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今年广东省中山市将继续实施红树林湿地恢复工程，再投入300多万元营造千亩（15亩=1hm^2，下同）红树林，进一步改善海洋湿地环境。 相似文献
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红树林湿地是生产力最高的湿地生态系统,通过红树林、鱼虾蟹贝、鸟类等之间持续不断的能量流动和物质循环,保持它生机勃勃的自然景象.红树林本身还有御浪固堤、降解污水等重要价值. 相似文献
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<正>滨海湿地是指低潮时水深不足6米的水域及其沿岸浸湿地带,包括河口、浅海、海滩、红树林、珊瑚礁、海草床、海湾等。我国华南地区拥有独特的热带季风气候和地质环境特征,滨海湿地广泛分布,类型多样。广州海洋地质调查局甘华阳博士从事滨海湿地调查已有10年,曾组织开展了"华南西部滨海湿地地质调查和生态环境评价"等项目,查明了 相似文献
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以海南岛湿地为研究对象,运用Meta分析构建海南岛湿地生态系统服务价值转移模型,对其1990、2000、2010和2020年4个时期各类型湿地的价值及其动态变化进行了评估,并探讨了影响价值评估结果的因素及有效性。结果表明：1990—2020年间海南岛湿地生态系统服务价值呈现递增的趋势,30年间湿地价值共增加了95.32亿元,增长率达41.32%,其中水产养殖场和库塘价值增加最多,分别增加了66.55亿元和42.61亿元;2020年海南岛湿地生态系统服务价值为326.02亿元,平均价值为24.17万元/hm2,其中红树林湿地单位面积价值最高,达38.25万元/hm2,其次为河流湿地,单位面积价值为25.81万元/hm2,盐田湿地单位价值最低,为14.37万元/hm2;在Meta回归模型中,湿地面积、盐田、碳税法、保护力度等变量对湿地单位面积价值表现为负效应,而红树林、物质生产、气候调节、保持土壤、旅游休闲、人口密度等变量对湿地单位面积价值表现为正效应;模型的平均转移误差为18.82%,在可接受的误差范围内,表明本研究构建的Meta价值转移模型可以作为快速评估海南岛湿地价值的一种有效方法。研究结果可为海南岛湿地资源保护和生态系统服务价值提升管理提供科学依据。 相似文献
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A report is presented of esophagoscopy and gastroscopy in cats and dogs using flexible endoscopes. Following consideration of the basic equipment, an account is given of patient preparation and anesthesia, topography, investigation technique and normal findings. Diagnostic potential, indications and risks involved are discussed. 相似文献
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中国鲟鱼的保护、管理与产业化 总被引：9，自引：1，他引：9
1 世界现存鲟鱼的种类和资源鲟鱼是一类起源早、具有重要科学研究价值和极高经济价值的稀有物种 ,多数种类个体大 ,半数种为溯河洄游产卵鱼类。按目前较为公认的分类系统 ,现存鲟鱼类有 2科 6属 2 7个种 ,隶属于硬骨鱼纲、软骨硬鳞总目、鲟形目 (Acipenseriformes) ,其中鲟属有 17个种 ,主要经济种类在其中。它们全部分布于北半球 ,现存 9个自然分布区为 :太平洋东岸、北美大湖地区、大西洋西北部、北美密西西比河流域和墨西哥湾、大西洋东北部、里海地区、西伯利亚及北冰洋流域、黑龙江和日本海、长江和珠江。鲟鱼自然种群资源稀少 ,在过… 相似文献
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J A Beardmore 《Aquaculture Research》2005,36(10):1035-1036
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D. C. Dauwalter 《Fisheries Management and Ecology》2013,20(4):289-301
Energy development threatens fish and wildlife resources worldwide. This study used constrained ordinations to show fish assemblage structure associated with oil and gas well densities in the Colorado River Basin, Wyoming, but well densities explained only 6.4% of assemblage structure when compared to other factors. Threshold Indicator Taxonomic ANalysis showed significant negative threshold responses by some species to small levels of development (<0.15 wells km?2), whereas positive thresholds were less distinct. Some native and imperilled species could be disproportionately affected if future oil and gas development proceeds in a manner that will impact aquatic resources. Although existing development has not substantially influenced regional fish assemblage structure, it appears to affect a subset of species. Understanding assemblage‐level responses to development can help land managers determine appropriate development levels, prioritise areas for monitoring associated with future development and identify where land protection measures may be needed to offset potential risks. 相似文献
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20 0 1年 ,江苏省高邮市农林局与中国水产科学研究院淡水渔业研究中心及扬州市春申生物化工有限公司共同承担了江苏省水产更新工程项目———“虾、蟹专用肥料的开发研究与推广”。经项目组人员的共同努力 ,现已顺利完成项目任务 ,研究开发的虾、蟹专用肥在试用和大面积推广应用中取得了显著效果。虾、蟹专用肥已被列为江苏省第一批无公害水产品基地拟用鱼药、饲料推荐产品 ;也是江苏省水产技术推广站、安徽省水产技术推广站、江苏省高邮市农林局、江苏省兴化市水产局、江苏省宝应县水产局、安徽寿县水产局等十多个水产行政主管和技术推广部… 相似文献
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Analysis of intestinal contents of silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis) showed that silver carp consumed primarily phytoplankton while bighead carp consumed large quantities of zooplankton and detritus in addition to phytoplankton. The size of particles filtered by the bighead carp was larger (17–3,000 μm) than that filtered by silver carp (8–100 μm). Artificial feed was readily consumed by bighead carp but not by silver carp. No growth difference was indicated for silver carp in fertilized ponds and ponds receiving artificial feed. Growth of bighead carp increased substantially with the addition of artificial feed. Silver carp grew more rapidly in cages than bighead carp. 相似文献
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Claude E. Boyd Louis R. D'Abramo Brent D. Glencross David C. Huyben Lorenzo M. Juarez George S. Lockwood Aaron A. McNevin Albert G. J. Tacon Fabrice Teletchea Joseph R. Tomasso Jr Craig S. Tucker Wagner C. Valenti 《Journal of the World Aquaculture Society》2020,51(3):578-633
Important operational changes that have gradually been assimilated and new approaches that are developing as part of the movement toward sustainable intensive aquaculture production systems are presented via historical, current, and future perspectives. Improved environmental and economic sustainability based on increased efficiency of production continues to be realized. As a result, aquaculture continues to reduce its carbon footprint through reduced greenhouse gas emissions. Reduced use of freshwater and land resources per unit of production, improved feed management practices as well as increased knowledge of nutrient requirements, effective feed ingredients and additives, domestication of species, and new farming practices are now being applied or evaluated. Successful expansion into culture of marine species, both off and on shore, offers the potential of substantial increases in sustainable intensive aquaculture production combined with integrative efforts to increase efficiency will principally contribute to satisfying the increasing global demand for protein and food security needs. 相似文献
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“十一五”以来,我国农垦加快体制机制改革、结构调整和经济增长方式的转变的步伐,参与市场竞争,努力提升企业和产品竞争力,经济社会事业发展较快,对国家的贡献提升,职工收入、生活质量明显提高和改善,示范引领作用不断增强。本文针对农垦体制机制创新进展滞缓,战略定位与发展方向不明,经济增长方式转变和结构调整缺乏资本、人才、技术的支撑,没有处理好改革、发展、稳定、民生的关系,投资匮乏,发展后劲不足,人才短缺和劳动力素质低下的现状,提出在未来农垦体制机制创新中要特别关注改革方向、目标设定与评估,改革要在现行法律法规的框架内运作,改革时机的选择,处理好改革发展稳定与民生的关系,调整好内部利益分配关系,自觉融入区域经济,与地方协同发展等问题。为了促进农垦的发展,建议国家加大对农垦体制机制创新、现代农业建设、国有农场土地资源的保护、社会保障体系的完善等财政和政策的支持力度。 相似文献
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本试验利用饲养试验方法,研究玉米-豆粕型日粮中添加植酸酶时不同磷水平和钙磷比对生长肥育猪血清指标和骨骼性能的影响。试验选用162头20kg左右的杜长大三元杂交猪进行2×3(磷水平×钙磷比)因子饲养试验,试验分2个阶段进行,前期为生长期体重在20-60kg,后期为肥育期体重为为60-100kg。结果表明:添加植酸酶日粮磷水平对血清磷含量和碱性磷酸酶的活性影响显著(P<0.05);钙磷比对血清钙和血清磷含量的影响显著(P<0.05);添加植酸酶日粮磷水平和钙磷比对生长肥育猪骨骼性能的影响不显著(P>0.05)。在添加植酸酶条件下,降低日粮磷水平不影响猪的正常生长发育。 相似文献