anwar A. EL‐Fiky Müfit Bahadir 《洁净——土壤、空气、水》2011,39(3):301-312
Sediment samples were collected from 30 different locations in Abu Qir Bay (Mediterranean Sea), East Alexandria, Egypt and analyzed for trace elements. The highest concentrations of most of the elements were observed in the nearshore stations in the vicinity of the major anthropogenic activities as industrial settlements, wastewater discharges, and agricultural drainage. In addition, mussel samples of Mactra corallina and Tapes decussata were collected corresponding to the sediment samples. Concentrations of As, Cd, Cr, Mn, and Zn in the mussel tissues were higher than concentrations in sediments, thus indicating their relatively high bioavailability. Sequential extraction procedure was performed on selected sediment samples. Significant correlations were observed between the concentrations of Cu, Mn, Pb, and Zn in the exchangeable fraction of the sediments and the corresponding tissues of M. corallina. The output of the risk assessment applied on the sediments revealed that adverse ecological effects to benthic species could occur and that a higher level of risk is expected from the exposure to Cd, Cr, Hg, and Zn. No adverse carcinogenic or non‐carcinogenic human health effects are expected from the consumption of the two mussel species from Abu Qir Bay. 相似文献
6.
Mercury flux to estuarine sediments, derived from Pb-210 and Cs-137 geochronologies (Guaratuba Bay, Brazil) 总被引：1，自引：0，他引：1
A sediment core from Guaratuba Bay was used to indicate possible Hg modifications to this coastal environment brought about by growing agricultural activity. Sedimentation rates were estimated to be 6.1 mm/year and 5.2 mm/year through 210Pb and 137Cs geochronologies, respectively. Mercury concentrations and organic matter ratios in the surface layers are greater than in the older sediments, supporting the hypothesis of anthropogenic enrichment. Results show that the Hg flux has raised more than twofold during the second half of the 20th century. These results point to the need for further studies to substantiate the hypothesis of anthropogenic enrichment and to quantify point sources of Hg to this estuary. 相似文献
7.
太湖表层沉积物重金属元素的来源分析 总被引：42，自引：4，他引：38
根据太湖MS岩芯重金属元素与Al的线性回归分析及元素/Al、V/Al比率散点图变化规律,讨论了太湖沉积物中重金属元素的来源特征。结果表明:20世纪20年代中期以前,重金属元素主要为自然来源;20年代中期—70年代中期,尽管沉积物中Al、Fe、Zn、Mn、V、Cr等重金属元素含量随沉积物粒度变粗而明显下降,但除Hg受到一定程度的人为污染之外,其它重金属元素仍以自然来源为主,物源有所变化;70年代末期以来,沉积物中重金属元素人为污染逐渐加重,Pb、Cu、Zn、Hg、As等元素既有流域母质来源,又受到一定程度的人为污染。 相似文献
8.
Data on the microelement composition of bottom sediment and water samples from Lake Dautkul for recent years are presented.
Concentrations of more than 30 chemical elements are determined using instrumental neutron-activation analysis. This allowed
the authors to reveal the regularities in the distribution and accumulation of chemical elements in water and bottom sediments.
It is shown that bottom sediments exhibit a cumulative effect and prolonged activity, which adversely affect the aquatic medium
and can serve an indicator of anthropogenic impact on the area under consideration. 相似文献
9.
Results of studying group and constituent composition of natural organic and mineral substances in silt bottom sediments of non-contaminated freshwater bodies are presented. The chemical composition of the investigated bottom sediments is shown to be complicated, diverse, and include products of autochthonous and allochthonous substance transformation. The necessity of further studying the concentrations of nutrients found in the bottom sediments of non-contaminated freshwater bodies, regarded as the “background” in estimating their environmental state, in studying processes occurring within water bodies, in determining natural and anthropogenic components of mineral and organic substances, as well as in estimating the balneologic value of the water bodies in question is substantiated. 相似文献
10.
D. M. Polyakov 《Water Resources》2017,44(4):654-661
Atomic-emission spectroscopy was used to determine the concentrations of Be, Ga, Nb, Ta, Y, Zr, Hf, Sc, Mo, U, and Th in subcolloidal, medium-pelite, coarse-pelite, fine-aleurite, and coarse-aleurite fractions of bottom sediments of Razdol’naya R. marginal filter. The concentrations of examined elements are maximal for the subcolloidal sediment fraction. The average concentration (n = 10) of elements in the soil and fluvial sediments (upstream of the mixing zone) were calculated and taken as background concentrations. The highest concentrations of Y, Be, U was shown to correspond to sediments in the zone of fresh and sea water mixing, which is accompanied by flocculation and sorption on Fe and Mn hydroxides and clay minerals (hydromica in fluvial sediments, and smectite in marine sediments). 相似文献
11.
The distribution of cadmium, copper, iron, manganese, lead, and zinc in sediments of Port Phillip Bay, Victoria, Australia was investigated, and the impact of industrial discharges studied. The pre-cultural levels for these metals are in nearly all cases far less than the post-cultural levels, especially in those sediments deposited in the last half century in the vicinity of urbanized areas. 相似文献
12.
Water Resources - The average concentrations of elements Fe, Mn, Zn, Pb, Cu, Cr, V, Co, Cd, Ni, As, and Mo in the subcolloidal fraction of bottom sediments were determined in the northern and... 相似文献
13.
The data given are the results of many-year studying the distribution of the concentrations of main oil components (hydrocarbons, surfactants, and asphaltene-tarry substances) in the water mass, vertically settling particulate matter, and bottom sediment cores taken from the section Lower Don-The Gulf of Taganrog-Russian sector of the Sea of Azov in summer and autumn periods in 2006–2011. Spatial and seasonal regularities in the distributions of the total concentration of oil components and the values of their ratios in water, as well as the spatial and annual features of their accumulation in bottom sediments have been established. Radiological methods have been used for layer-by-layer dating of bottom sediment cores and determine the thickness of the layer that had formed under the maximal anthropogenic impact on ecosystems. The presence of considerable amounts of hydrocarbons of modern biological origin has been revealed in all components of examined aquatic complexes. 相似文献
14.
The state of the water area in the Bays of Koz’mina and Lake Vtoroe (Nakhodka Gulf is evaluated. The data given include water
temperature and salinity, biochemical oxygen demand, pH, alkalinity, chlorophyll a, organic matter, biogenic elements, oil
products, detergents, polycyclic aromatic hydrocarbons, phenols, and organochlorine pesticides in water and bottom sediments.
Pollutants may enter the system of bights from both onshore sources and the open part of the bay. The water and bottom sediments
in this part of the bay show higher values of BOD5 and the concentrations of oil products, polycyclic aromatic hydrocarbons,
phenols, and organochlorine pesticides. The anthropogenic load on the water body is shown to increase because of the new industrial
construction on its shore. 相似文献
15.
Concentrations of heavy metals (Cu, Ni, Cd, Pb, Cr, and Zn) in bottom sediments, water, snow, and biota of the Uvod Reservoir,
as well as of rare-earth elements (Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Y, and Yb) in its water are assessed. Geochemical
studies of concentrations of Cu, Ni, Cd, Pb, Cr, and Zn in soils, water, and snow allow us to state that the metals enter
the reservoir mostly from natural sources; however, some part of them are of anthropogenic origin. The sum of concentrations
of light rare-earth elements (La, Ce, and Nd) make almost the total of all rare-earth elements in the reservoir—from 70 to
97%, depending on the sampling site. The highest concentrations of metals (and the highest percentage of their labile forms)
are recorded in the Priplotinnyi and Kolbaskinskii (in macrophite deposits) pools and at the site of water inflow from the
Volga-Uvod canal. There is also reason to suppose a secondary entry of the elements under study into the water mass. The largest
variations in metals’ concentrations are observed during the periods of spring and autumn floods, when a great quantity of
terrigenous suspended matter enters the water body. The distribution of the above metals and rare-earth elements in water
is uneven; their highest concentrations are observed in the site of water inflow from the canal and in the Uvod River (the
latter is likely to be due to the effect of the settlement of Pistsovo). The analysis of biota (fennel-leaved pondweed and
zooplankton) has shown that the Uvod Reservoir is polluted with heavy metals. 相似文献
16.
Sediment (surface and core) sampling was conducted during the period from August 96-December 98 from intertidal and offshore areas in Kuwait Bay. The highest (and most variable) concentrations of total mercury (T-Hg; 36500+/-34930 ng g(-1)) are encountered around the previous industrial outfall where sediments are disturbed by shipping activities. The concentrations of T-Hg are lower in the Shuwaikh Port area (650+/-210 ng g(-1)) and continue to decrease towards the northern coastline of Kuwait Bay (average concentrations in the wider Bay region are 50+/-30 ng g(-1)). These values are still above background concentrations of 15-20 ng g(-1). Calculation of the total inventory of mercury in all the surface sediments of the studied area indicates that approximately 22.5 ton is present which is similar to the estimated industrial discharges of approximately 20 ton suggesting that the contamination is largely confined to the Bay and that releases to the wider Gulf region are small. The distributions of MeHg are similar to those of T-Hg and represent ranges between 0.23% and 0.5% of the T-Hg indicating that surface sediments within Kuwait Bay contain approximately 80 kg of this chemical. 相似文献
17.
I. A. Nemirovskaya 《Water Resources》2009,36(1):64-75
Aliphatic and polycyclic aromatic hydrocarbons were studied in water, filtration and separation particulate matter, seston, and bottom sediments with the aim to determine their concentrations and origin and compare them with the concentrations of lipids and Corg (August 2006). The effect of anthropogenic hydrocarbons was identified mostly in the Northern Dvina mouth area and in the apex of Dvina Bay. In other parts of the sea, natural compounds dominate in all examined objects, since anthropogenic hydrocarbon cannot pass through the Northern Dvina-the White Sea geochemical barrier. The low temperatures in the high-latitude water areas are shown not to reduce the rate of diagenetic processes in the sedimentary strata. 相似文献
18.
The top‐soil samples were collected from urban, industrial, agricultural, and rural sites to investigate the modification in the elemental composition due to anthropogenic influence in one of the biggest city of Turkey, namely Izmir. The elemental profiles were dominated by lithophilic elements such as Al, Ca, Fe, Mg, K, and sea salt element, Na, which is typical for Mediterranean region. The trace elemental concentrations showed significant variation with higher concentrations in the industrial sites, particularly in the vicinity of iron‐steel producers from scrap materials (EAF‐Steels). Lead, Zn, and Cd around EAF‐Steels were found to be higher than other sites. Comparison to universal upper crusts and local reference soil has shown that Izmir top‐soils were contaminated in terms of many trace elements, most probably due to anthropogenic activities. Correlation matrix, crustal enrichment factors, and factor analysis were applied to investigate the extent of soil modification and possible sources. The results indicated that the elemental profiles of top‐soils were mainly determined by parent materials; however, anthropogenic activities were found to be factor effective on the profile. 相似文献
19.
This paper presents information on the levels of trace elements in sediments collected at Deception and Penguin Islands and tracks the sources of natural and anthropogenic inputs of metals into this sub-Antarctic region. The results suggest that natural processes, such as volcanic activity, hydrothermal processes and sediment transport, are more important than anthropogenic inputs in accounting for the metal concentrations measured in sediments at Deception Island. The higher levels of trace metals recorded in sediments at Penguin Island seem to reflect the composition of the source rocks of the island, which are dominated by the olivine-basalt group. Our findings show that human activities in the study areas may contribute to negligible levels of trace metals associated with anthropogenic inputs (e.g., Cr and Zn) in sediments, and these results can be used in the future as background levels related to low anthropogenic impacts. 相似文献
20.
The distribution of oil hydrocarbons in bottom sediments of Onega Lake was examined. Their qualitative and quantitative composition was examined by methods of IR-spectroscopy and chromatography-mass spectrometry. The background concentrations of oil hydrocarbons in bottom sediments are evaluated and the polluted area is determined. The major regularities in oil hydrocarbon transformations under natural conditions and anthropogenic impact are identified. The quantitative development of the bacterial groups that take part in the transformation of complex organic substances and oil product derivatives in the case of emergency pollution of Petrozavodsk Bay water area by oil products is demonstrated. 相似文献