辽宁开展节水型渔业存在的问题及其对策     

孙建富 《渔业经济研究》2009,(1):31-34

文章以辽宁水资源和渔业生产的现状为研究背景,以介绍节水型渔业的概念、意义等为基础,分析了辽宁开展节水型渔业存在的认识问题、投入问题、体制问题,提出了辽宁开展节水型渔业的四项基本对策,即在建设节约型社会,发展节约型经济的框架下开展节水型渔业;完善政策法规,制定节水型渔业建设规划;转变渔业增长方式,推行节水技术;限制和制止浪费水严重、污染严重的渔业项目。  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   

A dynamic mass-balance model for marine protected areas   总被引：2，自引：0，他引：2  

Watson  Alder  & Walters 《Fish and Fisheries》2000,1(1):94-98

A modified Ecosim model was used to investigate the impact of establishing marine protected areas (MPAs) in ecosystems defined by existing Ecopath models. The impact of MPAs of various sizes was simulated, and changes in biomass and catch over a range of years observed. The response of biomass and catch to MPA size depended on the time period examined. For some ecosystem groups, the initial response was negative, but for all groups there were increases after 10 years. The greater the biomass exchange rate across the MPA boundary, the larger the MPA required to increase biomass levels. Within the range of exchange rates simulated, the maximum increases in catch and overall biomass levels were reached when 20% of the system was protected.  相似文献   

中国鱿鱼钓机装备研究现状及展望   总被引：1，自引：0，他引：1  

刘健  黄洪亮  李灵智  冯春雷  王磊  戴阳  陈帅  张禹  徐国栋 《现代渔业信息》2012,27(2):113-119

鱿鱼钓机是远洋鱿钓渔业的重要生产工具。目前鱿鱼钓机装备发展面临的主要问题是机钓产量低。本文介绍了我国鱿鱼钓机装备的研究现状,对钓机运转速度、作业水深控制、抖动模式设置及结构设计等方面的研究趋势进行了探讨。最后,提出了我国鱿鱼钓机发展对策,研究指出需重点解决钓机结构优化设计、控制系统性能优化、运行参数优化等问题,为远洋鱿钓渔业的可持续发展提供参考依据。  相似文献   

广东省海水养殖贝藻类碳汇潜力评估   总被引：8，自引：0，他引：8  

齐占会  王珺  黄洪辉  刘永  李纯厚  陈胜军  孙鹏 《南方水产》2012,8(1):30-35

大型藻类和滤食性贝类可以直接或者间接吸收水体中的碳（C）,收获养殖产品形成了一个＂可移出的碳汇＂,提高了海域的碳汇潜力。文章从物质量评估和价值量评估两方面对广东省贝、藻养殖的碳汇贡献进行了定量评估。物质量评估结果显示,2009年广东省海水养殖的贝类和藻类收获可以从海水中移出C约11×104t,相当于39.6×104t二氧化碳（CO2）;价值量评估结果显示封存固定这些CO2所需要的费用约0.59×108～2.38×108美元。因此,基于贝、藻养殖的碳汇渔业具有巨大的经济效益、生态效益和社会效益。  相似文献   

Reconciling poverty alleviation with reduction in fisheries capacity: boat aid in post-tsunami Aceh, Indonesia     

A. TEWFIK  & N. L. ANDREW  C. BENE  L. GARCES 《Fisheries Management and Ecology》2008,15(2):147-158

Abstract  The tremendous loss of life and assets resulting from the 2004 tsunami dealt a devastating blow to the coastal communities of Aceh Province, Indonesia. An assessment of the fishing fleet structure pre- and post-tsunami, including associated pattern in boat aid, in 15 coastal communities was conducted and compared with data on boat relief efforts over 17 districts of the Province. Aid was found to be not proportionally allocated to losses incurred by communities and was in many cases below what could be seen as a trend toward overcapacity. The distribution of aid appeared to be done without consideration of the former structure of the fleet, which changed significantly over time (pre- and post-tsunami), and resulted in a new fleet of reduced diversity with a strong focus on the smaller boat categories. If this situation perpetuates after the initial post-disaster period, it may further exacerbate the pre-existing economic and geographic marginalisation of some remote communities, and reduce the capacities of the fleets to diversify and develop multi-species harvesting strategies; thus, increasing the risk of ecologically unsustainable exploitation in near shore areas.  相似文献   

Potential effects of global warming on northern European freshwater fish and fisheries     

H. LEHTONEN 《Fisheries Management and Ecology》1996,3(1):59-71

Abstract Global warming is expected to result in considerable changes in northern European freshwater fish populations, fisheries and aquaculture. Shifts towards cyprinid and percid dominance in fish assemblages are expected, together with a decrease and collapse of salmonid and other coldwater fish populations. Most of the evident changes will occur in shallow lakes, where no thermal stratification occurs. The potential ranges of some fish species will shift northwards but pronounced changes will occur in the relative abundance of individual fish species. Total fish production will increase but because of changed composition of fish communities the commercial and recreational value of catches will decrease. Salmonid aquaculture productivity will increase provided that fish farmers adapt to new circumstances and cold, oxygenated water is available in larger quantities during summer.  相似文献   

Non-commercial invertebrate discards in an experimental trammel net fishery   总被引：1，自引：0，他引：1  

J. M. S. GONÇALVES  L. BENTES  R. COELHO  P. MONTEIRO  J. RIBEIRO  C. CORREIA  P. G. LINO  & K. ERZINI 《Fisheries Management and Ecology》2008,15(3):199-210

Abstract  Non-commercial invertebrate discards in an experimental trammel net fishery were studied in relation to selectivity of the gear, depth, soak time and season. Forty experimental fishing trials were carried out over a 1-year period with six combinations of small mesh (100, 120 and 140 mm) inner and large mesh (600 and 800 mm) outer panels. On average, 43.8 ± 12.2 (SD) (individuals 1000 m⁻¹ of net) of non-commercial invertebrates were discarded, accounting for 48% and 65% of the total catch and total discards by numbers, respectively. Within non-commercial invertebrates discards, the six most abundant species by number were Phallusia mammillata (Cuvier) (27.5%), Cymbium olla (L.) (13.0%), Sphaerechinus granularis (Lamarck) (11.3%), Paracentrotus lividus (Lamarck) (10.9%), Astropartus mediterraneus (Risso) (8.2%) and Astropecten aranciacus (L.) (8.1%); Echinoderms (43.1%) particularly important. The highest and lowest discard ratios were found in autumn and winter, respectively. Discards generally decreased with depth, varied considerably in relation to soak time and were not related to mesh size combinations. Trammel nets seem to be the most important gear in terms of ecological impacts on benthic invertebrates compared with other coastal fishing gears and at the depths studied (15–60 m).  相似文献   

Optimising codend configuration in a multispecies demersal trawl fishery     

M. K. BROADHURST  R. B. MILLAR  M. E. L. WOODEN  & W. G. MACBETH 《Fisheries Management and Ecology》2006,13(2):81-92

Abstract The relative efficiencies and selectivities of conventional and modified codends were examined in a demersal trawl fishery targeting several species, including eastern king prawns, Penaeus plebejus (Hess), whiting, Sillago spp. and cephalopods. The modifications to codends included: (i) reducing the circumference; (ii) increasing the mesh size in conventional diamond‐mesh designs; and (iii) orientating meshes on the bar so that they were square shaped. The codends were tested against a fine‐meshed control in paired comparisons onboard three commercial trawlers. The conventional codend comprised 41‐mm diamond‐shaped mesh attached to an anterior extension section at a ratio of 150 to 100 meshes and was demonstrated to be non‐selective for the targeted species. Reducing codend circumference to 100 meshes and increasing the size of mesh to 45 mm both improved selection for eastern king prawns, but the lateral mesh openings were estimated to be insufficient to allow juveniles of the other key species to escape. By contrast, codends made from 35‐ and 41‐mm mesh hung on the bar improved the size selection for eastern king prawns and selected stout whiting, Sillago robusta (Stead) (the smallest commercial‐sized fish) across narrow selection ranges and at 50% sizes of retention (L₅₀s) that were closely correlated to the transverse morphology of fish and the maximum mesh opening. With the exception of a reduction in catches of octopus, Octopus spp., by the 41‐square codend, there were no other impacts on commercial catches by the square‐mesh designs. It was concluded that diamond‐mesh codends are inappropriate for use throughout this multispecies fishery and that a modified design comprising at least 35‐mm mesh hung on the bar is required to minimise the fishing mortality of unwanted sizes of the key target species. The results are discussed in terms of the utility of these types of modifications for closely regulating selection in penaeid‐shrimp trawls.  相似文献