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151.
152.
The Gothenburg Protocol set national emission ceilings for transboundary air pollutants in 2010. These ceilings were formulated in 1999 using the Regional Air Pollution Information and Simulation (RAINS) model and national forecast data. The 2010 ceiling deadline is approaching as is a revision process which may lead to the setting of emission ceilings for 2020. This paper considers the original 1999 projections of six countries that were used within the RAINS model to inform the setting of their respective Gothenburg Protocol 2010 emission ceilings. These data are then contrast against recent inventory data and contemporary short-term forecasts out to 2010. These recent forecasts indicate that major downward shifts in the trends of pollutant emissions have been achieved, and whilst compliance challenges remain, there is a clear indication of the potential of such international agreements and their associated legislative and policy driven mechanisms. However, in a process governed by a maxim of achieving international environmental objectives at ‘least-cost’, the recent experience offers some valuable lessons. Specifically, in relation to the accuracy of energy projections and assumptions of other relevant variables in the modelling process. This paper considers these lessons and opens a discussion on the role of more adaptable mechanisms for the ongoing management of international agreements with long-term compliance horizons.  相似文献   
153.
Many chemicals are released into the environment, and chemical contamination has been suggested as a contributing factor to amphibian declines. To add to a growing body of knowledge about the impact of individual chemicals on non-target organisms, we examined the specificity of deformities induced by exposure to four pesticides (atrazine, 2,4-dichloropheoxyacetic acid (2,4-D), triadimefon, and glyphosate) in the model amphibian species, Xenopus laevis. We focused on the period of organ morphogenesis, as it is frequently found to be particularly sensitive to chemical exposure yet also commonly overlooked.We found similar levels of intestine malformations and edemas, as well as disruption of skeletal muscle, in atrazine and triadimefon exposed tadpoles. The e ects of 2,4-D were only apparent at the highest concentrations we examined; glyphosate did not induce dramatic malformations at the concentrations tested. While researchers have shown that it is important to understand how chemical mixtures a ect non-target organisms, our results suggest that it is first crucial to determine how these chemicals act independently in order to be able to identify consequences of individual pesticide exposure.  相似文献   
154.
总结了美国斯坦福大学和橡树岭国家实验室等在美国能源部田纳西州橡树岭综合试验基地进行的铀污染原位微生物修复阶段性试验结果.本试验利用微生物以乙醇为电子供体还原地下水和沉积物中的六价铀为不溶解的四价铀,使之原位固定化.随后通过加入溶解氧和硝酸盐来试验微生物还原后的地下水层中还原固定态铀的稳定性.通过预处理和长期间隔注入乙醇...  相似文献   
155.
156.
Fungicides are moderately hydrophobic and have been detected in water and sediment, particularly in agricultural watersheds, but typically are not included in routine water quality monitoring efforts. This is despite their widespread use and frequent application to combat fungal pathogens. Although the efficacy of these compounds on fungal pathogens is well documented, little is known about their effects on nontarget fungi. This pilot study, a field survey in southwestern Idaho from April to December 2010 on four streams with varying pesticide inputs (two agricultural and two reference sites), was conducted to assess nontarget impact of fungicides on gut fungi, or trichomycetes. Tissues of larval black flies (Diptera: Simuliidae), hosts of gut fungi, were analyzed for pesticide accumulation. Fungicides were detected in hosts from streams within agricultural watersheds but were not detected in hosts from reference streams. Gut fungi from agricultural sites exhibited decreased percent infestation, density and sporulation within the gut, and black fly tissues had elevated pesticide concentrations. Differences observed between the sites demonstrate a potential effect on this symbiotic system. Future research is needed to parse out the details of the complex biotic and abiotic relationships; however, these preliminary results indicate that impacts to nontarget organisms could have far‐reaching consequences within aquatic ecosystems.  相似文献   
157.
Concentrations of products of biotransformation of polycyclic aromatic hydrocarbons (PBPAH) were measured in bile of five fishes of nutritional, cultural and ecological relevance from the Athabasca/Slave river system. Samples were collected in Alberta and the Northwest Territories, Canada, during three seasons. As a measure of concentrations of PBPAHs to which fishes are exposed and to gain information on the nature and extent of potential exposures of people or piscivorous wildlife, concentrations of biotransformation products of two- and three-ringed, four-ringed and five-ringed PAHs were measured using synchronous fluorescence spectroscopy. Spatial and seasonal differences were observed with greater concentrations of PBPAHs in samples of bile of fish collected from Fort McKay as well as greater concentrations of PBPAHs in bile of fish collected during summer compared to those collected in other seasons. Overall, PBPAHs were greater in fishes of lower trophic levels and fishes more closely associated with sediments. In particular, goldeye (Hiodon alosoides), consistently contained greater concentrations of all the PBPAHs studied.  相似文献   
158.
159.
水生真菌对于河流中的落叶降解这一重要的生态系统服务有着重要的作用。然而,杀真菌剂对于参与落叶降解的水生真菌和大型无脊椎动物的影响却鲜有了解。本实验将美国红枫(Acer rubrum)的叶片在河流中进行处理(处理组)以获得微生物(细菌与真菌),或是在自来水下进行淋洗(未处理组)以模拟杀真菌剂可能带来的微生物生物量减少的情况。将处理组叶片分别置于绿钩虾属动物Hyalella azteca(端足类动物,在暴露开始时7日龄,是一种落叶分解物种)存在或不存在的环境中,在23 ℃条件下暴露于复合杀真菌剂QUILT(嘧菌酯和丙环唑)或是PRISTINE(啶酰菌胺和唑菌胺酯)培养14天。QUILT(~ 0.3 μg?L-1, 1.8 μg?L-1, 8 μg?L-1)有加速端足类动物分解落叶的趋势(不显著),却没有促进端足类动物本身生物量的同时增长,表明端足类动物对于落叶消费量的上升应该主要由于落叶营养成分的减少。PRISTINE(~ 33 μg?L-1)显著地抑制了端足类动物的生长,降低其生物量(P<0.05),在未处理组中也观察到类似结果。PRISTINE对于端足类动物生长显著的抑制作用以及随QUILT浓度升高而加快的落叶降解的趋势表明受到杀真菌剂影响的河流中落叶降解这一过程很可能被改变。在河流生态系统相关的条件下,如温度的变化和与杀虫剂混合后脉冲式的暴露,杀真菌剂对于落叶降解的影响需要进一步的研究。
精选自Adria A. Elskus, Kelly L. Smalling, Michelle L. Hladik, Kathryn M. Kuivila. Effects of 2 fungicide formulations on microbial and macroinvertebrate leaf decomposition under laboratory conditions. Environmental Toxicology and Chemistry: Volume 35, Issue 11, pages 2834–2844, November 2016. DOI: 10.1002/etc.3465
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3465/full
  相似文献   
160.
The activity and movement of the Redlip Parrotfish, Scarus rubroviolaceus, near Wawaloli reef, Hawaii (19°43′06″N, 156°03′11″W), was investigated with active and passive tracking techniques from April through November 2007. Site fidelity was determined and home range sizes were measured for 21 individuals. All individuals showed strong diurnal activity patterns and relatively stable home ranges. Terminal phase individuals had larger home range areas than initial phase fish, and home range size increased with depth. Occasional long forays from the home range were observed in many individuals. Forays often occurred in crepuscular hours and may represent migrations to/from nocturnal sheltering sites. Findings from this study underscore the importance of depth and nighttime shelter migrations as design considerations for effective marine protected areas (MPA) for large parrotfishes.  相似文献   
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