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1.
In the Pacific Northwest of the United States, it is urgent to assess accurately the various options proposed to restore wild salmon. For the past 150 years, a variety of analytic approaches have been employed to assess the ecological consequences of salmon management options. Each approach provided useful information to decision makers, but each also suffered from limitations, some relatively minor, others sufficient to undermine any potential utility. Risk assessment has become the most widely used analytic approach to evaluate environmental policy options. To date its use in ecological policy has been largely constrained to evaluating relatively simple technical questions (e.g., regulatory actions associated with specific chemicals or hazardous waste sites). Recently, however, there has been interest in applying risk assessment to more complex ecological policy problems (e.g., the decline of wild salmon in the Pacific Northwest). Although its use has become commonplace and widely accepted, especially among regulatory and land management agencies, risk assessment remains contentious. The most heated debates revolve around delineating the specific meaning of risk; that is, framing the risk “question” to be answered.  相似文献   

2.
The effectiveness and credibility of environmental decisions depend on the information provided by scientific assessments. However, the conflicting assessments provided by government agencies, industries, and environmental advocacy groups suggest that biases occur during assessment processes. Sources of bias include personal bias, regulatory capture, advocacy, reliance on volunteer assessors, biased stakeholder and peer review processes, literature searches, standardization of data, inappropriate standards of proof, misinterpretation, and ambiguity. Assessors can adopt practices to increase objectivity, transparency, and clarity. Decision-makers, managers of assessors, and institutions that commission assessments can adopt other practices that reduce pressures on assessors and reduce opportunities for expression of the personal biases of assessors. Environmental assessment should be recognized as a discipline with its own technical and ethical best practices.  相似文献   

3.
Sandy beaches constitute high natural value ecosystems which have been worldwide a target for growing human activities and ensuing pressures in the last decades, which caused ecological damages on these environments and led to its environmental quality decline. However, little is known about the responses of these ecosystems to distinct stressors and pressures, and holistic and integrated coastal management actions that protect beach environments and their ecological processes are yet to be developed. The aim of this viewpoint article is to present and discuss the utility of using a population approach to macrofaunal key species as a helpful tool for the assessment, management, and sustainable use of sandy beaches. The role of macrofaunal key species as indicators of environmental changes and of ecological quality condition is discussed and illustrated by some practical examples from the literature. The population is presented as a highly relevant ecological unit in management and one of the easiest ones to use, responding more rapidly to disturbances in the ecosystem than the most complex units. In this context, bio-ecology and population dynamics models are presented as tools and their potential, to improve the way we assess and manage ecological quality conditions of beach ecosystems aiming at its sustainable use, are discussed. Also, the advantages and drawbacks of the use of these tools in the population approach are evaluated. Monitoring, assessment and management practices focusing on beach key species bio-ecology as ecological indicator hold large potential in nowadays fast changing scenario, and should be encouraged as a function of their identifiable responses to manmade and natural disturbances.  相似文献   

4.
In this study we discuss impact categories and indicators to incorporate local ecological impacts into life cycle assessment (LCA) for aquaculture. We focus on the production stages of salmon farming—freshwater hatcheries used to produce smolts and marine grow‐out sites using open netpens. Specifically, we propose two impact categories: impacts of nutrient release and impacts on biodiversity. Proposed indicators for impacts of nutrient release are (1) the area altered by farm waste, (2) changes in nutrient concentration in the water column, (3) the percent of carrying capacity reached, (4) the percent of total anthropogenic nutrient release, and (5) release of wastes into freshwater. Proposed indicators for impacts on biodiversity are (1) the number of escaped salmon, (2) the number of reported disease outbreaks, (3) parasite abundance on farms, and (4) the percent reduction in wild salmon survival. For each proposed indicator, an example of how the indicator could be estimated is given and the strengths and weaknesses of that indicator are discussed. We propose that including local environmental impacts as well as global‐scale ones in LCA allows us to better identify potential trade‐offs, where actions that are beneficial at one scale are harmful at another, and synchronicities, where actions have desirable or undesirable effects at both spatial scales. We also discuss the potential applicability of meta‐analytic statistical techniques to LCA.  相似文献   

5.
Successful ecological risk assessments are all alike; every unsuccessful ecological risk assessment fails in its own way. Tolstoy posited a similar analogy in his novel Anna Karenina: “Happy families are all alike; every unhappy family is unhappy in its own way.” By that, Tolstoy meant that for a marriage to be happy, it had to succeed in several key aspects. Failure on even one of these aspects, and the marriage is doomed. In this paper, I argue that the Anna Karenina principle also applies to ecological risk assessments involving multiple stressors. In particular, I argue that multiple stressors assessments and environmental decision making will not have a happy marriage unless the following can be achieved: (1) there must be societal and political buy-in to the assessment and decision-making process; (2) the assessment must have the latitude to consider a wide range of stressors and potential risk management options; (3) there must be a commitment to following a rigorous focusing of the assessment and to expending resources for model development and data collection; and (4) an adaptive management strategy must be adopted wherein risk management actions are undertaken, system response intensively observed and assessed, and revised management actions taken as appropriate. Failure to meet any of the above criteria for success will doom a multiple stressors assessment and prevent its use in effective decision-making.  相似文献   

6.
In applying game theory to problems in biology, differences between individuals are often ignored. In particular, when analysing the evolution of cooperation it is often implicitly assumed that ignoring variation will produce predictions that approximate the solution when differences are included. This need not be true. As we demonstrate, differences are not innocuous noise, but can fundamentally change the nature of a game. Even small amounts of variability can stabilize cooperation by, for example, maintaining the need to deal with cheaters. Differences promote the need to learn about others in an interaction, leading to contingent behaviour that can reduce conflict, and to negotiated outcomes that may or may not be more cooperative than unconditional actions. Once there are mechanisms such as mutation and environmental influences that maintain variation within populations, whether cooperation evolves may depend on the variation in the cooperativeness trait. Variation means that it may be worth taking a chance that a partner is cooperative by being cooperative. When there are markets, so that individuals can break off interactions to seek a better partner, variation promotes choosiness and hence penalizes those uncooperative individuals, who are rejected. Variation promotes the need to monitor the previous behaviour of others, and once this social sensitivity exists, the need to maintain a good reputation can promote cooperation.  相似文献   

7.
Closely integrated research between archaeologists and ecologists provides a long-term view of human land use that is rare in the ecological literature, allowing for investigation of activities that lead to enduring environmental outcomes. This extended temporal perspective is particularly important in aridlands where succession occurs slowly and ecosystem processes are mediated by abiotic, geomorphic factors. Numerous studies show that impacts from ancient human actions can persist, but few have explored the types of practices or mechanisms that lead to either transient or long-term environmental change. We compared plant and soil properties and processes from a range of landscape patch types in the Sonoran Desert of the US Southwest that supported different, well-documented prehistoric farming practices from AD 750–1300. Our results show that the types of ancient human activities that leave long-term ecological legacies in aridlands are those that fundamentally alter “slow variables” such as soil properties that regulate the timing and supply of water. Prehistoric Hohokam floodwater-irrigation practices, but not dryland farming techniques, substantially altered soil texture, which was strongly associated with desert plant community and functional composition. However, prehistoric agriculture did not consistently alter long-term nutrient availability and thus had no impact on “fast variables” such as production of seasonal annual plants that are restricted to periods of ample rainfall. In this arid ecosystem, the inverse texture model explained patterns in plant functional composition at large scales, but is less predictive of production of short-lived desert annuals that experience a more mesic precipitation regime.  相似文献   

8.
Current controversy regarding how and when the precautionary principle should be applied to the introduction of new technology has created a false dichotomy, a dichotomy between conventional, risk-based decision making and an alternative paradigm that seemingly denounces risk assessment. As we compare views of the precautionary principle relative to our own operating standards for ensuring human and environmental safety, we perceive no irreconcilable conflict. Due precaution is entirely consistent with sound, cost-effective management of the risks and uncertainties inherent in new technologies. The principle guides prudent risk management actions under a prescribed set of circumstances, i.e., potentially serious or irreversible risks, or incomplete characterization (high uncertainty). In order to enable technological innovation toward a more sustainable future, it is critical that any preventative measures taken under these circumstances be provisional in nature, pending adequate risk characterization. As with all risk management decisions, we contend that the principle requires consideration of a suite of factors beyond risk assessment, including political, social, legal and cultural considerations to tailor the measures proportionately to the risk at hand. Overall, we are encouraged to find relatively broad agreement in this interpretation with a number of key multinational governmental and trade institutions.  相似文献   

9.
Marine fisheries science is a broad field that is fundamentally concerned with sustainability across ecological, economic, and social dimensions. Ensuring the delivery of food, security, equity, and well-being while sustaining ecosystems in the face of rapid change is, by far, the main challenge facing marine fisheries. A tighter integration of modeling and empiricism is needed to confront this challenge. In particular, improved incorporation of empirically grounded and realistic representation of human behaviors into models will greatly enhance our ability to predict likely outcomes under alternative adaptive strategies. Challenges to this integration certainly exist, but many of these can be overcome via improved professional training that reduces cultural rifts between empiricists and modelers and between natural and social sciences, ideally ending the presumption that there is a divide between empiricism and modeling.  相似文献   

10.
Due to resource scarcity and environmental degradation, a new development concept emphasizing environmental concerns, called the circular economy (CE), has been enacted in legislation in China. This environmental management concept can be implemented at three levels, namely, region, industrial zone, and individual enterprise, with the objective of boosting economic development while lessening environmental and resource challenges. Environmental supply chain cooperation (ESCC), an approach that utilizes customer and supplier cooperation in environmental management, has been initiated among Chinese enterprises. Using survey data collected from 396 Chinese manufacturers, we examine the role of ESCC practices in influencing the relationship between implementing CE practices and the achievement of performance outcomes by testing the moderation and mediation effects of ESCC practices on the CE practice‐performance relationship through hierarchical regression analysis. Our data analyses indicate that ESCC practices are useful by moderation and, in some cases, essential by mediation, for Chinese manufacturers seeking to realize the performance targets desired in CE practices. The results highlight the need for Chinese manufacturers to improve supply chain coordination in their implementation of CE. On the policy side, our research findings suggest that ESCC practices are beneficial and, in some cases, necessary for the development of CE in China.  相似文献   

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13.
Recent reports in the scientific literature and the media, related to elevated levels of polychlorinated biphenyls (PCBs) and polybrominated diethyl ethers (PBDEs) in farmed and wild salmon have had significant impacts on public opinion and consumer behavior, influencing the sales of farmed salmon in North America and Europe. The assessment of contaminants in fatty fish, an important source of omega-3 fatty acids, is therefore an exercise in balancing risks and benefits. Human health risk assessors and risk managers will benefit from an understanding of the level of uncertainty that is integrated into all aspects of evaluating risk in this context. Significant variability exists in the way in which analyses are conducted, how data are reported, and how they are used in risk assessments. We conducted an analytical review of PCB and PBDE data in farmed and wild salmon, and identified critical issues having implications on human health risk assessment from fish consumption. These issues include: analytical methodologies used, quantification issues, reporting of QA/QC information, tissue sampling, nature of tissue analyzed, and laboratory competence. This article reviews and outlines these issues, discusses their implications for human health risk assessment, and recommends the consistent application of analytical fish tissue data in human health risk assessment.  相似文献   

14.
A regional ecological risk assessment was conducted for the Mountain River catchment in Tasmania, Australia. The Relative Risk Model was used in conjunction with geographic information systems interpretations. Stakeholder values were used to develop assessment endpoints, and regional stressors and habitats were identified. The risk hypotheses expressed in the conceptual model were that agriculture and land clearing for rural residential are producing multiple stressors that have potential for contamination of local waterbodies, eutrophication, changes in hydrology, reduction in the habitat of native flora and fauna, reductions in populations of beneficial insects in agricultural production systems, increased weed competition in pastures, and loss of aesthetic value in residential areas. In the risk analysis the catchment was divided into risk regions based on topography and land use. Stressors were ranked on likelihood of occurrence, while habitats were ranked on percentage land area. Risk characterization showed risks to the maintenance of productive primary industries were highest across all risk regions, followed by maintenance of a good residential environment and maintenance of fish populations. Sensitivity analysis was conducted to show the variability in risk outcomes stemming from uncertainty about stressors and habitats. Outcomes from this assessment provide a basis for planning regional environmental monitoring programs.  相似文献   

15.
Goal, Scope and Background Calculating LCA outcomes implies the use of parameters, models, choices and scenarios which introduce uncertainty, as they imperfectly account for the variability of both human and environmental systems. The analysis of the uncertainty of LCA results, and its reduction by an improved estimation of key parameters and through the improvement of the models used to convert emissions into regional impacts, such as eutrophication, are major issues for LCA. Methods In a case study of pig production systems, we propose a simple quantification of the uncertainty of LCA results (intra-system variability) and we explore the inter-system variability to produce more robust LCA outcomes. The quantification of the intra-system uncertainty takes into account the variability of the technical performance (crop yield, feed efficiency) and of emission factors (for NH3, N2O and NO3) and the influence of the functional unit (FU) (kg of pig versus hectare used). For farming systems, the inter-system variability is investigated through differentiating the production mode (conventional, quality label, organic (OA)), and the farmer practices (Good Agricultural Practice (GAP) versus Over Fertilised (OF)), while for natural systems, variability due to physical and climatic characteristics of catchments expected to modify nitrate fate is explored. Results and Conclusion For the eutrophication and climate change impact categories, the uncertainty associated with field emissions contributes more to the overall uncertainty than the uncertainty associated with emissions from livestock buildings, with crop yield and with feed efficiency. For acidification, the uncertainty of emissions from livestock buildings is the single most important contributor to the overall uncertainty. The influence of the FU on eutrophication results is very important when comparing systems with different degrees of intensification such as GAP and OA. Concerning the inter-system variability, differences in farmer practices have a larger effect on eutrophication than differences between production modes. Finally, the physical characteristics of the catchment and the climate strongly affect the results for eutrophication. In conclusion, in this case study, the main sources of uncertainty are in the estimation of emission factors, due both to the variability of environmental conditions and to lack of knowledge (emissions of N2O at the field level), but also in the model used for assessing regional impacts such as eutrophication. Recommendation and Perspective Suitable deterministic simulation models integrating the main controlling variables (environmental conditions, farmer practices, technology used) should be used to predict the emissions of a given system as well as their probabilistic distribution allowing the use of stochastic modelling. Finally, our simulations on eutrophication illustrate the necessity of integrating the fate of pollutants in models of impact assessment and highlight the important margin of improvement existing for the eutrophication impact assessment model.  相似文献   

16.
Risk assessment is necessary for registration and risk management of new pesticides. The aim of this article is to discuss challenges that risk assessors in Africa face when conducting risk assessment of pesticides. Risk assessment requires toxicity assessment, environmental fate studies, and the use of models for occupational, dietary, residential, and environmental exposure assessments. Toxicity studies are very costly with the result that toxicity data used to register pesticides in Africa are often sourced from northern hemisphere countries. Assessors also often use exposure modeling results from the northern hemisphere. This is not an ideal approach as occupational exposure is influenced by agricultural practices, climatic conditions, and other factors. Furthermore, residential exposure models require time-location-activity information, exposure factors, and toxicokinetic rate constants for particular pesticides. Dietary exposure assessment needs accurate and comprehensive local food consumption data. Authorities in African countries should therefore generate the required data, despite these being very costly and tedious. Authorities should also provide guidance on the type of models and standard scenarios for estimating predicted environmental concentrations in various environmental compartments. It is recommended that higher educational institutions in Africa should incorporate risk assessment in general and pesticide toxicity and exposure models in particular in their curricula.  相似文献   

17.
Life-cycle assessment (LCA) is a technique for systematically analyzing a product from cradle-to-grave, that is, from resource extraction through manufacture and use to disposal. LCA is a mixed or hybrid analytical system. An inventory phase analyzes system inputs of energy and materials along with outputs of emissions and wastes throughout life cycle, usually as quantitative mass loadings. An impact assessment phase then examines these loadings in light of potential environmental issues using a mixed spectrum of qualitative and quantitative methods. The constraints imposed by inventory's loss of spatial, temporal, dose-response, and threshold information raise concerns about the accuracy of impact assessment. The degree of constraint varies widely according to the environmental issue in question and models used to extrapolate the inventory data. LCA results may have limited value in two areas: (I) local and/ortransient biophysical processes and (2) issues involving biological parameters, such as biodiversity, habitat alteration, and toxicity. The end result is that impact assessment does not measure actual effects or impacts, nor does it calculate the likelihood of an effect or risk Rather, LCA impact assessment results are largely directional environmental indicaton. The accuracy and usefulness of indicators need to be assessed individually and in a circumstance-specific manner prior to decision making. This limits LCAs usefulness as the sole basis for comprehensive assessments and the comparisons of alternatives. In conclusion, LCA may identify potential issues from a systemwide perspective, but more-focused assessments using other analytical techniques are often necessary to resolve the issues.  相似文献   

18.
Motorola is a large electronics company that uses design for environment (DfE) t o address our customers' environmental needs. In working to integrate environmental considerations into product design, Motorola has encountered new challenges in product design, and as a result has had to develop new frameworks and employ new analytical tools. This article describes those challenges and Motorola's efforts to date. The examination of how products are designed in Motorola led to the realization that there are distinct phases in design: concept development, detail design, and prototype manufacture. In the earlier phases where the greatest flexibility for product reconfiguration exists, there is the least amount of detailed information available for use in making environmental assessments. In an effort to match the data availability to the environmental assessment needs, Motorola developed a tiered approach to DE using a matrix-based abridged life-cycle assessment (LCA) in the concept development stage, a scoring system based in part on multiattribute value theory in the detail design stage, and potentially full-scale life-cycle assessment in the prototype manufacturing stage.  相似文献   

19.
最佳管理措施评估方法研究进展   总被引:1,自引:0,他引:1  
孟凡德  耿润哲  欧洋  王晓燕 《生态学报》2013,33(5):1357-1366
针对流域非点源污染的关键源区,进行最佳管理措施(BMPs)的配置,是非点源污染控制的有效途径.污染削减效率的准确识别对于BMPs在目标流域内的有效实施具有非常重要的意义.通过综合对比和分析实地监测、养分平衡、风险评估以及模型模拟等四类最佳管理措施评估方法的有效性、特点、适用条件及其局限性,得出以下结论:养分平衡法较为简便且易于使用,相较于其他方法,所需时间短且又可以消除评估效果的滞后效应,但对污染物削减的时间效应和传输过程影响考虑较少.风险评估和模型模拟方法可以更好地应对不同时空尺度下削减措施效率的评估,但需要大量实测数据的支持,同时模型模拟中普遍存在的时空不确定性影响很难消除.由于各种评估方法都有一定的适用条件,单一方法难以有效地完成评估目标,需要综合应用各类方法,才能最大程度地发挥这些方法的潜在功能和有效性,进而实现BMPs措施使用的成本-效益目标.  相似文献   

20.
Data and knowledge mobilisation are significant challenges in ecology and resource management, with the journey from data collection through to management action often left incomplete due to difficulties sharing information across diverse and dispersed communities. This disconnect between science and management must be resolved if we are to successfully tackle the increasing impact of human activity on our ecosystems. Across their North Atlantic range, Atlantic salmon (Salmo salar L.) populations are in steep decline in many areas and urgent actions are required to curb this decline. Being commercially important this species has been subject to intense research, but management action often suffers from both a lack of access to this knowledge resource and support for its integration into effective management strategies. To respond to this challenge, the science and management communities must place higher priority on mobilising existing and emerging knowledge sources to inform current and future resource use and mitigation strategies. This approach requires a more complete picture of the current salmon ecology data and knowledge landscape, new mechanisms to enable data mobilisation and re-use, and new research to describe and parameterise the responses of wild populations to habitat changes. Here we present a unique interface for registering and linking data resources relevant to the Atlantic salmon life cycle that can address the data mobilisation aspect of these challenges. The Salmon Ecosystem Data Hub is a salmon-specific metadata catalogue, natively interoperable with many existing data portals, which creates a low resistance pathway to maximise visibility of data relevant to Atlantic salmon. This includes the capacity to annotate datasets with life-stage domains and variable classes, thereby permitting dispersed data to be formally contextualised and integrated to support hypotheses specific to scenario-based modelling and decision-making. The alignment and mobilisation of data within the Salmon Ecosystem Data Hub will help advance the development of appropriate environmentally driven forecast models and an ecosystem-based management approach for Atlantic salmon that optimises future management strategies.  相似文献   

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