首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1篇
  完全免费   2篇
  水产渔业   3篇
  2017年   1篇
  2013年   1篇
  2008年   1篇
排序方式: 共有3条查询结果,搜索用时 139 毫秒
1
1.
林海  周刚  李旭光  周军 《水产学报》2013,37(3):417-424
为探讨夏季池塘养殖河蟹系统温室气体的排放规律及综合增温潜势,试验采用静态暗箱-气相色谱法对池塘养殖河蟹生态系统温室气体(CO2 、CH4 、N2O)的排放进行原位测定。结果显示,夏季河蟹养殖池塘均表现为CO2 、CH4 和N2O的源,其中CH4夏季排放量达(42.62±9.55~95.09±10.89)g/m2,CO2排放量达(6.91±2.18~12.52±3.11)g/m2,N2O有微弱排放;夏季河蟹池塘保持一定的水生植物覆盖能显著减少CO2/ CH4的排放,较无水草种植区域,减少CO2排放 52.47g/m2,减少CH4排放 5.61 g/m2,对N2O排放无显著性影响;种植水生植物减缓综合温室效应的潜力是不种植水生植物的1.85倍,池塘养殖河蟹生态养殖温室气体减排空间巨大。  相似文献
2.
This paper evaluates the resource and energy requirements of six different types of land-based, hatchery production systems located in the U.S. Pacific Northwest: flow-through with a gravity water supply, flow-through with a pumped water supply, flow-through with pure oxygen, partial reuse system, partial reuse with heating, and a reuse system for the production of Atlantic salmon (Salmo salar) smolts. Key parameters used in the evaluation include direct energy, indirect energy, transportation energy, greenhouse gas emissions, and pollutant discharges.Power (electricity and natural gas) and feed energy accounted for the majority of the required energy for all the rearing option evaluated. The sum of the fixed capital and chemicals components accounted for less than 2–12% of the total energy budget for any rearing option. The energy efficiency (energy output/energy input) of the six options ranges from 0.97% for flow-through with pumped supply to 3.49% for the flow-through with gravity supply. The rearing options with the three highest energy efficiencies were flow-through with gravity supply (3.49%), partial reuse (2.75%), and reuse (2.64%).On a kg of smolt produced basis, the six rearing options showed a wide range in performance. The reuse system had the lowest water (2 m3 kg− 1) and land (0.13 m2 kg− 1) requirements and the third lowest total energy requirement (288 MJ kg− 1). The partial reuse system had the second lowest total power requirement (276 MJ kg− 1), a low land requirement (0.21 m2 kg− 1), and moderate water requirements (33 m3 kg− 1). The partial reuse with temperature control had the second highest total power requirement (657 MJ kg− 1) and land and water requirements similar to the partial reuse system without temperature control. The flow-through system with pumped water supply had the highest water (289 m3 kg− 1), land (2.19 m2 kg− 1), and energy requirements (786 MJ kg− 1) of any of the rearing options. By comparison, the flow-through system with gravity water supply had the lowest energy requirement (218 MJ kg− 1), a moderate land requirement (0.78 m2 kg− 1), and a high water requirement (214 m3 kg− 1). The ranking of the six rearing options based capital and operating costs are likely to be quite different from those based on energy, water, and greenhouse gas emissions.  相似文献
3.
The literature on sustainable diets is broad in its scope, and application yet is consistently supportive of a move away from animal‐based diets towards more plant‐based diets. The positioning of seafood within the sustainable diet literature is less clear. A literature review was conducted to examine how the environmental impacts of seafood consumption are assessed and what conclusions are being drawn about the inclusion of seafood in a sustainable diet. Seafood is an essential part of the global food system but is not adequately addressed in most of the sustainable diet literature. Aquaculture, the world's fastest growing food sector, was considered by very few papers. Seafood consumption was commonly presented as a dilemma due to the perceived trade‐offs between positive health outcomes from eating seafood and concerns of overfishing. A number of studies included seafood as part of their sustainable diet scenario, or as part of a diet that had lower impacts than current consumption. Most of the indicators used were biophysical, with a strong focus on greenhouse gas emissions, and very few studies addressed biological or ecological impacts. The assessment of seafood was limited in many studies due to relevant data sets not being incorporated into the models used. Where they were used, data sources and methodological choices were often not stated thereby limiting the transparency of many studies. Both farmed and wild‐capture production methods need to be integrated into research on the impacts of diets and future food scenarios to better understand and promote the benefits of sustainable diets.  相似文献
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号