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61.
根据2013年1–9月辽宁远洋渔业有限公司“福荣海”轮南极磷虾拖网调查数据,以3n mile/h拖曳获得的产量作为CPUE指标,对南极磷虾资源时空分布进行了分析。结果显示,1–6月的月均CPUE值相对稳定,7–9月逐月下降。各渔区中平均CPUE值以48.1区最高,为(25.12±31.04) t/h;48.3区最低,为(11.49±12.06) t/h;CPUE值的波动幅度48.1区大于48.2和48.3区。48.1区的南极磷虾群主要分布于0 –100 m水层,CPUE值以25–50 m水层为最高;48.2区虾群主要分布于50–150 m水层,CPUE值以100–150 m水层最高;48.3区虾群主要分布于100–250 m水层,CPUE值以200– 250 m水层最高。海底深度<500 m的近岸海域是磷虾主要集群分布区和商业捕捞渔场,以水深<250 m的浅水区渔场虾群密度最大,平均CPUE值为(17.54±35.26) t/h,水深250–1500 m的深水区渔场平均CPUE值变化较小,在12.0–14.0 t/h之间波动,但水深>1500 m时,平均CPUE值降到(9.62±9.54) t/h。作业渔场的表温SST主要集中在-1–2℃,当SST为-1–0℃时,平均CPUE值最高。探捕调查发现了5个主要的磷虾集群,集群时间可达30 d以上,但集群密度随时间发生变化。调查结果可为研究南极磷虾渔场形成机制和渔业管理提供基础数据,并为商业捕捞提供参考。 相似文献
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Pelagic fish stocks in the Java Sea have been exploited intensively since the beginning of the 1970s. However, due to the effect of increased fishing power of the fleets and the changing nature of spatial and temporal distribution of the fishing effort, assessment of stock trends based on commercial data of catch and effort requires the standardization of both effort and catch data. Here we present the first attempt to reconstruct a standardized time series of commercial catch per unit of effort (CPUE) for the main pelagic species exploited by the purse seine fleet in the Java Sea. The results showed that all the stocks analysed have largely declined since the beginning of the 1990s. For bigeye scad, Indian mackerel and sardine, current estimates are only between 3 and 19% of the maximum observed value while round scads and spotted sardine biomass estimates lie between 18 and 34%. However, our assumptions about the effect of lamp power and level of creeping and the fact that the influence of fish density on catchability and the effect of targeting were not taken into account thus observed decline is a rather conservative estimate of the real decline of the stocks. If effective management actions are not put in place as a matter of urgency in the Java Sea for small pelagic fisheries, one runs the risk of adding those species to the long list of overexploited stocks of the world oceans. 相似文献
64.
W. M. POTTS A.-R. CHILDS W. H. H. SAUER & A. D. C. DUARTE 《Fisheries Management and Ecology》2009,16(1):14-20
Abstract The characteristics and contribution of a developing recreational fishery to the local, regional and national economy of Angola were evaluated in 2006. Annual angling effort was 13 435 h, while the estimated total catch of the three target species [leerfish, Lichia amia (L.), west coast dusky kob, Argyrosomus coronus (Griffiths & Heemstra) and shad, Pomatomus saltatrix (L.)], was 5913 fish with a mass of 27 975 kg. Catch per unit effort (CPUE) for all teleost species combined was 0.44 fish per angler h−1 and 2.08 kg per angler h−1 . Total harvest of the three species was 576 fish with a total mass of 2221.6 kg. The total contribution of this recreational fishery (mostly anglers from South Africa) to the local economy was US$ 1007 per harvested fish and US$ 243 per harvested kg. This equated to a contribution to the local, regional and national economies of US$ 151 685, US$ 44 767 and US$ 344 364 respectively. Although the regional contribution was less than half of the national contribution, it was regionally significant when the low population density and the general absence of other formal sector employment opportunities are considered. As a result of the largely undisturbed nature of the southern Angolan coastline, the catch, effort and CPUE information was considered suitable as a baseline for a cost-effective method of future fisheries monitoring in the region. 相似文献
65.
我国东、黄海鲐鱼灯光围网渔业CPUE标准化研究 总被引:8,自引:1,他引:7
日本鲐是我国近海重要的中上层鱼类资源之一,评估其资源量需要对单位捕捞努力量渔获量(CPUE)进行标准化。影响CPUE标准化的因素很多,包括季节、区域和海洋环境等。本文利用广义线型模型(GLM)和广义加性模型(GAM),结合时空、捕捞船、表温等因子,对1998-2006年东、黄海大型灯光围网渔业鲐鱼CPUE进行标准化,并评价各因子对CPUE的影响。首先应用GLM模型评价时间、空间、环境以及捕捞渔船参数对CPUE的影响,并确定显著性变量。其次,将显著性变量逐一加入GAM模型,根据Akaike信息法则(AIC),选择最优的GAM模型。最后,利用最优的GAM模型对CPUE标准化,并定量分析时间、空间、环境以及捕捞渔船参数对鲐鱼CPUE的影响。GLM模型结果表明:8个变量对CPUE有重要影响,依次为年、船队、船队与年的交互效应、月、船队与月份的交换效应、经度、纬度和海表温。根据AIC,包含上述8个显著性变量的GAM模型为最优模型,对CPUE偏差的解释为27.78%。GAM模型结果表明:高CPUE分别出现在夏季海表温为28~31 ℃的东海中部和冬季海表温为12~16 ℃的黄海;1998-2006年,标准化后的CPUE呈逐年下降趋势,与持续增长的捕捞努力量有关。 相似文献
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Ana T. Silva Martyn C. Lucas Theodore Castro‐Santos Christos Katopodis Lee J. Baumgartner Jason D. Thiem Kim Aarestrup Paulo S. Pompeu Gordon C. O'Brien Douglas C. Braun Nicholas J. Burnett David Z. Zhu Hans‐Petter Fjeldstad Torbjørn Forseth Nallamuthu Rajaratnam John G. Williams Steven J. Cooke 《Fish and Fisheries》2018,19(2):340-362
Much effort has been devoted to developing, constructing and refining fish passage facilities to enable target species to pass barriers on fluvial systems, and yet, fishway science, engineering and practice remain imperfect. In this review, 17 experts from different fish passage research fields (i.e., biology, ecology, physiology, ecohydraulics, engineering) and from different continents (i.e., North and South America, Europe, Africa, Australia) identified knowledge gaps and provided a roadmap for research priorities and technical developments. Once dominated by an engineering‐focused approach, fishway science today involves a wide range of disciplines from fish behaviour to socioeconomics to complex modelling of passage prioritization options in river networks. River barrier impacts on fish migration and dispersal are currently better understood than historically, but basic ecological knowledge underpinning the need for effective fish passage in many regions of the world, including in biodiversity hotspots (e.g., equatorial Africa, South‐East Asia), remains largely unknown. Designing efficient fishways, with minimal passage delay and post‐passage impacts, requires adaptive management and continued innovation. While the use of fishways in river restoration demands a transition towards fish passage at the community scale, advances in selective fishways are also needed to manage invasive fish colonization. Because of the erroneous view in some literature and communities of practice that fish passage is largely a proven technology, improved international collaboration, information sharing, method standardization and multidisciplinary training are needed. Further development of regional expertise is needed in South America, Asia and Africa where hydropower dams are currently being planned and constructed. 相似文献
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CPUE标准化方法与模型选择的回顾与展望 总被引:4,自引:1,他引:3
单位捕捞努力量渔获量(Catch Per Unit Effort, 简称CPUE)常被假设与渔业资源量成正比关系而广泛应用于渔业资源评估与管理中, 但大量研究表明, CPUE与资源量间的正比关系常因受众多因素的影响而难以成立。为能有效利用CPUE数据, 渔业工作者常使用各种统计模型对CPUE进行标准化, 以重新构建该正比关系。因此, 在渔业资源评估与管理中, CPUE标准化是一项极为重要的基础性工作。本文对CPUE标准化的基本概念、构建过程、统计模型和模型选择方法进行了全面回顾, 并强调了模型选择的不确定性, 介绍了基于模型平均的多模型推断方法。同时, 对CPUE标准化所面临的问题及处理方法进行介绍与讨论, 对其未来研究工作进行展望, 以期为CPUE标准化研究提供理论参考。
相似文献70.
黄河水土保持监测站点标准化建设研究——以黄委天水、西峰、绥德监测站点建设为例 总被引:2,自引:2,他引:0
从多年的小流域水土保持水沙监测实践出发,总结了近几年监测站点建设的经验.从监测站点总体结构、监测内容、监测手段与方法、监测数据管理以及站点运行管理等方面,探讨了水土保持监测站点标准化建设的有关问题.提出了现代化水土保持监测的手段、方法和监测数据管理系统的基本架构与功能,为进一步开展标准化监测站点建设提供参考. 相似文献