What makes them follow the rules? Empirical evidence from turtle egg harvesters in Costa Rica     

《Marine Policy》2013

This paper presents an empirical analysis of the factors that determine individual compliance with a locally devised set of rules for harvesting and selling marine turtle eggs, as well as for protecting the turtles and their hatchlings. Individuals who violate the rules receive a monetary penalty, which implies a reduction in the income from sale of eggs. While some individuals do not have income reductions due to infractions, others have reductions of up to 40% of the total income. Using written records of deductions due to sanctions between May 2008 and May 2010 and information from a survey of 108 local turtle egg harvesters, the paper presents the results of econometric analyses of factors that influence the amount of fines received by individuals. The results suggest that individual dependence on the income from sale of eggs, perceptions of rules and their legitimacy, and demographic factors such as age and gender are all important factors explaining rule breaking behavior. The findings also highlight new threats to the long-term survival of local institutions responsible for protection of marine turtles and their sustainable consumptive use.  相似文献   

MPA policy: What lies behind the science?     

《Marine Policy》2013

What the current policy debate on marine protected areas (MPAs) and marine reserves (MRs) has failed to address is the fact that protection of the marine environment has as much to do with scientists, and others values as it has to do with science. To date natural science has played a dominant role in the implementation of MPAs, yet normative considerations which are embedded in the way scientists and the wider community think about the condition the marine environment should be in, and which may influence decision-making, are rarely acknowledged or discussed. This paper seeks to correct that deficiency by investigating the values that lie behind the natural science of MPAs. With the aid of epistemic community, advocacy coalition and discourse coalition theories of policy networks, this article explores the role science and scientists have played in influencing policy on MPAs at the global and national level, and looks at the extent to which normative conceptualisations within and beyond natural science have influenced the debate.  相似文献   

The impact of four ethylene oxide–propylene oxide block copolymers on the surface tension of dispersions of soils and minerals in water     

《Physics and Chemistry of the Earth》2012

A comprehensive series of aqueous solutions of four ethylene oxide–propylene oxide–ethylene oxide block copolymers (EPE) of varying concentrations have been prepared. The EPE molecules are amphiphilic with the P blocks providing the hydrophobic segment of the molecules and the E blocks providing the hydrophilic parts. The surface tension of these solutions has been measured and compared with the surface tension of dispersions of soils (a clay soil and a sandy soil) and minerals (quartz–silica sand, bentonite and kaolinite) in the same aqueous solutions. It is observed that all the block copolymers reduce the surface tension of water; the extent to which it is reduced is determined by the surface activity of the EPE block copolymer, which in turn is related to the balance between the sizes of the P and E blocks. It is further observed that the in the presence of soil the surface tension increases as a result of block copolymer adsorption to the soil/water interface. The extent of adsorption appears to be related to the texture of the soil – the clay soil used in this investigation adsorbs more block copolymer than the sandy soil. In the presence of the mineral phases the surface tension reductions are variable. With bentonite the EPE block copolymers are completely adsorbed at low EPE concentrations as shown by surface tension values that are the same as those measured for pure water. Adsorption to kaolinite is limited and once the adsorption sites have been filled the surface tension of the aqueous phase is approaches the surface tension of the same solution without the presence of bentonite. On the other hand the silica sand is a poor adsorbent. Adsorption to the mineral phases is also dependent upon the relative hydrophobicity of the block copolymer. The more hydrophobic (as inferred by the critical micelle concentration) the copolymer the less readily it is adsorbed by the mineral phases. Thus relatively hydrophobic EPE block copolymers produce a relatively large decrease in surface tension and are less readily adsorbed by the soil and mineral phases. It is concluded that the presence of EPE block copolymers in soils can result in the drainage of soil water from the saturated zone as a result of surface tension reductions. However the extent of drainage is related to the surface activity/molecular composition of the EPE block copolymer; the textural class of the soil and the nature of the minerals present in the soil.  相似文献   

A GIS for desert locust forecasting and monitoring     

R. G. HEALEY  S. G. ROBERTSON  J. T. MAGOR  J. PENDER  K. CRESSMAN 《International journal of geographical information science》2013,27(1):117-136

Abstract

Desert locust plagues can affect up to 20 per cent of the surface of the Earth. Data on locust breeding, environmental conditions and swarm movements in affected countries, are collected at the headquarters of the U.N. Food and Agriculture Organization in Rome. GIS technology coupled with remote sensing inputs allows these data to be utilised for monitoring and forecasting purposes much more effectively than heretofore. Design requirements and the implementation strategy for such a GIS are examined, emphasizing the role of global digital map datasets such as the Digital Chart of the World, the importance of effective data integration and the need for an ergonomic user interface that facilitates both data capture and analysis.  相似文献   

Rates,distributions and mechanisms of change in meander morphology over decadal timescales,River Dane,UK     

J. M. Hooke  L. Yorke 《地球表面变化过程与地形》2010,35(13):1601-1614

This paper analyses types and rates of change in river meander morphology and the links between mechanisms of change and emergent behaviour of planform morphology. It uses evidence of four dates of aerial photography combined with annual field mapping and ground photography to examine the morphological changes and mechanisms of change in a series of bends on an active meandering river, the River Dane in NW England, over a 25 year period. This unique data set allows insight into the spatial and temporal variability of bank line movement and component processes. Bank lines were mapped photogrametrically from air photos of 1984, 1996, 2001 and 2007 and the digitised courses compared in ArcGIS to produce calculations of erosional and depositional areas and rates. Most bends exhibit morphological change that largely follows the autogenic sequence, identified in qualitative models of meander development, from low sinuosity curves through simple symmetric and asymmetric bends to compound forms with lobe development in the apex region. Rates of erosion and bankline movement increase through this sequence until the compound phase. Relationships of amounts of movement to various curvature measures of bend morphology are complex. Several new loops, distinct from compound bend behaviour, have developed during the study period in formerly straight sections. Mechanisms of morphological change are illustrated for four types of bends: new, rapid growth bend; sharp‐angled bend with mid‐channel bar development; symmetric migrating bend; and simple to compound bend development. The changes take place in phases that are not simply related to discharge but to inherent sequences and feedbacks in development of bars and bend morphology and timescales for these are identified. Overall, emergent behaviour of systematic planform change, moderated by channel confinement and boundary features, is produced from spatially and temporally varied channel processes. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Lessons for fisheries management from the EU cod recovery plan     

《Marine Policy》2013

The performance of the EU long-term management plan for cod stocks, in force since 2009, is analysed focusing on the human and institutional factors. The plan operates through landings quotas (TACs) and effort restrictions following a Harvest Control Rule, and deploys a novel instrument allowing Member States to ‘buy back’ or increase fishing effort for fleet segments engaged in cod-avoidance measures. The stipulated fishing mortality reductions have not been achieved. On the positive side, the ‘buy-back’ instrument has led to increased uptake of selective gear and implementation of permanent and real-time temporary closures. On the negative side, ignoring the dimension of fishers as reactive agents in the design, the impact assessment, and the annual implementation of the measures has contributed to the failure to adequately implement the plan and achieve its objectives. The main problem is that the landings quotas taken in a mixed fishery did not limit catches because fishers were incentivised to continue fishing and discard overquota catch while quota for other species was available. The effort limitations intended to reduce this effect were insufficient to adequately limit fishing mortality in targeted fisheries, although fishers experienced them as prohibiting the full uptake of other quotas. Recommendations for future plans include (i) management through catch rather than landings quotas, (ii) the internalisation of the costs of exceeding quotas, (iii) use of more selective gear types, (iv) the development of appropriate metrics as a basis for regulatory measures and for evaluations, (v) participatory governance, (vi) fishery-based management, (vii) flexibility in fishing strategy at vessel level.  相似文献   

Management objectives of Queensland fisheries: Putting the horse before the cart     

《Marine Policy》2013

A review of future management arrangements for the Queensland East Coast Trawl fishery was undertaken in 2010 to develop a management plan for the next 10 years. A key question raised at the start of the review process was: what should the management plan achieve? As with fisheries management in most countries, multiple management objectives were implicit in policy statements, but were poorly specified in some areas (particularly social objectives) and strongly identified in others (e.g., an objective of sustainability). As a start to the management review process, an analysis of what objectives the management system should aim to achieve was undertaken. A review of natural resource management objectives employed internationally was used to develop a candidate list, and the objectives most relevant to the fishery were short-listed by a scientific advisory group. Additional objectives specific to Queensland fisheries management, but not identified in the international review, were also identified and incorporated into the objective set. The relative importance of the different objectives to different stakeholder groups was assessed using the Analytic Hierarchy Process. As with other studies, the relative importance of the different objectives varied both within and between the different stakeholder groups, although general trends in preferences were observed.  相似文献   

Temporary exposures of the Eocene London Clay Formation at Highgate, north London: rediscovery of a fossiliferous horizon ‘lost’ since the nineteenth century     

Steve TraceyStephen K. Donovan  Diana ClementsJohn Cooper  Phil RyeCaroline Hensley 《Proceedings of the Geologists' Association. Geologists' Association》2002,113(4):319-331

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First Palaeogene sedimentary rock palaeomagnetic pole from stable western Eurasia and tectonic implications   总被引：1，自引：0，他引：1  

Jason R. Ali  David J. Ward  Chris King  Alexandra Abrajevitch 《Geophysical Journal International》2003,154(2):463-470

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Apport de la modélisation géophysique pour la compréhension de la structuration du pas de Calais     

Bruno Minguely  Jean-Louis Mansy  Michel Everaerts  Geoffrey M. Manby  Olivier Averbuch 《Comptes Rendus Geoscience》2005,337(3):305-313

This study is based on an analysis of seismic, gravimetric and magnetic data to model the structure of the Dover Straits area. The Dover Straits are set in a transitional position within the Brabant para-autochthon, which lies between the Ardennes allochthon to the south and the Brabant Massif to the north. The seismic profiles show that this area is characterised by several superimposed Mesozoic basins, whose evolution has been controlled by the reactivation of Lower Palaeozoic faults. In common with the adjacent Weald–Wessex and southern North Sea basins, the Dover Straits area records a Jurassic extensional phase and a post-Cretaceous tectonic inversion. The geophysical modelling reveals the presence of a basement to these Mesozoic basins that exhibits Ordovician to Silurian structures, which cannot be detected on the seismic reflection profiles. In contrast to earlier interpretations, the modelling presented here suggests that the Brabant Massif continues southward beyond the Dover Straits and under the Brabant para-autochthon. Gravity data also provides evidence for the presence of granitic body at depth, in the vicinity of Km 27 on the seismic profile, which may have driven the uplift of the Silurian rocks in the area of the Straits. Similar granitic intrusions have been proposed to explain gravity anomalies along the Rhenohercynian Margin in Belgium, eastern and southern England. The geophysical modelling demonstrates the continuity of the basement and Mesozoic basin structures across the Dover Straits, suggesting a common geological evolution of the adjacent southern England–northern France regions. To cite this article: B. Minguely et al., C. R. Geoscience 337 (2005).  相似文献