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1.
为了研究桁杆虾拖网40 mm方目分离网片对渔获物的分隔效果和选择性,作者采用"套网法"于2015年8月在南海北部近海渔场进行了试验。计算分离网片对主要渔获物的尾数分隔率和质量分隔率,使用Logistic曲线作为选择性模型,运用极大似然估算法估算选择性参数。结果表明:虾拖网的目标种类为刀额新对虾(Metapenaeus ensis)和周氏新对虾(Metapenaeus joyneri),优势副渔获为丽叶鲹(Caranx(Atule)kalla);刀额新对虾和周氏新对虾的尾数分隔率和质量分隔率均大于90%;尾数分隔率和质量分隔率均大于80%的种类有:杂食豆齿鳗(Pisoodonophis boro)、黄斑蓝子鱼(Siganus oramin)、高体若鲹(Carangoides equula)和卵鳎(Solea ovata Richardson);丽叶鲹和脊突猛虾姑(Harpiosquilla raphidea)的尾数分隔率和质量分隔率均大于60%;周氏新对虾、脊突猛虾姑、丽叶鲹和黄斑蓝子鱼对分离网片的接触率分别为0.51、0.69、0.41和0.39,其50%选择体长(L50)分别为57.96±2.07、69.62±2.13、68.19±0.49和73.12 mm±1.26 mm。研究结果可为提高南海桁杆虾拖网的选择性积累数据,为缓解其对渔业资源补充群体的不良影响提供参考。 相似文献
2.
渔业的副渔获作为本世纪初以来全球渔业管理的重大问题已被科学家们承认,并对其引起了极大的关注。80年代初以来,多种水产刊物上发表的大量关于渔业副渔获问题的论文和报告,副渔获及抛弃已成为全球渔业管理的一个焦点,也是国际渔业论坛的热门话题。全球目标渔获量为7 700万mt,抛弃量估算为1 790～3950万mt,平均为2 700万mt, 相似文献
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为了探明南海北部虾拖网副渔获的种类组成、优势种类和幼鱼比例等情况,2012年8月1~5日作者于湛江近海进行了虾拖网副渔获调查。结果表明:湛江近海虾拖网副渔获种类极多,副渔获物与虾类的质量比为3.9:1;副渔获物的主要种类为蟹类和鱼类;蟹类副渔获物的优势种类分别为红星梭子蟹(Portunus sanguinolentus)、三疣梭子蟹(Portunus trituberculatus)和远海梭子蟹(Portunus pelagicus),其相对重要性(IRI)分别为7558.72、6540.72和2826.41;鱼类优势副渔获物的种类分别为褐斑三线舌鳎(Cynoglossus trigrammus)、少鳞鱚(Sillago japonica)、多齿蛇鲻(Saurida tumbil)和六带石斑鱼(Epinephelus sexfasciatus),其IRI分别为3158.94、1755.57、1294.44和1058.46;副渔获物的幼鱼比极高。最后,作者结合相关研究,对如何从技术层面解决南海区虾拖网严重的副渔获问题进行了探讨,以促进南海区虾拖网渔业的可持续发展。 相似文献
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挪威的渔业管理政策长期以来保证了海洋资源的合理开发。50年代后期,由于鳕和平鲉幼鱼副渔获量巨大而封禁了100米以浅的虾渔场。此后在60年代中期,又由于出现零年龄级群体的鳕和黑线鳕而把渔场限制区扩大到北挪威270米以浅水域。当时拖网捕鱼避开副渔获(尤其幼鱼副渔获)的基本 相似文献
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在澳大利亚新南威尔士,河口对虾拖网作业遍及5个渔港,年产值约700万澳元,与世界大多数对虾拖网渔业一样,大量非目标生物,即副渔获,与目标对虾一起被附带捕获。 80年代中期,虾拖网渔业的副渔获成为各国家日趋担忧的问题。1990年～1992年为期3 相似文献
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使用小网目网具被认为是一个特别令人忧虑的问题。因为,大量幼鱼和非目标鱼种被作为副渔获物捕获并杀害。这些副渔获中多数是没有市场价值的或是无用的。因此导致很大浪费。美国南部的虾渔业对鳍鱼和海龟种群造成颇大的死亡数,1985～1989年仅美国墨西哥湾近海水域虾队船每年的鳍鱼副渔获总量大约为 相似文献
8.
近年来,澳大利亚研究人员已研制了各种副渔获减少装置(BRDs)来减少通常在虾拖网副渔获中占优势的小鱼渔获量。这些BRDs有许多(如“鱼眼”、方形网目窗等)是根据鱼的游泳能力比虾强这一特点来帮助鱼类排出拖刚的。这些BRZDs安装在网囊的上部,泳力较强的鱼游过逃逸口,虾被动地落入网囊之中。 相似文献
9.
斜向入射波与反射波的分离 总被引：7，自引：0，他引：7
提出了一种分离斜向入射波和反射波的方法,波浪可以是规则波、不规则波,波向可以任意.在一定的限制条件下,采用两点浪高仪的波浪信号就可将斜向入射波和反射波分离. 相似文献
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11.
《Marine Policy》2017
Small-scale fisheries have been estimated to contribute up to 30% of the global landed value, which is caught by approximately 22 million fishers, some of which can be attributed to developed countries. Socio-economic analysis of small-scale fisheries often focuses on developing countries and fails to recognize the presence and contribution of small-scale fisheries in the developed world. Fisheries in British Columbia are diverse and often regarded as being industrialized and large-scale when analyzed in a global context. This study aims to demonstrate that features of small-scale fisheries are present within British Columbia's fleets. A list of re-occurring features of small-scale fisheries is curated from the literature to capture physical, economic and social features of small-scale fisheries. These commonly identified features of small-scale fisheries are applied to Aboriginal Food, Social and Ceremonial fisheries and all commercial fisheries in British Columbia are analyzed to determine the presence or absence of each small-scale fishery feature. The results of this research create a gradient of fisheries from smallest to largest scale. This approach determines that Aboriginal Food, Social and Ceremonial fisheries are the most small-scale, while the sablefish fishery is the largest scale. The qualitative nature of this framework creates an opportunity for any group of fisheries in the world to be compared. 相似文献
12.
Small-scale marine fisheries policy in Vietnam 总被引：1，自引：0，他引：1
Vietnam's marine fisheries are considered to be small scale and are concentrated in coastal near-shore waters. This has resulted in heavy pressure on near-shore fisheries resources. Near-shore fisheries are considered by fishers and the government to be over-exploited, causing hardship for many coastal communities. This paper reviews and analyzes changes in policy towards small-scale fisheries in Vietnam over the last two decades. The primary issues facing the small-scale fisheries in Vietnam are to restructure the near-shore fisheries and to address over-capacity. Recommended actions include improved fisheries statistics, resources for provincial fisheries staff, and a coordinated and integrated approach involving a mixed strategy of resource management; resource restoration; economic and community development; and new governance arrangements. 相似文献
13.
渔业社区管理在中国的实施探讨 总被引：4，自引：0，他引：4
传统的渔业管理强调了政府的直接控制管理,忽视了渔区在其中的作用。渔业社区管理是随着市场经济和政府管理的发展而被作为一种解决传统渔业管理困境的途径提出。为此,首先总结了渔业社区管理的概念,并对目前有关各国的实践进行分类。在此基础上,利用制度经济学的理论分析该管理制度的作用机制及实施条件。然后,分析该管理制度在我国实施的必要性和可行性,渔业社区管理是解决目前我国渔业管理中存在诸多问题的一种合适方案,且当前国家政策和渔区实际也为其提供良好的实施环境。最后,提出从政府管理者和渔民或与渔业相关的利害人两个方面创造实施渔业社区管理的条件。 相似文献
14.
Designing ITQ programs for commercial recreational fishing 总被引：1，自引：0，他引：1
This paper discusses the potential for implementing individual transferable quota (ITQ) schemes in commercial recreational fisheries, focusing particularly on charter and headboat fisheries. After a brief discussion of ITQs in commercial fisheries, the paper discusses the manner in which rents get dissipated in commercial recreational fisheries. Fishing mortality in recreational fisheries is determined as a joint outcome of angler behavior and trip supply. In the recreational sector under open access conditions, there are likely to be too many vessels providing too many trips at prices that are too low. Vessel input configurations are likely to be distorted in a manner that generates excessive fishing mortality. Designing ITQs for recreational fisheries requires consideration of issues not prominent in the design of commercial fisheries. Among the most important is the manner in which angler preferences and types affect overall mortality from both landings and discards. While catch and release fisheries and pure food fish recreational fisheries are relatively easy to manage with recreational ITQs, fisheries with both angler types present difficult monitoring problems that add complexities to ITQ design. Various ways to design programs that account for both landings and discard mortalities and that generate incentives for anglers and vessel owners to reduce discard mortality are discussed. 相似文献
15.
Fisheries observers can both collect scientific data and report on compliance with fisheries regulations. Observers are used only for scientific purposes in most US fisheries. However, North Pacific groundfish fisheries observers are required to report violations of fisheries regulations that they witness. Based on evaluation of historical enforcement incidents and survey data, this paper considers the effects of mandatory reporting in the North Pacific. The goal of this analysis is to determine whether and how observer enforcement in the North Pacific differs from observer enforcement in other US fisheries and to determine what benefits observer enforcement might yield if adopted in other fisheries. 相似文献
16.
《Marine Policy》2017
Eco-labeling is a market-driven mechanism to promote sustainable fisheries. The most widely used certification scheme for seafood eco-labeling is issued by the Marine Stewardship Council (MSC), but the MSC has been criticized for favoring large-scale industrial fisheries. The benefits from eco-labeling can potentially be significant, ranging from price premiums to enriched understanding of fisheries management among fishers; however, anecdotal evidence from MSC-certified fisheries across various countries highlights the struggle of many small-scale fisheries to meet the costs of certification. The lack of environmental awareness in domestic markets can impede the spread of MSC eco-labeling among small-scale fisheries. In the absence of consumer preferences for seafood sustainability, and without subsidies, the certification may not be an appropriate tool for small-scale seafood producers. Examination of the case of an MSC-certified small-scale fishery suggests some efforts to achieve economies of scale; multi-species fisheries can apply for MSC certification as a single unit of assessment, and fisheries can cooperate with neighboring fisheries that target the same fish stock to share assessment costs. In a market where no price premium has been generated, effective face-to-face marketing is pivotal. The MSC will need to be committed to pursuing price premiums in new markets if it is to extend its reach further to small-scale fisheries. 相似文献
17.
Systems engineering principles in fisheries management 总被引：3，自引：0，他引：3
Fisheries management receives valuable, but often fragmented information from academic disciplines such as biology, economics, and social sciences. A multi-disciplinary perspective seems to be necessary if the fisheries are to become sustainable. Globally, overcapacity is considered as the most serious threat to sustainable fisheries, which indicates the need for a stronger integration of technological aspects into fisheries management. This paper discusses application of systems engineering principles and integration of technology into fisheries management. The systems engineering process facilitates implementation of multi-disciplinary information from researchers to fisheries managers in the decision-making towards sustainable fisheries, but may also be used to overcome multi-disciplinary obstacles among scientists. The article concludes that use of systems engineering principles may become a valuable contribution to fisheries management because of increased transparency and reduced risk associated with the decision-making process. 相似文献
18.
Since the 1970s, small-scale fisheries have had an important place in fisheries social science and in fisheries management. While there has been substantial discussion of what constitutes the category of small-scale fisheries, its considerable ambiguity is nevertheless often passed over. This paper argues that while the category of scale fisheries can be best understood in terms of scale, the underlying reason for the power of the category lies in the values of social justice and ecological sustainability that it has come to represent in response to dominant high modern narratives of change. Fisheries governance may better be served by prioritising these values rather than by making a fetish out of small-scale fisheries. 相似文献
19.
Sustainable fisheries are the main objective of Norwegian fisheries management. Despite powerful management tools, sustainability in the fisheries sector is not an easy task. There is no formal definition of the concept, and operationalization is vague. In recent years, private actors and non-governmental organizations (NGOs) have increased their impact on defining sustainability in the fisheries, which has reduced the power of the traditional fisheries management to determine its content. The lack of a clear strategy for fisheries management to increase sustainability makes it timely to address three research questions: (i) what is meant by “sustainable fisheries”, (ii) to what extent has the institutionalization of the Norwegian fisheries management channeled the sustainability concept towards specific trajectories, and (iii) what are the options and hard choices available to increase sustainability in the Norwegian fisheries in the future? These questions are investigated in this article. 相似文献
20.
《Marine Policy》2014
There are tradeoffs in managing fisheries, and ideally such tradeoffs should be known when setting fisheries policies. An aspect of this, which is rarely considered, is the spin-off effect of different fisheries: the economic and social benefits that fisheries generate through processing through distribution and on to the end consumer. This study evaluated the benefits generated in the Peruvian marine fisheries sector through a comprehensive value chain analysis, based on a newly-developed combined ecosystem-economic modeling approach, which was integrated in the widely-used Ecopath with Ecosim approach and software. The value chain was parameterized by extensive data collection through 35 enterprise types covering the marine fisheries sector in Peru, including the world's biggest single-species fishery for anchoveta. While anchoveta is what is known about Peruvian fisheries, the study finds that anchoveta accounts for only 31% of the sector contribution to GDP and for only 23% of the employment. Thus, while anchoveta indeed is the fundamental fish species in the Peruvian ecosystem, there are other fisheries to be considered for management. The study indicates that the economic multipliers for Peruvian fisheries were 2.9 on average over the industry, and that these varied surprisingly little between fleets and between seafood categories indicating that the multipliers can be used beyond Peru to generalize the spin-off effect of the value chain. Employment multipliers vary much more across types of fisheries, but also around an average of 2.9; here it was clear that longer value chains result in more employment. 相似文献