北太平洋柔鱼脱钩率研究

北太平洋柔鱼个体大，腕足易断，脱钩率高，成为制约提高渔获量的主要因素之一，１９９３年７－８月和１９９４年８月在“舟渔１３０１”等鱿钓调查船上的测试结果表明，机钓的平均脱率在２５％－４０％间，手钓的平均脱率约为２０％。不同型号钓机和不同位置的钓机脱率不同，其中ＳＥ－８１型钓机和船中部位置的脱钩率最低。不同型号手钓钩和机钓钩，脱钩率也不同，并与柔鱼的个体大小有一定关系，改良型手钓钩可以降低原脱钩率４２     

大型鱿鱼钓脱钩率问题初步研究

在北太平洋鱿钓实践生产发现,西经海域鱿鱼个体大,脱钩率高,本文就舟渔1301轮,在使用水下灯的情况下,对减少鱿鱼脱钩率进行探讨。一、材料与方法1、材料调查船只为舟渔1301,其钓渔具材料配置:水上灯76盏,每盏功率为2KW;水下灯为金属卤素灯,2盏,功率均为5KW;水下灯装置左舷电缆200米,右舷电缆250米;钓机全部为SE-58型,两舷各9台,总共18台,实际使用12台。2、方法(1)调查时间:2000年5月15日~7月8日,历时55天;(2)调查范围:39°N~42°N,180°W~171°W;(3)手钓和机钓的渔获产量对比;(4)不同规格、颜色钓钩上钩率与脱钩率的对比试验;(5)钓机采…     

中东太平洋长鳍金枪鱼延绳钓作业分析

根据辽宁远洋渔业有限公司“海泰”船于2001~2002年在中东太平洋进行的金枪鱼延绳钓探捕的生产数据,分析了长鳍金枪鱼延绳钓作业的捕捞努力量、渔获量及上钓率的月变化和年间变化,并对上钓率与作业渔场表层水温的关系进行了初步研究。“海泰”船平均每月下钓68568钩,2001年月均产量为2960尾;2002年月均产量为1290尾。以重量计,2001年月均产量为31373kg;2002年月均产量为15889kg。两年间相比,2002年月均产量明显低于2001年。不同月份间实际日产量波动较月产量波动小,两年间的平均日产量差异显著。不同月份间上钓率亦差异显著,而年间平均上钓率无显著性差异。不同作业海区日产量和上钓率差异极显著,A、D、E和H区日产量和上钓率较高。在水温15~22℃范围内,上钓率在0.7%~11.1%之间波动,平均值为3.64±0.156%;水温24~30℃范围内时,上钓率在0.25%~3.7%之间,平均值为1.06±0.085%。两个温度范围的上钓率差异极显著。月平均上钓率与作业渔场月平均表层水温成显著负相关。     

海洋环境因子和渔具对吉尔伯特群岛海域镰状真鲨误捕率的影响

为了减少延绳钓渔业中镰状真鲨的误捕率,本研究利用2009年10月-12月和2010年11月-2011年1月在吉尔伯特群岛海域作业的延绳钓渔业调查数据:钓钩深度数据,温度、盐度、溶解氧浓度和叶绿素浓度垂直剖面数据,作业参数,渔获统计数据等,采用逐步回归的方法建立钓钩预测深度计算模型,利用Wilcoxon检验对2种钓具和2种钓钩钩型之间镰状真鲨误捕率进行显著性检验,利用统计和聚类分析的方法分析镰状真鲨的捕获环境.结果显示,(1)实验钓具和18/0圆型钓钩可显著降低镰状真鲨的误捕率;(2)镰状真鲨误捕率最高的深度、温度、盐度、叶绿素、溶解氧范围分别为40.0 ～79.9 m,24.0 ～ 24.9℃、29.0 ～ 29.9℃,35.40～35.99,0.120 ～0.199μg/L和4.50 ～ 4.99 mg/L.研究建议,(1)在生产中增加18/0圆型钓钩和80 m以深的钓钩投放量;(2)减少镰状真鲨误捕率最高的深度、温度、盐度、叶绿素和溶解氧范围内的钓钩数量.     

中西太平洋金枪鱼延绳钓主要渔获物垂直结构的初步研究

根据2012年7~11月金枪鱼科学观察员在中西太平洋采集的钩位深度以及渔获物的钓获钩位数据,分析了各钩位的上浮率和钓获鱼种的垂直分布结构,并比较了不同鱼种垂直分布的差异性。结果表明:(1)钓钩绝对上浮率变化范围为0.49~44.73 m,相对上浮率的变化范围为0.65%~16.69%,平均绝对上浮率为23.29 m,平均相对上浮率为8.87%。(2)12种主要渔获钓获深度范围差异很大,大魣(Lampris guttatus)的平均钓获深度最浅,为75.92 m,蓝枪鱼(Makaira nigricans)的平均钓获深度最深,为228.19 m。聚类分析显示12种主要渔获物可以分成3种垂直分布结构。(3)11种主要兼捕渔获钓获深度均与长鳍金枪鱼(Thunnus alalunga)钓获深度呈显著性差异。     

恢复发展钓业生产大有可为

<正> 近年来,由于捕捞强度的不断加大,海洋渔业资源的衰退,台州市主要作业(如拖虾作业、双拖作业等)单位产量大幅度滑坡,严重困扰着渔区的广大干部和渔民群众。面对现实,我们对渔区生产情况进行了全面的调查。在调查中发现:主要作业均有不同程度的减产,可钓业和中深海流钓却是前景喜人。玉环县仅存的2艘钓机和6艘小钓,1996年1～6月份钓机平均产值为93.75万元;小钓平均产值为23.2万元;中深海流钓作业一般单位产量为60t左右,平均单位产值120万元,高的单位产量67.5t,产值144万元。截止1996年10月20日,钓机平均216万元,小钓30.5万元。这些作业投入成本低、风险     

一种操作简单且实用的中水层延绳钓机设备——滚筒和射钓机

金枪鱼延绳钓业是钓渔业中最重要的一类，是远洋渔业中比较国际性的产业之一。渔法是使用钓线、钓钩并利用鱼饵诱使鱼类上钩而捕获的作业方法。国内的金枪鱼钓船基本上都在沿用台湾产的起钓机（或日产的功能相似的起钓机）。然而，一种操作简单省力且实用的中水层金枪鱼延绳钓船的钓机设备在南太平洋的个别岛国却很流行，这种由滚筒和射钓机配套使用的钓机设备最优越的特点就是它可简单的随意调整钓钩水层范围，特别是较深水层。可根据不同鱼类栖息的水层范围来调整放钓的深度，从而提高了渔获的比例，能够适应钓捕不同水层的鱼类和有效地钓…     

斯坦格延绳钓设备简介

与拖网捕捞作业相比、延绳钓是一种真正具有选择性的捕捞方法。最近德国的斯坦格技术开发公司（STAGAtechComPany）对新研制的延绳钓机进行海上钓捕试验。试验表明：延绳钓作业是一种既省油，又不破坏海洋环境的作业方式．不会危及到海豚、海鸟、海龟等其它海洋动物。STAGA延绳钓机适于近海、外海及深水延绳钓作业、适于单丝及复丝的主干线且适于不同规格的钓钩及钓饵。正是由于该设备较强的适应性，因此不仅可用于钓捕鳍鱼等底层鱼类．而且可用干钓捕箭鱼、小型井地所等中卜层菌类斯坦格兰延绳钓设备工作示意图该设备（如图所示）的放…     

石斑鱼钓捕技术

钓石斑鱼(即手持单钩钓),俗称鲙钓,按钓具结构不同可分为单门钓和双门钓。这两种钓具均由手线、钓线、钓钩、沉锤组成,但在生产中其作业渔期有所不同。一、钓具1.双门钓(1)手线:材料为50拉力的尼龙线,直径0.9mm,     

光诱鱿鱼手抄捕技术

鱿鱼是我县海洋捕捞的主要生产对象之一。但长期来捕鱿工具一直沿用传统的单一手钓,捕捞技术落后,单产较低,因而阻碍了捕鱿生产的发展。在上级水产部门的支持下,我县水产科技人员与广大渔民、干部积极探索,大胆改革传统渔具渔法,采用光诱手钓抄捕技术,大大提高了鱿鱼产量。至1985年,全县基本采用了光诱手抄捕技术,平均单船产魷鱼889公斤,1988年,平均单船产量1286公斤,人均产量105.5     

利用栖息地指数模型预测秘鲁外海茎柔鱼热点区

利用栖息地指数模型准确地预测了秘鲁外海茎柔鱼的热点区。根据2008-2010年1-12月期间我国鱿钓渔船在秘鲁外海的生产数据,结合实时的海表温及海表面高度数据,分别建立以作业次数、单位捕捞努力量渔获量为基础的适应性指数。利用算术平均数模型建立基于海表温和海表面高度的栖息地指数模型,并利用2011年生产及环境数据对栖息地指数模型进行验证。结果显示,以作业次数为基础的适应性指数符合正态分布,而以单位捕捞努力量渔获量为基础的适应性指数显著性检验不显著,因此,只建立以作业次数为基础的模型。结果表明,以作业次数为基础的栖息地指数模型都高估了茎柔鱼热点区的范围,但大体范围基本一致,这说明其能较好地预测茎柔鱼的热点区。     

智利外海茎柔鱼产量分布及其与表温的关系

根据2004年4～6月我国鱿钓船在智利外海生产统计数据和表温资料,用Marineexplore4.0绘制各月产量、CPUE与表温关系的分布图并进行分析。结果表明,4～6月茎柔鱼产量主要分布在28°～30°S、76°～78°W附近海域,平均CPUE在10t/d以上。作业渔场的表温范围为17～20℃,主要集中在表温为17～19℃海域。     

An assessment of the west winter–spring cohort of neon flying squid (Ommastrephes bartramii) in the Northwest Pacific Ocean

In the Northwest Pacific, the squid jigging fisheries targeted the west winter–spring cohort of neon flying squid (Ommastrephes bartramii) from August to November. Total annual catch by the Chinese mainland squid jigging fleet during 2000–2005 ranged from 64,100 to 104,200 t. The unique life history of this squid species makes the use of traditional age- or length-structured models difficult in evaluating the effect of intensive commercial jigging on this stock. We fitted a modified depletion model to the Chinese jigging fisheries data to estimate the squid stock abundance during 2000–2005. Monthly biological data were randomly sampled from the five squid jigging vessels during the fishing seasons. Effects of using different natural mortality rates (M) and three different error assumptions were evaluated in fitting the depletion model. Based on sensitivity analyses, the log-normal error model was found to be preferred for the squid assessment. The assessment results indicated that the initial (pre-fishing season) annual population sizes ranged from 199 to 704 million squid with the M value of 0.03–0.10 during 2000–2005. The proportional escapement (M = 0.03–0.10) for different fishing seasons over the time period of 2000–2005 ranged from 15.3% (in 2000) to 69.9% (in 2001), with an average of 37.18%, which was close to the management target of 40%. Thus, the current fishing mortality of the squid jigging fishery was considered to be sustainable. We inferred its annual maximum allowable catch ranging from 80,000 to 100,000 t. This study suggests that the modified depletion model provides an alternative method for assessing short-lived species such as O. bartramii.     

Interactions between seabirds and pelagic squid-jigging vessels in the south-west Atlantic

1. The waters of the Patagonian Shelf in the south-west Atlantic are nutrient rich, support large concentrations of wildlife, and are exploited by several fisheries, including the large Asian squid-jigging fishery. Although the squid-jigging fishery has previously been observed to have few problems with the accidental mortality of seabirds, the deliberate catch for consumption of seabirds by the crew has been identified as a possible issue.
2. Four cruises were made between Uruguay and the Falkland Islands during 2005–2006 to quantify the impact of jiggers on seabirds from indirect observation platforms. Monitoring included closely approaching 116 jigging vessels and boarding seven for inspection.
3. The use of non-jigging fishing gear, either for catching fish or seabirds, was observed at the stern of 33 vessels. Twelve seabird carcasses were observed floating close to vessels during 13 days of monitoring. Although the results recorded here are not sufficient to put a confident estimate on the magnitude of this mortality, the density of carcasses floating in the water among the jigging fleet indicated the potential significance of this problem.
4. The results were considered sufficiently concerning for the Falkland Islands Government to take preventative actions, including educational efforts, improving humanitarian conditions onboard vessels, introducing relevant legislation and licence conditions, and prosecuting intentional seabird take inside the Falkland Islands jurisdiction. This has resulted in the apparent elimination of these mortalities within Falkland waters since the late 2000s.
5. Nevertheless, it is likely that the same initial conditions exist for the crews of squid jiggers on vessels operating on the high seas, and so the possibility of the targeting of seabirds for consumption continues. Squid fisheries with substantial numbers of jiggers overlap with important foraging areas for a range of albatross and other species in high-seas areas such as the Patagonian Shelf, the Humboldt and Kuroshio currents, and the south-west Pacific Ocean. These areas of overlap may be important to investigate, especially in the foraging grounds of declining seabirds.

     

The effect of lunar cycle,tidal condition and wind direction on the catches and profitability of Japanese common squid Todarodes pacificus jigging and trap-net fishing

Jigging with artificial lights (squid jigging) and deploying of large scale trap-net (also known as a set-net in Japan), are the major methods to capture Japanese common squid Todarodes pacificus in western Japan. Squid jigging is a highly selective fishing method. However, it consumes large amount of energy for steaming to the fishing ground and for lighting. In contrast, trap-net fishing requires substantially less energy but its capture efficiency is strongly influenced by its stationary mode of capture. The primary objective of this study was to analyze how various environmental and biological factors such as the lunar cycle, tidal condition, wind direction and squid abundance affect the capture efficiency of squid jigging and trap-net fishing. We analyzed the effect of these factors on squid catch in five Fisheries Cooperative Associations located on four islands in Nagasaki Prefecture, western Japan. Our analysis shows that squid catch in jigging and trap-net fishing is mainly influenced by the lunar cycle but also tide and wind direction play a marked role. In addition, squid abundance significantly affects the catches in trap-net fishing. Recommendations are made to improve the overall profitability of squid fishing by proper choice of the capture method, location and season.     

西北太平洋公海7~9月秋刀鱼渔场分布及其与水温的关系

根据2003~2005年7~9月西北太平洋公海秋刀鱼生产数据和水温遥感数据,对西北太平洋公海秋刀鱼作业渔场分布及其与表温和上层水温结构的关系进行了分析。结果认为,随着时间的推移,7~9月西北太平洋公海秋刀鱼渔场重心有从西南向东北变动的趋势;各月产量重心处水温结构有较大差异,9月混合层深度较7月和8月有所加深,渔场也较后者向北移动;各月高产渔区0~15m温度梯度都在0.25℃/m以下,0~40m温度梯度在0.1℃/m左右,40~60m温度梯度在0.25~0.42℃/m之间。灰色关联度分析表明,渔区月产量受到众多因素的影响,其中捕捞努力量、渔区平均日产量和表温是其主要影响因子,对渔区平均日产量影响较大的有表温、0~15m温度梯度、0~40m温度梯度和月份,其关联度都在0.80以上。     

南极大西洋扇区磷虾渔业渔获率突变特征及其致因分析

本研究利用CCARMLR数据库中提取的南极大西洋扇区(含48.1、48.2和48.3亚区)1982-2011年30年间的南极磷虾(Euphausia superba)年平均渔获率数据,运用Mann-Kendall法分析了其时间序列的发展趋势及突变特征.从趋势特征看,48区月均名义CPUE由1982年的5t/h左右,变化至2011年的10t/h左右.CPUE值时间序列呈现显著性周期波动,线性趋势年均增幅为0.221t/h.48.1亚区为主要捕捞区域,其CPUE线性趋势增幅最小,为年均0.088 t/h;而48.2亚区增幅最大,年增幅达0.323 9 t/h; 41.3亚区的年增幅为0.261 t/h.就渔获率突变特征而言,过去30年48区磷虾渔获率变化趋势为先缓后快的逐渐上升过程,渔获率突变点发生在1999年,这个突变在2001年后显著性存在.3个亚区磷虾渔获率均存在“上升突变”突变点.48.1亚区渔获率分别于2001年和2004年出现相交突变点,但均未通过α=0.05的显著线检验.48.2亚区分别于1995-1996年“向下突变”,但未通过α=0.05的显著线检验,1996-1997年出现“向上突变”,2000年通过α=0.05的显著线检验.48.3亚区突变发生在1992年,突变点通过α=0.05的显著线检验.结合海冰面积和捕捞(包括般队、捕捞技术、加工工艺)等因子分析突变的致因时,发现:(1)捕捞技术和加工工艺是最主要的致突变因子;(2)海冰面积在1983-1993年对渔获率突变有明显贡献;(3)空间上,越靠近南大陆,环境因子对突变的发生越容易产生作用.     

Relationships between catch and effort in Fijian multispecies reef fisheries subject to different levels of exploitation

Abstract The catch-per-unit-effort (CPUE) and value-of-catch-per-unit-effort (VPUE) of reef-associated fish species from six Fijian native fishing grounds ( qoliqoli ) subject to different fishing intensities were determined using records of fishing activity from a voluntary logbook scheme. Line and spear fishing techniques were used for more than half the total fishing time (h person^-1 d^-1) in all qoliqoli , and yet the favoured technique in a given qoliqoli was frequently less efficient (lower CPUE) than other techniques. The popularity of relatively ineffective fishing methods implies that fishermen did not always attempt to maximize their catch rates. To compare fishing effort in different qoliqoli , all effort was rescaled on the basis of its recorded efficiency (measured as multispecies CPUE) and expressed as hours equivalent to boat-based spear fishing over coral by day to catch fish for sale. Total fishing intensity in the six qoliqoli ranged from 72 to 4310 h km^-2 reef year^-1. The relationship between catch and effort was linear at all fishing intensities, suggesting that the qoliqoli were all fished on a sustainable basis. Furthermore, whilst there was a significant difference in CPUE and VPUE between the one or two qoliqoli with lowest fishing intensity and all the others, there were no significant differences between these other qoliqoli in terms of the VPUE of the saleable multispecies boat catch or the CPUE of species from piscivorous and carnivorous genera ( Epinephelus, Lethrinus and Plectropomus ) which the fishermen prefer to catch.     

Effect of a stepwise lighting method termed “stage reduced lighting” using LED and metal halide fishing lamps in the Japanese common squid jigging fishery

Lighting systems combining light-emitting diodes (LEDs) and metal halide lamps (MHs) are expected to be energy-saving tools in Japan??s squid jigging fishery. Previous research has shown the need for light stronger than LEDs (9?kW) and 36 MHs (108?kW) to catch the Japanese common squid Todarodes pacificus. We tested a stepwise lighting method termed ??stage reduced lighting?? in the Tsushima Strait in January and February 2010 using nine fishing boats. LEDs (9?kW) and 50 MHs (150?kW) were lit for 3.9?h on average, and then the number of MHs was reduced to either 30 or 36 until the end of fishing (7.3?h on average). This method reduced fuel consumption by 22?C25?% compared to the continuous use of all fishing lamps (159?kW). We carried out a catch analysis of nine experimental boats and 21 commercial boats during the experimental period. Generalized linear modeling analysis suggested that the squid catch can be explained by the illuminated fraction of the moon and monthly changes in squid abundance, and the lighting method. The stage reduced lighting using LEDs and MHs has the potential to reduce fuel consumption while maintaining the squid catch.     

南海鸢乌贼产量与表温及水温垂直结构的关系

根据2012年9—10月秋季航次及2013年3—4月春季航次南海灯光罩网船各站点的水温数据及生产数据,对鸢乌贼(Symplectoteuthis oualaniensis)产量与表温(SST)及水温垂直结构的关系进行了分析。结果显示,春季是鸢乌贼的高产渔期,总产量及平均网产都明显高于秋季;鸢乌贼作业渔场的季节变化较为明显,春季南沙和西中沙海域都有渔场分布,产量主要集中在10°~15°N、111°~117°E海域内,而秋季鸢乌贼产量主要集中在13°~15°N、117°~118°E海域;鸢乌贼春季和秋季作业渔场的SST范围有所差异,春季作业渔场表温范围为25.6~29.6℃,秋季作业渔场表温范围为27.6~30.0℃,但最适表温都分布于28.5~29.5℃的海域;不同季节作业渔场水温垂直结构差异明显,从5~50 m水温垂直梯度来看,春季鸢乌贼0.00~0.05℃/m组距内平均网产较高,且随着水温垂直梯度的增加而减少;而秋季鸢乌贼平均网产随水温垂直梯度的增加而增加,并于0.15~0.20℃/m组距内达到最高。灰色关联度分析表明,5~50 m水温垂直梯度是对鸢乌贼产量影响最显著的因子,关联度为0.84,纬度、5~100 m水温垂直梯度、表温和经度影响次之。