K型网目对渔用乙纶网片拉伸力学性能的影响     

贾家武 《福建水产》2004,(2):21-25

以网片断裂强力、网片断裂伸长率和网片断裂强力保持率为指标，研究了不同K型网目对渔用乙纶网片拉伸力学性能的影响。结果表明：K型网目下网目内径之比在1.01～1．20时，网片断裂强力随着网目内径之比的增大而下降，两者呈密函数相关。同规格线的网片，K型网目下且两网目内径之比相同时，小规格网目尺寸的网片断裂强力损失小，断裂伸长率高，而大规格网目尺寸的网片断裂强力损失大．断裂伸长率低。  相似文献   

Examining changes in participation in recreational fisheries in England and Wales     

M. W. APRAHAMIAN  P. HICKLEY  B. A. SHIELDS  G. W. MAWLE 《Fisheries Management and Ecology》2010,17(2):93-105

Abstract Inland fisheries in England and Wales have high economic and social values. Managing participation to maximise fishery performance is key to maintaining this status. The capital value of fishing rights for migratory salmonid fisheries is €165 million. Coarse fisheries contribute €1030 million to the economy. The central tenet to increasing participation in recreational salmonid fisheries is that an increase in stock size will result in more anglers accessing the fishery. This was examined for salmon on the rivers Usk and Lune where exploitation restrictions increased the number of salmon available to anglers. On the River Lune, the number of salmon available post‐intervention increased by 66%. There was no significant increase in catch while the number of anglers decreased by 16.3%. On the River Usk, the closure of the net fishery potentially resulted in an additional ～1200 salmon being available. Following closure, there was no significant change in rod catch or in the number of anglers. Increased participation is dependent less upon stock manipulation for coarse fisheries and more upon facilitating the activity. In recent years, urban fishery development programmes have provided improved access to local fishing opportunity. Also, new anglers have been targeted through campaigns such as Get Hooked on Fishing and the Scout Angler Badge.  相似文献   

Most fish destined for fishmeal production are food‐grade fish          下载免费PDF全文

Tim Cashion  Frédéric Le Manach  Dirk Zeller  Daniel Pauly 《Fish and Fisheries》2017,18(5):837-844

Marine fisheries target and catch fish both for direct human consumption (DHC) as well as for fishmeal and fish oil, and other products. We derived the fractions used for each for 1950–2010 by fishing country, and thus provide a factual foundation for discussions of the optimal use of fisheries resources. From 1950 to 2010, 27% (~20 million tonnes annually) of globally reconstructed marine fisheries landings were destined for uses other than DHC. Importantly, 90% of fish destined for uses other than DHC are food‐grade or prime food‐grade fish, while fish without a ready market for DHC make up a much smaller proportion. These findings have implications for how we are using fish to feed ourselves or, more appropriately, how we are not using fish to feed ourselves.  相似文献   

水产品进出口贸易对渔业经济增长的影响——基于沿海地区的面板数据实证分析     

邹欢  武戈 《广东农业科学》2010,37(5):127-131

随着沿海地区经济的不断发展,沿海地区渔业和水产品进出口贸易的发展取得了巨大的成就。以我国沿海地区11个省市2003—2007年的水产品进出口贸易额、固定资产投资额、渔业劳动力和渔业经济产值数据为样本,采用出口扩展型生产函数模型,运用面板数据进行实证分析。实证结果表明:沿海地区各省市水产品出口、进口都对渔业经济增长有正向的拉动作用,且拉动作用的趋势相同。  相似文献   

我国渔业政策与渔业管理问题探讨     

刘克岚  黄硕琳 《上海海洋大学学报》2000,(2):169-171

70年代以来 ,我国黄渤海和东海海域的主要鱼业资源 (ｆｉｓｈｅｒｙｒｅｓｏｕｒｃｅｓ)长期处于衰退状况 ,我国政府意识到海洋资源衰退的时间并不算太晚 ,为此制定和实施了一系列的保持渔业资源的文件和管理法规。建国以来 ,与渔业管理相关的法律、法规性规范性文件达 50 0多件[1] 。表 1　渔船总吨位前 5位的国家 (1 995年 )Ｔａｂ .1　Ｄｅｃｋｅｄｆｉｓｈｉｎｇｖｅｓｓｅｌｓ:ｔｏｐｆｉｖｅｃｏｕｎｔｒｉｅｓｂｙｇｒｏｓｓｔｏｎｎａｇｅ(1 995 )国　　家渔船 (百万吨 )中国 5 .5 5俄罗斯 2 .99日本 1.5 1美国 1.40印度 1.0 8　　…  相似文献   

生物技术在畜牧业上的应用研究   总被引：1，自引：0，他引：1  

陈丽红 《家畜生态》2007,(6)

从生物技术与畜禽品种、动物遗传育种,动物饲料资源开发,动物疫病的预防与诊断几个方面,论述了其在畜牧业中的应用,以期用生物技术来推动我国畜牧业的更快发展。  相似文献   

柴达木盆地资源开发与经济社会发展   总被引：2，自引：0，他引：2  

毛汉英  贾绍凤 《干旱区资源与环境》1998,12(4):14-20

柴达木盆地是中国著名的“聚宝盆”,以盐湖资源、石油天然气、有色金属和多种非金属为主体的矿产资源十分丰富,水土资源开发潜力亦较大。本文分析了柴达木盆地的资源优势,论述了资源开发利用方向,指出了资源开发同盆地经济和社会发展的关系。  相似文献   

植物资源库的建立和管理   总被引：1，自引：0，他引：1  

林欢 《广东林业科技》2000,16(2):48-50

文章阐述了保护和开发植物资源的重要性，据此提出了要建立植物资源库以保存珍、稀濒危植物的种质资源。并根据植物资源库建立的规模，提出了具体的规划方案和管理措施。同时论证了植物资源库的利用价值。  相似文献   

内蒙古杭锦旗穿沙公路沿线水资源合理开发利用   总被引：3，自引：0，他引：3  

张武文  蒋有则  杨存良  刘继萍  姬永明 《干旱区资源与环境》2000,14(1):49-54

内蒙古杭锦旗“穿沙公路”,穿越库布齐沙漠 ,沿线防沙治沙工程及生态工程的建设 ,均与水资源的合理开发利用有密切关系。本文根据已有资料和野外调查结果 ,对公路沿线水资源的基本特征进行了分析 ,提出了水资源合理开发利用的措施和建议 ,可为实践工作所参考。  相似文献   

The fallacy of the missing middle: physics →…→ fisheries     

MICHAEL BAUMANN 《Fisheries Oceanography》1998,7(1):63-65

In this paper I discuss some of the shortcomings of today's marine science in response to a recently published paper by Ann Gargett (1997). Three problem areas have been identified in the field linking climate forcing and fish production: First, the yet-to-be established observational proof for a relationship between the two; Second, the strongly neglected biology of organisms at evolutionary and ecological time scales; and thrird, the disregard for spatial and temporal scales in the discussion of mechanisms and supporting data.  相似文献