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321.
This study presents the results of a field survey that focused on the views of Tasmanian abalone fishery stakeholders (commercial and non-commercial divers, processor, enforcement agency and management) with regards to non-compliance in the abalone fishery. The primary data was collected through 22 face-to-face interviews with stakeholders and the Wilcoxon's signed-rank test was used to determine if significant differences existed between the means of responses from primary and secondary stakeholders. It was found that there is no significant difference in mean responses of primary and secondary stakeholders in regard to the factors that have the potential in influencing the non-compliance in the fishery. The similarity of views between the regulators and resource users on the source and nature of non-compliance in the fishery would form the basis for improved compliance strategies. 相似文献
322.
In the past decade, the European Commission has developed the Marine Strategy Directive and the Maritime Policy. Both policies aim at governing the marine environment; yet the two policies have a differing signature in policy formulation and implementation. From a fisher's perspective these policies present a change in institutional setting; major policy measures no longer descend from the EU Common Fisheries Policy alone, but increasingly are derived from general environmental policy developments. In this paper, the policy arrangement approach is used to analyse the differences between the two maritime policies, and the way in which they can affect fisheries management. 相似文献
323.
Over the next several decades, arctic marine mammals will face threats from six areas of human influence: climate change, environmental contaminants, offshore oil and gas activities, shipping, hunting, and commercial fisheries. This paper reviews these factors, the nature and magnitude of the threats they pose, current scientific understanding and management of those threats, and the potential for effective conservation action. Climate change, offshore oil and gas activities, and commercial fisheries likely pose the greatest threats. Addressing the combined effects of all six factors, however, will be particularly difficult but essential to prevent declines beyond those that have already occurred. 相似文献
324.
Natalia A. Yaragina Andrey V. Dolgov 《Deep Sea Research Part II: Topical Studies in Oceanography》2009,56(21-22):2141
Abundance and biomass of the most important fish species inhabited the Barents and Norwegian Sea ecosystems have shown considerable fluctuations over the last decades. These fluctuations connected with fishing pressure resulted in the trophic structure alterations of the ecosystems. Resilience and other theoretical concepts (top-down, wasp-waste and bottom-up control, trophic cascades) were viewed to examine different response of the Norwegian and Barents Sea ecosystems on disturbing forces. Differences in the trophic structure and functioning of Barents and Norwegian Sea ecosystems as well as factors that might influence the resilience of the marine ecosystems, including climatic fluctuation, variations in prey and predator species abundance, alterations in their regular migrations, and fishing exploitation were also considered. The trophic chain lengths in the deep Norwegian Sea are shorter, and energy transfer occurs mainly through the pelagic fish/invertebrates communities. The shallow Barents Sea is characterized by longer trophic chains, providing more energy flow into their benthic assemblages. The trophic mechanisms observed in the Norwegian Sea food webs dominated by the top-down control, i.e. the past removal of Norwegian Spring spawning followed by zooplankton development and intrusion of blue whiting and mackerel into the area. The wasp-waist response is shown to be the most pronounced effect in the Barents Sea, related to the position of capelin in the ecosystem; large fluctuations in the capelin abundance have been strengthened by intensive fishery. Closer links between ecological and fisheries sciences are needed to elaborate and test various food webs and multispecies models available. 相似文献
325.
空间关联规则挖掘是一个过程,主要包括数据选取、数据预处理、数据变换、数据挖掘算法实施以及模式解释与评估等。目前,相关研究的重点在于各种空间关联规则挖掘算法的实施,而对其他几个步骤的研究比较少,如多个字段的综合处理、连续数据的离散化等。同时,农业普查数据尤其是第二次全国农业普查数据涵盖了丰富的"三农"信息,像座宝藏,期待人们运用各种技术开发利用。空间关联规则挖掘无疑是挖掘农业普查数据宝藏的最理想工具。本文将空间关联规则挖掘首次引入中国农业普查当中,以其在甘肃农业普查中的应用实例详细描述空间关联规则挖掘各步骤处理过程及各技术关键的处理方法,最后得出一些甘肃省各界最为感兴趣的知识,为甘肃省解决"三农"问题提供决策依据。 相似文献
326.
327.
James T. Julian John A. Young John W. Jones Craig D. Snyder C. Wayne Wright 《Journal of Geographical Systems》2009,11(1):89-106
We examined whether spatially explicit information improved models that use LiDAR return signal intensity to discriminate
in-pond habitat from terrestrial habitat at 24 amphibian breeding ponds. The addition of Local Indicators of Spatial Association
(LISA) to LiDAR return intensity data significantly improved predictive models at all ponds, reduced residual error by as
much as 74%, and appeared to improve models by reducing classification errors associated with types of in-pond vegetation.
We conclude that LISA statistics can help maximize the information content that can be extracted from time resolved LiDAR
return data in models that predict the occurrence of small, seasonal ponds.
相似文献
328.
In a recently published paper, Worm et al. [Impacts of biodiversity loss on ocean ecosystem services. Science 2006;314:787–90.] project “the global collapse of all taxa currently fished” by 2048. Using their criteria and data, this paper shows that the number of not-collapsed fisheries actually increased over time to a plateau of about 5600 in 1985–2003. Furthermore, if trends are projected into the future, more than half of the world's fisheries would always be in a recovered state. 相似文献
329.
Successful species conservation typically results in conflicts between wildlife protection and economic uses of natural resources as in fisheries and aquaculture. This article shows why managing these conflicts require a more comprehensive approach than currently pursued by endangered species conservation programmes. Against the background of several case studies focussing on wildlife conflicts in European waters this article derives two challenges for institutional response: First, the question of mandate—which societal actor initiates management related processes that require multiple actors to collaborate? Second, how can continuous processes of collaboration be sustained? 相似文献
330.
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