排序方式： 共有32条查询结果，搜索用时 15 毫秒
11.
12.
13.
14.
A suite of management options for a prawn trawl fishery in Torres Strait, Australia was assessed for impacts on the benthic fauna using a dynamic management strategy evaluation approach. The specification of the management options was gained through consultation with stakeholders. Data for the model was drawn from several sources: the fleet data from fishery logbooks and satellite vessel monitoring systems, benthic depletion rates from trawl-down experiments, benthic recovery rates from post-experiment recovery monitoring studies, and benthic distribution from large-scale benthic surveys. Although there were large uncertainties in the resulting indicators, robust measures relevant to management were obtained by taking ratios relative to the status quo. The management control with the biggest effect was total effort; reducing trawl effort always led to increases in benthic faunal density of up to 10%. Spatial closures had a smaller benefit of up to 2%. The effect of closing a set of buffer zones around reefs to trawling was indistinguishable from the status quo option. Closing a larger area, however, was largely beneficial especially for sea cucumbers. When the spatial distributions of fauna prior to fishing were accounted for, fauna with distributions positively correlated with effort improved relative to those negatively correlated. The reduction in prawn catch under effort reduction scenarios could be ameliorated by introducing temporal closures over the full-moon period. 相似文献
15.
Understanding where people depend the most on natural resources for their basic human needs is crucial for planning conservation and development interventions. For some people, nature is a direct source of food, clean water, and energy through subsistence uses. However, a high direct dependency on nature for basic needs makes people particularly sensitive to changes in climate, land cover, and land tenure. Based on more than 5 million household interviews conducted in 85 tropical countries, we identified where people highly depend on nature for their basic needs. Our results show that 1.2 billion people, or 30% of the population across tropical countries, are highly dependent on nature. In places where people highly depend on nature for their basic needs, nature-based strategies that protect, restore or sustainably manage ecosystems must be carefully designed to promote inclusive human development alongside environmental benefits. 相似文献
16.
Many articles have been published in recent years criticizing the management of living marine resources based solely on biological stock conservation criteria. In the United States and in many parts of the rest of the world, multiple management objectives and goals in addition to stock conservation must be met by fishery managers responsible for the marine resources under their control. An alternative management metric, conservation efficiency, is recommended based instead on a multi-disciplinary scientific framework that captures these different goals and the behavior of participants in the fishery. On the basis of the constraints facing managers, resources can be conserved and the quality of life of consumptive and nonconsumptive fishery participants improved. 相似文献
17.
Lyne Morissette Martin Castonguay Claude Savenkoff Douglas P. Swain Denis Chabot Hugo Bourdages Mike O. Hammill J. Mark Hanson 《Deep Sea Research Part II: Topical Studies in Oceanography》2009,56(21-22):2117
In order to have a global view of ecosystem changes associated with the collapse of groundfish species in the Gulf of St. Lawrence during the early 1990s, Ecopath mass-balance models were constructed incorporating uncertainty in the input data. These models covered two ecosystems (northern and southern Gulf of St. Lawrence; NAFO divisions 4RS and 4T), and two time periods (before the collapse, in the mid-1980s, and after it, in the mid-1990s). Our analyses revealed that the ecosystem structure shifted dramatically from one previously dominated by piscivorous groundfish and small-bodied forage species during the mid-1980s to one now dominated only by small-bodied pelagic species during the mid-1990s in both southern and northern Gulf. The species structure in the northern Gulf versus southern Gulf was different, which may explain why these two ecosystems did not recover the same way from the collapse in the early 1990s. Productivity declined in the northern Gulf after the collapse but increased in the southern Gulf. The collapse of groundfish stocks resulted in declines in the mean trophic level of the landings in both the northern and the southern Gulf. Even though fishing mortality was then intentionally reduced, this part of the total mortality was taken up by predation. The temporal changes in the internal structure of both ecosystems are reflected in their overall emergent properties. 相似文献
18.
19.
Louise Crabtree 《Geoforum》2006,37(4):519-535
This paper responds to challenges made by Castree [Castree, N., 2004. Environmental issues: signals in the noise? Progress in Human Geography 28 (1), 79-90] and Sneddon [Sneddon, C., 2000. ‘Sustainability’ in ecological economics, ecology and livelihoods: a review. Progress in Human Geography 24 (4), 521-549] for human geography to clarify its contribution to environmental debates and engage with recent formulations of sustainability as informed by the ‘new ecology’. This approach focuses on resilience, functional diversity, flexibility and complexity, here used to examine housing sustainability within an industrialised sub/urban context in terms of design philosophy, ownership, management bases, community engagement and funding mechanisms. This framework highlights areas of concern for enhancing the functional diversity of housing systems, echoing recent assertions that challenges for sustainability arise more from trust and power sharing issues, than from physical design and maintenance issues. It is argued that it is precisely human geography’s place-by-place consideration of power, embeddedness, scale and politics that can lend new ecology the social relevance it requires. 相似文献
20.
从生产资产到生态资产：资产—资本完备性 总被引：9，自引：0，他引：9
本研究探讨从生产资产（produc edassets）到生态资产的完备化理论。其内容主要包括：资产-资本完备化;生态资产定义、构成、分类与比较;经济权与完备化,为该研究的第一部分内容。首先,回顾了国内外环境、资源与生态经济学领域有关资产和资本的研究概况,指出当前该领域的前沿热点之一是从生产资产走向生态资产的综合与系统化,这一发展趋势突出体现在关于资产-资本的完备化研究。通过简要地分析新古典经济学中资产和资本范畴的局限性及其所产生的不完备性,总结出其主要表现是概念不完备性、价值不完备性和权义不完备性,而价值不完备性是当前研究的核心问题。在此基础上,进一步评述了现代经济学在资产或资本完备化研究中所取得的重要进展及有待解决的重大问题。该文从系统学意义上提出,推出完备化过程首先需要建立系统资产和资本概念,并进一步讨论了系统资产和资本的基本内涵,提出了资产-资本完备化的 5个法则。 相似文献