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 288 毫秒
1.
An animal’s suitability as a biomonitor of environmental change can be determined by biological, reproductive and ecological characteristics determined at the class, order and species level. The animal’s habitat where the research is to be performed and the form, function and structure of the environmental change being studied within that habitat also determines suitability. Non-threatened populations of large, non-migratory, long-lived, seasonally-breeding tertiary avian predators, whose dietary preferences are narrow and known, can be useful as monitors of environmental chemical contaminants. If chemicals are being monitored, a quantifiable endpoint effect must be demonstrated in the species, or a similar species under experimental laboratory conditions. Logistical and economic issues as well as public and regulatory authority acceptance should also be considered when assessing the suitability of a species as a biomonitor.  相似文献   

2.
Based upon ecological data provided by a 6-year study of native species assemblage structure and function in near-pristine Limahuli Stream (Kauai), The Hawaii Stream Index of Biological Integrity (HS-IBI) incorporates 11 metrics covering five ecological categories (taxonomic richness, sensitive species, reproductive capacity, trophic–habitat capacity, and tolerance capacity). The HS-IBI was shown to effectively distinguish stream biological condition on a continuum from undisturbed (near-pristine) to severely impaired in sampling of 39 sites (6 estuarine reaches) on 18 Hawaiian streams located on all major islands. A significant relationship was validated between relative levels of human impact occurring within-watersheds (determined through use of a landscape indicator) and IBI ratings with metrics responding predictably to gradients of human influence. For management interpretation of HS-IBI results, a framework comprised of five “integrity classes” (excellent–good–fair–poor–impaired) is provided which can be used to operationalize HS-IBI results obtained through standardized sampling of stream sites that “…translates into a verbal and visual portrait of biological condition.” Through its focus on native species, the HS-IBI incorporates evolutionary and biogeographic variation for the region with biological expectations based upon reference condition benchmarks established in near-pristine stream environments where ecological functioning is naturally self-sustaining and resilient to normal environmental variation. The methods and tools described in this study are appropriate for application in all perennial streams in Hawaii and may be adapted for use in streams on other tropical Pacific islands where native species assemblages persist in near-pristine stream environments.  相似文献   

3.
湖泊微生物生态过程研究是深入了解湖泊生态系统结构与功能的关键。论述了湖泊微生物多样性时空分布规律及群落构建机制研究进展,总结了微生物群落构建机制的分析方法,介绍了微生物生态网络构建原理及应用。群落构建机制分析方法分为统计分析法、模型推断法和生态网络分析法。统计分析法包括群落结构差异分析、群落结构-环境因子关联分析和方差分解分析等,此类方法能够初步识别驱动群落组成与结构时空差异的影响因子,判别空间因素与已知环境变量对群落构建过程的相对贡献;模型推断法包括中性群落模型方法和零模型方法等,能够进一步实现对群落构建生态过程的区分,量化和比较随机性因素及确定性因素的相对重要性;生态网络分析法可用于揭示物种共现模式,探究作为确定性因素的生物相互作用,也可用于物种-环境响应关系的研究,探究环境选择过程对群落结构的影响。  相似文献   

4.
Transplanted Mytilus galloprovincialis and native Ruditapes philippinarum were deployed in 10 sampling stations with different pollution impact within the Lagoon of Venice to evaluate the temporal variations and the suitability of the following cytochemical and histochemical biomarkers just as indicators of environmental stress: lysosomal membrane stability, lipofuscins, neutral lipids and lysosome to cytoplasm volume ratio. The physiological status of the organisms was also investigated by determining the survival in air capability and the reburrowing rate (clams). The biological parameters were assessed in June and October. Furthermore, for a better definition of the environmental aspects of the study sites, heavy metal, PAH and PCB concentrations were also evaluated in the sediments. As a whole, the biological responses examined in both species from all the sampling sites showed significant differences between the two seasonal campaigns, only lysosomal membrane stability exhibited less variability. Pollutants in sediments generally showed low-intermediate contamination levels, few hotspots persisting mostly in the inner areas of the lagoon, the most influenced by the industrial zone. Transplanted mussels were more responsive than native clams and the biological responses of both species varied temporally. The range of the spatial variability was always narrow and reflected only partially the broader variability shown by the chemical content in the sediments. In this sense, biological responses seemed to be particularly influenced by the high temporal and spatial heterogeneity that characterise the Lagoon of Venice, as well as most of the transitional environments.  相似文献   

5.
In this report, predictions of the species that were expected to occur at stream sites were generated and probable stressors to fish species that were predicted to occur but were absent were diagnosed. Predictions were generated based on the hierarchical screening method of Smith and Powell (1971, Am. Mus. Novit. 2458, 1–30), using fish abundance in conjunction with 25 environmental variables at 895 sites. The sites were sampled throughout Maryland and represent the entire range of environmental quality from severely degraded to minimally degraded. Stressor variable values that exceeded tolerance thresholds for species that were expected to occur, but were absent, were considered to be probable stressors. This method was tested for efficacy in stream site assessments and stressor diagnosis using an independent data set. Sites that were classified as degraded according to the IBI and to non-biological criteria had fewer predicted species present compared to minimally influenced sites, indicating that the proportion of predicted species present accurately represents the biological integrity of a stream site. The nine stressors that were applied to the test data set accounted for species absences in 43.7% of degraded sites. Impervious land cover was the most common stressor identified. In addition to assessing stream biological integrity and identifying stressors to fish species, this approach also provides tolerance thresholds for predicted fish species that are useful endpoints necessary to plan effective restoration of fish species in Maryland.  相似文献   

6.
We present data on the distributional changes within an order of macroinvertebrates used in biological water quality monitoring. The British Odonata (dragonflies and damselflies) have been shown to be expanding their range northwards and this could potentially affect the use of water quality metrics. The results show that the families of Odonata that are used in monitoring are shifting their ranges poleward and that species richness is increasing through time at most UK latitudes. These past distributional shifts have had negligible effects on water quality indicators. However, variation in Odonata species richness (particularly in species-poor regions) has a significant effect on water quality metrics. We conclude with a brief review of current and predicted responses of aquatic macroinvertebrates to environmental warming and maintain that caution is warranted in the use of such dynamic biological indicators.  相似文献   

7.
Composition of the vegetation and the properties of its environment are related, as was shown by research. In these, mostly statistical-correlative studies, both the vegetation and some growth factors, such as plant nutrients and moisture supply were analyzed and studied on interdependence. At present the environmental conditions can be estimated in the field from the floristic composition with regard to differences both in the combination of plant species and in their relative biomass production. With a vegetation survey the spatial pattern of the different environmental conditions can be indicated. For instance, the places where moisture supply gradients occur can be detected, also a better understanding is obtained of the environmental equalization and the decreasing number of plant species and spatial diversity. Conclusions can be drawn about changes in the vegetation to be expected, from the combined occurrence of, a terrestrial vegetation indicating an eutrofied environment and a water vegetation indicating a relatively oligotrophic environment. By comparing vegetation recordings of the past and present, environmental changes that have occurred in the same place can be indicated. By vegetations situated in different places in relation with soil profile properties the consequences of environmental changes can be predicted. For instance, lowering of the ground water table and intensifying the agricultural use. On the other hand, measures can be suggested to increase the biological value of land and water, for instance, indication of seepage areas and floristically rich areas in the field.  相似文献   

8.
We review ways in which the new discipline of ecoinformatics is changing how environmental monitoring data are managed, synthesized, and analyzed. Rapid improvements in information technology and strong interest in biodiversity and sustainable ecosystems are driving a vigorous phase of development in ecological databases. Emerging data standards and protocols enable these data to be shared in ways that have previously been difficult. We use the U.S. Environmental Protection Agency’s National Coastal Assessment (NCA) as an example. The NCA has collected biological, chemical, and physical data from thousands of stations around the U.S. coasts since 1990. NCA data that were collected primarily to assess the ecological condition of the U.S. coasts can be used in innovative ways, such as biogeographical studies to analyze species invasions. NCA application of ecoinformatics tools leads to new possibilities for integrating the hundreds of thousands of NCA species records with other databases to address broad-scale and long-term questions such as environmental impacts, global climate change, and species invasions.  相似文献   

9.
The importance of eating habits and the number of fish sampled in the estimation of mercury environmental contamination through biological indicators was studied. The species used were one with piscivorous habits (Anguilla anguilla) and another with omnivorous habits (Ciprinus carpio). From one original sample for each species, randomized samples were generated using the subroutine GGSRS from the mathematics library IMSL, and later the statistical significance of Pearson's correlation coefficient for the relationship between fish weight and mercury concentrations in muscle was obtained for each random sample. The results show that the use of omnivorous species such as Ciprinus carpio as a biological indicator of contamination enables us to carry out estimations with a greater degree of confidence than when piscivorous species such as Anguilla anguilla are used.  相似文献   

10.
Mussels have the ability to control biomineral production and chemical composition, producing shells with a range of functions. In addition to biological control, the environment also seems to influence the process of biomineralization; thus, shells can be used as archives of ambient water parameters during the calcium carbonate deposition. Past and present environmental conditions are recorded in the shells in the form of various proxies including Mg/Ca or Sr/Ca ratios. For such proxies to be accurate and robust, the influence of biological effects including the size of studied organism must be examined and eliminated or minimized, so that the environmental signal can be efficiently extracted. This study considers mineralogy and elemental composition of shells representing four size classes of Mytilus trossulus from the Baltic Sea. Obtained results suggest that mineralogy and chemical composition change throughout the shell development due to most likely a combination of environmental and biological factors. The content of aragonite increases with increasing shell size, while the bulk concentrations of Na, Cd, Cu, U, V, Zn and Pb were found to decrease with increasing height of the shells. Therefore, using mussels for environmental monitoring requires analysis of individuals in the same size range.  相似文献   

11.
Island Lake, Saskatchewan, has become eutrophic, subsaline (salinity between 0.5 and 3.0 g I–1) and contaminated with several metals over the last decade. In this study, the crustacean zooplankton community in the lake in early summer 1989 is compared to the community during the early summers of the baseline years 1978 and 1979, based on archived environmental impact assessment samples. Community composition has changed, probably because of salinization and perhaps, to a lesser extent, eutrophication. Calanoid copepods have disappeared, while the numbers of species of cyclopoid copepods and cladocerans have increased. Ceriodaphnia reticulata, present in 1988 only, was more numerous than any other species during all three years. Densities of all other species were very low in 1989, which has led to lower diversity (Simpsons Index). Predation by Chaoborus probably contributed to the low abundances in 1989. The characteristics of the zooplankton community in 1989 were very similar to those of zooplankton in culturally acidified lakes, and indicate that Island Lake is in poor health. The success of Ceriodaphnia, a standard toxicity bioassay genus, is noteworthy under such contaminated conditions. While the taxonomic changes are obvious, the zooplankton data are limited; therefore causes can only be inferred. The study demonstrates the need for more and better ecosystem-specific biological information in order to do environmental impact assessments, in this case for mining in the north.  相似文献   

12.
Assessment of environmental and occupational exposure to chemicals can be performed with environmental monitoring (EM) and biological monitoring (BM). Biological monitoring was for a long time considered as a method complementary to environmental monitoring. At present this attitude is changing and in certain areas biological monitoring is applied as the method of choice for exposure and health-risk assessment. This paper examines advantages and disadvantages of those two approaches. In occupational settings environmental monitoring of exposure to VOCs seems to be superior to biological monitoring (possibility of simultaneous determination of components of mixtures, simple interpretation, possibility of evaluation of short-term exposure to local irritants). In the case of this group of compounds BM can be useful in selected cases such as evaluation of dermal absorption or efficiency of protective measures. In the case of metals both forms of monitoring can be used depending on the available methods for interpretation of results. BM of exposure may be considered as superior for evaluating the effects of exposure to lead, cadmium and mercury. However, quantitative evaluation of cancer risk after exposure to arsenic or chromium is possible only on the basis of determination in the air and the use of unit risk values. Both environmental and biological monitoring are useful for evaluation of occupational and environmental exposure to polycyclic aromatic hydrocarbons (PAHs). In certain areas such as evaluation of exposure to external tobacco smoking, cytostatic drugs, and pesticides, biological monitoring is the method of choice used for individual exposure assessment or tracing the trends of environmental exposure.  相似文献   

13.
Small-bodied fishes are more commonly being used in environmental effects monitoring (EEM) studies. There is a lack of understanding of the biological characteristics of many small-bodied species, which hinders study designs for monitoring studies. For example, 72 % of fish population surveys in Canada’s EEM program for pulp and paper mills that used small-bodied fishes were conducted outside of the reproductive period of the species. This resulted in an inadequate assessment of the EEM program’s primary effect endpoint (reproduction) for these studies. The present study examined seasonal changes in liver size, gonad size, and condition in seven freshwater and estuarine small-bodied fishes in Atlantic Canada. These data were used to examine differences in reproductive strategies and patterns of energy storage among species. Female gonadal recrudescence in all seven species began primarily in the 2-month period in the spring before spawning. Male gonadal development was concurrent with females in five species; however, gonadal recrudescence began in the fall in male three-spined stickleback (Gasterosteus aculeatus) and slimy sculpin (Cottus cognatus). The spawning period for each species was estimated from the decline in relative ovary size after its seasonal maximum value in spring. The duration of the spawning period reflected the reproductive strategy (single vs multiple spawning) of the species. Optimal sampling periods to assess reproductive impacts in each species were determined based on seasonal changes in ovary size and were identified to be during the prespawning period when gonads are developing and variability in relative gonad size is at a minimum.  相似文献   

14.
The Ephemeroptera family Baetidae is one of the most specious families in the Neotropical region and a great effort to improve the taxonomy of this group has been made over the last 10 years in South America. Such studies now enable the development of biomonitoring tools at species-level in the region. A total of 2,199 baetids were collected from seven sampling sites, collected three times (autumn, winter and summer), representing an environmental gradient, draining an area of Atlantic Forest remnants. We describe the mesohabitat of nine Baetidae species and evaluate their responses to environmental degradation and water chemistry by means of biological measures (richness and abundance) and multivariate analysis (Canonical Correspondence Analysis), in order to assess their potential capacity as indicators of these impacts. Most species were found predominantly associated with stony substrates, but some were associated with pool litter, and one species was found predominantly in riffle litter substrate. Species distribution was influenced by the environmental gradient. Based on the CCA ordination, we were able to identify which species were found in pristine versus the most impaired areas, therefore enabling us to establish the sensitivity of each species.  相似文献   

15.
The increase in aquaculture activities in the last few decades has not been accompanied by a corresponding increase in environmental controls and regulations. In this context, the application of environmental monitoring plans (EMPs) has become necessary to assess the environmental impact associated with fish farming wastes. The objective of this review paper is to evaluate the suitability of experimental and analytical procedures as monitoring tools for inclusion in EMPs for intensive land-based marine fish farms (LBMFFs). The strong hydrodynamics and, in particular, the lack of sediment on the rocky coasts where LBMFFs are usually located, greatly limit the monitoring tools that can be used. We propose EMPs that employ a weight-of-evidence approach to evaluate: contamination, trophic and toxic effects, and ecological integrity. Laboratory tests, in situ bioassays and field surveys of local species are presented as key tools for assessing the impact of LBMFFs on ecosystems. The δ(15)N signal along a spatial gradient is proposed for evaluating exposure to contaminants. Trophic effects can be determined by growth of transplanted macro- and microalgae. Toxic effects can be evaluated by responses at different levels of biological organization, including biochemical and histological changes, physiological alterations and survival, in species from different trophic levels. Fouling tests and analysis of community structures are recommended for assessing ecological integrity. This review contributes to the development of environmental controls for intensive LBMFFs, and for other activities that discharge wastewater to rocky shores.  相似文献   

16.
This paper considers the use of meiofauna (benthic metazoa 45 to 500 m in size) as biological indicators for monitoring marine environmental health. To date, this abundant and ubiquitous group of invertebrates has been largely neglected in applied sampling programmes; instead, emphasis has been placed upon more conspicuous biological components such as seagrass, macrofauna and epiphytes. In an attempt to redress this balance, this paper sets out three objectives: (1) to explain the reasons for selecting biological response indicators from across the whole spectrum of phylogenetic organisation, (2) to summarise those aspects of meiofaunal life-history and demography that render this group suitable for monitoring anthropogenic pollution and disturbance, (3) to suggest how to optimise the inclusion of meiofauna in monitoring programmes so that they provide maximum information for management purposes. To achieve these objectives the environmental impact assessment framework of Ward and Jacoby (1992) is adopted as a matrix into which the relevant components of meiofaunal ecology are fitted. Using this matrix, meiofauna are shown to have advantages that include their sessile habit, high species diversity, short generation time, direct benthic development and ubiquitous distribution. Disadvantages include their small size, high level of spatial and temporal variability, the potential cost of sample processing and the limited taxonomic literature accessible to non-specialist workers. The paper concludes with a discussion of sampling strategies and methods of analysis that may be used to efficiently incorporate meiofauna as biological response indices into environmental monitoring. Emphasis is placed on cost-effective techniques such as taxonomic minimalism.  相似文献   

17.
水环境生物监测是环境监测的重要内容,它应重点说清环境胁迫的生物效应。简述了总量管理、流域管理、风险管理、生态管理等环境管理对水环境生物监测有迫切需求,应引入"生态系统健康"、"生物完整性"、"环境胁迫"、"全排水毒性"等现代环境生物监测的基本概念,建立水环境生物监测技术发展的理论基础,发展生物完整性、综合毒性等监测与评价核心技术;革新现行监测方法体系,建立包括QA/QC、快速方法等支持系统在内的现代水环境生物监测业务化方法体系;创新评价技术体系,建立水环境生态健康评价及综合毒性评价指标体系、基准及分级管理标准,确立水环境质量管理的生物学目标。  相似文献   

18.
The use of biological species in the monitoring of marine environmental quality allows the evaluation of biologically available levels of contaminants in the ecosystem and the effects of contaminants on living organisms. The seagrass Posidonia oceanica is a useful bioindicator because through the lepidochronology technique it is possible to obtain a historical contamination trend of a given area. This study aims to assess the temporal trend contamination by heavy metal investigations on dead sheaths of 100 samples of P. oceanica collected in the Protected Marine Area of "Plemmirio" (Sicily) and in the Siracusa bay. Important results were obtained because data show a significant negative temporal trend for the metals analysed especially for As, Co, Cr, Hg, Pb, Se, U and V that in the past had higher concentrations, with a stronger contamination in the Plemmirio area, the site much more exposed to the pollution of the nearby petrochemical complex. This study confirms the relevance of the use of P. oceanica as a biological indicator of metal contamination in coastal ecosystems. Thus the usefulness of P. oceanica as a tracer of spatial metal contamination and as a good tool for water quality evaluation is reinforced.  相似文献   

19.
In this paper levels of four (Hg, Cd, Pb, As) potential harmful elements (PHE) were measured in three different environmental matrices (sediments, macroalgae and fishes) from the Aeolian Archipelago and control areas both after 1 and 10 months from a volcanic activity of particular relevance occurred at the end of October 2002. Results were analysed on a multivariate statistical basis with the aim to evaluate: (I) general levels of pollution and increase of PHE due to the event; (II) differences observed among tested matrices in the time of recovery after the occurrence of the critical event; (III) the biological enrichment of PHE along the trophic web produced by the geological event. Results evidenced that volcanic emissions could represent a local source of particular relevance able to determine great enrichments of considered PHE in sediments and biological species. After 10 months from the event, levels in sediments and macroalgae notably decreased, whereas fish species evidenced an increase, principally related to the bioaccumulation phenomena. On the basis of the biological enrichment factors (BEF), major enrichments were evidenced after 1 month whereas, after 10 months, were recorded values reliable to an incomplete recovery. Concerning Cd, the BEF higher levels reported for the species Serranus cabrilla was probably related both to the diet and to the specific detoxification rates of this species.  相似文献   

20.
Natural emissions of Hg are attracting increased interest both for their environmental implications and for possible applications in the exploration of mineral, petroleum and geothermal fields. However, daily and seasonal fluctuations in concentrations of Hg in the atmosphere, caused by meteorological and environmental variables, has made it very difficult to assess Hg anomalies by conventional analytical procedures. Some species of widespread foliose lichens from an abandoned cinnabar mining and smelting area (Mt. Amiata), geothermal fields (Larderello, Bagnore and Piancastagnaio, Central Italy), and active volcanic areas (Mt. Etna and Vulcano, Southern Italy) seem to be very suitable biomonitors of gaseous Hg; especially as lichen thalli have an Hg content which reflects average values measured in air samples. We discuss the advantages of quantitative biological monitoring by lichens with respect to conventional air sampling in large-scale monitoring.  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