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1.
Sulfate reduction is an important oxidation process involving transformation of organic matter and its components and taking place in the aquatic environment and bottom sediments of water bodies (both fresh and marine) under anaerobic conditions. The intensification of sulfate reduction in water bodies is a sign of a stronger anthropogenic impact on the environment and natural water bodies. The development of sulfate reduction under natural conditions reflects the influence of many environmental factors. The effect of the most important factors (the concentration of organic matter and its components and sulfates, the temperature of aquatic environment, and the abundance and activity of sulfate-reducing bacteria) on the process of sulfate reduction in the aquatic environment and bottom sediments in water bodies is considered. 相似文献
2.
From a molecular level to an ecosystem scale, different coupling mechanisms take place during coupled carbonnitrogen-water(C-N-H_2O) cycle, of which essential are water flux and related biogeochemical processes through physicochemical reactions associated with terrestrial and aquatic ecosystems. Meanwhile, regional coupled C-N-H_2O cycle will subsequently impact regional gross primary productivity(GPP) and C and N exchanges during air-water interactions that occur downstream of watersheds. This study aimed to first synthetically analyze the regional dynamics of C, N and H_2O cycles in ecosystems and determine their interactional relationships; second, to specify regional C-N-H_2O coupled relationships of ecosystems and their theoretical ecological principles; third, to classify coupled regional response and adaptation of the C-N-H_2O cycle to climatic and environmental changes under anthropogenic activities, providing a theoretical basis to fully understand and make adjustments to interactional C, N and H_2O cycling relationships at different ecosystem scales and under associated coupling processes. 相似文献
3.
The physical conditions at which a model ecosystem in an artificial aquatic ecosystem is still similar to the parent ecosystem are considered. A similarity criterion for the parent and model ecosystems is created based on optical data. An experimental proof is given for the fact that the optical characteristics of a model ecosystem that has not been subjected to anthropogenic load remain similar to those of the parent ecosystem for several weeks. It is shown that the optical characteristics of polluted artificial ecosystems can be assessed from the spectra of the brightness coefficients of the upward irradiance from water. 相似文献
4.
D. B. Denisov 《Water Resources》2007,34(6):682-692
Paleoecological studies of small water bodies were carried out in a model subarctic lake-river system. The degree of transformations of aquatic ecosystems under a set of anthropogenic factors is shown to vary depending on the load and individual features of water bodies. Data on the state of aquatic ecosystems before the industrial development of the region are collected. The species composition of diatom algae and their ecological characteristics are examined. 相似文献
5.
Reinaldo L. Bozelli Adriano Caliman Rafael D. Guariento Luciana S. Carneiro Jayme M. Santangelo Marcos P. Figueiredo-Barros Joo J.F. Leal Adriana M. Rocha Letícia B. Quesado Paloma M. Lopes Vinicius F. Farjalla Claudio C. Marinho Fabio Roland Francisco A. Esteves 《Limnologica》2009,39(4):306-313
Human activities are exposing freshwater ecosystems to a wide range of stressors, whose direct and indirect effects can be alleviated or exacerbated through interactive effects with dynamic environmental drivers. This study used long-term data from two Neotropical lacustrine freshwater systems (Batata Lake, an Amazonian floodplain lake and Imboassica lagoon, an Atlantic coastal lagoon) subjected to different kinds of environmental fluctuations (i.e., flood pulse and sandbar opening) and anthropogenic impacts (i.e., siltation and eutrophication). Our objective was to determine whether the effects of human perturbations are contingent on modifications of important biotic and abiotic characteristics through environmental variability. For both ecosystems, environmental variability consistently interacted with anthropogenic perturbations to alter most of the variables analyzed, such as nutrient dynamics, chlorophyll-a concentration, zooplankton and benthic invertebrate species richness, and temporal community stability, which indicates that interactive effects between environmental variability and anthropogenic perturbations may impact a myriad of ecosystem properties. Furthermore, the nature of these interactive effects was highly dependent on the variable considered and on the ecosystem analyzed. For example, at Imboassica lagoon, sandbar openings interacted synergistically with trophic state to increase the phosphorus concentration in the water column. At Batata Lake, flooding generally alleviated the negative effects of siltation on species richness by both diluting inorganic suspended material concentration and by promoting local recruitment from the regional species pool. Such results indicate that our ability to understand and predict the outcome of anthropogenic impacts on inland aquatic systems can be hampered if we consider human stressors as “static” phenomena disconnected from dynamic interactions with major local environmental drivers. 相似文献
6.
Measurements of the production and consumption of organic material have been a focus of aquatic science for more than 80 years.
Over the last century, a variety of approaches have been developed and employed for measuring rates of gross primary production
(Pg), respiration (R), and net ecosystem production (Pn = Pg − R) within aquatic ecosystems. Here, we reconsider the range of approaches and applications for ecosystem metabolism measurements,
and suggest ways by which such studies can continue to contribute to aquatic ecology. This paper reviews past and contemporary
studies of aquatic ecosystem-level metabolism to identify their role in understanding and managing aquatic systems. We identify
four broad research objectives that have motivated ecosystem metabolism studies: (1) quantifying magnitude and variability
of metabolic rates for cross-system comparison, (2) estimating organic matter transfer between adjacent systems or subsystems,
(3) measuring ecosystem-scale responses to perturbation, both natural and anthropogenic, and (4) quantifying and calibrating
models of biogeochemical processes and trophic networks. The magnitudes of whole-system gross primary production, respiration
and net ecosystem production rates vary among aquatic environments and are partly constrained by the chosen methodology. We
argue that measurements of ecosystem metabolism should be a vital component of routine monitoring at larger scales in the
aquatic environment using existing flexible, precise, and durable sensor technologies. Current and future aquatic ecosystem
studies will benefit from application of new methods for metabolism measurements, which facilitate integration of process
measurements and calibration of models for addressing fundamental questions involving ecosystem-scale processes. 相似文献
7.
Current methodology of environmental impact assessment in connection with the environmental consequences of hydrocarbons production in the shelf area is analyzed. Basing on the ecosystem approach, a scheme of environmental impact estimates is suggested, envisaging the use of a set of gradations (scales) to characterize spatial and temporal scope of impacts and their consequences, as well as criteria (thresholds) of impact permissibility, taking into account the natural variability in the population and ecosystem parameters. Estimates of the environmental and fishery-related consequences of hydrocarbon production in the sea shelf area at different stages of the process are compared to the available measured and calculated data. The suggested scheme of environmental impact assessment and criteria of permissible impacts are recommended for expert analysis, forecasting, and monitoring of the environmental situation in the sea shelf areas of Russia under the conditions of anthropogenic impact. 相似文献
8.
The evolution of Lake Ladoga ecosystem under the effect of a long period of critical anthropogenic phosphorus load is analyzed.
It is shown that relatioships between organic matter accumulation and mineralization with considerable predominance of destruction
over autochthonous production have formed in the lake by the moment when the input of P of anthropogenic origin dropped to
the estimated admissible level. Studying the transformation of aquatic organic matter of tributaries in the water of Lake
Ladoga suggest that a considerable portion of it, primarily, the conservative humic fraction, is now involved in turnover
and serves as an additional source of C and P both for producer and destructor organisms. The processes taking place in Lake
Ladoga suggest the allochthonous variant of ecosystem evolution. 相似文献
9.
Analysis of long-term regime hydrochemical data collected by the State Service of Environmental Monitoring (SSEM) was used
to assess the anthropogenic load on the near-delta area of the Enisei mouth area near Igarka and Dudinka towns. Main trends
in the accumulation of biogenic compounds and pollutants, such as oil products, phenols, and copper and iron compounds are
identified. It is shown that the current anthropogenic load and the degree of aquatic environment pollution bring about a
trend toward the transition of the Enisei near-delta ecosystem from equilibrium into a crisis state. 相似文献
10.
Tatyana I. Moiseenko Andrey N. Sharov Lubov P. Kudryavtseva Catherine Rose 《Limnologica》2009,39(1):1-13
In this study, published data on Lake Imandra, north-west Russia, have been synthesised to investigate trends in lake contamination and recovery due to changing inputs of heavy metals and nutrients over time. Records of water chemistry, phytoplankton, zooplankton and fish communities have been used to determine the status of aquatic ecosystem health in three distinct phases of Lake Imandra's recent history. Firstly, background (reference) conditions within the lake have been established to determine lake conditions prior to anthropogenic influences. Secondly, a period of ecosystem degradation due to anthropogenic inputs of toxic metals and nutrients has been described. Finally, evidence of lake recovery due to recent decreases of toxic metals and nutrients has been explored. Pollution of Lake Imandra began in the 1930s, reaching a peak in the 1980s. Increases in heavy metal and nutrient inputs transformed the typical Arctic ecosystem. During the contamination phase, there was a decrease in Arctic species and in biodiversity. During the last 10 years, pollution has decreased and the lake has been recolonised by Arctic water species. Ecosystem recovery is indicated by a change of predominant species, an increase in the individual mass of organisms and an increase in the biodiversity index of plankton communities. In accordance with Odum's ecosystem succession theory, this paper demonstrates that the ecosystem has transformed to a more stable condition with new defining parameters. This illustrates that the recovery of Arctic ecosystems towards pre-industrial reference conditions after a reduction in anthropogenic stresses occur, although a complete return to background conditions may not be achievable. Having determined the status of current ecosystem health within Lake Imandra, the effect of global warming on the recovery process is discussed. Climate warming in Arctic regions is likely to move the ecosystem towards a predominance of eurybiontic species in the community structure. These organisms have the ability to tolerate a wider range of environmental conditions than typical Arctic inhabitants and will gain advantages in development. This indicates that the full recovery of Arctic ecosystems in a warming climate may not be possible. 相似文献
11.
Comprehensive physicochemical (Selector software package), paleoecological, and hydrobiological studies of two lakes-Pai-Kunjavr (Gol’tsovoe) and Bol’shoi Vudjavr (the Khibiny Mountain Massif) was carried out for the first time. Reconstruction of natural waters and wastes was performed, the present-day state of the ionic composition of natural waters, diatomic complexes, and zooplankton communities was assessed with the aim to determine the degree of transformation of Lake Bol’shoi Vudjavr under technogenic impact. The results are of practical and methodological significance for the assessment of long-term anthropogenic impact on subarctic aquatic ecosystems. 相似文献
12.
The present-day environmental state of some artificial (Irkutsk, Bratsk, and Novosibirsk reservoirs) and natural (lakes in Altai Territory and Yamal-Nenets Autonomous Okrug and the Tom River) water bodies in Western and Eastern Siberia was evaluated using biogeochemical indicators. The biogeochemical approach is presented as the best for establishing zones of risk and environmental disaster, since biogeochemical cycles play important role in aquatic ecosystems and unite all their blocks as a result of biogenic migration of chemical elements. Aquatic ecosystems transformed under anthropogenic impact are recognized and local sources of water pollution are identified. 相似文献
13.
We conducted an analysis of heavy metals content, including As, Cd, Cr, Cu, Hg, Pb, and Zn in sediments from aquatic ecosystems in China measured in recent publications. Then, we evaluated the extent of heavy metal pollution in these ecosystems in seven different industrial districts in China (Dongbei, Huabei, Huazhong, Huanan, Huaxik, Xibei, and Huadong) with the potential ecological risk index. We found that Cd was the most concentrated pollutant, followed by Hg and As, while Cr, Cu, Pb, Zn were found in low concentrations in sediments from all types of aquatic ecosystem in China. Sediments collected from all seven industrial districts were heavily polluted, and the sequence, from most to least polluted was Dongbei>Huabei>Huazhong>Huanan>Huaxi>Xibei>Huadong. All four types of aquatic ecosystem were found to be seriously polluted and the sequence, from most to least polluted was: river>sea>lake>wetland. Specifically, Cd and Hg were the most serious pollutants in all four aquatic ecosystems, and As was also a serious pollutant in rivers. For the seven industrial districts studied the sea was the most polluted ecosystem in Dongbei, the river was the most polluted ecosystem in Huabei, Huanan, Huazhong, and the lake was the most polluted in Huadong, Huaxi, and Xibei. 相似文献
14.
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
15.
Gomiero A Da Ros L Nasci C Meneghetti F Spagnolo A Fabi G 《Marine pollution bulletin》2011,62(11):2483-2495
Despite a large number of gas platforms existing in the Adriatic Sea, which is a semi-enclosed basin characterized by a slow turnover rate and increasing industrial as well as other anthropogenic activities, the effects of these structures on the aquatic ecosystem require further investigation. Since 1998, multidisciplinary studies have been performed by CNR-ISMAR to comply with legislation and to support the development of protocols for the monitoring of offshore activities in the Adriatic Sea. The present study was developed to implement a biomonitoring plan to assess the ecotoxicological effects of the extraction activities of an off-shore gas platform. Biomarkers were evaluated in mussels collected from the platform in relation to physiological stress, DNA damage, cellular damage, oxidative stress and exposure effects. Organic contaminants and trace element bioaccumulation were also assessed in the soft body of the mussels to correlate bioaccumulation of pollutants with biomarker responses. The results indicate an absence of platform-related environmental stress. 相似文献
16.
受气候变化和人类活动影响,湖泊水生态系统及其服务功能发生改变,研究湖泊水生态系统生产总值动态变化及其影响因素,对于维护湖泊健康生命、实现湖泊功能永续利用具有重要意义。选择位于气候敏感区和生态脆弱区的青海湖作为研究对象,根据青海湖水生态系统特征及当前保护状况,筛选调节服务及文化服务2类8个评估指标,构建湖泊水生态系统生产总值指标体系,核算2010—2020年青海湖水生态系统生产总值,分析其变化趋势及主要影响因素。结果表明,2010—2020年青海湖水生态系统生产总值总体呈波动上升趋势,变化范围为6903.47亿～7848.55亿元;调节服务是青海湖水生态系统主要的服务类型,占比高达91%。近十年,气候调节和水质净化价值有所减少,其他服务功能价值均呈增加趋势。水源涵养价值增加最多,增长760.70亿元;气候调节价值下降最多,减少658.59亿元。偏最小二乘回归分析表明,水温、水位是影响青海湖水生态系统生产总值的主要因素。气候变化影响下,水温升高引起初级生产力增加及鱼类数量增长,同时近年来水体矿化度下降有利于水生生物生长,提高了固碳释氧和物种保育价值。水位与水面面积增加引起水源涵养、洪水调蓄... 相似文献
17.
The bioindication role of macropytes in the assessment of the environmental conditions of small water bodies under the conditions of a megalopolis is discussed. A comparative characteristic is given to the significance of macrophytes from different ecological groups, including hygrophytes (cattail, reed), hydrophyte (pondweed), and hydatophytes (Canada water weed, hornweed), growing in small water bodies in St. Petersburg, for the biogeochemical indication of environmental pollution by microelements (Fe, Mn, Zn, Cu, Cr, Ni, Pb, and Cd) and biogenic elements (K, Ca, Na, P, S). Possible mechanisms of detoxication of heavy metal ions in macrophyte organisms and their role in the stable functioning of water bodies in urban territory under the conditions of anthropogenic pollution are discussed. The prospects of the use of macrophyte groups for the bioindication of pollution and phytoremediation of aquatic ecosystems are analyzed. 相似文献
18.
Biological invasions as a component of global change in stressed marine ecosystems 总被引：13，自引：0，他引：13
Biological invasions in marine environment are the lesser known aspect of global change. However, recent events which occurred in the Mediterranean Sea demonstrate that they represent a serious ecological and economical menace leading to biodiversity loss, ecosystem unbalancing, fishery and tourism impairment. In this paper we review marine bioinvasions using examples taken from the Mediterranean/Black Sea region. Particular attention is given to the environmental status of the receiving area as a fundamental pre-requisite for the colonisation success of alien species. The spread of the tropical algae belonging to the genus Caulerpa in the northwestern basin of the Mediterranean Sea has been facilitated by pre-existing conditions of instability of the Posidonia oceanica endemic ecosystem in relation to stress of both natural and anthropogenic origin. Human interventions caused long-term modification in the Black Sea environment, preparing a fertile ground for mass bioinvasion of aquatic nuisance species which, in some cases, altered the original equilibrium of the entire basin. Finally, the Venice lagoon is presented as the third example of an environment subjected to high propagule pressure and anthropogenic forcing and bearing the higher "diversity" of non-indigenous species compared to the other Mediterranean lagoons. Stressed environments are easily colonised by alien species; understanding the links between human and natural disturbance and massive development of non-indigenous species will help prevent marine bioinvasions, that are already favoured by global oceanic trade. 相似文献
19.
The Paul do Boquilobo is an important wetland ecosystem classified by Unesco as a MAB Biosphere reserve also awarded Ramsar site status, representing one of the most important habitats for the resident nesting colony of Cattle Egret (Bulbucus ibis). Yet owing to its location, it suffers from human induced impacts which include industrial and domestic effluent discharges as well as agricultural land use which have negatively impacted water quality. The current study reports the results obtained from the introductory monitoring programme of surface water quality in the Nature Reserve to emphasize the detrimental impact of the anthropogenic activities in the water quality of such an important ecosystem. The study involved physicochemical and biotic variables, microbial parameters and biological indicators. Results after 3 years of monitoring bring to evidence a poor water quality further impaired by seasonal patterns. Statistical analysis of data attributed water quality variation to 3 main parameters – pH, dissolved oxygen and nitrates, indicating heavy contamination loads from both organic and agricultural sources. Seasonality plays a role in water flow and climatic conditions, where sampling sites presented variable water quality data, suggesting a depurative function of the wetland. 相似文献
20.
E. A. Kriksunov V. Ya. Pushkar F. S. Lobyrev V. A. Burmenskii N. M. Shchegol’kova A. E. Bobyrev 《Water Resources》2006,33(6):651-660
Materials of structural-functional studies regarding the organization of the Moskva River ecosystem within the boundary of the city are presented, and the impact of the treated water discharged from Kur’yanovskaya Aeration Station onto aquatic biota is assessed. The conclusion is made that the structural-functional organization of biocenoses in different river reaches is related with the environmental factors that form under the effect of this water. 相似文献