The Pacific herring stock that spawns at Cherry Point, northwest of Bellingham, WA, has undergone a dramatic decline in the last 20 years. The population decline corresponds with a collapse of the age structure. The Cherry Point area contains three deep water shipping piers, two refineries, an aluminum smelter, and urban development. The Cherry Point Aquatic Reserve was formed initially to protect the spawning habitat of the Cherry Point Pacific herring run. We conducted a retrospective assessment using the relative risk model (RRM) to investigate the causes of the current decline of the Cherry Point run. The RRM combines aspects of the weight-of-evidence (WoE) approach and other methods of establishing causality into a framework that deals with multiple stressors, uncertainty, and spatial scale.
An analysis of the Cherry Point Pacific herring age structure and population dynamics indicates that the loss of reproductive potential of the older age class fish was the population characteristic that led to the decline of the run. Exploitation, habitat alteration and climate change are the risk factors that contribute to the decline of the Cherry Point Pacific herring. The retrospective assessment identified the cyclic nature of climate change, as expressed by the warmer sea surface temperatures associated with a warm Pacific Decadal Oscillation (PDO), as the primary factor altering the dynamics of the Pacific herring. Other factors are ranked accordingly along with the associated uncertainty. Criteria for selecting alternative endpoints for managing the Cherry Point Aquatic Reserve are also provided.
The strengths of the retrospective RRM include its ability to combine a WoE and causality criteria with a multitude of stressors at a regional scale. The difficulties include how to deal with differences in the magnitude of effects, and expressing the uncertainty as distributions. 相似文献
After reviewing recent attempts to develop sustainability indicators, this article shows how the principles of productive efficiency can be used to elaborate such indicators at the firm level. The theory of productive efficiency is somewhat expanded to incorporate fundamental issues of sustainable development: environment, equity, and futurtty. Efficiency, in the expanded notion of productive efficiency, is viewed as a necessary condition for sustainability. Working with aggregate performance indicators, it is important not to lose track of the relevant basic information. Therefore, instead of elaborating one unique indicator; we propose to implement several kinds of indicators, each of which stresses one particular focus (e.g., environmental vs. social concems). The definition of sustainable development indicators is illustrated with reference to a small data set of U.S. fossil fuel-fired electric utilities. In a sustainabiltty perspective, two important aspects are stressed, namely, the use of nonmewable resources and the inclusion of employment as a variable to maximize rather than an input to minimize. The article ends with a discussion of the significance of, and limits to, the proposed indicators. 相似文献
With an increasing pressure on forested landscapes, conservation areas may fail to maintain biodiversity if they are not supported by the surrounding managed forest matrix. Worldwide, forests are managed by one of two broad approaches—even‐ and uneven‐aged silviculture. In recent decades, there has been rising public pressure against the systematic use of even‐aged silviculture (especially clear‐cutting) because of its perceived negative esthetic and ecological impacts. This led to an increased interest for uneven‐aged silviculture. However, to date, there has been no worldwide ecological comparison of the two approaches, based on multiple indicators. Overall, for the 99 combinations of properties or processes verified (one study may have evaluated more than one property or process), we found nineteen (23) combinations that clearly showed uneven‐aged silviculture improved the evaluated metrics compared to even‐aged silviculture, eleven (16) combinations that showed the opposite, and 60 combinations that were equivocal. Furthermore, many studies were based on a limited study design without either a timescale (44 of the 76) or spatial (54 of the 76) scale consideration. Current views that uneven‐aged silviculture is better suited than even‐aged silviculture for maintaining ecological diversity and processes are not substantiated by our analyses. Our review, by studying a large range of indicators and many different taxonomic groups, also clearly demonstrates that no single approach can be relied on and that both approaches are needed to ensure a greater number of positive impacts. Moreover, the review clearly highlights the importance of maintaining protected areas as some taxonomic groups were found to be negatively affected no matter the management approach used. Finally, our review points to a lack of knowledge for determining the use of even‐ or uneven‐aged silviculture in terms of both their respective proportion in the landscape and their spatial agency. 相似文献
Flow-focussing technology was harnessed to enable generation of large droplet aerosols within high-level microbiological containment.
The Collison nebuliser and flow-focussing aerosol generator (FFAG) produced aerosols from distilled water with average mass
median aerodynamic diameters (MMAD) of 4.19 and 11.93 μm, respectively. The medium type [water, phosphate buffered saline
(PBS) or microbiological broth] had minimal effect on the droplet size generated by the FFAG. The FFAG can be modulated to
generate reproducible aerosols with a wide range of MMADs (9–105 μm). The number of particulates (i.e. fluospheres) contained
within the droplets increased as the MMAD increased from 12 to 50 μm. The technology described can be used for the exposure
of small-animal models to large droplet aerosols (>10 μm) and has applications in healthcare, pharmaceutical, agricultural
and biodefence environments. 相似文献
Indicator species (IS) are used to monitor environmental changes, assess the efficacy of management, and provide warning signals for impending ecological shifts. Though widely adopted in recent years by ecologists, conservation biologists, and environmental practitioners, the use of IS has been criticized for several reasons, notably the lack of justification behind the choice of any given indicator. In this review, we assess how ecologists have selected, used, and evaluated the performance of the indicator species. We reviewed all articles published in Ecological Indicators (EI) between January 2001 and December 2014, focusing on the number of indicators used (one or more); common taxa employed; terminology, application, and rationale behind selection criteria; and performance assessment methods. Over the last 14 years, 1914 scientific papers were published in EI, describing studies conducted in 53 countries on six continents; of these, 817 (43%) used biological organisms as indicators. Terms used to describe organisms in IS research included “ecological index”, “environmental index”, “indicator species”, “bioindicator”, and “biomonitor,” but these and other terms often were not clearly defined. Twenty percent of IS publications used only a single species as an indicator; the remainder used groups of species as indicators. Nearly 50% of the taxa used as indicators were animals, 70% of which were invertebrates. The most common applications behind the use of IS were to: monitor ecosystem or environmental health and integrity (42%); assess habitat restoration (18%); and assess effects of pollution and contamination (18%). Indicators were chosen most frequently based on previously cited research (40%), local abundance (5%), ecological significance and/or conservation status (13%), or a combination of two or more of these reasons (25%). Surprisingly, 17% of the reviewed papers cited no clear justification for their choice of indicator. The vast majority (99%) of publications used statistical methods to assess the performance of the selected indicators. This review not only improves our understanding of the current uses and applications of IS, but will also inform practitioners about how to better select and evaluate ecological indicators when conducting future IS research. 相似文献
Extensive economic growth, tourism activities and over-exploitation of resources have become the common causes of environmental degradation in Langkawi. The sudden development leap resulting from UNESCO's recognition of Langkawi Archipelago as a Global Geopark in 2007, leads to continuous conflicts between enhancing environmental protection and meeting tourism and development needs. Environmental sensitivity evaluation is a basis upon which the concept of environmentally sensitive areas (ESAs) can be practised in order to protect the environment, regulate development activities and promote sustainable land use planning. This study embarks on evaluating and classifying environmental sensitivity as well as comparing different ESA approaches applicable for land use planning in Langkawi. A GIS-based integrated evaluation model was performed on two assessment sets (Set A and Set B) using a standard grading system and weights determined with analytic hierarchy process (AHP) method. Of these sets, the former consists of selected indicators from the Malaysian integrated ESA instrument while the latter are derived from previous eco-environmental studies conducted in China. The projected final ESA maps of Langkawi indicate spatial distribution of four environmental sensitivity classes. More highly and moderately sensitive areas are observed in Set A, accounting for 339.15 km2 or 72.24% of the total land area compared to Set B with only 259.04 km2 or 55.18% respectively. The results also reveal large proportion of low sensitivity areas in Set A, covering areas of 117.42 km2 (25.01%). In contrast, more areas with non-sensitivity are widely distributed in Set B, occupying areas of 123.02 km2 (26.20%). Taking into consideration the natural and cultural characteristics of the islands, it is suggested that Set A is a better approach to portray current environmental concerns and to coordinate future land use planning as well as fits Langkawi's aspiration in becoming a sustainable, world-class Global Geopark. This study provides beneficial information and opportunity for reasonable rearrangement of zoning and development guidelines and strategies within sensitivity areas. It promotes effective utilization of the natural resources, minimizes negative tourism impacts and adequately highlights ecosystem functions to prosper local socio-economic growth. It also represents an early step for the design of universal ESA instruments to regulate local development activities and promote sustainable land use planning in vulnerable areas at global levels. 相似文献
This research establishes a residential indirect carbon emissions model through input–output structure decomposition analysis (IO-SDA) and LMDI, analyses the influencing factors affecting urban and rural residential carbon emissions indicators in Beijing through input–output tables from 2000 to 2010, and calculates the direct carbon emissions from residential consumption. As the results suggest, the total carbon emissions from residential consumption in Beijing showed volatility. Growing rural and urban differences in direct emissions, and for indirect emissions, mean that urban greatly exceeds rural in this regard. Rising per capita GDP and population, as well as intermediate demand and sectoral emissions intensity change induce growth in indirect emissions in both urban and rural settings: of which, per capita GDP contributes the most. Declining energy intensity contributes the most to emission reductions, followed by residential consumption rates, the rural to urban consumption ratio and consumption structure effects are much smaller. 相似文献
The growth in the use of sustainability indicators and ratings in the real estate industry has been accompanied by strong criticism of the most commonly used rating systems designed to evaluate the sustainability performance of real estate developments. Most of these criticisms focus on the content of the different rating systems. A systematic evaluation of the methodologies of sustainability ratings is lacking. This article builds a framework that can be used to evaluate the methodologies of sustainability ratings and applies the evaluation framework to five widely used sustainability ratings for homes and communities (BREAAM, CASBEE, Estidama, Green Star, LEED). The evaluation results highlight three major shortcomings in the rating systems that have been evaluated. First, the systems lack unambiguous definitions of sustainability. They give insufficient explanation of why certain components are included in the ratings and on what basis these components have been accorded their weights. Second, the rating systems put more emphasis on sustainable design than performance, especially for the ratings for communities. Finally, the ratings are generally not responsive to local conditions of a project. Each rating system has its particular strengths and weaknesses and no system is superior on all dimensions. The proposed evaluation framework can be applied to sustainability ratings in different industries and is adaptable depending on stakeholder requirements. 相似文献