基于DEMATEL-ISM-MICMAC法中国远洋鱿钓渔业脆弱性指标选择与分析

远洋鱿钓渔业是我国远洋渔业的重要组成,该渔业极易受到环境等因素的影响。为可持续高质量发展我国远洋鱿钓渔业,本文结合脆弱性理论和方法,从气候与环境、物种、社会经济三大方面建立了我国远洋鱿钓渔业社会—生态系统脆弱性指标体系,运用决策试验与评价实验室(DEMATEL)法、解释结构模型(ISM)法以及交叉影响矩阵相乘(MICMAC)法对影响指标及其关联性进行分析。研究表明,鱿鱼渔业资源是最核心的因素,对我国远洋鱿钓渔业脆弱性起决定性作用;科技投入、政策与管理、捕捞强度是最具影响力或驱动力的因素;我国远洋鱿钓渔业脆弱性指标可分五大类,要把重点放在关联因素、调整因子和驱动因素上,其次为依赖因素,自主因素无需过多关注。研究认为,除渔业资源外,脆弱性系统可分为四个层级,长期监控L3和L4层指标,重视L2和L3层的指标,针对性地调整L1层指标,是保持我国远洋鱿钓渔业长期健康发展的有效路径。该研究不仅能识别影响我国远洋鱿钓渔业脆弱性的关键因素,同时可为远洋鱿钓渔业的科学管理提供理论指导,并为脆弱性实证评估奠定基础。     

仿生鱿鱼肉鳍扑动推进机理数值研究

在仿生机器鱿鱼的设计制作中,通过肉鳍摆动辅助腕的收缩以及喷水推进的组合,使得鱿鱼可以以多种运动形式进行游泳。为研究鱿鱼肉鳍的扑动推进机理,采用计算流体力学(CFD)方法对生物鱿鱼外形进行等比例数值建模,计算分析鱿鱼肉鳍在不同扑动角度下的水动力特性。在此基础上,通过改变肉鳍占体比例、肉鳍形状等参数,研究不同参数对鱿鱼肉鳍扑动推进性能的影响。结果显示:鱿鱼肉鳍扑动过程中肉鳍上下表面出现明显涡流区与压力差,鱿鱼在该压力差的作用下完成升沉运动与水平运动;当鱿鱼肉鳍占体比例超过0.3时,升沉力与水平推进力均随肉鳍占体比例的增加呈明显上升趋势,而阻力变化趋于稳定,适当增加肉鳍的占体比例可获得更高的扑动推进效率;横菱形肉鳍具有较高的推进效率与较低的游动阻力,在仿生鱿鱼设计中是一种较为理想的选择。研究结果为仿生机器鱿鱼的设计制作提供了计算方法和理论参考。     

北太平洋西经海域(175°W-170°W)温盐分布及其与柔鱼渔场关系的初步研究

根据2000年5-7月北太平洋鱿钓探捕调查所收集的海水盐度、温度及渔获量等数据,分析了调查海域表层盐度、不同水层水温的分布特征及鱿钓渔场的形成.利用聚类和相关分析方法,研究了单位捕捞努力量渔获量与表层盐度及不同水层水温的关系.结果表明,鱿钓渔场形成于表层低盐水舌和100m层水温暖水舌的交汇区,单位捕捞努力量渔获量与100m层水温相关性最好,但表层海水盐度的分布对鱿钓渔场的确定仍具有一定指示意义.     

基于最大熵模型分析西南大西洋阿根廷滑柔鱼栖息地分布

根据2008—2010年中国鱿钓船在西南大西洋海域得到的生产数据及海洋环境数据(海表面温度,sea surface temperature,SST;海面高度sea surface height,SSH;叶绿素-a浓度,chlorophyll-a,chl.a),利用最大熵模型(Max Ent)分析捕捞主渔汛期间(1—4月)阿根廷滑柔鱼的潜在栖息地分布,同时与实际作业位置相比较,结合海洋环境因子分析不同年份分布差异的原因。模型运算结果显示:阿根廷滑柔鱼潜在分布区域的变化与实际作业位置变动基本一致;南北方向上,2008年和2009年的潜在分布区域较为广泛,而2010年的潜在分布区域较为狭窄,且主要分布在45°S以南的区域。Jackknife检验表明,SST是影响阿根廷滑柔鱼分布的首要环境因子,SST等温线分布可用来表征海流的强弱进而影响阿根廷滑柔鱼的分布,其中12°C等温线可以作为寻找渔场的一个指标。SSH等高线分布及其涡的变化也会影响到阿根廷滑柔鱼分布。chl.a只能间接地反映阿根廷滑柔鱼渔场的分布,不能很好地作为表征其分布的环境因子。研究表明,分析阿根廷滑柔鱼栖息地分布及其差异原因应主要观察SST和SSH的变化。     

鱿钓船水上集鱼灯的光照度分布及钓捕效果分析

根据2003年10月在印度洋鸢乌贼渔场中鱿钓船周围某一断面水中光照度的实测数据和渔获生产统计数据,对金属卤化物灯和高压钠灯的光照度分布及其钓捕效果进行了比较分析。在120盏×2kW金属卤化物灯作用下,在距船舷3.0m的垂直断面,其水深5m内的光照度多在100lx以上,10lx的等光照度曲线在20m水层左右,0.01lx的等光照度曲线在55m水层附近。但在20盏×500W高压钠灯作用下,在距船舷3.0m的垂直断面,其海面的平均光照度为3lx左右,0.01lx的等光照度曲线在20m水层附近。以一些头足类的适宜光照度(0.01～10lx)为例,其在该照度范围内的水体体积仅为120盏×2kW金属卤化物灯作用下的1/5左右。这说明采用高压钠灯可以使鱿鱼聚集密度增大,钓捕深度变浅,从而提高渔获效率,且其平均产量比采用高压钠灯前高1～3倍。另外,研究表明大型专业鱿钓船钓捕鸢乌贼时的最适集鱼灯功率为112～160kW,鸢乌贼的最适光照度为0.01lx左右。     

Can fermented soybean meal and squid by‐product blend be used as fishmeal replacements for Japanese flounder (Paralichthys olivaceus)?

An experiment was carried out to evaluate fermented soybean meal and squid by‐product blend (1:1) (FP) as replacement of fishmeal (FM) for Japanese flounder, Paralichthys olivaceus. Five isocaloric (19 kJ g^?1) diets were prepared by replacing 0 (FP0), 12 (FP12), 24 (FP24), 36 (FP36) and 48% (FP48) FM protein with FP. Triplicate groups of juveniles (mean weight of 3.9 g) were delivered the test diets for 8 weeks in a flow‐through sea water system. The results showed that there were no significant differences (P > 0.05) among the growth rates of fish fed FP0, FP12, FP24 and FP36 diets. Growth and nutrient utilization parameters were significantly reduced in fish fed FP48 diet. Although, whole body proximate composition of fish were not significantly affected by the dietary treatments compared to the control; methionine and phenylalanine contents were significantly decreased in FP48 group. Protein retention was also significantly decreased in the similar group of fish. Dietary treatments did not alter most of the plasma metabolites, while some of the health parameters were improved in the replacement groups. Results suggested that FP is a potential candidate for alternative protein ingredient in aquafeed and can replace 36% FM protein in the diet of Japanese flounder.     

Preparation and Characterization of Protein Hydrolysates From Little Loligo Squid (Uroteuthis chinensis)

Research on the little loligo squid (Uroteuthis chinensis) protein hydrolyzed by papain and Flavourzyme and characterization of hydrolysates was carried out in this article. The optimum hydrolysis conditions of papain were obtained by orthogonal experiments, and the influence factors on the degree of hydrolysis such as enzyme/substrate ratio, hydrolysis time, pH, and temperature were investigated. The effect of Flavourzyme on the degree of hydrolysis was also studied. The characteristics of freeze-dried hydrolysates such as yield, moisture, nitrogen recovery, molecular mass distribution, and amino acid composition were determined. The results showed that papain and Flavourzyme could hydrolyze the little loligo squid protein efficiently, and the degree of hydrolysis was up to 25.82% under the optimum hydrolysis conditions. The average molecular mass of hydrolysates obtained with papain and Flavourzyme was 1,246 Da, and the low molecular mass peptides were the main fraction of hydrolysates. The yield, moisture, and nitrogen recovery of freeze-dried hydrolysates was 19.8, 4.4, and 74.2%, respectively. Compared with suggested patterns of amino acid requirements by the Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO), the hydrolysates of the little loligo squid had high nutritional value, and was a potential nutritious supplement used in various food products.     

中国鱿鱼钓机装备研究现状及展望

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。     

花生种子发芽率快速测定法

用TTC氯化三苯四氮唑)染色法和红墨水染色法对35份花生品种进行种子生活力的测定,并与其发芽率比较,研究结果表明,TTC法和红墨水法测定的种子生活力和发芽率之间存在极显著的正相关关系。TTC染色法和红墨水法都可用于花生种子发芽率的快速测定,其中TTC染色法的测定结果可靠性高于红墨水染色法。     

Interannual variability in stock abundance of the neon flying squid, Ommastrephes bartramii, in the North Pacific Ocean during 1979–1998: impact of driftnet fishing and oceanographic conditions

Variability in catch-per-unit-effort (CPUE) was examined for the autumn cohort of Ommastrephes bartramii collected with research driftnets during 1979–1998 along five longitudinal transects passing through the Subarctic, Transitional and Subtropical Domains in the North Pacific. CPUE was generally low during the period of intensive commercial driftnet fishing (1980–1992) and increased following the 1992 moratorium on the use of large-scale driftnets. However, CPUE levels were low for the cohorts hatched in 1992 and 1996 (captured in subsequent years owing to a one-year life of O. bartramii ) that experienced low sea surface temperatures from hatching to recruitment. Among similar-aged squid collected from 180° and 179°30'W in June, mantle lengths were significantly greater in 1997 than during 1995–96. These findings suggest that the driftnet fishery and sea surface temperatures from hatching to recruitment strongly affected stock abundance and possibly growth.