首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
This paper focuses on the management and socio-economic principles for allocation of the commercial fish resources of Lake Peipsi-Pihkva. The fish resources of this cross border lake are very important both for Russia and Estonia. Recent changes in the Estonian and Russian economies, and the appearance of the state border dividing the lake, have resulted in deep changes in economic, social and legal issues related to the fishery. As the lake is now an international waterbody, the Intergovernmental Estonian–Russian Fishery Commission (ERFC) agreed for co-operative management measures annually from 1994. The ERFC is responsible for all general decisions on management strategies and technical measures used in fishery management. The stocks of most commercial fish species in Lake Peipsi-Pihkva are still abundant, and the economic status of the fishermen is relatively good. It may be concluded that co-operative management of the Lake Peipsi-Pihkva fisheries have been successful.  相似文献   

2.
Abstract  In England and Wales, freshwater anglers have shifted their behaviour towards visiting catch-and-release lake fisheries that are intensively stocked, mainly of large common carp, Cyprinus carpio L., to maintain high catch rates. Of 187 fish kills investigated in these intensively stocked lake fisheries in 2004 and 2005, most occurred between April and June and were mainly caused by parasitic or bacterial infections. Bacteria were usually associated with ulcerative diseases caused by strains of the bacterium Aeromonas salmonicida (Emmerich & Weibel) and secondary infections of opportunistic bacteria of the Genus Aeromonas (excluding salmonicida ) and Pseudomonas . Parasites involved in fish kills included Ichthyophthirius multifiliis (Fouquet), Chilodenella sp., Ichthyobodo necator (Henneguy) and Argulus sp. Outbreaks were typically in fisheries with high extant stock densities (>1500 kg ha−1) and sub-optimal habitats, for example of low habitat heterogeneity with few macrophytes in the littoral zone. Recent stocking was also a key factor when only carp was affected. Thus, certain fisheries management practices that aim to enhance fishery performance may instead trigger fish kills during spring.  相似文献   

3.
为探究白洋淀“以渔养水”生态修复效果其发展方式,以白洋淀水生生物资源环境调查及水域生态修复示范项目研究进展为依据,分析白洋淀水域存在的生态环境问题,介绍白洋淀主要的生态修复措施、取得的效果、以及实施“以渔养水”所面临的主要问题,总结白洋淀“以渔养水”生态修复技术的启示并提出相关发展建议。可为下一步开展白洋淀“以渔养水”生态修复研究提供思路,也可为全国大水面生态渔业发展和水域生态修复提供参考。  相似文献   

4.
5.
The present study demonstrates the declining state of the major commercial fisheries of Lake Victoria, Kenya, a situation threatening sustainability of the lake's fishery. Data in the present study were derived from resource monitoring programmes that included hydro‐acoustics (2009–2018), trawl net fishing (2011–2018), frame surveys (2000–2016) and catch assessment surveys (2000–2015). The activities provided information on fish stocks and supported advice for fisheries management. The average fish stock densities for Tanzania, Uganda and Kenya of 8.92, 8.25 and 8.19 t/km2, respectively, were relatively similar. Diplomatic and sustainable efforts for harmony in fish harvesting among the fishers of the riparian countries are encouraged given the interdependence of the lake. The Kenyan and River Kagera regions had a higher proportion (≈ 4% each) of big‐sized Nile perch (≥50 cm total length) in 2018, signifying the critical breeding areas for Nile perch. To sustain the fishery, there is need to enforce a 36%–44% effort reduction for all the major fisheries, and enforcement of gear limits to avoid harvesting of immature fish and destruction of the lake ecosystem.  相似文献   

6.
为客观地揭示全球主要渔业国家水产科学的研究态势及其研究热点,以2000—2018年InCites和Web of Science核心合集中文献数据作为统计源,利用文献计量学方法,对其文献的增长趋势、被引情况及期刊分布进行分析,并基于合作网络分析、关键词共现的知识图谱等方法,探究全球水产科学的研究态势及其研究热点。结果显示,在水产科学研究文献的年度发文态势方面,美国的文献数量总体维持在较高水平并呈现动态波动,近年来略有下降趋势;中国大陆的研究文献基本上呈指数增长,并呈稳步上升趋势,至2018年接近美国的发文数量;其他国家都呈现较为平稳的动态波动。载文期刊分布均符合布拉德福提出的文献离散规律,各国载文量排名在前20的期刊大多为国际顶级期刊,其学术上的影响力较大。优势学科领域基本集中在海洋淡水生物学、兽医学、海洋学、动物学、免疫学、湖沼生物学以及生物化学与分子生物学等,但各国侧重点不一致。研究表明,全球主要渔业国家研究热点主要为:①基于生物学参考点的渔业管理与保护研究;②渔业资源评估与管理评价研究;③开展渔业资源的基础生物学研究;④开展基于生态系统的管理措施及政策目标研究等主题。各研究热点间均呈现高度融合的现象,促进了综合性交叉学科的发展。  相似文献   

7.
8.
Community-based management of subsistence fisheries in Samoa   总被引:2,自引:0,他引:2  
Much subsistence fishing in tropical regions is based in discrete communities which have a high level of marine awareness and some degree of control of adjacent waters. These factors provide an ideal basis on which to motivate communities to manage their own marine resources. A fisheries extension programme in Samoa encouraged each village community to define its key problems, discuss causes, propose solutions and take appropriate actions. Various village groups, including women's and untitled men's groups, provided information which was recorded (as problem/solution trees) on portable white-boards. The extension process culminated in a community-owned Fisheries Management Plan which listed the resource management and conservation undertakings of the community. Undertakings ranged from enforcing laws banning destructive fishing methods to protecting critical marine habitats. Within the first 2 years, the extension process commenced in 65 villages, of which 44 have produced Village Fisheries Management Plans to date. A large number (38) of these villages chose to establish community-owned Marine Protected Areas.  相似文献   

9.
刘汉斌 《河北渔业》2016,(10):47-50
渔业风险管理是渔业经济持续健康发展的重要保障。在科学厘定渔业风险综合管理范畴的基础上,指出我国渔业高风险及风险管理低效率的困境在于割裂了渔业风险间的联系及渔业与其他产业的关联性、管理方式单一性和风险作用的复杂性,并从渔业风险管理的基本环境管理、致险因子管理、体制机制管理等方面明确渔业风险综合管理的新思路,提出从组织机构健全、法律法规完善、风险基金设立及渔业风险信息系统建设等方面推进渔业风险综合管理,提高我国渔业抵御风险和降低风险的能力。  相似文献   

10.
We have developed a set of tools that operate within an aquatic geographic information system to improve the accessibility, and usability of remote‐sensed satellite and computer‐modeled oceanographic data for marine science and ecosystem‐based management. The tools form the Pelagic Habitat Analysis Module (PHAM), which can be applied as a modeling platform, an investigative aid in scientific research, or utilized as a decision support system for marine ecological management. Applications include fisheries, marine biology, physical and biological oceanography, and marine spatial management. The GIS provides a home for diverse data types and automated tools for downloading remote sensed and global circulation model data. Within the GIS environment, PHAM provides a framework for seamless interactive four‐dimensional visualization, for matching between disparate data types, for flexible statistic or mechanistic model development, and for dynamic application of user developed models for habitat, density, and probability predictions. Here we describe PHAM in the context of ecosystem‐based fisheries management, and present results from case study projects which guided development. In the first, an analysis of the purse seine fishery for tropical tuna in the eastern Pacific Ocean revealed oceanographic drivers of the catch distribution and the influence of climate‐driven circulation patterns on the location of fishing grounds. To support management of the Common Thresher Shark (Alopias vulpinus) in the California Current Ecosystem, a simple empirical habitat utilization model was developed and used to dynamically predict the seasonal range expansion of common thresher shark based on oceanographic conditions.  相似文献   

11.
为加强渔业资源保护、增殖、开发和合理利用,维护渔业生产者的合法权益,保障渔业生产安全和水产品质量安全,促进渔业发展,经修订后的《河北省渔业条例》,于2007年11月23日省十届人大常委会第三十一次会议审议通过,2008年1月1日起施行。  相似文献   

12.
13.
In 1977, Peter Larkin published his now‐famous paper, ‘An epitaph for the concept of maximum sustained yield’. Larkin criticized the concept of single‐species maximum sustained yield (MSY) for many reasons, including the possibility that it may not guard against recruitment failure, and the impossibility of maximising sustainable yields for all species simultaneously. However, in recent years, there has been a fundamental change in the perception of the fishing mortality associated with MSY (FMSY) as a limit to be avoided rather than a target that can routinely be exceeded. The concept of FMSY as a limit is embodied in several United Nations Food and Agriculture Organization (FAO) agreements and guidelines, and has now been incorporated into the US Magnuson–Stevens Fishery Conservation and Management Act. As a result, the United States now requires the development of overfishing definitions based on biological reference points that treat the FMSY as a limit reference point and must also define a lower limit on biomass below which rebuilding plans with strict time horizons must be developed. This represents a major paradigm shift from the previously mandated (but often unachieved) objective to simply maintain fishing mortalities at levels below those associated with recruitment overfishing. In many cases, it requires substantial reductions in current fishing mortality levels. Therefore, the necessity of the new paradigm is continually questioned. This paper draws on examples from several fisheries, but specifically focuses on the recent US experience illustrating the practical difficulties of reducing fishing mortality to levels below those corresponding to MSY. However, several studies suggest that even more substantial reductions in fishing mortality may be necessary if ecosystem considerations, such as multispecies interactions, maintenance of biodiversity and genetic diversity, and reduction of bycatch and waste, are taken into account. The pros and cons of moving beyond single‐species assessment and management are discussed. A US plan for improving stock assessments indicates that even a ‘basic’ objective such as ‘adequate baseline monitoring of all managed species’ may be extremely costly. Thus, the suggestion of Larkin (1983, 1997) that the costs of research and management should not exceed 10–20% of the landed value of the catch may preclude comprehensive ecosystem management. More importantly, neither single‐species nor ecosystem‐based fisheries management is likely to improve appreciably unless levels of fishing capacity are aligned with resource productivity, as is currently being promoted by FAO and several individual nations.  相似文献   

14.
Abstract  To deal with excessive fishing capacity, a part of the fishing rights, both volume quotas and gear use rights, in all Estonian fisheries was allocated each year during 2001–2003 through auctions while the remainder was allocated on the basis of the recent fishing rights use history. All fishing rights depreciated in a geometric manner by 10% annually. This was carried out for the first time in 2001, but the system was abandoned for political reasons in 2003. In this paper, the development of the small-scale Estonian inland fisheries, as well as the results of the auctions of fishing rights in those fisheries, are discussed. The auctions led to some increase in the number of owners of fishing rights. In most cases, however, new enterprises were formed on the basis of fishers active up to 2001 as employees of other enterprises. The auctions did not lead to a concentration of ownership of fishing rights in large enterprises. On the contrary, the share of smaller owners increased. According to the Fishing Act, in Estonia there is a fishing fee for all professional fishing gears. The official fishing fee was always used as the starting price in bidding, and this increased greatly during the bidding. Finally, the auction system served as a real incentive for fishers to cooperate more than they did during the previous management system based only on earlier rights.  相似文献   

15.
Successful fisheries management systems tend to be underpinned by harvest strategies, specifying formally agreed data collection systems, assessment approaches and management measures used to regulate fishing pressure. While harvest strategies can be effective even in data- and capacity-limited (DCL) situations, their development remains challenging in such contexts. We present a process and decision-support tool, FishPath, to guide the identification of suitable harvest strategy component options given often debilitating conditions: (i) resource limitations and lack of technical management capacity; (ii) ‘uniqueness’ of DCL fisheries; (iii) the concept of harvest strategies is unfamiliar to managers and scientists, and the universe of options is hard to navigate; and (iv) the lack of an effective participatory process to identify solutions tailored to local contexts. These conditions can lead to either management paralysis or generic solutions that may be poor fits to specific conditions. The FishPath Tool uses a diagnostic questionnaire that elicits the key characteristics and specific circumstances of a fishery. It compares these with the requirements of alternative options from an inventory of possible harvest strategy components, identifies where these requirements are met and provides customised, transparent guidance on the appropriateness of component options of a harvest strategy, specific to the fishery of interest and its governance context. The FishPath Process is a facilitated multi-stakeholder, participatory engagement process aimed to set fisheries on the path to develop a harvest strategy. The FishPath Process and Tool combine to ensure a bottom-up, documented, transparent, replicable and efficient process.  相似文献   

16.
Diagnosis and management of small-scale fisheries in developing countries   总被引:2,自引:0,他引:2  
Small‐scale fisheries (SSF) make important but undervalued contributions to the economies of some of the world’s poorest countries. They also provide much of the animal protein needed by societies in which food security remains a pressing issue. Assessment and management of these fisheries is usually inadequate or absent and they continue to fall short of their potential as engines for development and social change. In this study, we bring together existing theory and methods to suggest a general scheme for diagnosing and managing SSF. This approach can be adapted to accommodate the diversity of these fisheries in the developing world. Many threats and solutions to the problems that beset SSF come from outside the domain of the fishery. Significant improvements in prospects for fisheries will require major changes in societal priorities and values, with consequent improvements in policy and governance. Changes in development policy and science reflect these imperatives but there remains a need for intra‐sectoral management that builds resilience and reduces vulnerability to those forces beyond the influence of small‐scale fishers.  相似文献   

17.
The role of spatial management, including marine protected areas, in achieving fisheries outcomes alongside conservation goals is debated. In fisheries that fail to meet fishing mortality targets, closed areas are sometimes implemented to reduce fishing mortality. However, fisheries with stronger management, including rights‐based approaches that can address overcapacity and overfishing problems, often employ spatial management as well. Here, we compare the objectives, design, and performance of spatial management in nine temperate demersal fisheries in North America, Oceania, Europe, and Africa that employ rights‐based systems. Common objectives of spatial management included protecting habitat, juveniles, and spawners and reducing discards. Recovering age structure and creating scientific reference sites were less common objectives, despite being widely cited benefits of spatial management. Some fisheries adopted single closures to achieve single objectives, whereas others adopted diverse networks to achieve multiple objectives. Importantly, many spatial protections are implemented primarily through industry initiatives. Environmental change compromised the efficacy of spatial management in some cases, suggesting the need to design spatial management systems that are robust to changing ocean conditions. Fisheries with diverse and extensive spatial management systems have generally healthier fish stocks. Whether this implies that spatial management contributed substantially to fishery performance is unclear due to an absence of large‐scale, long‐term studies aimed at discerning different drivers of success. Although these targeted monitoring studies of closed areas are limited, such studies are necessary to help resolve the ongoing debate and to enable more purposeful design of spatial management for fisheries and conservation.  相似文献   

18.
Takeuchi Y, Ochi H, Kohda M, Sinyinza D, Hori M. A 20‐year census of a rocky littoral fish community in Lake Tanganyika. Ecology of Freshwater Fish 2010: 19: 239–248. © 2010 John Wiley & Sons A/S Abstract – Tropical fish communities are highly diverse with large numbers of allied species coexisting. Concerns have been raised about changes in such communities caused by anthropogenic disturbances, but little is known about long‐term changes. We investigated changes in the littoral fish community of Lake Tanganyika. A 10 × 40‐m quadrat was placed on a rocky shore in the southern part of the lake, and fish censuses were conducted once a year during most years in 1988–2008. In total, 54 cichlid and 6 non‐cichlid species were recorded. Aufwuch feeders were most abundant, followed by plankton feeders, detritus feeders, piscivores, shrimp eaters, zoo‐benthos eaters, and scale eaters. Species richness and abundance were sustained over the study period, with biodiversity, as evaluated by the Shannon–Wiener index, remaining high. However, Mantel tests between the Bray–Curtis index and the difference in years between compared censuses revealed that the species composition of the community gradually changed with time. The fish community gradually underwent a change that may be due to low anthropogenic impacts on food condition. Our results promote awareness about the conservation of diversity in Lake Tanganyika.  相似文献   

19.
Views expressed on the potential impact of ocean acidification range from wholesale degradation of marine ecosystems through to no discernable impact with minimal consequences. Constraining this range of predictions is necessary for the development of informed policy and management. The direct biological impacts of acidification occur at the molecular and cellular level; however, it is the expression of these effects at the population and ecosystem level that is of societal concern. Here, we consider the potential impact of ocean acidification on fisheries with particular emphasis on approaches to scaling from physiological responses to population‐ and ecosystem‐level processes. In some instances, impacts of ocean acidification may lead to changes in the relative species composition at a given trophic level without affecting the overall productivity, whilst in other instances, ocean acidification may lead to a reduction in productivity at a given tropic level. Because of the scale at which ecological processes operate, modelling studies are required. Here, ocean acidification is situated within ongoing research into the ecological dynamics of perturbed systems, for which many models have already been developed. Whilst few existing models currently explicitly represent physiological processes sensitive to ocean acidification, some examples of how ocean acidification effects may be emulated within existing models are discussed. Answering the question of how acidification may impact fisheries requires the integration of knowledge across disciplines; this contribution aims to facilitate the inclusion of higher trophic level ecology into this ongoing debate and discussion.  相似文献   

20.
渔业管理中生物学参考点的理论及其应用   总被引:3,自引:3,他引:3  
生物学参考点常被表示为与渔业管理相关联的捕捞死亡率和生物量,是单从生物学角度来衡量渔业资源及其开发状况的指标。通常可分为目标参考点、限制参考点和阈值参考点。目标参考点是为了持续获得某一目标渔获量所需的最小生物量和相应捕捞死亡率,包括目标生物量(Bmsy)、目标产卵亲体量(Smsy、SSB35%、SSB40%)、目标捕捞死亡率(Fmsy、Fmax、F0.1、Fmed、F40%、F40%)等参数。限制参考点用于保证捕捞死亡率不会高到危害鱼类种群的可持续利用和其生物量不会低到危害其生存,主要包括Fmsy、Fmax、F0.1、Fcrash、F20%、Bloss等参数。阈值参考点介于目标参考点和限制参考点之间,包括预防性捕捞死亡率Fpa、预防性生物量Bpa,主要对渔业资源的开发和管理进行预警,防止生物量小于BL。生物学参考点主要应用动态综合模型、产量模型和亲体量补充量关系模型来估算,估算过程中需要考虑到补充、生长、死亡等生命史过程中的不确定性。本文对生物学参考点的发展和应用进行了综述,并以金枪鱼渔业为例阐述它在渔业管理上的应用。近几十年来,我国近海渔业资源出现衰退,亟需利用生物学参考点的原理和方法对重要渔业资源种类进行...  相似文献   

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