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211.
Community-based approaches to fisheries management has emerged as a mainstream strategy to govern dispersed, diverse and dynamic small scale fisheries. However, amplifying local community led sustainability outcomes remains an enduring challenge. We seek to fill a theoretical gap in the conceptualization of ‘scaling up community-based fisheries management’. We draw on literature of agriculture innovations to provide a framework that takes into account process-driven and structural change occurring across multiple levels of governance, as well as different phases of scaling. We hypothesize that successful scaling requires engagement with all aspects of a governing regime, coalescing a range of actors, and therefore, is an enterprise that is larger than its parts. To demonstrate where the framework offers value, we illustrate the development of community-based fisheries management in Vanuatu according to the framework’s main scaling dimensions.  相似文献   
212.
Increased education of consumers can be an effective tool for conservation of commercially harvested marine species when product labeling is accurate and allows an informed choice. However, generic labeling (e.g., as white fish or surimi) and mislabeling of seafood prevents this and may erode consumer confidence in seafood product labels in general. We used DNA barcoding to identify the species composition of two types of convenience seafood (i.e., products processed for ease of consumption): fish fingers (long pieces of fish covered with bread crumbs or batter, n = 241) and seafood sticks (long pieces of cooked fish, n = 30). In products labeled as either white fish or surimi, four teleost species were present. Less than 1.5% of fish fingers with species-specific information were mislabeled. Results of other studies show substantially more mislabeling (e.g., >25%) of teleost products, which likely reflects the lower economic gains associated with mislabeling of convenience seafood compared with whole fillets. In addition to species identification, seafood product labels should be required to contain information about, for example, harvesting practices, and our data indicate that consumers can have reasonable confidence in the accuracy of the labels of convenience seafood and thus select brands on the basis of information about current fisheries practice.  相似文献   
213.
Abstract:  Fishing activities worldwide have dramatically affected marine fish stocks and ecosystems. Marine protected areas (MPAs) with no-take zones may enhance fisheries, but empirical evidence of this is scant. We conducted a 4-year survey of fish catches around and within an MPA that was previously fully closed to fishing and then partially reopened under regulated comanaged fishing. In collaboration with the fishers and the MPA authority, we set the fishing effort and selected the gear to limit fishing impact on key fish predators, juvenile fish stage, and benthic communities and habitats. Within an adaptive comanagement framework, fishers agreed to reduce fishing effort if symptoms of overfishing were detected. We analyzed the temporal trends of catch per unit of effort (CPUE) of the whole species assemblages and CPUE of the four most valuable and frequent species observed inside the opened buffer zone and outside the MPA investigated. After the comanaged opening, CPUE first declined and then stabilized at levels more than twice that of catches obtained outside the MPA. Our results suggest that working closely with fishers can result in greater fisheries catches. Partial protection of coastal areas together with adaptive comanagement involving fishers, scientists, and managers can effectively achieve conservation and fishery management goals and benefit fishing communities and alleviate overfishing.  相似文献   
214.
A Bioeconomic Model of Marine Reserve Creation   总被引:1,自引:0,他引:1  
This paper employs a dynamic and spatial model of renewable resource exploitation to investigate the effects of marine reserve creation. The model combines a metapopulation model incorporating resource patch heterogeneity and dispersal with a behaviorally based spatially explicit harvesting model that assumes that fishermen choose location in a manner that eliminates spatial arbitrage opportunities. The combined spatial bioeconomic model is used to simulate the effects of reserve creation under various ecological structures. We identify parameter configurations and ecological dispersal processes that give rise to a double-payoff in which both aggregate biomass and harvest increase after an area of the fishery is set aside and protected from exploitation.  相似文献   
215.
Emission of NOx is of primary environmental concern in the oil sands industry. Selective catalytic reduction (SCR) is one of the best NOx reduction technologies. The present study discusses the testing of a mechanistic kinetic model for the SCR of NOx to describe the kinetics of V2O5/TiO2 catalysis at atmospheric pressure and a temperature of 623 K in a monolith honeycomb reactor. The modeling results impart insight into the significance of the diffusion with reaction steps and guidance for optimal monolith design for SCR. The validated expression would predict the conversion performance of the catalysts for different values of temperature inlet and ammonia concentration. A good agreement between experimental and model results has been obtained. A heterogeneous numerical model consisting of coupled mass and momentum balance equations was solved using the finite elements method without neglecting the axial dispersion term. The operating range for the catalyst relies on the NO conversion and emission. The optimum operating range for the best performance of the reactor is discussed.  相似文献   
216.
A complex, pre-existing local property rights system, characterized by overlap and conflict, comprises the local basis for managing inland fisheries in communities of the Lower Songkhram River Basin (LSRB) of Northeastern Thailand. The components, conflicts and changes of the system are analyzed for fourteen communities, focusing on the auction system for barrages, an illegal and destructive, yet tolerated, fishery. These rights, adapted to gear type, seasonality, and habitat of the LSRB fisheries, are a critical social resource and proven management system that should be legitimized. Recommendations are made for both improving general inland fisheries policy and reforming the barrage fishery.  相似文献   
217.
The paper develops a biological-economic evaluation tool to analyse the consequences for trawl fishers of implementing more selective fishing technologies. This is done by merging a dynamic biological population model and an economic cost–benefit evaluation framework to describe the consequences for the fish stocks, fishermen and society. The bio-economic evaluation is applied to the case of the Danish trawl fishery in Kattegat and Skagerrak, which experiences a high level of discards and bycatches of several species. Four different kinds of selectivity scenarios are evaluated in comparison with a baseline. The results from the evaluation are indicators for the consequences on ecological and economic levels. The results show that implementation of different selective fishing gear in the Kattegat and Skagerrak mixed trawl fisheries generally implies a trade off over time between rebuilding the stocks and economic loss. Moreover, the analysis shows that implementation of more selective gear is not always beneficial.  相似文献   
218.
Deliberative forms of stakeholder participation have been widely embraced as a key measure for addressing legitimacy deficits and non-compliance in environmental governance. However, the great significance of such collaborative structures for state-stakeholder interaction is much too often accepted uncritically as an established truth in the environmental policy discourse. Building on examples from the literature on fisheries co-governance, this article constructs a conceptual and normative framework for interpreting and assessing such views about co-governance, legitimacy and compliance. Analysing central claims in this discourse in relation to different concepts and standards of legitimacy helps us identify and distinguish many powerful reasons to welcome co-governance. However, the article defends the need to do so cautiously and reflectively. It is conceptually misleading to suggest that more intense forms of co-governance will generally improve the overall level of social legitimacy and, thereby, compliance rates among stakeholders. Furthermore, it is argued that the democratic value of co-governance is not fundamental. The democratic desirability of such arrangements should be primarily assessed on instrumental-pragmatic grounds, focusing on their capacity to serve the wider ideals of equal citizenship and public reason.  相似文献   
219.
● A series of Cu-ZSM-5 catalysts were tested for DMF selective catalytic oxidation. ● Cu-6 nm samples showed the best catalytic activity and N2 selectivity. ● Redox properties and chemisorbed oxygen impact on DMF catalytic oxidation. ● Isolated Cu2+ species and weak acidity have effects on the generation of N2. N, N-Dimethylformamide (DMF), a nitrogen-containing volatile organic compound (NVOC) with high emissions from the spray industry, has attracted increasing attention. In this study, Cu-ZSM-5 catalysts with different CuO particle sizes of 3, 6, 9 and 12 nm were synthesized and tested for DMF selective catalytic oxidation. The crystal structure and physicochemical properties of the catalyst were studied by various characterization methods. The catalytic activity increases with increasing CuO particle size, and complete conversion can be achieved at 300–350 °C. The Cu-12 nm catalyst has the highest catalytic activity and can achieve complete conversion at 300 °C. The Cu-6 nm sample has the highest N2 selectivity at lower temperatures, reaching 95% at 300 °C. The activity of the catalysts is determined by the surface CuO cluster species, the bulk CuO species and the chemisorbed surface oxygen species. The high N2 selectivity of the catalyst is attributed to the ratio of isolated Cu2+ and bulk CuO species, and weak acidity is beneficial to the formation of N2. The results in this work will provide a new design of NVOC catalytic oxidation catalysts.  相似文献   
220.
Illegal fishing poses a major threat to conservation of marine resources worldwide. However, there is still limited empirical research that quantifies illegal catch levels. We used the randomized response technique to estimate the proportion of divers and the quantities of loco (Concholepas concholepas) they extracted illegally. Loco have been managed for the past 17 years through a territorial user rights for fisheries system (TURFs) in Chile. Illegal fishing of loco was widespread within the TURFs system. Official reported landings (i.e., legal landings) accounted for 14–30% of the total loco extraction. Our estimates suggest that ignoring the magnitude of illegal fishing and considering only official landing statistics may lead to false conclusions about the status and trends of a TURFs managed fishery. We found evidence of fisher associations authorizing their members to poach inside TURFs, highlighting the need to design TURFs systems so that government agencies and fishers’ incentives and objectives align through continuous adaptation. Government support for enforcement is a key element for the TURFs system to secure the rights that are in place.  相似文献   
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