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91.
In Western democracies, rising levels of political alienation have prompted concerned political authorities to improve the quality of citizenship by such means as civic education. As well, the several international conventions underpinning the sustainable development discourse mandate participation to empower people in their own development. Active citizenship and the participation fundamental to it can be problematic for island communities with a history of economic and political dependence, since there exist a number of structural and agentic barriers to its practice and to the exercise of ecological responsibility through participation. Both the barriers to and the prospects for ecological sustainability are elaborated in this study of aspects of community, participation, citizenship and ecological literacy among the communities of the Huon Valley region of southern Tasmania.  相似文献   
92.
Identifying drivers of ecosystem change in large marine ecosystems is central for their effective management and conservation. This is a sizable challenge, particularly in ecosystems transcending international borders, where monitoring and conservation of long‐range migratory species and their habitats are logistically and financially problematic. Here, using tools borrowed from epidemiology, we elucidated common drivers underlying species declines within a marine ecosystem, much in the way epidemiological analyses evaluate risk factors for negative health outcomes to better inform decisions. Thus, we identified ecological traits and dietary specializations associated with species declines in a community of marine predators that could be reflective of ecosystem change. To do so, we integrated count data from winter surveys collected in long‐term marine bird monitoring programs conducted throughout the Salish Sea—a transboundary large marine ecosystem in North America's Pacific Northwest. We found that decadal declines in winter counts were most prevalent among pursuit divers such as alcids (Alcidae) and grebes (Podicipedidae) that have specialized diets based on forage fish, and that wide‐ranging species without local breeding colonies were more prone to these declines. Although a combination of factors is most likely driving declines of diving forage fish specialists, we propose that changes in the availability of low‐trophic prey may be forcing wintering range shifts of diving birds in the Salish Sea. Such a synthesis of long‐term trends in a marine predator community not only provides unique insights into the types of species that are at risk of extirpation and why, but may also inform proactive conservation measures to counteract threats—information that is paramount for species‐specific and ecosystem‐wide conservation. Evaluación de las Correlaciones Ecológicas de las Declinaciones de Aves Marinas para Informar a la Conservación Marina  相似文献   
93.
Safeguarding the Pantanal Wetlands: Threats and Conservation Initiatives   总被引:2,自引:0,他引:2  
Abstract:  The Pantanal, one of the largest wetlands on the planet, comprises 140,000 km2 of lowland floodplain of the upper Rio Paraguai basin that drains the Cerrado of central Brazil. The diverse mosaics of habitats resulting from the varied soil types and inundation regimes are responsible for an extraordinarily rich terrestrial and aquatic biota, exemplified by the bird richest wetland in the world—463 birds have been recorded there—and the largest known populations of several threatened mammals, such as Pampas deer ( Ozotoceros bezoarticus ), marsh deer ( Blastocerus dichotomus ), giant otter ( Pteronura brasiliensis ), and jaguar ( Panthera onca ). Until recently, deforestation of the adjoining Brazilian central plateau was considered the major threat to this area, but now deforestation is a critical problem within the floodplain itself. More than 40% of the forest and savanna habitats have been altered for cattle ranching through the introduction of exotic grasses. And there are other threats that lead to large-scale disruption of ecological processes, severely affecting biodiversity. Although the Pantanal wetland is a Biosphere Reserve and is considered a Wetland of International Importance, only 2.5% of the upper Paraguai River basin is formally protected. To date, protected areas have been created opportunistically and as such, although of undoubted value, protect only a fraction of the Pantanal's wildlife and habitats. Among the conservation initiatives in the area, the private sector is increasingly participating in the establishment of private reserves. The prospects are far from optimistic, however, and the major challenge is to find alternative socioeconomic models that allow for conservation and economic uses of the land in association with the development of specific environmental legislation that reflects the unique characteristics of the region.  相似文献   
94.
Environmental Science and Pollution Research - The paleolimnological method was used to decouple geogenic and anthropogenic metal (loids) contributions in a sediment stabilization basin (Boat...  相似文献   
95.
The moments of the concentration distribution obtained using a recent analytical solution of the steady-state two-dimensional advection–diffusion equation are presented. The solving methodology is the Generalized Integral Laplace Transform Technique, which allows obtaining a reliable solution of the advection–diffusion equation without any restrictive assumption about the eddy diffusivity coefficients and wind speed profiles. The first four moments and value and position of maximum ground level concentration are calculated. The concentration standard deviation is compared against the semi-empirical ones used in operative Gaussian models.  相似文献   
96.
This study examined the effects of two selection treatments (elevated water temperature and air exposure) on the genetic and physiological characteristics of the juvenile marine mussel, Mytilus edulis (<10 mm). Genetic effects were measured on five allozymes and fitness assessed using physiological tests to estimate energy balance (scope for growth) as well as size, growth and survival. The in vitro treatments resulted in 48% mortality from an air exposure of 11 h at 27°C and 76% mortality from a 6-h exposure to 33°C water. Survivors (n = 1,152) of each treatment along with controls (n = 2,304) were measured and randomly placed in compartmentalized cages. Mussels were deployed to three bays in Prince Edward Island, Canada and monitored over a 10-month period. Initially, both of the treatments had an effect on mussel size and increased the heterozygosity of the surviving mussels. Physiological analyses after 3 months in the field showed that the two treated mussels showed lower metabolic rate that the control group. After 10 months in the field, the treated mussels were larger and had lower mortality than the untreated control mussels. Unexplained environmental interaction in each of the bays had an effect on allelic frequencies and heterozygosity. Overall, the results demonstrate that simple husbandry techniques can be used to increase the productivity of mussel seed and heterozygosity measures can be used to assess fitness. However, more field data is needed to determine the consistency of the increased productivity and if the increased productivity justifies the costs of a selective treatment. Furthermore, because the level of heterozygosity in juvenile mussel populations can vary considerably, both spatially and temporally, it may be effective as a warning of future natural mass mortality when overall heterozygosity levels are found to be low.  相似文献   
97.
98.

Antibiotimicrobial resistance was investigated in 537 Enterococcus spp. isolates recovered from 22 samples of crude inflow, treated effluent and sludge collected in wastewater treatment plants of eight poultry slaughterhouses of Portugal. No significant differences (P > 0.05) were found in the resistance to each antimicrobial agent with regards to the origin of the sample (inflow, sludge and effluent). Many of the isolates displayed resistance to tetracycline (85.7%), erythromycin (45.7%), nitrofurantoin (34.0%) and rifampicin (17.8%). Resistance was also observed, but to a lesser extent, to ciprofloxacin (10.2%), ampicillin (8.0%), chloramphenicol (4.6%), vancomycin (0.9%) and gentamicin (0.4%). Resistance to three or more antimicrobial classes was present in 37.1% of the isolates. Wastewater treatment resulted in viable enterococci decrease between less than 1 log and 4 log; nevertheless, more than 4.4 × 105 colony forming units (CFU)/100 mL were present in the outflow of the plants and thus resistant enterococci are not prevented from reaching the general environment.  相似文献   
99.
This paper is directed to those concerned with the effect of changes in lead consumption by motor vehicles on atmospheric lead concentrations. Atmospheric lead concentrations in the Los Angeles area have been found to be dependent on lead consumption, meteorology, and source-receptor relationships. Mathematical relationships between these variables for selected Los Angeles area sites are derived. Los Angeles County experienced a 50% reduction in annual average atmospheric lead concentrations between 1971 and 1976, which was found to be due to a decrease in vehicular emissions of lead. Seasonal variations in lead concentration were found to be mainly a product of seasonal variations in weather. Projections of atmospheric lead concentrations for the next decade show a continued downtrend, based on regulation of fuel lead content and introduction of additional catalyst equipped vehicles. By the mid-1980's most locations in the Los Angeles area are expected to attain the California and federal ambient air quality standards for lead, 1.5 micrograms per cubic meter, based on a monthly average.  相似文献   
100.
Desires to enhance the energy security of the United States have spurred renewed interest in the development of abundant domestic heavy hydrocarbon resources including oil shale and coal to produce unconventional liquid fuels to supplement conventional oil supplies. However, the production processes for these unconventional fossil fuels create large quantities of carbon dioxide (CO2) and this remains one of the key arguments against such development. Carbon dioxide capture and storage (CCS) technologies could reduce these emissions and preliminary analysis of regional CO2 storage capacity in locations where such facilities might be sited within the U.S. indicates that there appears to be sufficient storage capacity, primarily in deep saline formations, to accommodate the CO2 from these industries. Nevertheless, even assuming wide-scale availability of cost-effective CO2 capture and geologic storage resources, the emergence of a domestic U.S. oil shale or coal-to-liquids (CTL) industry would be responsible for significant increases in CO2 emissions to the atmosphere. The authors present modeling results of two future hypothetical climate policy scenarios that indicate that the oil shale production facilities required to produce 3 MMB/d from the Eocene Green River Formation of the western U.S. using an in situ retorting process would result in net emissions to the atmosphere of between 3000 and 7000 MtCO2, in addition to storing potentially 900–5000 MtCO2 in regional deep geologic formations via CCS in the period up to 2050. A similarly sized, but geographically more dispersed domestic CTL industry could result in 4000–5000 MtCO2 emitted to the atmosphere in addition to potentially 21,000–22,000 MtCO2 stored in regional deep geologic formations over the same period. While this analysis shows that there is likely adequate CO2 storage capacity in the regions where these technologies are likely to deploy, the reliance by these industries on large-scale CCS could result in an accelerated rate of utilization of the nation's CO2 storage resource, leaving less high-quality storage capacity for other carbon-producing industries including electric power generation.  相似文献   
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