首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
《Ecological Indicators》2008,8(4):360-372
This study deals with the application of macrozoobenthos-based biotic indices (BI) within the frame of the implementation of the European Water Framework Directive. More precisely, this study aimed at assessing the performance of five recently developed methodologies (BI) for the assessment of ecological quality status (EcoQ) in two semi-enclosed, sheltered coastal ecosystems and in one transitional water body situated along the Western French coast, namely Marennes-Oléron Bay, Arcachon Bay, and the Seine Estuary. This study showed that these five indices rarely agreed with each other, describing very different pictures of the overall EcoQ of the three study sites. This work also clearly underlined the limitations of these approaches, notably the dependency of most of these BI and the resulting EcoQ classifications on habitat characteristics, more particularly to natural levels of sediment silt–clay content and the location of stations in the subtidal or the intertidal. The implication of our observations concerning the use of these BI for implementation of the WFD is discussed in terms of definition of habitat-specific reference conditions and necessity to adjust thresholds to the particular habitat occurring in semi-enclosed ecosystems. Meanwhile, the unmodified use of these BI severely impaired accurate assessment of EcoQ and decision-making on the managers’ point of view.  相似文献   

2.
Identifying and quantifying the factors that contribute to the potential misclassification of the ecological status of water bodies is a major challenge of the Water Framework Directive (WFD). The present study compiles extensive biomonitoring data from a range of macrophyte-based classification methods developed by several European countries. The data reflect spatial and temporal variation as well as inter-observer variation. Uncertainty analysis identified that factors related to the spatial scale of sampling generally contributed most to the uncertainty in classifying water bodies to their ecological status, reflecting the high horizontal and depth-related heterogeneity displayed by macrophyte communities. In contrast, the uncertainty associated with temporal variation was low. In addition, inter-observer variation, where assessed, did not contribute much to overall uncertainty, indicating that these methods are easily transferable and insensitive to observer error. The study, therefore, suggests that macrophyte-based sampling schemes should prioritize large spatial replication over temporal replication to maximize the effectiveness and reliability of water body classification within the WFD. We encourage conducting similar uncertainty analyses for new/additional ecological indicators to optimize sampling schemes and improve the reliability of classification of ecological status.  相似文献   

3.
In the context of the requirements of the European Water Framework Directive (WFD) numerous benthic indices have been proposed recently to assess the ecological quality of marine and transitional waters. In several studies these metrics were applied to coastal and estuarine environments under diverse anthropogenic pressures. Although currently the dumping of dredged material is one of the most prominent human impacts that modify estuaries, the performance of benthic indices to detect effects of dredged sediment relocation has not yet been tested explicitly. Hence we examined a selection of common metrics (species richness, Shannon diversity, AMBI, M-AMBI, W-value, BO2A) at 11 dumping and 11 nearby reference areas in the highly modified Elbe estuary (Germany), where permanent dredging is necessary to maintain the depth of the navigation channel. In order to cover the entire estuary, the study area spanned over the whole salinity gradient from limnic to euhaline. Additionally, we investigated changes in benthic communities due to dredged material placement. All indices, except the W-value, were suitable to differentiate between dumping and reference areas and showed significantly better index values exclusively at reference areas. The applicability of AMBI and M-AMBI was restricted in the limnic stretch due to the more frequent occurrence of freshwater species there. The W-value and BO2A were non-satisfactory in the case of azoic sediment, and in most cases these two indices indicated much better ecological status classifications than the other indices tested. Furthermore, the BO2A had restricted applicability with increasing salinity. At eight of eleven sites the benthic communities differed significantly between dumping and reference areas. Our findings show that the power of conventional benthic indices to detect physical disturbances like the dumping of dredged sediment varies greatly. Having this in mind, we suggest to choose carefully the benthic indices for ecological quality assessments according to the WFD in estuaries in order to avoid misclassifications. Such errors may lead to unnecessarily expensive remediation activities or, in the opposite case, to inactivity although actions were necessary. Furthermore, in order to better meet the WFD requirements we suggest that, regarding frequency and volume, dumping should be adapted as far as possible to the natural processes of sediment movement.  相似文献   

4.
The Water Framework Directive 2000/60/EC (WFD) requires the analysis of biological elements of aquatic ecosystems to assess water quality. Diatoms are the component of the periphyton most commonly used to classify lotic environments. Within the context of the WFD the concept of ‘reference conditions’ was introduced and biological quality of watercourses is expressed as Ecological Quality Ratio (EQR). This study was carried out in Alto Adige/Südtirol (Province of Bolzano-Bozen, northern Italy), belonging to the Alpine eco-region, and to the hydro-ecoregion Inner Alps. During 2006–2009, epilithic diatoms were sampled from monitoring and reference sites of seven stream types. Diatom assemblages were analysed with TWINSPAN and CCA analyses to investigate species association and distribution in relation to stream characteristics. Altitude and geology resulted to be the most important factors influencing diatom assemblage composition, and were used to describe new stream types. Indicator species analysis was used to characterize reference assemblages. The biological quality of watercourses was assessed using different diatom indices: Specific Pollution sensitivity Index (IPS), Eutrophication and Pollution Index with Diatoms (EPI-D), Trophic Index (TI). We tested also the Intercalibration Common Metric index (ICM).  相似文献   

5.
Spatial and temporal variability in the concentration of saprophytic bacteria was investigated in surface waters of Paranaguá and Antonina bays.Seven points along a profile from the entrance of Paranaguá Bay to the innermost part of Antonina Bay, were sampled monthly from November 1985 to November 1986. Temperature, dissolved oxygen, pH and precipitation data were also measured.ZoBell 2216E culture medium was utilized with freshwater and 32% salinity water.Principal component analysis of biotic and abiotic data showed a gradient from the innermost bay to the baymouth bar with an increase in bacteria concentration at Antonina Bay. Significant variation was not observed among sampling stations at Paranaguá Bay, except for February 1986 when there was a homogeneous increase of bacteria throughout both bays in association with an increase in temperature and precipitation. There was also no strong variation of saprophyte numbers at sampling locations near Paranaguá city, despite domestic and harbour waste input.We conclude that the outer region of the estuary is highly influenced by the adjacent ocean and that the inner part has typical estuarine characteristics. The region may be considered little polluted.  相似文献   

6.
Rolauffs  Peter  Stubauer  Ilse  Zahrádková  Svetlana  Brabec  Karel  Moog  Otto 《Hydrobiologia》2004,516(1-3):285-298
The use of saprobic systems has long traditions in the water management in Austria, the Czech Republic and Germany. Within the context of water quality assessment they are applied to indicate the effects of anthropogenic caused organic impact leading to a decrease in the dissolved oxygen content of running waters. In December 2000 the European Union Water Framework Directive (WFD) came into force. It demands homogeneous procedures and methods for assessing inland surface waters as well as groundwater, coastal and transitional waters. The WFD focuses on the assessment of biotic elements and the ecological status has to be defined based on type specific approaches and reference conditions. To incorporate the saprobic approach into the new integrative methodology of the European assessment of the ecological status of water bodies, the national saprobic systems need to be adjusted. This paper describes the according methodological developments and adaptations of Austria, the Czech Republic, and Germany required to harmonise the traditional procedure with the guidelines of the WFD. In the three countries national databases were established to provide species lists from largely undisturbed stream sites. Such reference sites build the basis for calculating stream type specific reference values. The calculation has been done in slightly different ways dependent on the country. In addition to that boundaries were defined to characterise the 5 saprobic quality classes.  相似文献   

7.
8.
High concentrations of chloride ions inhibit the growth of acidophilic microorganisms used in biomining, a problem particularly relevant to Western Australian and Chilean biomining operations. Despite this, little is known about the mechanisms acidophiles adopt in order to tolerate high chloride ion concentrations. This study aimed to investigate the impact of increasing concentrations of chloride ions on the population dynamics of a mixed culture during pyrite bioleaching and apply proteomics to elucidate how two species from this mixed culture alter their proteomes under chloride stress. A mixture consisting of well-known biomining microorganisms and an enrichment culture obtained from an acidic saline drain were tested for their ability to bioleach pyrite in the presence of 0, 3.5, 7, and 20 g L−1 NaCl. Microorganisms from the enrichment culture were found to out-compete the known biomining microorganisms, independent of the chloride ion concentration. The proteomes of the Gram-positive acidophile Acidimicrobium ferrooxidans and the Gram-negative acidophile Acidithiobacillus caldus grown in the presence or absence of chloride ions were investigated. Analysis of differential expression showed that acidophilic microorganisms adopted several changes in their proteomes in the presence of chloride ions, suggesting the following strategies to combat the NaCl stress: adaptation of the cell membrane, the accumulation of amino acids possibly as a form of osmoprotectant, and the expression of a YceI family protein involved in acid and osmotic-related stress.  相似文献   

9.
Understanding the response of long-lived species to natural climatic variability at multiple scales is a prerequisite for forecasting ecosystem responses to global climate change. This study investigated the response of piñon pine (Pinus edulis) to natural climatic variability using information on physiology and growth as recorded in leaves and tree rings. δ13C of annual leaf cohorts (δ13Cleaf) and tree rings (δ13Cring) were measured at an ecotonal/xeric site and a mid-range/mesic site. Ring width indices (RWI) were used to estimate annual growth of individual trees. Relationships between seasonal and annual climate parameters and δ13C and growth were investigated. δ13C–climate relationships were stronger for δ13Cleaf than for δ13Cring especially at the xeric site. The mean monthly maximum summer temperatures over May through September (summer T max) had the strongest influence on δ13Cleaf. There was a strong negative relationship between RWI with summer T max and a strong positive relationship between RWI with October to October precipitation (water–year PPN) at both sites. This suggests that piñon pine populations could be vulnerable to decreased growth and, perhaps mortality, in response to warmer, drier conditions predicted by models of global climate change.  相似文献   

10.
The Water Framework Directive (WFD) has provided the means of standardizing the way surface water bodies are monitored throughout the European Union (EU), using a common evaluation measure, the percentage of surface water bodies at good status, based largely on the structure and functioning of aquatic ecosystems. However, the evaluation of good status is based on the way the WFD is implemented, which differs in each country. In this article, we analyze how the WFD is implemented in France, how the water agencies divide up the water bodies, the areas covered by their monitoring networks, and the modalities of obtaining data to provide the EU with the percentage of water bodies at good status. This analysis reveals that it is this hyperindicator itself that is at stake, obtained by successively aggregating values measured in time and space, from the monitoring station to the River Basin District (RBD), reducing vast amounts of information to a single measure per RBD, while long-term monitoring of the major European rivers and their sedimentary budgets, which show improvements in certain quality aspects, are largely overlooked by the WFD. When drawing up the indicator, the agencies identify certain biases but not others. This raises the question of its use and relevance for managers and politicians, at both national and European level.  相似文献   

11.
This study applies ecological indices to determine the anthropogenic-based metal enrichment and potential ecological and ecotoxicological risks posed by each metal in the sediments of Lake Akta?, NE Turkey. Sediment samples were collected from nine stations (St1–St9) within the Turkish boundary of Lake Akta? and the heavy metal, total organic carbon %, CaCO3%, chlorophyll degradation products (chlorophyll-α), total sulfur %, and total phosphate % contents in the sediment samples were determined. Enrichment factor (EF), pollution load and potential ecological risk (PER) indices were calculated to shed light on the ecological effects of heavy metals. The metal content was ranked in descending order of Al > Fe > Mn > Zn > Ni > Cr > Cu > Pb > As > Cd > Hg. The EF values ranged 0.87–1.0 for Cu, 1.04–1.14 for Pb, 1–1.08 for Zn, 0.88–0.95 for Ni, 0.99–1.24 for Mn, 0.89–0.93 for Fe, 0.82–1.01 for As, 0.96–1.19 for Cd, 0.94–1.0 for Cr, and 1.42–1.90 for Hg. Minimal contamination was found for Hg. Pollution load, PER, and toxic risk indices indicated no ecological risk currently. However, considering the PER index for metals individually, a moderate potential risk was detected for Hg. The data obtained from multivariate statistical analyses indicate that Hg and Mn originate from the atmosphere, while other elements have lithogenic sources.  相似文献   

12.
The European Water Framework Directive (WFD) represents a transformation of the guidelines for water quality assessment and monitoring across all EU Member States. At present, it is widely accepted that the WFD requires holistic and multidisciplinary ecological approaches by integrating multiple lines of evidence. Within the scope of the WFD, the scientific community identified clear opportunities to take advantage of an ecotoxicological line of evidence. In this context, ecotoxicological tools, namely biomarkers and bioassays, were proposed to contribute to the integration of the chemical and biological indicators, and thus to provide an overall insight into the quality of a water body. More than one decade after the publication of the WFD, we reviewed the studies that have attempted to integrate ecotoxicological tools in the assessment of surface water bodies. For this purpose, we reviewed studies providing an ecological water status assessment through more conventional community based approaches, in which biomarkers and/or bioassays were also applied to complement the evaluation. Overall, from our review emerges that studies at community level appear suitable for assessing the ecological quality of water bodies, whereas the bioassays/biomarkers are especially useful as early warning systems and to investigate the causes of ecological impairment, allowing a better understanding of the cause–effect-relationships. In this sense, community level responses and biomarkers/bioassays seem to be clearly complementary, reinforcing the need of combining the approaches of different disciplines to achieve the best evaluation of ecosystem communities’ health.  相似文献   

13.
Finite element models are frequently used to study lumbar spinal biomechanics. Deterministic models are used to reflect a certain configuration, including the means of geometrical and material properties, while probabilistic models account for the inherent variability in the population. Because model parameters are generally uncertain, their predictive power is frequently questioned. In the present study, we determined the sensitivities of spinal forces and motions to material parameters of intervertebral discs, vertebrae, and ligaments and to lumbar morphology. We performed 1200 model simulations using a generic model of the human lumbar spine loaded under pure moments. Coefficients of determination and of variation were determined for all parameter and response combinations. Material properties of the vertebrae displayed the least impact on results, whereas those of the discs and morphology impacted most. The most affected results were the axial compression forces in the vertebral body and in several ligaments during flexion and the facet-joint forces during extension. Intervertebral rotations were considerably affected only when several parameters were varied simultaneously. Results can be used to decide which model parameters require careful consideration in deterministic models and which parameters might be omitted in probabilistic studies. Findings allow quantitative estimation of a model׳s precision.  相似文献   

14.
The objective of this study was to determine the effects of physical and chemical water quality parameters in the Augustów Canal on the abundance and taxonomic diversity of aquatic fungi. The studies were conducted in the hydrological year 2012 along the environmentally valuable area of the Augustów Canal. The mean abundance of fungi was 2 160 ± 1840 CFU ml−1. The lowest abundances were observed in the uppermost part of the canal, and the highest abundances in the southern part. A total of 38 species were identified, including 13 potentially pathogenic fungi, which predominated in the central region of the canal, called the natural lake part. Redundancy analysis (RDA) indicated that variation in water chemistry caused significant changes to fungal species diversity. The results showed that fungal species diversity and abundance in the canal were particularly dependent on the extent of water pollution, as indicated by chloride and sulphate(VI) ions and electrolytic conductivity. Other water quality parameters that influenced the development of aquatic fungi were organic matter and algal biomass, responsible for water eutrophication. We propose that mycoplankton be considered a sensitive biological indicator of water quality.  相似文献   

15.

Background

Chronic pain is recognized as a public health problem that affects the general population physically, psychologically, and socially. However, there is little knowledge about the associated factors of chronic pain, such as the influence of weather, family structure, daily exercise, and work status.

Objectives

This survey had three aims: 1) to estimate the prevalence of chronic pain in Japan, 2) to analyze these associated factors, and 3) to evaluate the social burden due to chronic pain.

Methods

We conducted a cross-sectional postal survey in a sample of 6000 adults aged ≥20 years. The response rate was 43.8%.

Results

The mean age of the respondents was 57.7 years (range 20–99 years); 39.3% met the criteria for chronic pain (lasting ≥3 months). Approximately a quarter of the respondents reported that their chronic pain was adversely influenced by bad weather and also oncoming bad weather. Risk factors for chronic pain, as determined by a logistic regression model, included being an older female, being unemployed, living alone, and no daily exercise. Individuals with chronic pain showed significantly lower quality of life and significantly higher psychological distress scores than those without chronic pain. The mean annual duration of absence from work of working-age respondents was 9.6 days (range 1–365 days).

Conclusions

Our findings revealed that high prevalence and severity of chronic pain, associated factors, and significant impact on quality of life in the adult Japanese population. A detailed understanding of factors associated with chronic pain is essential for establishing a management strategy for primary care.  相似文献   

16.
The probability that an observed infection has been transmitted from a particular member of a set of potential infectors is calculated. The calculations only use knowledge of the times of infection. It is shown that the probabilities depend on individual variability in latent and infectious times. The analysis are based on different background information and different assumptions on the progress of infectivity. The results are illustrated by numerical calculations and simulations.  相似文献   

17.
Climate change and anthropogenic activities have altered the terrestrial ecosystem dynamics around the globe. Due to the complex ecosystem-atmosphere interactions at different scales, these impacts are difficult to quantify and are poorly understood, especially in developing countries with limited ground-based observations. This study analyzed the impact of climatic changes and anthropogenic activities on ecosystem net primary productivity (NPP) in India using remote sensing-based observations, correlation analysis, and Residual Trend analysis (RESTREND). Using different climate variables such as precipitation, temperature, and solar radiation, along with Land Use and Land Cover (LULC) and NPP maps, we first classified the ecosystems (ES) into two categories: natural ecosystems – influenced only by climate change (ESc), covering about 19.7% of the area, and human-influenced ecosystems – influenced by both climate change and anthropogenic activities (ESc+a), covering about 80.3% of the area. RESTREND analysis was performed on both ESc and ESc+a to analyze the relative contributions of climate change and human activities to changes in NPP. The correlation analysis between NPP and climate variables suggested that precipitation was the dominant control of NPP in about 72% area, whereas temperature and solar radiation controlled NPP in Himalayan and forest-dominated regions, respectively. The human-influenced ecosystems (ESc+a) experienced an increasing trend in NPP, whereas natural ecosystems (ESc) experienced a decreasing trend, particularly in forest-dominated regions. Overall, NPP increased in the country during the study duration. The contributions of climatic changes and anthropogenic activities varied spatially and temporally. In general, climatic factors enhanced the NPP, whereas human activities contributed to a slight decline in NPP. These findings improve our understanding of how ecosystems in India are influenced by climate change and anthropogenic activities in recent decades. The results from this study will aid in identifying ecological hotspots and key drivers for better ecosystem management strategies.  相似文献   

18.
There was performed a comparative evaluation of the mean values of lipid metabolism parameters in youths and girls of the indigenous population (the Even), of the coming population of the north of Irkutsk province, and of the province center (the Europeoids). Gender differences in HDLP have been revealed in adolescents of the coming population, in the glutathione status and the content of liposoluble vitamins in the Even and coming adolescents and in retinol concentration in the province center adolescents. Adaptive changes in the ROS system were found in the Even girls (the higher α-tocopherol and GSH concentrations and the GSH/GSSG ratio as well as a decrease of GSSG relative to the Even youths and the coming population girls, an increase of α-tocopherol relatively to the coming population Europeoids) and youth of the coming population (the higher GSH content and the GSH/GSSG parameter relatively to the Even youths).  相似文献   

19.
Pit lakes (abandoned flooded mine pits) represent a potentially valuable water resource. However, acid mine drainage (AMD) generation due to mining activities often results in pit lake waters with low pH, high sulphate and dissolved metal concentrations. Sulphate reduction-based bioremediation offers tremendous scope for removal of acidity and metals from pit lake water. In this study, the effect of storing sewage on its carbon quality for bioremediation of acidic pit lake water was studied. In addition, the effectiveness of labile organic carbon (lactic acid and ethanol) on SRB activity was tested. Bioremediation experiments were performed in controlled and replicated microcosms with acidic (pH 2.2) water from a pit lake by addition of stored (3 years at 4 °C) sewage for stimulation of sulphate reducing bacteria (SRB) activity. This sewage had been previously used successfully in remediating to pH 7 water from this pit lake. The initial aim was to test the sewage at lower doses (18 and 28 g/L) and in a pulsed addition (over 5 weeks). Bioremediation efficacy was evaluated by measuring pit lake water pH increase, redox potential decrease, and acidity and sulphate removal. Though the stored sewage had retained a very similar high total organic carbon (TOC) equivalent to prior to storage, it failed to increase dissolved organic carbon (DOC) levels in pit lake water. Microcosms amended with doubled doses of sewage and an extended remediation time still failed to demonstrate any substantial improvement in water quality, other than a small amount of sulphate reduction and direct neutralisation by the sewage. In order to determine if low DOC concentrations in sewage were the cause of the bioremediation failure, labile organic carbon (LOC), consisting of 50:50 (w/w) lactic acid and ethanol, was added to all microcosm treatments at concentrations of 3000, 6000 and 9000 mg/L. After LOC addition, water quality improved with effective removal of acidity, sulphate and metals in the lowest carbon concentration (3000 mg/L). However, 6000 and 9000 mg/L LOC concentrations showed a delay in response due to the increased acidity associated with the lactic acid addition. The experiments showed that pulsed dosing of carbon simply slowed the commencement of remediation but it was ultimately able to reach the same effectiveness as the equivalent quantity added all at once. Prolonged storage of sewage leads to loss of LOC. In situ pit lake remediations which aim to make use of sewage as the main carbon source will need to factor in the storage time required to obtain sufficient sewage for the treatment into the design. Pulsing may help reduce issues with storage or supplementation with LOC may need to be considered. Results highlight that LOC is a more useful indicator of material effectiveness compared to a simple measures of TOC.  相似文献   

20.
A check-list of the macroalgae which colonize the artificial structures “dykes” formed by limestone blocks, placed between the northern Adriatic Sea and the Venice Lagoon to protect the wide sea inlets of Lido and Malamocco, the stone breakwaters and the submerged reefs parallel and perpendicular to the sea coastline of the Lido island “Murazzi” is presented. Macroalgae have been sampled monthly during one-year period (February 2007–January 2008) both in the lagoon inlets and along the marine coast. Flora was represented by 213 taxa: 61 Chlorophyta, 114 Rhodophyta, 38 Ochrophyta (37 Phaeophyceae, 1 Xanthophyceae), with the richest and luxuriant vegetation in the lagoon inlet areas. The application of the Rhodophyta/Chlorophyta (R/C) index and the Expert-Macrophyte Quality Index (E-MaQI) highlighted the “High” ecological status (EQR > 0.9) of the lagoon inlet areas.As E-MaQI is not applicable in marine areas, an adaptation of CARLIT to the anthropic structures of the north-western coasts of the northern Adriatic Sea and its integration with the dominant taxa is proposed.The application of the revised index to the Lido dykes and breakwaters placed along the marine littorals shows “Moderate” conditions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号