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391.
Fish Migration, Dams, and Loss of Ecosystem Services in the Mekong Basin   总被引:1,自引:0,他引:1  
The past decade has seen increased international recognition of the importance of the services provided by natural ecosystems. It is unclear however whether such international awareness will lead to improved environmental management in many regions. We explore this issue by examining the specific case of fish migration and dams on the Mekong river. We determine that dams on the Mekong mainstem and major tributaries will have a major impact on the basin’s fisheries and the people who depend upon them for food and income. We find no evidence that current moves towards dam construction will stop, and consider two scenarios for the future of the fisheries and other ecosystems of the basin. We conclude that major investment is required in innovative technology to reduce the loss of ecosystem services, and alternative livelihood strategies to cope with the losses that do occur.  相似文献   
392.
We investigate the effects of anthropogenic and biogenic sources on tropospheric CO enhancements and outflow over North America and the Atlantic during July–August 2006, the 3rd warmest summer on record. The analysis is performed using the 3D Regional chEmical trAnsport Model (REAM), satellite data from TES on the Aura satellite, MOPITT on the Terra satellite and surface monitor data from the SEARCH network. The satellite measurements of CO provide insight into the location of regional CO enhancements along with the ability to resolve vertical features. Satellite and surface monitor data are used to compare with REAM, illustrating model's ability to reproduce observed CO concentrations. The REAM model used in this study features CO emissions reduced by 50% from the 1999 EPA NEI and biogenic VOC emissions scaled by EPA-observed isoprene concentrations (20% reduction). The REAM simulations show large variations in surface CO, lower tropospheric CO and column CO, which are also observed by the surface observations and satellite data. Over the US, during July–August 2006, the model estimates monthly CO production from anthropogenic sources (5.3 and 5.1 Tg CO) is generally larger than biogenic sources (4.3 and 3.5 Tg CO). However, the model shows that for very warm days, biogenic sources produce as much CO as anthropogenic sources, a result of increased biogenic production due to warmer temperatures. The satellite data show CO outflow occurs along the East Coast of the US and Canada in July and is more broadly distributed over the Atlantic in August. REAM results show the longitudinally exported CO enhancements from anthropogenic sources (3.3 and 3.9 Tg CO) are larger than biogenic sources (2.8 and 2.7 Tg CO) along the eastern boundary of REAM for July–August 2006. We show that when compared with the impacts of both sources on increasing tropospheric CO exports, the relative impacts in August are greater than in July because of preferable outflow transport.  相似文献   
393.
Three fluorescent dye traces were designed by Zapata Incorporated at a large portion of Tinker Air Force Base (AFB) near Oklahoma City, Oklahoma, to replicate the migration of chlorinated ethene plumes from two target source areas and determine if commingling of those plumes has occurred. The target source areas are spatially separated, contributed contaminants into two aquifers, and were to be remediated from two different financial mechanisms. The nature of the shared fiscal responsibility for remediation of the commingled plumes was unclear. Background sampling was performed to verify that the preferred conservative dyes planned for use were suitable for the site. The fluorescent dyes used were fluorescein and eosine. Eosine dye was introduced into two wells in the upper saturated zone (USZ) under Building 3001 in July 2008. Fluorescein dye was introduced into four monitoring wells screened in the lower saturated zone (LSZ) and the lower lower saturated zone (LLSZ) in July 2008 at the industrial wastewater treatment plant. Zapata then conducted a second dye trace using fluorescein dye in a third USZ well to confirm the results of the eosine dye trace in the USZ under Building 3001. © 2010 Wiley Periodicals, Inc.  相似文献   
394.
Communication of knowledge between the scientific and management communities is a difficult process complicated by the distinctive nature of professional career goals of scientists and decision-makers. This article provides a case history highlighting a collaboration between the science and management communities that resulted from a response to a 2004 hypoxia, or low dissolved oxygen, event in Long Bay, off Myrtle Beach, South Carolina. A working group of scientists and decision-makers was established at the time of the event and has continued to interact to develop a firm understanding of the drivers responsible for hypoxia formation in Long Bay. Several factors were found to be important to ensure that these collaborative efforts were productive: (1) genuine interest in collaboratively working across disciplines to examine a problem; (2) commitment by agency leadership, decision-makers, and researchers to create successful communication mechanisms; (3) respect for each others’ perspectives and an understanding how science and management are performed and that they are not mutually exclusive; (4) networking among researchers and decision-makers to ensure appropriate team members are involved in the process; (5) use of decision-maker input in the formulation of research and monitoring projects; and (6) commitment of resources for facilitation to ensure that researchers and decision-makers are communicating effectively.  相似文献   
395.
Microsporidia parasites are commonly found in amphipods, where they are often asymptomatic, vertically-transmitted and have several effects on host sexuality and behaviour. As amphipods are often used as models in ecotoxicological studies, we investigated the effect of microsporidian infections on energy reserves and defence capacities of Gammarus roeseli under cadmium stress. Only females were infected by two microsporidia parasites: Dictyocoela roeselum or Dictyocoela muelleri. In physiological conditions, microsporidia had no major effect on energy reserves and defence capacities of G.?roeseli, while under cadmium exposure, energy reserves and antioxidant defence were weaker in infected females. Moreover, higher malondialdehyde levels detected in infected females revealed that they suffered more cellular damages. Our results suggest that microsporidia may affect gammarid fitness in stressful conditions, when parasitic stress cannot be compensated by the host. Consequently, microsporidia parasites should be a factor necessary to take into account in ecotoxicology studies involving amphipods.  相似文献   
396.
397.
Structuring sustainability science   总被引:2,自引:2,他引:0  
It is urgent in science and society to address climate change and other sustainability challenges such as biodiversity loss, deforestation, depletion of marine fish stocks, global ill-health, land degradation, land use change and water scarcity. Sustainability science (SS) is an attempt to bridge the natural and social sciences for seeking creative solutions to these complex challenges. In this article, we propose a research agenda that advances the methodological and theoretical understanding of what SS can be, how it can be pursued and what it can contribute. The key focus is on knowledge structuring. For that purpose, we designed a generic research platform organised as a three-dimensional matrix comprising three components: core themes (scientific understanding, sustainability goals, sustainability pathways); cross-cutting critical and problem-solving approaches; and any combination of the sustainability challenges above. As an example, we insert four sustainability challenges into the matrix (biodiversity loss, climate change, land use changes, water scarcity). Based on the matrix with the four challenges, we discuss three issues for advancing theory and methodology in SS: how new synergies across natural and social sciences can be created; how integrated theories for understanding and responding to complex sustainability issues can be developed; and how theories and concepts in economics, gender studies, geography, political science and sociology can be applied in SS. The generic research platform serves to structure and create new knowledge in SS and is a tool for exploring any set of sustainability challenges. The combined critical and problem-solving approach is essential.  相似文献   
398.
The human rights related controversies surrounding Anglo Platinum's Mogalakwena mine in South Africa's Limpopo Province hit the world stage in 2008, attracting public scrutiny and instigating much debate in the realm of international business and human rights discussions. We provide an in-depth analysis of the controversies at Mogalakwena, and Anglo Platinum's responses. This case study contributes to ongoing debates on mining company-community relations in the context of the emerging business and human rights agenda, specifically with respect to the notion of human rights ‘due diligence’. We argue that the Mogalakwena case study illustrates the risks of companies adhering to and emphasizing the technical and logistical facets of due diligence, without sufficient attention to the relational, communicative and emergent aspects, which are closely tied to corporate culture. We highlight the complexities of company-community relationships, with particular reference to the issues of legitimate community representation and participatory decision-making, and discuss the role that organizational culture plays in exacerbating or mitigating corporate-community conflict. The case study demonstrates how legal challenges often exacerbate rather than resolve the conflicts that arise due to a clash between corporate and community cultures. We suggest the need for corporate leaders to become more conscious of this cultural dimension of effective social management, particularly when interacting with communities whose cultures are markedly different from those of business corporations.  相似文献   
399.
This paper presents the results of a household survey designed to qualitatively evaluate the impacts of the invasive alien species Senna spectabilis on the distribution of welfare across dependent communities in the Budongo Forest Reserve (BFR) in Uganda. The BFR is the largest forest reserve in Uganda, with globally significant conservation values. The study establishes that households in the BFR have high levels of knowledge as to its conservation values; they are aware of the invasiveness of S. spectabilis and its potential to compromise the conservation values of the BFR, and that S. spectabilis confers tangible benefits to dependent households, whose levels significantly vary with proximity to the reserve. The study concludes by evaluating strategies that are designed to manage the spread of S. spectabilis in the BFR and which consider its demonstrated socio‐economic impacts.  相似文献   
400.
This article examines the thermal decomposition of alpha-cypermethrin, one of the most common pyrethroid pesticides. The objective was to identify its decomposition pathways and to gain an understanding into the formation of toxic species in the environment, including those that may behave in combustion systems, especially in fires in the environment, as precursors for PCDD/F (polychlorinated dibenzo-p-dioxins and dibenzofurans). The experiments were conducted under non-oxidative conditions using a tubular reactor housed in a three-zone heating furnace and operated with a dilute stream of alpha-cypermethrin in 99.999% nitrogen. The condensable products were identified and quantitated, after being collected in a cold solvent trap and in an activated charcoal cartridge. The study revealed the formation of pollutants including precursors of toxic PCDD/F such as diphenyl ether and phenol. It was also found that the decomposition of alpha-cypermethrin involved parallel pathways of an unusual vinylcyclopropane rearrangement-cum-aromatisation reaction transforming alpha-cypermethrin and a rupture of the C(O)OC(CN) linkage. The former is similar to that occurring in the decomposition of permethrin pesticide, whereas the latter constitutes a newly discovered channel for the formation of pollutants. Density functional theory (DFT) calculations allowed us to attribute the occurrence of the second pathway to the effect of the cyanide group in significantly weakening the OC bond.  相似文献   
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