低温盐水微冻保鲜技术在渔船上应用的研究

研究渔获物保鲜制冷技术,保证鱼货质量,是我们水产制冷行业工作者的重要课题,而渔船上的第一线保鲜则是保证渔获物质量最重要的环节。目前我省渔船采用的保鲜技术有带冰保鲜、冷海水保鲜和冻结保鲜等几种。其中带冰保鲜无需制冷设备,但每次出航都要随带大量的冰,不但增加了生产成本,而且在生产时的加冰保鲜操作劳动强度很大。特别是以捕中上层鱼类为主的围网作业,单位网次产量比较高,可达15—20吨/网次,难以全部及时地把渔获物人舱保鲜,鱼和冰也难以混合均匀,鱼货容易变质。采用冷海水保     

谈谈渔船绝热隔气问题——改造老船保鲜措施之一

保鲜问题在渔业生产中是一个极为重要的一环。目前大家的注意力都集中在制冷设备上，这毫无疑问是对头的。但是却不能忽视鱼舱的绝热隔气工作，否则将会因外界热量大量侵入鱼舱从而影响保鲜效果，降低鱼货质量指标。表一列出了渔轮某些部位的平均温度。由此表知如果不做好鱼舱的绝热隔气工作而要使鱼舱保持一定的低温是较困难的。目前我国现有的渔轮在这方面尚存在着许多问题。     

加冰与鱼舱制冷结合的微冻保鲜技术

加冰与鱼舱制冷相结合的保鲜技术，与以前的冷却水微冻保鲜相比，其优点为鱼体不会吸入盐水，因而不会导致鱼体变软，带咸味；保鲜期可延长３天左右。所以，这种方式在有条件的渔船上可以采用。     

中小型渔船制冷装置的几种型式及发展趋势

随著近海鱼类资源的衰退,群众渔船作业范围逐渐向外延伸,如何开发中、小型渔船保鲜制冷装置,这是摆在船用制冷行业的一个重要课题。近几年来制冷设备公司对不同类型的中小型渔船制冷保鲜装置进行研究,取得较为满意的效果。     

渔船主机尾气吸收式制冷装置研究

主机尾气制冷装置将渔船推进柴油机尾气热能回收转换为给鱼舱渔获物冷藏的冷能,在不增加能耗的基础上提高渔获物保鲜品质,减轻渔民工作负荷,符合国家节能降耗的政策方针。根据目标渔船船型与设备参数,设计了一套实用型渔船氨水吸收式制冷系统,利用热力学基本定律,建立数学模型,分析制冷系统各状态点参数,结合能量守恒和质量守恒定律,计算出整套系统的性能指标,最终得到发生器热负荷、溶液泵和冷却水等参数变化时制冷量和制冷系数的变化规律。装置经过多航次实船运行验证,制冷效果显著;而系统的能量利用效率偏低,有待后续借助模型量化参数后改进提高。     

冷海水制冷技术在木质灯光围网渔船上的应用

中上层鱼类的船上第一线保鲜问题,是当前渔业生产一项急需解决的问题。早在1973年,厦门市中上层鱼类保鲜试验小组就把冷海水制冷技术在木质灯光围网渔船上的应用进行了初步的探索,在厦门第二海洋渔业公司的405号船装上4F10制冷装置。经过了实船试验,初步证明在木质灯围渔船上安装制冷装置,用冷海水保鲜中上层鱼类是可行的,它具有提高鱼获物质量,增加生产,减轻劳动强度,节约成本等优点,是改善中上层鱼类保鲜技术的     

六十吨收鲜和冷藏运输渔船

江苏省水产供销公司为解决海上集体渔业的鱼货收购保鲜和减少烂鱼，提出设计收鲜船，要求进行带冰保鲜制冷保温，舱温保持在0℃±2℃。在收鲜淡季可以兼营冻鱼冻肉等的冷藏运输任务，舱温保持在-18℃左右。1980年6月提交了设计任务书。由我所为主并会同承造厂南通渔轮厂合作于1980年9月完成技术设计。同年11月份开工建造，翌年八月交船，正式投入营运。据营运后反映，     

福建省东山县灯光围网作业生产现状

<正> 东山灯围作业从1964年取得试验成功之后,经推广、发展、提高阶段,已有24年之久,是海洋捕捞一支生力军。目前灯围作业全部分布铜陵渔区,10个渔业公司有54组,5054吨,13567马力。经过几次更新换代,渔船更新,网具改革,光源变革和助渔导航电讯仪器充实,使渔具配套设备完整,渔船电船型,吨位80～100吨,主机185～350马力,锦纶网具有69张(新网12张),玻璃钢万光灯艇有162只(20千瓦5只),保鲜隔热舱有65舱,还有冷海水保鲜一套6舱,     

机帆船灯围鱼货的保鲜加工方法

鲐、鲹等中上层鱼,由于鱼体酶活性大,肌肉结缔组织少,在秋季天气酷热、海水温度高、渔场较远、机帆渔船保鲜设备条件差的情况下,鱼体肌肉组织自溶过程加快,僵硬期短,往往不到一天时间,就逐渐出现骨肉分离,腐败变质。因此,采取有效的保鲜措施和加工技术,对提高捕捞生产的经济效益是十分重要的。机帆船灯围鱼货的保鲜方法:1.隔热鱼舱保鲜。鱼舱热量主要来自甲板、舱口、前后舱横壁和两侧的舷窗。在这些地方装置隔热层能使鱼舱保冷。结构方式有固定式和板块活动式,采用泡沫塑料板作隔热材料,板块厚5厘米,隔热层厚10厘米。与普通鱼舱相比,具有保鲜周期长,耗冰省、鲜度好、效益高等优点。     

小型冷库制冷装置动态仿真技术在黄鳝片贮藏设备开发中的运用

随着人民生活水平的提高,对冰鲜产品的需求越来越大,运用仿真技术开发冰鲜设备以满足市场的需求,首先介绍冰温保鲜和冰温设备开发的依据,然后,使用modelica语言和ITI SimulationX 2.0软件运用小型冷库制冷装置动态仿真来开发黄鳝贮藏设备,并与试验设备试验结果进行对比,达到预期的目的。     

峰值法和数据包络分析法在中国远洋鱿钓渔业方面的应用与比较分析

概述了PTP和DEA法的基本理论，并将其应用于我国的远洋鱿钓渔业，结果表明，1999年我国北太平洋鱿钓渔业的“捕捞能力”尚未得到充分的发挥，仍有潜力可挖；影响西南大西洋鱿钓渔业“捕捞能力”的主要因素是制冷能力，钓机数，集鱼灯和水下灯，而船长，船舶总吨位，功率和舱容仅为次要因素。通过应用，本文分析比较了这两种方法的特点；PTP法长于在时间序列方面的一个纵向的分析，能够在一定程度上反映渔业技术和资源随时间的变化而发生的变化，而DEA法则擅于在捕捞单位间进行横向的“能力”比较，并能对影响“捕捞能力”的因素进行有效的灵敏度分析。     

Fishing capacity and capacity utilization of purse seiners using data envelopment analysis

Abstract:   The existence of excessive fishing capacity is globally recognized by resource managers as a major problem for fisheries, and it is responsible for the degradation of fishery resources and for significant economic waste. Estimates of fishing capacity and capacity utilization may provide helpful tools in designing an effective capacity management plan for Mediterranean fisheries. In this study, the fishing capacity and capacity utilization of eastern Mediterranean purse seiners were assessed using data envelopment analysis (DEA). Estimates were made for individual vessels based on the level of inputs used and outputs produced, relative to other vessels operating under similar conditions. Results indicated similar excess capacity for target species, which is in accordance with how the fishery operated. The 24–40-m fleet segment was found to be more efficient than the 12–24-m fleet segment in terms of landing weights. It was evidenced that purse seiners could have increased their catch during 2000–2005 by approximately 23% by increasing the variable inputs, for example days fished. Conversely, a fleet of smaller size could have achieved the reported catch. Under the condition that the remaining vessels will be fully utilized, a proportional decrease in the fleet size might seem a rational management measure towards reducing overexploitation and attaining sustainable fisheries in the eastern Mediterranean Sea.     

中西太平洋金枪鱼围网自由鱼群渔场重心变动及其与南方涛动指数的关系

文章根据2013—2017年中国中西太平洋金枪鱼围网船队捕捞日志,利用捕捞自由鱼群作业位置、作业时间和渔获量等数据信息,分析了自由鱼群渔场重心月间变化、年际变化与南方涛动指数(South Oscillation Index,SOI)的关系。结果显示,渔获量较高的海域海表温度(Sea surface temperature,SST)高于29℃;自由鱼群的渔场重心主要分布介于160°E—175°W;2013—2015年渔场重心有逐年向东偏移的趋势,但无明显的月间变化规律;SOI为正值时,中西太平洋“暖池”较正常年份向西偏移,自由鱼群渔场重心亦明显向西偏移;反之,自由鱼群渔场重心较正常年份向东偏移。相关性分析显示SOI和月间渔场重心的经度之间呈负相关(相关系数为?0.27,P<0.05),表明金枪鱼围网渔场变动和异常气候的发生存在密切联系。研究结果对于掌握中西太平洋金枪鱼围网渔场变动规律具有一定参考价值。     

A predator–prey model for evaluating the spatial behaviour of fishing fleets: a case study of the red grouper Epinephelus morio fishery of Yucatan,Mexico

A predator–prey model was applied to the red grouper Epinephelus morio fishery from Yucatan, Mexico, with the aim of understanding the spatial behaviour of a mid-sized fishing fleet. The heterogeneity of the environment was considered, and different habitat quality levels were determined to address environmental differences. The behaviour of the fleet was also evaluated based on a simulation of restricted fishing areas (RFA). The model was applied utilising 5 years of information on catch and fishing effort (1973–1977). Four levels of habitat quality were defined (low, medium, high and exceptional). The total costs and revenue for a fishing expedition in the areas of exceptional habitat quality were higher due to their location farthest from the base port. The fleet was most efficient during the winter at locations in the eastern continental shelf, with the number of these areas clearly decreasing in the autumn. The model simulation of the RFA showed a total revenue reduction of 7–27 % in scenarios of RFA for adult protection. When the RFA was implemented for the protection of juvenile fish, the total revenue was not reduced, indicating that this type of RFA might be a feasible management strategy for a sustainable fishery.     

中东大西洋中部海域中上层鱼类资源结构与渔场分布

为了解中东大西洋中部海域中上层鱼类资源结构与渔场分布,对2007-2014年入渔FAO34渔区3.11和1.32小区(毛里塔尼亚专属经济区)从事中上层鱼类捕捞的7艘国内渔船的生产数据进行了分析。结果表明,我国入渔船只数量、入渔渔船总产量和作业渔船平均日产量均呈现先增加、后减少的趋势,且在2011年入渔渔船总产量和作业渔船平均日产量到达最大值,2012年入渔船只数量到达最大值。渔获种类主要包括沙丁鱼(Sardina pilchardus)、短体小沙丁鱼(Sardinella maderensis)、金色小沙丁鱼(Sardinella aurita)、日本鲭(Scomber japonicus)和竹筴鱼(Trachurus trachurus),各渔获种类的渔获量年际间波动较为明显。月均产量在17.2~23.6 t/haul,最高值和最低值分别出现在12月和8月;月均总产量在1 279.0~2 414.2 t,最高值和最低值分别出现在1月和8月,12月至次年3月为渔汛旺期。渔场季节变化现象明显,夏秋季向北移动,冬春季向南移动,20.0°~20.8°N、17.4°~18.0°W区域为高产量海域。该海域中上层鱼类洄游现象明显,这可能主要与该海域的不同洋流在不同月份的强弱变化有关,该海域整体渔业资源呈现一定衰退现象。建议渔船入渔该海域从事中上层鱼类捕捞持谨慎态度,加强该海域渔业资源的研究与保护。     

Catch rate standardization for yellowfin tuna (Thunnus albacares) in Taiwan's distant-water longline fishery in the Western and Central Pacific Ocean,with consideration of target change

Catch per unit of effort (CPUE) needs to be standardized to remove the effects of factors such as fishing time and location, before it can be used as an index of abundance in fish stock assessments. One of the most substantial effects arises from a change of target species. This is particularly important for the Taiwanese distant-water longline fishery, which has a long history of fishery data from two fleets that target various tuna species across three oceans. We review the development of the Taiwanese distant-water longline fishery and compare five designs for standardizing the catch rate of yellowfin tuna (Thunnus albacares) in the western and central Pacific Ocean, using generalized linear models with lognormal and delta-lognormal error assumptions. Two approaches to address targeting effects were tested: separating fishing fleet data based on observer records, and including four target indicators calculated from catch data. Four statistical regions (relating to major fishing grounds) were treated as a single factor in the first three cases and were treated separately for the last two (one independent run for each region). The last case, which involved independent analyses for each fishing fleet for each region, and using the delta-lognormal approach, was considered to provide the most informative standardized CPUE trends for yellowfin tuna.     

Results of a short study on by-catches and discards in pelagic fisheries in Scotland (UK)

Observers were placed on pelagic vessels in the Scottish fisheries for mackerel (Scomber scombrus), herring (Clupea harengus), “maatje” herring (herring caught just before their first spawning) and argentines (Argentina silus) to monitor by-catch composition and discarding practices. A total of 67 days was spent at sea, 11 on the argentine fleet, 28 on the herring fleet, 12 on the “maatje” herring fleet and 16 on the mackerel fleet. The level of by-catch generally ranged from <1% to around 2.5% of the total catch. The argentine fishery took a significant proportion of blue whiting (Micromesistius poutassou) (approx. 10% of the overall catch) but this was landed and sold in the market. The greatest range of by-catch species was found in the argentine fishery, including 11 species of fish and one species of squid. Discarding rates in the fisheries varied, with herring and argentine fisheries showing no discards, the mackerel fishery a discard rate of around 4% and the “maatje” herring fishery a discard rate of around 11%. By-catches included small numbers of gannets (Morus bassanus) but no marine mammals. If the sampled trips were representative, results indicate that marine mammal by-catch events typically occur during less than one in 20 hauls in the fisheries studied. A larger scale study is needed to confirm this. Cetaceans were sighted in the vicinity of the fishing boats during 4% of observed fishing activities.     

Bioeconomic evaluation of fisheries enforcement effort using a multifleet simulation model

The economics of enforcement is traditionally modelled using rational agents assumed to act according to their expected economic utility. In this investigation we derive this expectation by implementing a stochastic simulation model to integrate across associated levels of uncertainty using Monte Carlo. The model is developed for the South Georgia toothfish longline fishery, in which legal catches are strictly managed according to the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) conservation measures. Assuming full compliance in the legal fishery, this investigation deals with the role of a fishing patrol vessel (FPV) in excluding illegal fishing vessels. Both legal and illegal fleets are dynamic. For the legal fleet, catch is set by a harvest control rule within the model framework, with vessels leaving if fishing becomes unprofitable. The illegal catch is determined by the number of vessels operating, which predicts catch on the basis of an estimated production function. The exit of illegal vessels is determined by the probability of detection by the FPV, which is a function of days spent on patrol, and estimated profits. The entry of illegal vessels occurs at a fixed mean rate, with the model integrating over uncertainty in this parameter. An obvious trade off exists in that higher levels of illegal activity lead to lower expected returns to the legal fleet. We thus provide a cost-benefit framework for investigating the trade-offs associated with decisions on enforcement in the fishery, and confirm that current enforcement effort levels are well justified.     

Does marine fish farming affect local small‐scale fishery catches? A case study in the NW Mediterranean Sea

Fish farms have been shown to aggregate large numbers of wild fish in their surroundings. Although little is known about how this affects the local fishery, two hypotheses have been put forward; a trapping and a protecting effect on wild fish. This study provides the first monitoring of commercial and recreational fishing activity at a fish farm. We assessed the effect on the small‐scale fishery analysing the differences between fishing in farm proximity and away from the farm (in terms of catch rate, income and catch composition). Moreover, we estimated the biomass removal from fishing activities by farm employees inside the farm. The study was conducted from January 2011 to June 2012 at a Gilthead seabream farm in the NW Mediterranean. The findings revealed a relevant amount of commercial and recreational fishing effort in farm proximity. Yet, the results showed no benefit or difference of fishing in close proximity to the farm compared with areas away from the farm. Thus, we conclude that farm‐aggregated fish are protected from the commercial fleet by the farm leasehold area, but remain vulnerable to hidden fishing practices inside the farm, where farm employees harvest more than 4 t of wild fish annually.     

Remotely sensed spatial dynamics of the Illex argentinus fishery, Southwest Atlantic

Illex argentinus, the Argentine short-finned squid, is an important species within the Patagonian shelf ecosystem, where it supports a major multi-national fishery. The fishing fleet operating in this region is comprised of jigging vessels which attract squid using powerful incandescent lights. These fishing lights are detectable in remotely sensed satellite imagery which makes the fishery unusually amenable to a large-scale analysis of its spatial dynamics. In this paper, long-term inter-annual variability in fleet distribution and extent is examined using imagery from the Defence Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) for the period 1993–2005. The fishery was found to occupy a wide area across the shelf and slope, with regions of consistent fishing activity observed on the high seas (45–47°S) and to the north of the Falkland Islands (Malvinas). Distribution of the fishery over the 13-year study period was variable, with 28% of the fished area occupied in 1–2 years, and 7% of the area occupied in 12–13 years. Annual catch levels were positively associated with the extent of the area occupied by the fleet. Higher catches corresponded to the fishery occupying a wide latitudinal range, whereas lower catches were observed during 2004 and 2005 corresponding to a contraction of the fishery away from the south of its range. In years of very high catches, fishing took place along almost the entire latitudinal range of the species. Due to the intensity of fishing, changes in the distribution of the fleet can reflect shifts in the distribution of I. argentinus; this has potential for the long-term monitoring of this highly variable squid fishery.