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51.
Evolution of a Mediterranean Coastal Zone: Human Impacts on the Marine Environment of Cape Creus 总被引:1,自引:0,他引:1
This study presents an integrated analysis of the evolution of the marine environment and the human uses in Cape Creus, a
Mediterranean coastal area where intense commercial fisheries and recreational uses have coexisted over the last fifty years.
The investigation synthesizes the documented impacts of human activities on the marine environment of Cap de Creus and integrates
them with new data. In particular, the evolution of vulnerable, exploited species is used to evaluate the fishing impacts.
The effects of area protection through the establishment of a marine reserve in the late 1990s and the potential climate change
impacts are also considered. The evolution of the human uses is marked by the increasing socioeconomic importance of recreational
activities (which affect species and habitats) in detriment to artisanal and red coral fisheries (which principally affect
at a species level). Overall, populations of sedentary, vulnerable exploited species, hard sessile benthic invertebrates,
and ecologically fragile habitats, such as seagrass meadows, the coralligenous and infralittoral algal assemblages have been
the most negatively impacted by anthropogenic activities. Albeit human uses currently constitute the largest negative impact
on the marine environment of Cap de Creus, climate change is emerging as a key factor that could have considerable implications
for the marine environment and tourism activities. The establishment of the marine reserve appears to have had little socioeconomic
impact, but there is some evidence that it had some positive biological effects on sedentary, littoral fishes. Results demonstrate
that the declaration of a marine reserve alone does not guarantee the sustainability of marine resources and habitats but
should be accompanied with an integrated coastal management plan. 相似文献
52.
创新水源型流域污染系统控制科技支撑战略,对我国流域水环境综合治理与管理具有前瞻意义.文章从引导科技支撑发展方向,发展多维流域认知系统,创立流域系统控制知识,创新水源流域环境技术,建立流域水环境经济学与完善流域环境管理体系六个方面构建了水源流域污染系统控制的科技支撑战略体系;从制定水源型流域环境区划、水源型流域安全发展规划、水源型流域环境保护规划与水源型流域保护工程规划四个方面提出了水源型流域污染系统控制科技支撑的战略行动;从转变治理方向、改变治理目标与调整控制范围、优化监控指标等方面提出了水源型流域污染系统控制科技支撑的战略建议. 相似文献
53.
Assessment of GM Crops in Commercial Agriculture 总被引:1,自引:0,他引:1
The caliber of recent discourse regarding geneticallymodified organisms (GMOs) has suffered from a lack of consensuson terminology, from the scarcity of evidence upon which toassess risk to health and to the environment, and from valuedifferences between proponents and opponents of GMOs. Towardsaddressing these issues, we present the thesis that GM should bedefined as the forcible insertion of DNA into a host genome,irrespective of the source of the DNA, and exclusive ofconventional or mutation breeding.Some defenders of the commercial use of GMOs have referred to thescientific work of GMO critics as ``junk science.' Such a claim isfalse and misleading, given that many papers critical of both theutility and safety of GMOs have been published in peer reviewedjournals by respected scientists. In contrast, there is a dearthof peer reviewed work to substantiate the frequently heardassertions of either safety or utility in GMOs. The polarity,which now characterizes much of the public discourse on GMOs,reflects not simply scientific disagreement, but alsodisagreement in underlying value assumptions. Value differencesstrongly affect the assessment of both benefit and harm fromGMOs.The concept of substantial equivalence occupies a pivotalposition in the GMO risk assessment process that is used in bothCanada and the US. A GMO judged to be substantially equivalent toa conventional product – as have all submissions to date – ispresumed to be safe enough for commercialization. The conclusionof safety – from both human health and environmental perspectives– should be based on scientific evidence, corroborated by actualexperimentation. However, regulators infer safety largely fromassumptions-based reasoning, with little or no experimentalvalidation. The judgement of safety because of substantialequivalence is a dubious argument by analogy. 相似文献
54.
通过对四川省科技人力资源的潜力、结构变化的分析,提出建立统一规范的科技人才培养经费投入政策,加强科技人才资源的再开发,不拘一格引进科技人才,建立四川省科技人力资源监测系统等对策。 相似文献
55.
生态城市特征性指标的辨析及其应用 总被引:2,自引:0,他引:2
生态城市是依据生态学原理提出的一类社会、经济、自然协调发展的城市.基于生态城市内涵建立的城市特征性指标对城市特征性要素的量化和评价,是将生态城市个性这一主观观念变为可操作性目标的主要途径.基于城市复合生态系统理论和生态城市"健康、安全和发展"内涵,探讨了生态城市特征性指标的辨析方法.以厦门为例构建了厦门生态城市特征性指标体系.评价结果揭示了厦门城市特有的生态环境和资源的总体状态为亚健康状态(0.69)、比较脆弱的中警状态(0.39)和一般持续的发展状态(0.63).与现实的分析调研结果相符.这表明生态城市特征性指标有助于研究者辨识和评价城市生态系统的特定复合特征,更有针对性地明确城市生态规划和建设的重点行动领域,从而为城市实施可持续发展战略提供决策依据. 相似文献
56.
为给出更严谨的安全定义,通过结合经济学中人的有限理性基本假设,系统科学中的整体涌现性,以及认识论中的客观主义和建构主义2种哲学理论,从基本假设、系统论、认识论、限定条件等4个维度深入分析安全的属性和特性,提出新的安全定义:安全是“一定环境内,系统免受不可接受的风险的状态”;基于此,分析新安全定义的内涵和外延。研究表明:安全的本质是风险可接受,安全的研究内容是找到确定风险可接受的方法并制定符合我国国情的可接受风险标准。研究过程中要以系统为研究对象,并建立合适的有限理性模型,同时要考虑社会建构因素的影响。 相似文献
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