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61.
This article discusses the current problems and issues associated with the implementation of a National System of Marine Protected Areas in Brazil. MPA managers and higher governmental level authorities were interviewed about their perceptions of the implementation of a national MPA strategy and the recent changes in the institutional arrangement of government marine conservation agencies. Interviewees’ narratives were generally pessimistic and the National System was perceived as weak, with few recognizable marine conservation outcomes on the ground. The following major flaws were identified: poor inter-institutional coordination of coastal and ocean governance; institutional crisis faced by the national government marine conservation agency; poor management within individual MPAs; problems with regional networks of marine protected areas; an overly bureaucratic management and administrative system; financial shortages creating structural problems and a disconnect between MPA policy and its delivery. Furthermore, a lack of professional motivation and a pessimistic atmosphere was encountered during many interviews, a malaise which we believe affects how the entire system is able to respond to crises. Our findings highlight the need for a better understanding of the role of ‘leadership’ in the performance of socio-ecological systems (such as MPA networks), more effective official evaluation mechanisms, more localized audits of (and reforms if necessary to) Brazil’s federal biodiversity conservation agency (ICMBio), and the need for political measures to promote state leadership and support. Continuing to focus on the designation of more MPAs whilst not fully addressing these issues will achieve little beyond fulfilling, on paper, Brazil’s international marine biodiversity commitments.  相似文献   
62.
Nucella lapillus (dog whelk) imposex levels were assessed along the mainland Portuguese coast in 2006 and 2008 and were compared with available data from 2003 for the same area. Given that specimen size has been described as a factor inducing variation in some of the imposex assessment indices, and thus resulting in less reliable results, new monitoring and data analysis procedures are described and applied to study change of imposex levels from 2003 to 2008. A significant decline in imposex intensity was observed in the study area during the study period, and the Portuguese coast ecological status (under the terms defined by the OSPAR Commission) notably improved after 2003, confirming the effectiveness of the Regulation (EC) No. 782/2003 in reducing TBT pollution. Nevertheless, N. lapillus populations are still extensively affected by imposex, and fresh TBT inputs were detected in seawater throughout the coast in 2006. These recent inputs are attributed to vessels still carrying TBT antifoulants applied before 2003, as their presence in vessels was only forbidden in 2008. Considering that Regulation (EC) No. 782/2003 is an anticipation of the IMO global ban entered into force in September 2008, a worldwide-scale decrease in TBT pollution can be expected in the near future.  相似文献   
63.
Food and Environmental Virology - Norovirus is a major cause of foodborne-associated acute gastroenteritis (AGE) outbreaks worldwide. Usually, food products are contaminated either during...  相似文献   
64.
Food and Environmental Virology - Enteric viruses have been described as important contaminants in fresh and ready-to-eat foods such as sandwiches, deli meat and dairy products. This is a...  相似文献   
65.
Journal of Polymers and the Environment - Aiming at minimizing the issues associated with the disposal of polymers, in this study, elastomeric materials derived from 100% recycled feedstocks were...  相似文献   
66.
Environmental Science and Pollution Research - The growing demand for products with lower environmental impact and the extensive applicability of cellulose nanofibrils (CNFs) have received...  相似文献   
67.
The main objective of this paper is to implement a coupled three-dimensional physical and ecological model for the Aveiro coast, and to apply it to study the temperature and the phytoplankton biomass spatial distributions along the coastal ecosystem. The Aveiro coast is located at Portugal within the upwelling system of the Atlantic Iberian coast, characterized by nutrients availability and phytoplankton biomass accumulation, from April to October. In order to implement the ecological model, its validation was assessed by comparing simulations to data relative to the horizontal and vertical distributions of the temperature, nutrients and phytoplankton biomass, obtained during the CICLOS I survey off the Portuguese coast [Moita, M.T., 2001. Estrutura, Variabilidade e Dinâmica do Fitoplâncton na Costa de Portugal Continental. PhD Thesis. Faculdade de Ciências da Universidade de Lisboa, 272 pp.]. A sensitivity analysis of the model has been performed in order to assess the influence of the main ecological model variables. The simulation results show that the model is capable of predicting realistic the temperature, the nutrients and the chlorophyll-a distributions for the study area. The scenarios evidence the setup of a thermal stratification pattern resulting from the upwelling of deep and rich in nutrients water to the surface layer and a chlorophyll-a maxima extending offshore, along the picnocline and the nutricline. The results confirm the crucial role played by the physical processes in the phytoplankton bloom along the Aveiro coast. They also evidence the close link between the surface phytoplankton distribution and the surface temperature distribution.  相似文献   
68.
Evaluation of boron removal from water by hydrotalcite-like compounds   总被引:7,自引:0,他引:7  
Layered double hydroxides (LDHs) or hydrotalcite (HT)-like compounds with different kinds of metal ions (Mg-Al and Mg-Fe) in the brucite-like sheets were prepared and their adsorption properties were studied in the boron removal from aqueous solution under laboratory conditions. The hydrotalcites were synthesized by the coprecipitation method and were characterized by chemical analyses, X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR) and specific surface area measurements (BET). The affinity of these materials with a mixture of B(OH)(3) and B(OH)(4)(-) was studied as a function of contact time, initial pH of the solutions, HT quantity and B concentration (adsorption isotherms). It was found that 120 min is enough time for the equilibrium state to be reached in boron adsorption. Boron removal was independent of the initial pH of the solutions because of the high buffering capacity of the LDHs. On the other hand, the adsorption capacity increases with increasing the adsorbent quantity. The adsorption isotherms, described by the Langmuir model, are of L-type, suggesting that B(OH)(4)(-) is adsorbed preferentially on HT-like materials. Besides, Mg-Al hydrotalcites showed higher adsorption capacity than Mg-Fe. We proposed that in Mg-Al hydrotalcites, the boron removal occurs by both adsorption on external surface and ion exchange, whereas for Mg-Fe it occurs only by surface adsorption. After treatment of a solution containing 5.2 mgBl(-1) with Mg-Al hydrotalcites the final boron concentration reached the recommended limit by WHO for drinking water (0.5 mgl(-1)).  相似文献   
69.
The Anguillid juvenile glass eel must deal with the osmoregulatory consequences of highly variable environmental salinities on its recruitment migration from coastal to fresh waters. Changes in ionoregulatory parameters and branchial ion transport protein [Na+/K+-ATPase, Na+:K+:2Cl cotransporter (NKCC), cystic fibrosis transmembrane regulator (CFTR) anion channel, V-type proton ATPase] expression (activities, protein and/or mRNA level expression and/or cellular localization) in response to acclimation to a broad range of ionic strengths [distilled water (DW) to hypersaline water (HSW; 150%) sea water (SW 32‰)] was studied. The estuarine glass eels were very euryhaline and successfully acclimated to acute changes in environmental ionic strength from 50% SW, with high mortality only observed in HSW (51%) and sublethal osmoregulatory indicators (whole body water content and sodium levels) disturbed at the extremes (DW and HSW). Central to a high salinity acclimation were elevated branchial Na+/K+-ATPase, NKCC and CFTR expression. At lower salinity, Na+/K+-ATPase expression was maintained and NKCC and CFTR expressions were reduced. Branchial chloride cells increased in size up to SW but decreased in HSW. During hypotonic disturbance (DW), no compensatory elevation in V-ATPase or Na+/K+-ATPase expression was observed.  相似文献   
70.
Sustainable use of the Amazon forest for timber production is conditioned by the effect of logging on the system's nutrient cycling. This paper reports the results of a soil moisture and soil water chemistry monitoring campaign before and immediately after a selective logging which removed 35 m3 wood/ha. Soil moisture was measured using tensiometers, and soil water chemistry using suction samplers in five disturbance classes: tractor tracks, clearing centres, clearing edges, forest edges and untouched forest. The results show that the soil under the tractor tracks and clearings contained more moisture than under the untouched forest. The suction samplers extracted substantially more nitrate, ammonium, calcium, magnesium and potassium from the clearing centres, the tractor tracks and the clearing edges than from the forest sites. The results are explained in terms of altered microbial activity, changes in crown interception and uptake by roots.  相似文献   
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