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21.
The increase of anthropogenic activities on coastal areas induces discharges of polycyclic aromatic hydrocarbons (PAHs) in aquatic ecosystem. PAH effects depend not only on their concentration and the way of contamination but also on the different developmental stages of the organism. Zebrafish were exposed to relevant concentration of pyrolytic PAHs from the first meal (i.e., 5-day post fertilization, dpf) to mature adults. Parental effect of this type of exposure was evaluated through the assessment of aerobic metabolic scope, cardiac frequency, and cardiac mRNA expression on larval and/or embryo progeny of contaminated fish. Our results suggest that cardiac frequency increased in larval descendants of fish exposed to the environmental concentration of pyrolytic PAHs (i.e., 5 ng.g?1 of food), while a lack of effect on aerobic metabolism in 5 dpf larvae was highlighted. A surexpression of mRNA related to the cardiac calcium transporting ATPase atp2a2a, a protein essential for contraction, is in accordance with this increasing cardiac frequency. Even if cardiac development genes cmlc1 and tnnt2a were not affected at early life stages tested, complementary work on cardiac structure could be interesting to better understand PAHs action.  相似文献   
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海平面上升的影响及损失预测   总被引:5,自引:0,他引:5  
气候变化引起的海平面上升对沿海国家和地区构及极大的威胁,造成了不同程度的破坏和损失,通过对海平面上升的可能影响进行了分析,提出了影响及损失的几种估算和评价方法。  相似文献   
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潮间带土壤盐度与电导率的关系   总被引:25,自引:0,他引:25  
以5:1的水土质量比浸提潮间带土壤,质量法测定的土壤盐度(质量分数),与电导法测定的稀释了5倍的土壤浸提液(5:1水土质量比)的电导率值之间有极显著的相关性。质量法实测的土壤盐度与电导率计算的土壤盐度之间的相对误差多在5%以下。因此,用电导法测定潮间带土壤盐度不失为一种简便、快速的方法,尤其是样品数较多时更可节约时间。  相似文献   
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Policies at multiple levels pronounce the need to encompass both social and ecological systems in governance and management of natural capital in terms of resources and ecosystems. One approach to knowledge production and learning about landscapes as social–ecological systems is to compare multiple case studies consisting of large spaces and places. We first review the landscape concepts’ biophysical, anthropogenic, and intangible dimensions. Second, we exemplify how the different landscape concepts can be used to derive measurable variables for different sustainability indicators. Third, we review gradients in the three dimensions of the term landscape on the European continent, and propose to use them for the stratification of multiple case studies of social–ecological systems. We stress the benefits of the landscape concepts to measure sustainability, and how this can improve collaborative learning about development toward sustainability in social–ecological systems. Finally, analyses of multiple landscapes improve the understanding of context for governance and management.  相似文献   
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研究三丁基氯化锡(TBT)对中国近海常见5种硅藻和甲藻(硅藻中丹麦细柱藻(Leptocylindrus danicus)、派格棍形藻(Bacilaria paxillifera)、聚生角毛藻(Chaetoceros socialis),甲藻中微型原甲藻(Prorocentrum minimum)、简裸甲藻(Gymnodinium simplex))的毒性效应,考察了有机锡对浮游藻光合活性(Fv/Fm)、粒径、生长的影响。结果表明:派格棍形藻、聚生角毛藻、简裸甲藻的光合活性(Fv/Fm)受TBT影响较显著;微型原甲藻、丹麦细柱藻的光合活性受TBT影响较小。高质量浓度TBT胁迫下海洋微藻峰值粒径显著减小,低质量浓度TBT对峰值粒径影响不显著。低质量浓度TBT对派格棍形藻、聚生角毛藻、简裸甲藻、微型原甲藻均有较强的毒性作用,非检测毒性浓度(NDEC)分别为1.17、1.07、0.23、3.73μg.L-1,丹麦细柱藻对TBT具有很强耐受性,NDEC为112.62μg.L-1。  相似文献   
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辽东湾东部砂岸严重蚀退及其原因分析   总被引:1,自引:0,他引:1  
辽东湾东部砂岸属冰后期淤长岸。近些年来遭到强烈侵蚀。不仅岬角、平直砂岸在蚀退.连一向稳定的湾内淤长岸也在转侵后退。目前,调查区100km海岸约有2/3的岸段出现严重蚀退现象,不少岸段年蚀退率已超过6m.有的沿海公路多次内迁,引起沙滩粗化、泻湖水量加大、海水倒灌、土地咸化等一系列严重灾害。  相似文献   
30.
Nattrass  Nicoli  Conradie  Beatrice  Stephens  Jed  Drouilly  Marine 《Ambio》2020,49(6):1222-1231

Populations of adaptable mesopredators are expanding globally where passive rewilding and natural recolonization are taking place, increasing the risk of conflict with remaining livestock farmers. We analysed data from two social surveys of farmers in the Karoo, South Africa, where black-backed jackals (Canis mesomelas) and caracals (Caracal caracal) have re-emerged as a threat to sheep farms in the context of falling agricultural employment and the expansion of natural areas. We show that irrespective of measurement approach, lethal control of mesopredators in this fragmented socio-economic landscape was associated with increased livestock losses the following year. Terrain ruggedness was positively, and number of farmworkers negatively, associated with livestock losses. Our study provides further evidence that lethal control of mesopredators in this context is probably counter-productive and supports calls to develop, share and financially support a range of non-lethal methods to protect livestock, especially where natural recolonization of mesopredators is occurring. A graphical abstract can be found in Electronic supplementary material.

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