厦门沿岸海域渔业资源变化和最适捕捞力量的估算

本文以厦门沿岸海域历次渔业资源和生物调查及１９８４－１９９５年渔业统计资料为背景,分析了该海域渔业资源的变动,重点对文昌鱼、真鲷、鳓鱼、大黄鱼、蓝点斑马鲛、长毛对、中国鲎等重要经济种类资源变动的原因进行探讨,针对目前资源的变动趋向,指出了近期重点的保护对象和有开发潜力的种类,并以三种标准捕捞力量,应用了Ｓｃｈａｅｆｅｒ和Ｆｏｘ两种剩余产量模式估算最大持续产量（ＭＳＹ）和最知捕捞力量。估算结果ＭＳＹ     

产量模型的比较及在小鳞鱼箴种群的应用(英文)

产量模型是渔业管理中预测最大持续产量（ＭＳＹ）的经典方法。ＭＳＹ仍然是渔业管理的重要目标之一。文章应用模拟数据比较了最常用的产量模型。蒙特卡罗研究表明ＷａｌｔｅｒｓａｎｄＨｉｌｂｏｒｎ的动态模型表现最好。这些方法被应用在小鳞鱼箴（ＨｅｍｉｒｈａｍｐｈｕｓｓａｊｏｒｉＴｅｍｍｉｎｃｋａｎｄＳｃｈｌｅｇｅｌ）种群。Ｗａｌ－ｔｅｒｓａｎｄＨｉｌｂｏｒｎ方法的Ｂｏｏｔｓｔｒａｐ结果是２２５０ｔ（吨）的ＭＳＹ和８０６艘船的最佳捕捞努力量。与目前２０００艘船的努力量水平比较,渔业处于过度捕捞状态,需要大力削减捕捞努力量     

基于北斗船位数据的渔业信息解译与应用研究——以中国毛虾限额捕捞管理为例

2020年6月15日—7月15日,我国首次中国毛虾(Acetes chinensis)限额捕捞试点于江苏连云港实施。本研究提取62艘毛虾网船在限额捕捞期间的421700条北斗船位数据经纬度、航速、航向等信息,运用缓冲区叠加分析法、DBSCAN密度聚类算法、平均中心算法、核密度估计以及数据库查询对捕捞努力量等管控要素进行分析研究。结果显示,所有毛虾网船累计作业239个航次、1942个网次,捕捞过程分为航行、抛锚布网、等待渔获、收渔获、停航等5个状态,中国毛虾捕捞状态船位点呈直线分布,总捕捞时长为4413.73h,82.4%的单网次捕捞时长为1.5—3.5h,各网次捕捞产量呈现多核心空间分布模式,总捕捞努力量为108106343 m~2·h,计算62艘的捕捞总产量值约为2328 t,比上报产量高12.6%;本文通过北斗船位数据解译和提取捕捞努力量以计算中国毛虾捕捞产量及资源空间分布情况,有效应用于中国毛虾限额捕捞,为解决我国单品种限额捕捞难点积累了宝贵经验。     

Distribution of biomass of zooplankton in the Kuroshio area of the East China Sea

ＤｉｓｔｒｉｂｕｔｉｏｎｏｆｂｉｏｍａｓｓｏｆｚｏｏｐｌａｎｋｔｏｎｉｎｔｈｅＫｕｒｏｓｈｉｏａｒｅａｏｆｔｈｅＥａｓｔＣｈｉｎａＳｅａ￥ＭｅｎｇＦａｎ;ＣｈｅｎＳｈｉｑｕｎａｎｄＷｕＢａｏｌｉｎｇ（ＦｉｒｓｔｉｎｓｔｉｔｕｔｅＯｆＯｃｅａｎｏｇｒａ...     

厦门海域渔业资源评估

以初级生产力和渔业统计资料为材 ,分别应用Tait沿岸海域生态系能流分析法、营养动态法和Cushing等 3种模式 ,估算厦门沿岸海域的渔业资源自然生产量。同时 ,分别应用Schaefer和Fox两种剩余产量模式估算最大持续产量和最大持续捕捞力量。前 3种模式估算该海域的资源生产量分别为 2 0 1 0 5t,1 8463t和 1 7489t,平均 1 8686t。后两种模式估算最大持续产量平均值分别为 9639t和 91 0 4t。估算的最大持续捕捞力量 :5种作业综合总功率为 1 5976kW ;以厦门机定置渔船单位功率渔捞效率为标准估算的总功率为 2 7351kW ;以厦门机刺网渔船单位功率渔捞效率为标准估算的总功率为 432 1 3kW。 1 997年实际渔获量和捕捞力量均超过了估算的最大持续产量和最大持续捕捞力量。文中还讨论了捕捞力量的调整问题。     

西南大西洋乌拉圭近海双船拖网捕捞调查

为促进我国海洋渔业"走出去",进一步发展远洋捕捞业,文章调查西南大西洋乌拉圭近海双船拖网捕捞的渔具和渔法等,并提出生产建议。研究结果表明:双船拖网的渔具包括渔船、网具、纲索和属具,网身采用加目和减目编缝的方式缝合而成;渔法包括放网准备、放网、曳网、起网和网具养护等环节;针对渔场、渔期和捕捞对象,应把握捕捞产量、成本和航次的关系,并结合主捕对象的生活习性,合理规划生产。     

关于80年代闽南—台湾浅滩渔场中上层渔获量变动原因的初探

近来，１９８６年中上层渔获量达７．４３３３万ｔ，１９８７年更创历史记录高达１２．０７万ｔ，并且１９８３年金色小洗涤 丁鱼产量也达到１．９５８７万ｔ，仅次于历史最高水平的１９７１年的产量，但到１９８８年的产量仅为２７７８ｔ，占中上层渔获量３．２１％，从而从历史上第一位下降到第４位，如此渔获量变动，其原因何在呢？笔者试就从海洋环境变异，捕捞力度等诸因素合理解释中上层渔获量变动，为科学管理和合理开发中上     

ENSO对长江口日本鳗鲡苗捕捞量的影响

ENSO是一种对世界渔业有重要影响的气候事件,对长江口日本鳗鲡苗的捕捞量也有一定影响．本文通过对1974～2003年的Nineo 3．4区的表层海水温度（SST）和长江口日本鳗鲡苗的捕捞量进行相关分析,以揭示彼此的相关性．1974～1982、1983～1993年崇明的鳗苗捕捞量和ENSO指标值基本成相反关系．1992—2003年长江口鳗苗总捕捞量和ENSO指标值也基本呈相反关系．此期厄尔尼诺发生时,鳗苗总捕捞量明显降低,而拉尼娜发生时则明显增加．进一步建立Nineo3．4区的水温距平值和当年鳗苗捕捞量增量关系,发现随着水温距平值增大,1974—1993年鳗苗捕捞量增量呈现增加趋势,但相关性并不显著．将其中3个强厄尔尼诺年的数据去除,则呈显著相关．相反,1993～2003年间,随着太平洋Nineo3．4区水温距平值增大,上海鳗苗捕捞量呈减少趋势,但相关性不显著,分别去除个别年份后则呈显著下降趋势．这主要是因为前一阶段是以拉尼娜事件为主体,水温距平值一定程度的增大,鳗苗捕捞量呈现增长趋势;而后一阶段主要以强厄尔尼诺事件为主．再采用当年鳗苗捕捞量增量和去年太平洋Nineo3．4区全年水温距平值建立相关,得出长江口鳗苗增量随去年水温距平值增加呈现显著上升趋势．其原因主要是由于ENSO影响长江口水温分布,而鳗苗补充需要一个最适温度范围．这进一步验证了非厄尔尼诺年后发生厄尔尼诺次年属鳗苗增产年度的理论．这些结果表明可将Nineo3．4区海表温度作为长江口日本鳗鲡苗捕捞量预测指标．     

我国主要海洋捕捞政策对浙江省海洋捕捞业的影响探究

随着海洋渔业资源的不断衰退,为了保护渔业资源、推动海洋渔业的可持续发展,自20世纪70年代后期,我国出台了许多海洋捕捞相关政策。文章从投入控制制度、产出控制制度和技术控制制度3个角度出发,以捕捞许可制度、捕捞限额管理和伏季休渔制度等政策为重点,通过整理1980—2017年浙江省渔业经济的相关资料,从海洋捕捞渔船数量和功率、海洋捕捞产量、渔业劳动力数量变化3个方面,深入分析浙江省海洋捕捞现状,提出了完善现有的海洋捕捞政策、加强渔业执法管理力量、加强普法宣传、建立渔业资源调查与评估体系、帮助捕捞从业人员转产转业等对策建议,以期为我国海洋捕捞管理部门提供决策参考。     

黄渤海区捕捞结构的研究

根据2010年对黄渤海沿海32个主要渔港、渔村和5家网具生产厂家的实地调查和现场测量资料,结合2009年度三省一市(河北、辽宁、山东、天津)的渔具渔法调查报告以及1983~2009年中国渔业年鉴中记载的捕捞产量分类统计资料,对黄渤海区捕捞结构进行了研究.研究结果表明,黄渤海区主要捕捞品种有30种之多,其中年渔获量超过万吨的有14种鱼类、5种甲壳类、4种头足类、2种海蜇和6种贝类.渔业资源品种的多样性决定了黄渤海区捕捞结构的多样化和多层次的特点,现有9大类19型23式130种网型或作业方式,同时受渔业资源变动的影响,捕捞网具也在变化,不断有旧的渔具消失和新的网具出现.其中,拖网是主要作业方式,贡献率为38.47%~51.79%,且近几年还有上升的趋势;其次为刺网,贡献率从1983年最低时的7.66%逐步上升到目前的30.14%;第三为张网,贡献率从1985年最高时的34.31%下降到目前的10.49%;围网和钓具的贡献率一直较低,均不足4%,其他渔具的贡献率为5.98%~13.30%.目前黄渤海区渔业结构的调整方向应当是减少拖网作业,控制刺网总量,限制张网、陷阱类渔具和地笼,鼓励发展钓渔业     

基于船位监控系统的拖网捕捞努力量提取方法研究

为了基于船位监控系统提取拖网捕捞努力量,通过统计航速获得3个峰值,拖网作业在第2个峰值,即1~2.1 m/s,拖网作业航向差一般在–50°~50°。利用航速、航向差阈值设定,把拖网船状态划分为慢速、作业、航行,然后提取出捕捞作业状态点,1 423艘拖网船共提取到处于捕捞状态的点318 433个,合计拖网捕捞时间15 921 h,利用反距离加权插值法生成捕捞强度分布变化趋势图。捕捞努力量在渔业资源研究中是重要的参考值之一,与传统的捕捞努力量计算方法相比,该方法具有实时、大范围、快速、分辨率高的特点,能够用于辅助渔业资源保护。     

台湾海峡海洋捕捞业管理策略和投资方向

本文收集了１９８５￣１９９４年福建省在台湾海峡生产的具有代表性的５０对拖网渔船、１２０艘单拖渔船、４８组灯光围网渔船、３８对大围缯渔船、３１艘定置网渔船的技术参数及生产资料，计算并分析了其适正捕捞力量、经济指标，得出了一些有益的结论：（１）根据台湾海峡渔业资源，把握正确的投资方向，已成为进一步发展海洋捕捞业的关键。（２）由于台湾海峡的渔业资源正遭受越来越大的压力，为了保护渔业资源，应当限制捕捞力量     

福建近海主要底层经济鱼类的种群动态

本文研究了1994年福建近海底拖网渔船主要捕捞对象－带鱼,白姑鱼,二长棘鲷,短尾大眼鲷和条尾绯鲤5种底层和近底层鱼类的种群结构,生长和死亡参数及其开发比率,与1976年比较,带鱼渔获的最大年龄由1976年7龄降至1994年的4齿,白姑鱼,二长棘鲷和短尾大眼鲷由1976年或1982年的5龄降至1994年的3龄,条尾绯鲤由1976年的5龄降至1994年的4龄,带鱼的捕捞死亡系数由1976年的0．491上升到1994年的0．956。二长棘鲷由0．340上升到1．273,短尾大眼鲷由0．505上升到0．868。条尾绯鲤由0．576上升到0．924,白姑鱼由1982年的0．235上升到1994年的0．789,开发比率均比1976年或1982年有较大提高,分别在0．495,0．706,呈现充分开发或过度利用,并讨论了种群变动原因,捕捞结构和底拖网捕捞力量调整及5种鱼类的最小可捕标准问题。     

Fisheries in the context of marine spatial planning: Defining principal areas for fisheries in the German EEZ

A method is presented to define principal areas for fisheries at high spatial resolution applicable to be implemented into marine spatial planning procedures. Vessel monitoring system (VMS) data from 2005 to 2006 are acquired to determine vessel-based fishing effort. Principal areas for the German exclusive economic zone (EEZ) are defined as areas in which 75% of the effort of either year is carried out. Examples are given for the 5 most abundant fisheries in the German EEZ in terms of vessel-based effort, i.e. gill netting, pelagic trawling, demersal otter board trawling and beam trawling >300 and <300 HP. A historical comparison for demersal otter board trawling shows relative stability of spatial utilization patterns in the North Sea section of the EEZ.     

The effects of spatial targeting of fishing effort on the distribution of the Norway lobster,Nephrops norvegicus,on the Farn Deeps grounds,northeast England

Nephrops norvegicus is an essentially sedentary species of lobster that forms the basis of valuable fisheries in the northwest Atlantic and western Mediterranean. Fishers exploiting a sedentary stock are likely to visit the most profitable (highest catch rate) areas first. Such spatial targeting of fishing effort is likely to have important consequences for stock monitoring and assessment. We used underwater television surveys of Nephrops burrow densities on the Farn Deeps grounds, northeast England, to describe changes in abundance and distribution between the beginning and end of a winter fishing season. Above a threshold of c. 0.6 burrows m^–2, overwinter depletion increased with burrow density, consistent with fishing effort being targeted at the highest densities. A simple simulation model showed that this pattern of mortality is an expected consequence of spatially targeted fishing behaviour. The model also predicted that there is decreased spatial variability in density after fishing. An overall decrease in variability was not evident from the survey data, but geostatistical analysis indicated that there was “flattening” of the density profile along a north‐south axis, consistent with the dominant direction of commercial trawling. We concluded that Nephrops fishers are able to find and exploit the highest densities of their target species. A potential consequence is that catch per unit effort (CPUE) data used to monitor trends in this stock potentially could mask declines in stock abundance. CPUE might be more effective if analysed at finer spatial scales, but this is not currently possible. In the absence of these fine scale commercial data, fishery‐independent surveys (e.g., underwater television) are an important source of information on trends in stock abundance.     

Removing derelict fishing gear from the deep seabed of the East Sea

The East Sea, with an average depth of 1700 m, has long been subject to heavy fishing pressure, resulting in derelict fishing gear. Most derelict fishing gears, such as fishing nets, fishing ropes, and crab pots, sink to the seabed and do not degrade. This gear results in “ghost fishing,” which has adverse impacts on deep benthic habitats. Recently, the Korean government has started to remove derelict fishing gears from the deep seabed of the East Sea by bottom trawling with heavy hooks (50–80 kg) and ropes. A total of 207.8 and 252.2 tons of marine debris in 2009 and 2010, respectively, were removed from the seabed, most of which were derelict fishing gears. Contrary to monitoring surveys and clean-up in shallow waters, removal of marine debris from remote deep habitats is much more difficult and dangerous for removal crews.     

Quantifying the relative intensity of fishing on New Zealand seamounts

New Zealand seamounts support major fisheries for several deepwater fish species, including orange roughy (Hoplostethus atlanticus) and smooth oreo (Pseudocyttus maculatus). Although a high proportion of features in the depth range 500–1000 m have been fished, very little is known about the ecological impacts of bottom trawling on seamounts. The potential impact is likely to be influenced by the spatial extent and frequency of fishing. A new index is presented to assess the relative intensity of trawling on New Zealand seamounts. The fishing effects index (FEI) incorporates information on the density of fishing on the seamount as a proportion of the seabed area and also on tow direction. Detailed fisheries data from more than 250 000 tows were examined to calculate FEI for New Zealand seamounts. The most intensively fished seamounts were on the south Chatham Rise, an area characterised by a large number of relatively small features which were fished serially for orange roughy in the 1980s and 1990s. Other seamounts with high FEI were on the north Chatham Rise, Challenger Plateau, and off the east coast of the North Island. A range of sensitivity analyses indicated that the general rankings of seamounts were relatively robust to the choice of arbitrary thresholds used to assign tows to seamounts.     

Developing a framework for displaced fishing effort programs in marine protected areas

As marine protected areas (MPAs) continue to be established, measures to address displaced effort are likely to become increasingly relevant. Recent experiences of displaced fishing effort programs for MPAs and recreational fishing reserves in Australia, together with two examples from the United States, are described. A practical framework for addressing displaced fishing effort is developed, which explores the likely displaced-effort scenarios and options when planning spatial commercial fishing closures for an MPA.