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Standardized diet compositions and trophic levels of sharks   总被引:3,自引:3,他引:10  
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宽纹虎鲨软骨细胞体外培养的启动   总被引:1,自引:1,他引:4  
以活体宽纹虎鲨(Heterodortus japonicus)的鳃软骨和鳍软骨组织为材料,利用透明质酸酶(hyaluronidase)、Ⅱ型胶原酶(type Ⅱ collagenase)和胰蛋白酶(trypsin)进行消化获得游离软骨细胞,对所得游离细胞连同软骨组织分别用含20%小牛血清的MEM培养液进行体外培养。对软骨细胞体外培养条件的优化结果显示,宽纹虎鲨鳍软骨细胞体外培养的最适pH为7.2~7.6、最佳温度为24℃,成纤维细胞生长因子(bFGF,basic fibroblast growth factor)对软骨细胞作用不显著。培养于pH7.2~7.6的MEM培养液(含20%小牛血清)中的宽纹虎鲨鳍软骨组织,在24℃启动培养3d后便有软骨细胞开始陆续从组织中迁出,新迁出细胞的形态多为圆形,随着培养时间的延长,部分细胞形态逐渐转变成上皮样。  相似文献
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Internationally, shark conservation is now being recognized as a major environmental challenge, but management efforts to halt the overexploitation of sharks have lagged behind. This review examines the state of knowledge for shark species in Canadian waters and analyzes the role of existing management and legislation in ensuring shark conservation. Despite Canada's early leadership, the present management framework reveals major shortcomings with regard to legal protection, bycatch and finning regulations. These problems are not unique to Canada but illustrate broader issues pertaining to the global management of endangered fish species. To strengthen the conservation and management of sharks, this paper recommends a set of key policies and management priorities, which exemplify proper precautionary management of endangered shark species in Canada and could serve as a blueprint for improving conservation efforts internationally. A structured approach for grading progress in shark conservation efforts against best practices is also presented and could be used as a goalpost elsewhere.  相似文献
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The current rate of shark global exploitation and mortality is arguably so high under current management regimes that unless a renewed initiative is undertaken some species of shark will become effectively extinct. Current efforts to sustainably manage shark mortality are driven primarily by domestic laws in a few countries, big international non-governmental organizations (BINGOs) promoting environmental laws in the countries or regions where they exist, a handful of regional fisheries management organizations (e.g., IATTC and ICCAT), and inter-governmental organizations such as CITES. The absence of enforcement capability is often argued as the critical component in the failure to protect sharks from overexploitation. The remedy advanced here goes far beyond the need for stepped up enforcement, and calls for the creation of an entirely new international management regime, the International Commission for the Conservation and Management of Sharks (ICCMS). Such an agency could learn from the experiences of management bodies tasked with conservation of species biologically similar to sharks, such as the International Whaling Commission (IWC), to improve its efficacy. Critics have identified many organizational flaws that reduced the IWC’s effectiveness during its earliest years. Some of those flaws are examined here and remedies are suggested that an ICCMS could use to create a more effective management regime. The life histories of elasmobranches and large whales are compared to illustrate their similarities as a biological foundation for the selection of the IWC as a model.  相似文献
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Sharks play a critical role in the ocean environment yet many species are under threat. Over the last ten years, the international community has taken significant steps to protect shark species and address the threats to them through the adoption and implementation of international laws, plans and programmes. Nevertheless, despite the attention given to this issue, many shark species continue to deteriorate in numbers. While the reasons for this decline are complex and varied, regulatory fragmentation is one contributing factor. Legal regulation is a critical element in achieving effective conservation and management of sharks. This article considers the international laws, plans and programmes that seek to conserve shark species, explores the current fragmented regime and outlines possible strategies to overcome this challenge and enhance shark protection in the future.  相似文献
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Taiwan is a major longline fishing nation with an interest in proactive conservation measures. Facing global concerns about the incidental catch in longline fisheries, Taiwan has focused on bycatch issues since the 2000s. This paper reviews the existing information on bycatch and the actions taken by Taiwan in the past ten years, including the establishment of observer programs, education and outreach, adoption of national plans of action and publicizing regulations for mitigation measures. This review suggests that continuing and improving the observer program, ensuring the compliance of mitigation measures, and encouraging information exchange and international cooperation will contribute to the conservation of non-commercial species of concern.  相似文献
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镰状真鲨(Carcharhinus falciformis)是金枪鱼(Thunnus)延绳钓渔业中常见的兼捕鱼种之一, 位于海洋食物链的顶端, 对海洋物种多样性和生态系统的稳定性有重要意义, 2017年10月1日作为濒危物种被正式列入濒危野生动植物种国际贸易公约附录Ⅱ中。作者根据中国金枪鱼渔业科学观察员在中西太平洋海域(7°S~9°N, 149°E~150°W)采集的1 150尾镰状真鲨样本, 对其叉长、体质量、繁殖和摄食等生物学信息进行初步研究与分析。结果表明: 雌、雄镰状真鲨的优势叉长范围分别为80~180 cm和60~150 cm, 雌性叉长均值显著大于雄性; 雌、雄的叉长和体质量关系无显著性差异(ANCOVA, P>0.05),叉长和体质量的幂函数关系为: W R=9×10–6×LF2.9712; 雌、雄性比符合1︰1比例; 镰状真鲨的鳍脚长度与叉长呈显著正相关性, 其线性关系为LC=0.1492×LF–6.5; 镰状真鲨的怀仔数为4~15尾, 平均怀仔数为8尾, 子宫内雌雄胚胎长度范围为24~56cm; 摄食等级以空胃率为主, 其次为1级, 分别为51.77%、35.07%。  相似文献
10.
The Acoustic Tracking Array Platform (ATAP) is a marine science programme that monitors the movements and migrations of inshore marine animals along the South African coastline. Acoustically tagged animals are monitored by an expanded network of approximately 100 automated data-logging acoustic receivers moored at strategic node sites, from Cape Point in the west to the South Africa–Mozambique border in the east. During five years since its inception, in 2011, the ATAP has achieved outstanding progress in terms of the numbers of animals and the variety of species tagged. To date, the ATAP has yielded over 2.6 million detections from more than 700 acoustically tagged animals, representing 27 different species from 20 families, including the African penguin Spheniscus demersus, fishery-at-risk species (e.g. dusky kob Argyrosomus japonicus) and iconic elasmobranchs (e.g. white shark Carcharodon carcharias). Following a period of considerable equipment loss in 2014, refinement of the receiver network was required and the deeper receivers at each site were decommissioned without influencing the integrity of the nationwide array. The platform, managed by the South African Institute for Aquatic Biodiversity, ultimately represents a low-cost method of collecting long-term data that currently benefits approximately 25 researchers from 14 organisations. Case studies are presented to expose the opportunities provided by the ATAP, which will undoubtedly yield new discoveries and provide a greater understanding of the movement patterns and migrations of a wide variety of inshore marine and estuary-associated species.  相似文献
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