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531.
Three methods (membrane filtration, multiple tube fermentation, and chromogenic substrate technology kits manufactured by IDEXX Laboratories, Inc.) are routinely used to measure indicator bacteria for beach water quality. To assess comparability of these methods, quantify within-laboratory variability for each method, and place that variability into context of variability among laboratories using the same method, 22 southern California laboratories participated in a series of intercalibration exercises. Each laboratory processed three to five replicates from thirteen samples, with total coliforms, fecal coliforms or enterococci measured depending on the sample. Results were generally comparable among methods, though membrane filtration appeared to underestimate the other two methods for fecal coliforms, possibly due to clumping. Variability was greatest for the multiple tube fermentation method. For all three methods, within laboratory variability was greater than among laboratories variability.  相似文献   
532.
Many public and large-scale construction projects inThailand have been faced with environmental and socialconflict problems. The major cause is that project sponsorsdo not address concerns of the public in a proper mannerduring EIA study. The Yadana Natural Gas Pipeline (YNGP)project is an example of a project which suffered theeffects of public demonstration. A public hearing, onetechnique of public participation, is a good mechanism tosolve conflict problems in a non-violent way which the ThaiGovernment usually adopts to settle conflict in constructionprojects. In the case of the YNGP, even after the conflictwas resolved hostility towards the project was noteliminated, as the opponents were not satisfied with thedecision. Therefore, this article examines the hearing on theYNGP project. The study found that it was too late to make any significantchanges to the project after the hearing was held, mostrespondents were not satisfied with the project. In otherwords, this hearing did not improve their perception ofenvironmental soundness of the project. The study showedthat the project's impact on the environment was notproperly addressed. The project sponsors did not providesufficient publicity for the meeting and the stage at whichthe hearing was conducted. Suggestions are made forimproving participation in future hearings.  相似文献   
533.
The ocelot (Felis pardalis) isan endangered neotropical cat distributed within asmall range in the Lower Rio Grande Valley (LRGV), inTexas, U.S.A. Studies of the impacts of environmentalcontaminants in wild cats are few. Approximately onefourth of the estimated population (about 100) ofocelots in the LRGV was sampled to evaluate theimpacts of chlorinated pesticides, polychlorinatedbiphenyls, and trace elements on the population. Hairwas collected from 32 ocelots trapped between 1986–1992,and blood was collected from 20 ocelots trappedbetween 1993–1997. A few blood samples were obtainedfrom individuals recaptured two or three times. Tissue samples from 4 road-killed ocelots were alsoanalyzed. DDE, PCBs, and Hg were some of the mostcommon contaminants detected in hair and blood. MeanHg levels in hair ranged from 0.5 to 1.25 g g-1 dw,Se from 1.5 to 3.48 g g-1 dw, and Pb from 0.56 to26.8 g g-1 dw. Mean DDE concentrations in plasma ranged from 0.005 g g-1 ww to 0.153 g g-1 ww, and PCBs ranged from 0.006 g g-1 ww to 0.092 g g-1 ww. Mean Hg levels in red blood cells rangedfrom 0.056 g g-1 dw to 0.25 g g-1 dw. Concentrations of DDE, PCBs, or Hg, did not increasesignificantly with age, although the highestconcentrations of DDE and Hg were found in olderanimals. Overall, concentrations of DDE, PCBs, and Hgwere low and at levels that currently do not pose anythreat to health or survival of the ocelot. This isfurther supported by good reproduction of the ocelotin the LRGV, where adult females averaged about 1.5kittens/litter. Thus, it seems that the current majorthreat to recovery of the ocelot in the LRGV may behabitat loss, although potential impacts of newgeneration pesticides, such as organophosphorus andcarbamate insecticides need further study.  相似文献   
534.
Studies designed to measure anthropogenic impacts on marine benthic communities depend on the ability of taxonomists to consistently discriminate, identify, and count benthic organisms. To quantify errors and discrepancies in identification and enumeration, 20 samples were completely reprocessed by another one of four participating laboratories. Errors were detected in 13.0% of the data records, affecting total abundance by 2.1%, numbers of taxa by 3.4%, and identification accuracy by 4.7%. Paired t-tests were used to test for differences in the Benthic Response Index (BRI), total abundance, numbers of taxa, and the Shannon-Wiener index between the original and the reanalysis data. Differences in the BRI were statistically insignificant. Although statistically significant differences were observed for numbers of taxa, total abundance, and the Shannon-Wiener index, the differences were small in comparison to the magnitude of differences typically observed between anthropogenically affected and reference sites.  相似文献   
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536.
World governments have committed to increase the global protected areas coverage by 2020, but the effectiveness of this commitment for protecting biodiversity depends on where new protected areas are located. Threshold‐ and complementarity‐based approaches have been independently used to identify important sites for biodiversity. We brought together these approaches by performing a complementarity‐based analysis of irreplaceability in important bird and biodiversity areas (IBAs), which are sites identified using a threshold‐based approach. We determined whether irreplaceability values are higher inside than outside IBAs and whether any observed difference depends on known characteristics of the IBAs. We focused on 3 regions with comprehensive IBA inventories and bird distribution atlases: Australia, southern Africa, and Europe. Irreplaceability values were significantly higher inside than outside IBAs, although differences were much smaller in Europe than elsewhere. Higher irreplaceability values in IBAs were associated with the presence and number of restricted‐range species; number of criteria under which the site was identified; and mean geographic range size of the species for which the site was identified (trigger species). In addition, IBAs were characterized by higher irreplaceability values when using proportional species representation targets, rather than fixed targets. There were broadly comparable results when measuring irreplaceability for trigger species and when considering all bird species, which indicates a good surrogacy effect of the former. Recently, the International Union for Conservation of Nature has convened a consultation to consolidate global standards for the identification of key biodiversity areas (KBAs), building from existing approaches such as IBAs. Our results informed this consultation, and in particular a proposed irreplaceability criterion that will allow the new KBA standard to draw on the strengths of both threshold‐ and complementarity‐based approaches.  相似文献   
537.
Conservation can be achieved only if sustainability is embraced as core to organizational cultures. To test the extent to which the related concepts of sustainability, conservation, response to climate change, poverty alleviation, and gender equity have been incorporated into organizational culture, we compared mission statements published from 1990 to 2000 with those published in 2014 for 150 organzations, including conservation nongovernmental organizations (NGOs), aid NGOs, government development agencies, resource extraction companies, and retailers (30 in each category). We also analyzed the 2014 home web pages of each organization. Relative to the earlier period, the frequency with which mission statements mentioned poverty alleviation, biodiversity conservation, and a range of sustainable practices increased only slightly by 2014, particularly among resource extractors and retail companies. Few organizations in any sector had embedded either climate change or gender equity into their mission statements. In addition, the proportional intensity with which any of the aspirations were expressed did not change between periods. For current home pages, conservation NGOs, resource extractors, and government agencies were significantly more likely to acknowledge the importance of matters that were not part of their core business, but few aid agencies or retail companies promoted goals beyond alleviation of crises and profit maximization, respectively. Overall, there has been some progress in recognizing poverty alleviation, biodiversity conservation, and sustainable practices, but gender equity and a determination to reduce impacts on climate change are still rarely promoted as central institutional concerns. Sustainability in general, and biodiversity conservation in particular, will not be achieved unless their importance is more widely apparent in core communication products of organizations.  相似文献   
538.
Mechanical and prescribed fire treatments are commonly used to reduce fuel loads and maintain or restore sagebrush steppe rangelands across the Great Basin where pinyon (Pinus) and juniper (Juniperus) trees are encroaching and infilling. Geospatial technologies, particularly remote sensing, could potentially be used in these ecosystems to (1) evaluate the longevity of fuel reduction treatments, (2) provide data for planning and designing future fuel-reduction treatments, and (3) assess the spatial distribution of horizontal fuel structure following fuel-reduction treatments. High-spatial resolution color-infrared imagery (0.06-m pixels) was acquired for pinyon and juniper woodland plots where fuels were reduced by either prescribed fire, tree cutting, or mastication at five sites in Oregon, California, Nevada, and Utah. Imagery was taken with a Vexcel UltraCam X digital camera in June 2009. Within each treatment plot, ground cover was measured as part of the Sagebrush Steppe Treatment Evaluation Project. Trimble eCognition Developer was used to classify land cover classes using object-based image analysis (OBIA) techniques. Differences between cover estimates using OBIA and ground-measurements were not consistently higher or lower for any land cover class and when evaluated for individual sites, were within ±5 % of each other. The overall accuracy and the K hat statistic for classified thematic maps for each treatment were: prescribed burn 85 % and 0.81; cut and fell 82 % and 0.77, and mastication 84 % and 0.80. Although cover assessments from OBIA differed somewhat from ground measurements, they are sufficiently accurate to evaluate treatment success and for supporting a broad range of management concerns.  相似文献   
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