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211.
Portman ME  Nathan D  Levin N 《Ambio》2012,41(7):670-681
Marine protected areas (MPAs) are critical to the well-being of threatened ecosystems and thus can be highly beneficial to humans, especially to those residing nearby. We explore the qualities of 117 MPAs in the Mediterranean basin and develop a taxonomy of their characteristics. We relate the spatial distribution of the MPAs to the various characteristics of the taxonomy (size, distance from shore, protection levels, management regimes, etc.) and to areas of high human impact and influence levels. To do this we use information on biogeographic regions and information from two different human influence models; one model developed for the marine environment and one covering the littoral terrestrial environment. Our analysis provides insights to planners and managers working in a regional capacity and trying to build MPA networks. Generally, current MPAs have not been established in high impact areas despite their being close to shores containing intense human activity. Decision-makers wishing to design and establish new MPAs may seek out areas of high cumulative human impacts (near the marine-terrestrial interface) or avoid them depending on marine conservation objectives, including the desire to vary types of MPAs within a network. Limitations of our analysis and methodology indicate areas for further research.  相似文献   
212.
Surfactants and cosolvents are useful for enhancing the apparent solubility of dense nonaqueous‐phase liquid (DNAPL) compounds during surfactant‐enhanced aquifer remediation (SEAR). In situ chemical oxidation (ISCO) with permanganate, persulfate, and catalyzed hydrogen peroxide has proven to be a cost‐effective and viable remediation technology for the treatment of a wide range of organic contaminants. Coupling compatible remedial technologies either concurrently or sequentially in a treatment train is an emerging concept for more effective cleanup of DNAPL‐contaminated sites. Surfactants are effective for DNAPL mass removal but not useful for dissolved plume treatment. ISCO is effective for plume control and treatment but can be less effective in areas where large masses of DNAPL are present. Therefore, coupling SEAR with ISCO is a logical next step for source‐zone treatment. This article provides a critical review of peer‐reviewed scientific literature, nonreviewed professional journals, and conference proceedings where surfactants/cosolvents and oxidants have been utilized, either concurrently or sequentially, for DNAPL mass removal. © 2010 Wiley Periodicals, Inc.  相似文献   
213.
Meighan MM  Fenus T  Karey E  MacNeil J 《Chemosphere》2011,83(11):1539-1545
In addition to increasing the mobility of metal ions in the soil solution, chelating agents such as EDTA have been reported to alter both the total metal accumulated by plants and its distribution within the plant structures. Here, mature Mini-Sun Hybrid dwarf sunflowers exposed to 300 μM Cd2+ in hydroponic solution had initial translocation rates of at least 0.12 mmol kg−1 h−1 and reached leaf saturation levels within a day when a 3-fold molar excess of EDTA was used. EDTA also promoted cadmium transfer from roots to the shoots. A threefold excess of EDTA increased the translocation factor (TF) 100-fold, resulting in cadmium levels in the leaves of 580 μg g−1 and extracting 1400 μg plant−1. When plants were exposed to dissolved cadmium without EDTA, the vast majority of the metal remained bound to the exterior of the root. The initial accumulation could be successfully modeled with a standard biosorption pseudo second-order kinetic equation. Initial accumulation rates ranged from 0.0359 to 0.262 mg g−1 min−1. The cadmium binding could be cycled, and did not show evidence of saturation under the experimental conditions employed, suggesting it might be a viable biosorbant for aqueous cadmium.  相似文献   
214.
Globally, seabirds are vulnerable to anthropogenic threats both at sea and on land. Seabirds typically nest colonially and show strong fidelity to natal colonies, and such colonies on low-lying islands may be threatened by sea-level rise. We used French Frigate Shoals, the largest atoll in the Hawaiian Archipelago, as a case study to explore the population dynamics of seabird colonies and the potential effects sea-level rise may have on these rookeries. We compiled historic observations, a 30-year time series of seabird population abundance, lidar-derived elevations, and aerial imagery of all the islands of French Frigate Shoals. To estimate the population dynamics of 8 species of breeding seabirds on Tern Island from 1980 to 2009, we used a Gompertz model with a Bayesian approach to infer population growth rates, density dependence, process variation, and observation error. All species increased in abundance, in a pattern that provided evidence of density dependence. Great Frigatebirds (Fregata minor), Masked Boobies (Sula dactylatra), Red-tailed Tropicbirds (Phaethon rubricauda), Spectacled Terns (Onychoprion lunatus), and White Terns (Gygis alba) are likely at carrying capacity. Density dependence may exacerbate the effects of sea-level rise on seabirds because populations near carrying capacity on an island will be more negatively affected than populations with room for growth. We projected 12% of French Frigate Shoals will be inundated if sea level rises 1 m and 28% if sea level rises 2 m. Spectacled Terns and shrub-nesting species are especially vulnerable to sea-level rise, but seawalls and habitat restoration may mitigate the effects of sea-level rise. Losses of seabird nesting habitat may be substantial in the Hawaiian Islands by 2100 if sea levels rise 2 m. Restoration of higher-elevation seabird colonies represent a more enduring conservation solution for Pacific seabirds.  相似文献   
215.
The recovery plan for Steller sea lions (SSL; Eumetopias jubatus) suggests critical habitat should be enhanced to incorporate the spatio-temporal variation in dynamic oceanographic features that influence the prey and survival of SSL. It is necessary, therefore, to determine which features affect SSL. Demographics for sub-regions of the endangered, western stock of SSL were examined with respect to corresponding average, maximum, and variance of chlorophyll-a data (SeaWIFS), a proxy for primary productivity. Overall, SSL trends (2000–2008) and pup productivity (1999–2009) were related to maximum values of chl-a in critical habitat. Additionally, conditions in critical habitat appeared worse in areas of decline (i.e., dispersed patterns of chl-a hotspots and greater distances from SSL sites to productive areas). Although there may be a low feasibility of mitigating the effects of dynamic features on the recovery of SSL, the interactive effects of primary productivity and other stressors should be investigated for safeguarding their prey.  相似文献   
216.
The transport of the s‐triazine herbicide, atrazine, through the red, calcareous earth soils of the South Australian Riverland was investigated. Small, undisturbed soil cores were extracted from the inter‐row topsoil of a vineyard adjacent to the River Murray, approximately 10 km south‐west of Overland Corner, South Australia. The vines were grown in a deep (1–4 m) reddish brown, strongly alkaline, sandy loam with a low organic carbon content (<2%). Atrazine concentrations in the leachate were dependent on application rate and soil type. High application rates on subsoil gave high rates of leaching for a longer time compared to the same application rate on topsoil and/or lower application rates on either topsoil or subsoil. Overall, 37–65% of the applied atrazine was detected in the leachate from subsoil cores, 14–25% in topsoil core leachates. Small amounts of atrazine (< 10% of applied dose) were found only in the top 2 cm of the core profiles. The results suggest that this herbicide is somewhat mobile in such strongly alkaline, sandy loam soils and that the irrigated soils of this region are likely to be prone to leaching of atrazine, and therefore that groundwater supplies in this area may be at risk of contamination through use of triazine herbicides.  相似文献   
217.
Gender, although gaining attention, remains under-researched in disaster risk reduction protocols and response and recovery efforts. This study examines women's experiences of two disasters in small towns in the United States, utilising qualitative interviews with residents of Granbury and West, Texas, during the first year of disaster recovery. Granbury was struck by an EF-4 tornado on 15 May 2013, whereas an explosion occurred at a local fertiliser facility in West on 17 April 2013. The paper explores how women's experiences of inter-gender power dynamics in decision-making, the prioritisation of childcare, and women's participation in the community affect their post-disaster recovery. Previous research highlights different forms of human response and recovery vis-à-vis ‘natural’ and technological disasters, with less attention paid to gender differences. The results point to the persistent, and similar, effect of gender stratification on women's experiences across different types of disasters in the US and the continued importance of gender-sensitive disaster policies and programmes.  相似文献   
218.
Climate change and accelerating socioeconomic developments increasingly challenge flood-risk management in the Vietnamese Mekong River Delta—a typical large, economically dynamic and highly vulnerable delta. This study identifies and addresses the emerging challenges for flood-risk management. Furthermore, we identify and analyse response solutions, focusing on meaningful configurations of the individual solutions and how they can be tailored to specific challenges using expert surveys, content analysis techniques and statistical inferences. Our findings show that the challenges for flood-risk management are diverse, but critical challenges predominantly arise from the current governance and institutional settings. The top-three challenges include weak collaboration, conflicting management objectives and low responsiveness to new issues. We identified 114 reported solutions and developed six flood management strategies that are tailored to specific challenges. We conclude that the current technology-centric flood management approach is insufficient given the rapid socioecological changes. This approach therefore should be adapted towards a more balanced management configuration where technical and infrastructural measures are combined with institutional and governance resolutions. Insights from this study contribute to the emerging repertoire of contemporary flood management solutions, especially through their configurations and tailoring to specific challenges.  相似文献   
219.
The good governance of institutions and regimes requires accountability suited to the particular context of each institution and regime. The paper examines the nature of accountability in climate change governance using the Caribbean region as a case study. In doing so, the paper makes two original contributions. First, using insights from the environmental governance literature, it presents a conceptual framework that categorises the types (levels, relationships and mechanisms) of accountability in governance that can be used to test accountability. The accountability framework comprises two levels (internal/external accountability); four relationships (normative, relational, decision and behavioural); and four mechanisms or processes through which accountability can be exercised (certification, monitoring, participation by stakeholders in the overseeing of projects and self-reporting). Second, through an analysis of survey and interview responses from Caribbean climate change experts, it reports on the nature of accountability in climate change governance in the context of Caribbean Small Island Developing States. To do this, first it identifies the actors involved in Caribbean climate governance at the regional and national scales. Then, using the framework, it examines which levels, relationships and processes exist within and between climate governance regional institutions, international partners, government agencies, non-governmental organisations and the private sector for climate change adaptation and mitigation efforts. The paper draws two main conclusions: first, generally actors valued accountability as a good governance norm. Secondly, limited resources and the perception that using the accountability mechanisms will retard policy implementation led to low levels of accountability in practice. Finally, the study examined how accountability can be enhanced in the climate change sector by ensuring that each of the elements of the framework is operationalised for both state and non-state climate change projects.  相似文献   
220.
Pyrethroid insecticides are hydrophobic compounds that partition to streambed sediments and have been shown to cause toxicity to non-target organisms; their occurrence is well documented in parts of California, but there have been limited studies in other urban and agricultural areas across the United States. To broaden geographic understanding of pyrethroid distributions, bed sediment samples were collected and analyzed from 36 streams in 25 states, with about 2/3 of the sites in urban areas and 1/3 in agricultural areas. At least one pyrethroid (of the 14 included in the analysis) was detected in 78% of samples. Seven pyrethroids were detected in one or more samples. Bifenthrin was the most frequently detected (58% of samples), followed by permethrin (31%), resmethrin (17%), and cyfluthrin (14%). The other three detected pyrethroids (cyhalothrin, cypermethrin and delta/tralomethrin) were found in two or fewer of the samples. Concentrations ranged from 0.3 to 180 ng g(-1) dry weight. The number of pyrethroids detected were higher in the urban samples than in the agricultural samples, but the highest concentrations of individual pyrethroids were split between urban and agricultural sites. The pyrethroids detected in the agricultural areas generally followed use patterns. Predicted toxicity was greater for urban areas and attributed to bifenthrin, cyfluthrin and cypermethrin, while in agricultural areas the toxicity was mainly attributed to bifenthrin.  相似文献   
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