排序方式： 共有19条查询结果，搜索用时 15 毫秒
1.
There is a growing body of evidence to suggest that certain polycyclic aromatic hydrocarbons (PAHs) pose a greater hazard to aquatic organisms than previously demonstrated, due to their potential to cause photo-induced toxicity when exposed to ultraviolet (UV) radiation. The consequences of photo-induced toxicity are reported here for embryo-larval stages of the pacific oyster Crassostrea gigas, following exposure to pyrene and benzo[a]pyrene. During laboratory investigations, significant increases in toxicity were observed in the presence of environmentally attainable levels of UV-radiation, compared with embryos exposed to PAH alone, at levels previously deemed to have little acute biological effect. The phototoxicity of pyrene and benzo[a]pyrene completely inhibited the development to the D-shell larval stage when embryos were simultaneously exposed to 5 microg l(-1) PAH and ultraviolet light (UVB = 6.3 +/- 0.1 microW/cm2 and UVA = 456.2 +/- 55 microW/cm2). A linear relationship was also demonstrated for benzo[a]pyrene phototoxicity with decreasing UV light intensity. 相似文献
2.
3.
Simon Mardle Sean Pascoe Jean Boncoeur Bertrand Le Gallic Juan J. García-Hoyo Ins Herrero Ramon Jimenez-Toribio Concepcin Cortes Nuria Padilla Jesper Raakjaer Nielsen Christoph Mathiesen 《Marine Policy》2002,26(6)
The main objectives of fisheries management are generally similar throughout the world. These are often stated in policy documents such as the Common Fisheries Policy and the Magnuson–Stevens Fishery Conservation and Management Act. However, at the local level often the key objectives of management are more detailed, characterised by both the overriding management structure and the status and type of fishery concerned. In this paper, we consider case study fisheries from the UK, France, Spain and Denmark to compare some of the various types of fisheries and fisheries management systems that exist in the European Union. From this, we define the key objectives for each management system. 相似文献
4.
5.
Economics, fisheries, and the marine environment 总被引：1，自引：2，他引：1
6.
Fisher's behaviour with individual vessel quotas—Over-capacity and potential rent: Five case studies
Frank Asche Hkan Eggert Eyjolfur Gudmundsson Ayoe Hoff Sean Pascoe 《Marine Policy》2008,32(6):920-927
Internationally, individual vessel quotas (IVQ) have become an increasingly popular management tool. The main attraction of IVQs is the incentives they create for cost savings, autonomous capacity adjustment and, subsequently, rent generation. In this paper, the extent to which different IVQ systems have facilitated resource rent generation and capacity adjustment in five European countries—Denmark, Iceland, Norway, Sweden and the UK—is examined. The potential economic rents and the capacity reduction necessary to achieve these rents in each of the fisheries are also estimated. Reasons why IVQs have not achieved their potential economic benefits in these fisheries are also examined. 相似文献
7.
Richard T. Pascoe John P. Penny 《International journal of geographical information science》2013,27(3):275-291
Abstract An interface is a software package used, alone or in conjunction with other interfaces, to transfer data from one geographical information system to another, or between different representations within a single GIS. The aim in this paper is to extend the traditional view of an interface to include interfaces that use communication networks to move data between (and within) GIS. We suggest that, to exchange data across a network, the best solution may be to construct a set of communicating interfaces, each able to send data to, and receive data from, other communicating interfaces. We describe a working set of communicating interfaces that transfer data between a number of GIS data representations. 相似文献
8.
Some economists have questioned the need for retaining boat licences in fisheries managed through rights-based systems on the assumption that licences act as an impediment to autonomous adjustment. In this paper, the role of boat licences in fisheries managed through rights-based instruments is explored through examining their use in several fisheries in Australian and elsewhere. The study concludes that any impediment to autonomous adjustment that is produced by boat licences is likely to be small relative to other factors. Further, boat licences play an important role in offsetting imperfections in the rights-based management systems that exist in most countries. 相似文献
9.
Sean Pascoe Rodrigo Bustamante Chris Wilcox Mark Gibbs 《Ocean & Coastal Management》2009,52(2):130-138
In many circumstances, quantitative assessment of fisheries management options is either impossible due to data deficiencies or impractical given the size of the fishery. Quantitative analysis of spatial management options in particular is complicated, as information on spatial fleet and stock dynamics is often unavailable and spatial models are difficult to construct. In this paper, a qualitative framework is presented that aids in the analysis of alternative spatial management options in coastal fisheries. The framework combines expert opinion and the Analytic Hierarchy Process (AHP) to determine which options perform best taking into account the multiple objectives inherent in fisheries management. 相似文献
10.
David James Pascoe 《中国天文和天体物理学报》2014,(7):805-830
Magnetohydrodynamic（MHD） processes are important for the transfer of energy over large scales in plasmas and so are essential to understanding most forms of dynamical activity in the solar atmosphere. The introduction of transverse structuring into models for the corona modifies the behavior of MHD waves through processes such as dispersion and mode coupling. Exploiting our understanding of MHD waves with the diagnostic tool of coronal seismology relies upon the development of sufficiently detailed models to account for all the features in observations. The development of realistic models appropriate for highly structured and dynamical plasmas is often beyond the domain of simple mathematical analysis and so numerical methods are employed. This paper reviews recent numerical results for seismology of the solar corona using MHD. 相似文献