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对中型草型湖泊网湖鲢、鳙、草鱼在混浊水体中、多水草区以及草排区内对声与网具反应行为研究表明，鲢、鳙能基本结群、草鱼能部分或大部分结群被驱集至预定区域。可用集中型渔具渔法来取代原分散型个体单船体网作业。对三种集中型渔具渔法进行了比较研究，结果表明第三种亦即插拦、驱集、刺缠、Ｓｈｅｎ捕集中型渔具渔法最适宜中型草型湖泊鲢、鳙、草鱼的捕捞，年起捕率为８６．２％－９８．６％。 相似文献
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1975年9月22～25日在美国加利福尼亚州圣迭戈举行了代号为“0cean75”的海洋环境工程讨论会和海洋技术学会第11届年会的联席会议。会上B．A．Christensin介绍了网渔具模型水槽试验的相似准则。过去已发表的网渔具模型相似准则，主要考虑阻力(惯性力)和重力， 相似文献
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梭子蟹在福建俗称:(虫戈)。厦门鼓浪屿一些海洋捕捞船只在70年代初始创的一种专捕三疣梭子蟹的钓渔具,由于没有装置刺挂渔获物的钓钩,只有诱捕渔获对象的“饵包”渔民根据渔获对象和渔具结构的特征,称这种钓渔具为:“(虫戈)包”(1)。 “(虫戈)包”的结构苘单、独特,其对应捕捞的性能比较完美,捕捞效果较佳,同时,在渔具研究的范畴,它填补、充实和丰富了渔具研究的内容;打破人们对钓渔具类渔具的认识局限;使渔具分类更加系统、完整,从这一角度看它更具有比较重要的学术价值。 相似文献
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幼鱼，俗称“海蜒”，又名鲅鱼食，每年９月下旬至１０月中旬集群索饵洄游山东龙口近海，成为该市沿海地方资源，但是要使这一丰富的地方资源得到合理利用，必须首先考虑经济幼鱼的保护。因此，根据各种鱼类洄游习性，龙口市水产技术站的技术人员对传统拉网渔具进行大胆革新改进，于１９９８年９月研制出一种能释放经济幼鱼，专捕“海蜒”的先进渔具——“双翼加裙拉网”。该渔具经沿海渔民几年的推广使用，并在生产实践中不断加以完善，达到了专捕“海蜒”，释放经济幼鱼超过９８％以上的好效果，获得水产专家的一致好评，受到沿海广大渔工… 相似文献
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长江流域是我国内陆最重要的鱼产区之一。由于地域广阔、地貌差异显著，水域类型众多．鱼类资源丰富、捕捞渔业历史悠久。长江流域渔具在我国内陆水域渔具中既有很强的代表性，又表现出一定的地域特征。本文依据《渔具分类、命名及代号》国家标准（GB5147—85）。将长江流域原分属于5部20类的161种渔具划分并命名为12类32型73式．比较、分析了不同分类、命名方法及划分结果，并对国家标准的个别条款提出了商榷。 相似文献
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人们习惯利用刺网或大型抄网轮捕池塘养殖的罗非鱼。虽然两者之捕捞效果均不错，但是，刺捕摘鱼相当麻烦费时，容易伤及其他养殖鱼类，而且渔获物不易暂养；抄捕则嫌网产不高，单位渔获物耗时多。为此，笔者把江河小型渔具——罾应用于池塘轮捕罗非鱼，收到了较好的效果。现总结如下。 相似文献
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为了提高拖网作业的经济效益，同时减轻底层鱼类的捕捞压力，1996年福建省莆田市对原有的单拖作业进行渔具渔法改革，改单拖作业为兼作流目网对拖作业，改变原有的单拖作业单纯捕捞底层鱼类为兼捕中上层鱼类。经过一年的实施．取得了一定的经济效益。现将单拖作业渔具渔法改革技术介绍如下：一、改革规模改20艘单拖作业渔船为门对兼作对施作业船。兼作对拖作业渔船中2IOk。。的渔船6对，198kw的渔船2对，265kw的渔船2对。每对作业渔船配备相应的疏目拖网l－2张。二、渔具1、网具规格：11Oh。。的对拖作业渔船配备的网具网四周长为80二X3m… 相似文献
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海南“石斑鱼苗网”渔具属性辨析 总被引：1，自引：2，他引：1
对在2004年7~8月间南海区小型海洋渔具渔法调查中发现的“石斑鱼苗网”的渔具结构、属性、性能和管理进行了分析讨论,研究认为“石斑鱼苗网”属于敷网类,网团型,延绳式。对石斑鱼苗有良好的诱捕效果,从保护资源的角度出发,应对其实施规范管理。 相似文献
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Fishing profiles of Danish seiners and bottom trawlers in relation to current EU management regulations 
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下载免费PDF全文 T. Noack R. P. Frandsen K. Wieland L. A. Krag F. Berg N. Madsen 《Fisheries Management and Ecology》2017,24(6):436-445
Danish seines and bottom trawls operate differently and have different catching processes. Both gears belong to the same legislative category in European fisheries, but different management strategies in other countries and criticism by fishers on grouping Danish seines and trawls together indicate disagreement on current gear classification. This study compared both gears in terms of their fishing characteristics and catches of commercial species based on 16 years of observer data. Danish seining is a specialised fishing method that targeted few species but with higher total catch rates than bottom trawlers. Bottom trawling is a more all‐purpose fishing method that targets a larger number of species, and bottom trawlers use larger engines than Danish seiners. A generalised additive mixed model indicated that catch rates of flatfish are generally higher for Danish seines, and catch rates of roundfish species are higher for trawlers. The results do not directly suggest a separation of the gears in terms of legislation as the quantities of fish below current minimum size were similar, but for example future survival studies may reach different conclusions. Additional factors were found to be important in determining catches of both gears. 相似文献
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Influences of gear type and analytical methodology on fish assemblage characterisations in temperate lakes 下载免费PDF全文
下载免费PDF全文 C. J. Sullivan D. P. Coulter Z. S. Feiner S. B. Donabauer T. O. Hk 《Fisheries Management and Ecology》2015,22(5):388-399
A variety of gears and analytical methods can be used to characterise lentic fish assemblages; however, the combined influence of gear type and analysis can affect conclusions about assemblage patterns. Fish assemblages sampled with night electric fishing, gillnets and trapnets from 153 lakes were evaluated using summary indices of species composition, pairwise community similarity comparisons and multivariate ordination. For a given amount of effort, electric fishing had the highest species richness, while gillnets had higher diversity and evenness. Pairwise comparisons between gears revealed that (1) richness was positively correlated among all gears, (2) diversity and evenness were generally not correlated across gears and (3) electric fishing and trapnets captured more similar species than all other pairwise comparisons. Gear‐specific multivariate correlation and ordination revealed that gillnet and electric fishing samples more similarly characterised variation in assemblages among lakes, while trapnets characterised assemblages along different gradients of species composition. These results indicate that either electric fishing or trapnetting can be used when assessing shallow‐water assemblages for diversity or evenness, gillnets and either electric fishing or trapnets should be used for whole‐lake assessments, and either gillnets or electric fishing should be used when evaluating regionwide variation in lake assemblages. 相似文献
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废弃渔具(ALDFG)像幽灵一样长期在海洋中飘荡,导致一些海洋生物被网具缠绕而死,对渔业资源造成持续危害,形成“幽灵捕捞”现象。废弃渔具类型主要包括陷阱、刺网、拖网等。通过探讨造成幽灵捕捞的原因,总结了幽灵捕捞的现状和国内外研究进展;针对容易形成幽灵捕捞的渔具种类,介绍了ALDFG的结构与捕捞作业机理,阐述了陷阱、刺网、拖网等的幽灵捕捞过程,并对各种渔具造成的幽灵捕捞的影响进行了评估。最后总结目前对幽灵捕捞渔具的预防和应对措施,提出了减少幽灵捕捞的方法和建议。 相似文献
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The relationship between fishing methods, fisheries management and the estimation of maximum sustainable yield 总被引：2，自引：0，他引：2
Mark N Maunder 《Fish and Fisheries》2002,3(4):251-260
The allocation of effort among fishing gears is as important as controlling effort with respect to both sustainable yield and ecosystem management. Differences in age‐specific vulnerability to the fishing method can modify the maximum sustainable yield (MSY) that is obtainable from a fish stock. Different gears or methods are more or less selective for the species targeted, and MSY is rarely, if ever, attainable simultaneously for all species. The different fishing methods capture different types of nontarget species. Some methods will often be more profitable than others, and different user groups will prefer different methods. In many fisheries, it is unlikely that fishing can be limited to a single gear or method, so compromises among them will be required. Global MSY is discussed as a possible reference point for fisheries management. The yellowfin tuna fishery in the eastern Pacific Ocean (EPO) shows all the above characteristics and is used to illustrate effort allocation among fishing methods. 相似文献
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为解决涉海工程深水渔业资源评估的问题,于2014~2015年在南海北部局部海域开展底拖网与灯光罩网联合调查渔业资源活动。结果表明:在深水区底拖网渔获组成与灯光罩网有明显的不同,并受到季节与海域的影响(P0.05)。拖网渔获物中鱼类平均占渔获总尾数的93.36%,头足类占3.53%,甲壳类占3.11%;灯光罩网渔获物中鱼类平均占渔获总尾数的63.33%,头足类占36.65%,甲壳类占0.02%。两种调查的相同渔获物1~6种,主要为鱼类和头足类,在拖网中所占比值较低,平均占渔获总尾数的2.07%,而在灯光罩网中比值极高,平均占渔获总尾数的67.03%。灯光罩网与底拖网调查的渔业资源密度直接比值平均为0.06,灯光罩网与底拖网扣除相同渔获种类后的资源密度比值平均为0.06,相应的质量密度直接比值平均为0.62,扣除相同渔获种类后的比值平均为0.67。研究认为,深水海域的渔业资源量应该是两种渔具调查结果之和,对两种渔具调查中出现的相同渔获物,宜取其评估数据的平均值。由于各站点调查结果差异较大,采用所有站点的平均值来计算评估海域的损害赔偿较为合适。建议对SC/T9110-2007技术规程修订,规范中上层渔业资源调查方法。 相似文献
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1. Preliminary estimates of the relative sensitivity of sea bed types and benthic species to physical disturbance, particularly fishing activity, have been made in order to identify areas where further studies are required and to help formulate management plans for sites of marine conservation importance. 2. Physical disturbance is considered in the context of a single encounter with fishing gear followed by a recovery period during which there is no fishing, but with a view to qualifying, in the future, the effect of multiple fishing events. Disturbance is considered in terms of the physical action of the gear on the sea bed and the unit area over which this action occurs. 3. The effects of a wide range of gears are considered. Static gears, which can be employed on a variety of substrata, generally result in low level impacts for single fishing events and impacts are localized compared with the effects of mobile gears, which can extend over considerable areas. 4. The theoretical sensitivity of individual species is assessed on the basis of how well they cope with an encounter with fishing gear and on their likely recovery from destruction in terms of their reproductive strategies. 5. Species considered of key importance in the structuring of communities are suggested and examples of particularly sensitive species, which are therefore likely indicator species of physical disturbance, are listed. 6. Fragile, slow recruiting animals are considered to be most susceptible to disturbance, while the least sensitive species are generally fast growing and have good recruitment. ©1996 by John Wiley & Sons, Ltd. 相似文献
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悬链线和抛物线理论在金枪鱼延绳钓渔业中的应用 总被引：2，自引：1，他引：2
本文依次用悬链线和抛物线理论分析推导了金枪鱼延绳钓具的两种投放方法以及在渔场各水层相同流态下钓具充分沉降后所有钓钩位置包括深度和相互间水平间距的计算公式 ,可用于作业参考。 相似文献
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The biological impact and the social characteristics of different artisanal (professional) and recreational fishing techniques on the marine resources of a coastal Mediterranean area were compared. Data were from artisanal and recreational surveys carried out between 2006 and 2010. Competition between recreational (particularly spear fishing) and artisanal fishers for the natural resources is important as 52% of the 98 species surveyed were caught by both types of fishers. A total of 87 species were caught by all artisanal fishing gears together (of which 84% were retained and 16% discarded). Recreational fishing caught 58 species of which none was systematically discarded. The two fishing techniques that raise major environmental concerns are spear fishing (very selective in terms of species and/or sizes and high intrinsic vulnerability of catches) and trammel netting (highest number of species discarded and highest number of species endangered). Important challenges from the social standpoint were found that need to be taken into account in the management of coastal fisheries in the Mediterranean Sea including: progressive disappearance of the artisanal fisheries, ageing of the artisanal fisher populations and decline in the number of fishing gears used by artisanal fishers. 相似文献