北太平洋秋刀鱼生活史和资源渔场研究进展

北太平洋秋刀鱼(Cololabis saira)是中国重要的远洋渔业鱼种,被北太平洋渔业委员会列为优先管理的种类之一。本文回顾和概述了秋刀鱼生活史、种群动力、资源渔场和栖息地适宜性等方面的研究进展,分析和展望了秋刀鱼生长生物学、繁殖生物学、洄游、资源波动和栖息地适宜性等研究现状和未来的发展趋势。主要建议包括:基于耳石微化学信息和最适环境参数的时空分布变动,探索秋刀鱼潜在的洄游路径和模式;建立繁殖栖息地适应性指数模型,分析海洋气候对秋刀鱼补充群体潜在栖息地的影响;建立秋刀鱼集群栖息地适宜性指数模型,开发秋刀鱼渔场渔情速报系统。本文的概述和分析旨在为秋刀鱼渔业资源等相关研究提供参考。     

西北太平洋秋刀鱼舷提网捕捞技术

自2003年我国大陆成功开发了西北太平洋秋刀鱼渔场之后，秋刀鱼已逐步进入中国大陆市场。对于秋刀鱼捕捞技术，在历经刺网、围网等渔具后，现基本以舷提网捕捞作业为主。根据2004年6—10月大连“国际903”号生产调查船在西北太平洋海域进行探捕调查的生产情况，对秋刀鱼舷提网的捕捞技术，从渔捞设备至捕捞具体操作技术进行介绍。     

Comparison of biomass estimates from multiple stratification approaches in a swept area method for Pacific saury Cololabis saira in the western North Pacific

Fishery-independent surveys using sea surface trawl nets for Pacific saury Cololabis saira in the western North Pacific since 2003 have enabled the investigation of their annual distribution patterns and total biomass during June and July, prior to the main fishing season in Japan. We compared biomass estimates and their associated variances derived based on five different post-stratification approaches in a swept area method, and then observed that these approaches have little effect on biomass estimates and their precision, owing to well-organized survey designs and homogeneously allocated sampling stations. We were able to utilize decreasing biomass estimates for 15 years as an essential abundance index in the ongoing stock assessment. Notably, examination based on stratification along with longitudinal survey lines indicated that the estimated biomass had decreased in the western survey area, resulting in an eastward shift in the gravity center of Pacific saury distribution after 2010. We recommend biomass estimation in an east–west direction based on longitudinal stratification as an effective measure to develop population dynamics models which reflect westward migration into the fishing grounds around Japanese coastal waters, and to forecast the expected catch during the subsequent fishing period.

     

基于贝叶斯Schaefer模型的西北太平洋秋刀鱼资源评估和管理

秋刀鱼(Cololabis saira)是西北太平洋温带海域的主要捕捞对象之一,也是西北太平洋渔业重要的组成部分。本研究根据北太平洋渔业委员会(NPFC)统计的2003～2017年渔获量数据以及中国秋刀鱼组织提交的单位捕捞努力渔获量数据(Catch per unit effort, CPUE),基于贝叶斯Schaefer剩余产量模型,分基准方案和敏感性分析方案对西北太平洋秋刀鱼资源状况进行了评估,并对其管理策略做了风险分析。结果显示,基准方案和敏感性分析方案下模型参数预测值以及生物学参考点估计值比较相近。在基准方案下,估算的最大可持续产量(Maximumsustainableyield,MSY)为75.26×10~4t,最大可持续产量的资源量BMSY为240.14×10~4t,此时的捕捞死亡率为0.32。在敏感性分析方案下,估算的最大的可持续产量MSY为70.03×104t,最大可持续产量的资源量BMSY为232.53×104t,此时的捕捞死亡率为0.31。该海域秋刀鱼资源状况良好,未经受过度捕捞。风险评估分析表明,为使秋刀鱼资源可持续利用,需将捕获率设定在0.3左右。     

以遥感夜间灯光数据为基础的西北太平洋秋刀鱼渔船识别

研究和开发利用大洋性生物资源是实现我国海洋渔业可持续发展的重大战略需求,西北太平洋秋刀鱼是近年来我国重点开发的大洋性渔业资源之一,因此利用卫星来监测渔船时空分布动态成为了解秋刀鱼渔业资源变动的重要数据源。本研究采用峰值检测和阈值分割等方法对西北太平洋夜间灯光数据进行识别,利用地理信息系统技术对渔船位置信息和数量进行提取分析。通过西北太平洋秋刀鱼资源调查的渔捞日志和经过筛选的北太平洋渔业委员会(NPFC)渔船列表数据对识别结果进行验证。结果显示,本研究所用的夜间灯光渔船识别方法可以精确识别西北太平洋密集作业及外围分散作业的秋刀鱼渔船。以此为基础可以有效地分析秋刀鱼渔场的时空变动。结合美国国家海洋和大气管理局(NOAA)提供的海表温度(SST)数据绘制等温线,进一步分析作业渔场的时空变化,发现夜间灯光渔船作业的温度范围随着秋刀鱼洄游而变化。2016年7—9月渔场的SST波动较大是因为这一时期秋刀鱼在黑潮—亲潮广泛的交汇区域洄游,分布更为广泛,9月之后作业渔场SST变动趋于稳定。该研究结果将来会对远洋渔场环境实时变化、鱼群分布预测、渔船动态及法律支撑等提供有效信息。     

Migration route of Pacific saury Cololabis saira inferred from the otolith hyaline zone

In order to establish the migration route of Pacific saury Cololabis saira, we measured the radius of otolith annual rings (ROA) in fish collected from areas off the Japanese coast up to 165°W in June and July (pre-fishing season) and from fishing grounds in August?CNovember (fishing season). The average ROA for six sea areas that each spanned 10° of longitude sampled during the pre-fishing season were compared with data obtained during each month of the fishing season. The average ROA decreased from west to east and also decreased monthly from August to November. The average ROA of fish caught after October at the peak of the fishing season was equivalent to that of the fish caught in the areas east of 160°E or 170°E. We conclude that Pacific saury caught by Japanese fishing vessels during the peak of the fishing season migrate from an area east of 160°E.     

Locations of early fishing grounds of saury in the northwestern Pacific

In the north-western Pacific, we found that locations of early fishing grounds of Pacific saury, Cololabis saira, are affected by two factors, the size composition and the meridional shift of the offshore Oyashio Front (OOF). Early fishing grounds are formed nearshore from the central Kuril Islands to Hokkaido in northward OOF years. In southward OOF years, they are far from the coasts. There also exists a tendency that early fishing grounds are formed south-westward (north-eastward) in years when a large (medium or small) size class of saury is dominant and when the OOF shifts north (south). These results support the hypothesis that saury migration is considerably influenced by oceanographic conditions, and that a large size class of saury leads to migration that can reach the vicinity of Japan early in the fishing season.     

基于GAM和权重分析的西北太平洋秋刀鱼渔情预报研究

为了提高秋刀鱼(Cololabis saira)渔情预报模型的时空分辨率,提升生产经济效益,本研究基于2013-2016年7-11月中国在西北太平洋公海的秋刀鱼生产数据及海洋环境数据,利用广义可加模型(generalized additive models,GAM)分别拟合单位捕捞努力量渔获量(catch per un...     

基于菲涅耳现象的LED集鱼灯最佳入射角研究

为了解决平板式LED集鱼灯安装不合理的现状,使得LED集鱼灯光能得到有效利用,提高诱、集鱼效果,实验分析了海面的菲涅耳现象,利用光学的临界条件原理推导出了菲涅尔公式,并利用透射率和折射率的定义式,得到光通过两个不同介质分界面时透射率和折射率的各分量与入射角的关系式,进而利用MATLAB仿真了光在通过海面时透射率和反射率随入射角改变而变化的函数图像。结果显示,透射光强最大时的入射角为53.6°,可以此入射角指导LED集鱼灯在渔船上的安装。对于平板式LED集鱼灯,安装角度可取36.4°;对于三列式LED集鱼灯,安装角度可取23.6°,相邻两列LED集鱼灯的夹角为160°。     

Direct estimation of stock abundance of Pacific saury <Emphasis Type="Italic">Cololabis saira</Emphasis> in the northwestern Pacific Ocean using a mid-water trawl

Drifting gill-nets were for a long time the main research gear for investigating the distribution of Pacific saury Cololabis saira. However, it has proven to be difficult to estimate the absolute abundance of saury using drifting gill-nets due to a lack of knowledge on the survey areas swept by these gill-nets. A mid-water trawl stock abundance estimation has the advantage of being able to estimate the absolute stock abundance before the commercial fishing season begins, whereas the conventional stock abundance estimation based on catch per unit efforts of commercial fisheries must be done after the commercial fishing season has ended. To confirm the practicality of a mid-water trawl to estimate the stock abundance of saury, we conducted a comparative survey in the northwestern Pacific Ocean using both a mid-water trawl and drifting gill-nets. We found that the geographic distribution pattern of catch per unit effort for both the mid-water trawl and driftnets was similar. Using the area-swept method and data on the fishing efficiency of the mid-water trawl obtained in a previous study, we were able to estimate the stock abundance plus confidence limits within the research areas. Our results suggest that the size composition of saury sampled by the mid-water trawl can be considered to approximate the actual size composition of saury.     

西北太平洋秋刀鱼CPUE标准化研究

秋刀鱼(Cololabis saira)是西北太平洋海域重要的渔业种类之一,其资源评估工作已成为热点问题,单位捕捞努力量渔获量(CPUE)标准化可以为开展有效的资源评估研究提供科学依据。为此,本研究利用2003~2017年中国大陆西北太平洋秋刀鱼渔业生产统计资料,结合卫星遥感获得的海洋环境数据,如海表面温度、海表温度梯度、海表面高度等,基于广义线性模型(General linear model, GLM)和广义可加模型(Generalized additive model, GAM)对中国大陆西北太平洋秋刀鱼渔业进行CPUE标准化。结果显示,根据BIC准则,在GLM模型结果中,年份、月份、经度、纬度、海表面温度、海表面高度、海表温度梯度及年份与月份对CPUE具有显著影响,并组成了GLM模型的最佳模型,对CPUE偏差的解释率为52.47%;在GAM模型结果中,除上述8个影响变量外,交互项月份与经度和月份与纬度也对CPUE影响较大,GAM的最佳模型对CPUE偏差的解释率为61.9%。通过5-fold交叉验证分析发现,GAM模型标准化结果较优于GLM模型,更适合于西北太平洋秋刀鱼渔业CPUE标准化。     

Comparisons of monthly and geographical variations in abundance and size composition of Pacific saury between the high-seas and coastal fishing grounds in the northwestern Pacific

The monthly and geographical abundances and size compositions of Pacific saury were compared between the high-seas and coastal fishing grounds in the northwestern Pacific during 2000–2005 based on Taiwanese fishery data. The large-sized saury was dominant (44.3–71.4% of the catch) in the beginning of the fishing season, while the medium-sized saury followed and dominated from September to the end of the fishing season (70.1–92.4% of the catch). In the high seas, the total catch per unit effort (CPUE) (about 71.2% of the mean coastal value) and both the large- (about 55.0%) and medium-sized saury CPUEs (about 81.8%) were significantly smaller than those in the coastal waters. The mean proportions of the large- and medium-sized saury in the high-seas catch were about 86.6 and 107.0% of the coastal values, respectively. CPUEs for the total catch and the catch of medium-sized saury varied in a highly consistent way. The total and medium-sized CPUEs were negatively correlated with the sea-water temperature. When the temperature was held the same statistically, the total and medium-sized CPUEs were larger in the shoreward, southward, and shallower waters of the fishing grounds, while the large-sized CPUE was larger in the shoreward waters.     

On the relationship between the Oyashio front and saury fishing grounds in the north-western Pacific: a forecasting method for fishing ground locations

The relationships between fishing ground locations of Pacific saury (Cololabis saira) and the two Oyashio fronts, the offshore front between 146^oE and 155^oE and the coastal Oyashio intrusion, before the saury fishing season, were examined using data from 1971 to 1991. Interannual geographical shifts of both the offshore Oyashio front and saury fishing grounds had a dominant interdecadal fluctuation. In years when the offshore front shifted north (south), the fishing grounds were formed relatively nearshore (offshore). When the offshore front shifted north, the fishing grounds were formed further nearshore in years the coastal Oyashio intrusion extended south. When the offshore front shifted south, on the other hand, the southward extension of the coastal intrusion did not necessarily cause formation of coastal fishing grounds. These results showed that locations of the fishing grounds depend not only on local and instantaneous oceanographic environments around the fishing grounds, but also on oceanographic conditions over an extensive range of the Oyashio area. This might indicate that the ecology of the saury's northward migration, through mixed water regions between the Kuroshio and Oyashio fronts in spring and summer, has a close relation to the shift of the offshore Oyashio front over a time range of months. A practical forecasting method for locations of saury fishing grounds is proposed based on the oceanography before the fishing season.     

Modelling the impacts of environmental variation on habitat suitability for Pacific saury in the Northwestern Pacific Ocean

We developed habitat suitability index (HSI) models for two size classes of Pacific saury Cololabis saira in the Northwestern Pacific Ocean. Environmental data, including sea surface temperature, sea surface height, salinity, and net primary production, and catch and effort data from Taiwanese distant‐water stick‐held dip net fisheries during the main fishing season (August–October) during 2002–2015 were used. Habitat preferences and suitable habitat area differed between size classes. The suitable habitat was located between 40–47.5°N and 145–165°E for large‐sized Pacific saury but encompassed a greater area (35–47°N and 140–165°E) for medium‐sized Pacific saury. Both size classes were affected by substantial interannual variation in the environmental variables, which in turn can be important in determining the potential fishing grounds. We found a significant negative relationship between the suitable habitat area and the Niño3.4 indices with a time‐lag of 6 months for the large‐sized (r = ?0.68) and medium‐sized (r = ?0.42) Pacific saury, respectively, as well as the total landings of Pacific saury by all fishing fleets (r = ?0.46). As remotely‐sensed environmental data become increasingly available, HSI models may prove useful for evaluation of possible changes in habitat suitability resulting from climate change or other environmental phenomena and in formulating scientific advice for management.     

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。     

Purification and characterization of lipovitellin from Pacific saury Cololabis saira

ABSTRACT:   Lipovitellin (Lv), the major yolk protein derived from vitellogenin (Vg), was purified from vitellogenic ovaries of Pacific saury Cololabis saira using hydroxylapatite column chromatography followed by gel filtration. The apparent native mass of purified Lv was approximately 420 kDa, while the tertiary structure of Lv revealed by sodium dodecylsulfate–polyacrylamide gel electrophoresis was typical of teleost Lvs, consisting of a heavy chain (∼99 kDa) and a light chain (∼34 kDa). Western blot analysis using rabbit antiserum raised against Pacific saury Lv revealed a specific reaction with a polypeptide (∼194 kDa) that is present in serum from female Pacific saury but not in male serum, suggesting the approximately 194-kDa polypeptide to be the Vg monomer. This study describes the first step toward the development of specific immunoassays for Pacific saury Vg, which will be an effective tool for monitoring the reproductive development of this species.     

Initial design for a fish bioenergetics model of Pacific saury coupled to a lower trophic ecosystem model

A fish bioenergetics model coupled with an ecosystem model was developed to reproduce the growth of Pacific saury. The model spatially covers three different oceanographic spatial domains corresponding to the Kuroshio, Oyashio, and interfrontal (mixed water) regions. In this coupled model, three (small, large, and predatory) zooplankton densities which were derived from the lower trophic level ecosystem model were input to the bioenergetics model of saury as the prey densities. Although certain model parameters were imposed from other species’ bioenergetics, several model parameters were estimated from observational data specific to Pacific saury. The integrated model results reproduced appropriate growth rates of Pacific saury. Model sensitivities to water temperature and prey density are examined and observational methods to evaluate the model parameters are discussed.     

Spatial and temporal migration modeling for stock of Pacific saury Cololabis saira (Brevoort), incorporating effect of sea surface temperature

ABSTRACT:   A model is proposed that expresses the spatial and temporal migration pattern for stock of Pacific saury Cololabis saira (Brevoort), in order to investigate the effect of sea surface temperature (SST) on migration rates. Two factors are considered: (i) Saury emigrate to waters of an optimal SST zone; and (ii) saury immigrate from water zone that is extremely cold for saury. Parameters of migration and initial levels of stock are estimated with a maximum likelihood method based on catch per unit effort (CPUE) data for 1995–2001. The best model was selected using Akaike's information criteria. The results suggested that the emigration rate to southern adjacent regions is dependent on the coverage proportion of their waters under some threshold temperatures; 20°C to Doutou and Sanriku, 23°C to Joban and Izu.     

不同工作姿态下立式双曲面网板水动力及周围流场特性研究

网板是单拖网中实现网具扩张的重要属具,其稳定状态直接决定拖网网口扩张程度,进而影响渔获效率和经济效益。该研究以立式双曲面网板为研究对象,利用水槽模型试验和数值模拟(Computational fluid dynamics,CFD)探究立式双曲面网板在不同倾斜状态(内、外倾斜,前、后倾斜)和冲角下的水动力性能变化,并对网板周围流场和表面压力进行可视化。结果显示:1)模型试验和数值模拟的网板升力系数均在倾角为0°,冲角为25°时达到最大值,分别为1.69和1.88;而两者的阻力系数均随倾角增大逐渐减小。2)模型试验和数值模拟的升阻比均随倾角增大逐渐减小;当内倾角为5°时,两者的升阻比均达到最大,分别为3.27和3.69。3)压力中心系数Cpb随倾角变化基本保持不变;但当网板处于前倾状态时,Cpc随倾角增大而增加;而网板处于后倾状态时,Cpc随倾角增大逐渐减小。4)CFD结果显示,网板中心面后部旋涡随倾角增大逐渐减小;当网板处于内、外倾状态时,前端流速衰减区随倾角增大逐渐增加;但当网板处于前、后倾状态时,衰减区随倾角增大逐渐减小;网板处于前倾状态时,压力中心随倾角增大逐渐向网板上端翼弦移动,网板处于后倾状态时则出现相反结果。研究结果可为今后研究网板稳定性和合理使用及调整网板提供科学参考。     

西北太平洋公海秋刀鱼夏季索饵场浮游动物的分布

根据2005年7-9月于西北太平洋公海秋刀鱼渔场所采集到的浮游动物的有关数据,对调查海域表层浮游动物的组成、数量和分布进行了研究。在30个站点所采集的浮游动物样品中,分别测得甲壳纲、矢足纲、原生动物、腔肠动物的25种代表种,其中以桡足类、箭虫类、端足类、糠虾类和磷虾类的平均丰度最高。浮游动物生物量分布不均匀,近专属经济区和 46º30´N以北各站点的生物量较高,站点平均值为430.06±251.18 mg/m^3,超过500 mg/m^3的站点共有11个。分别利用灰色关联和胃含物法对其与秋刀鱼渔场分布之间的关系进行了探讨。秋刀鱼的平均日产量为7.72±5.25t/d,日均网次产量为0.78±0.33t/net,都与桡足类、端足类、箭虫类的分布关系非常显著。秋刀鱼胃含物样本频数最高依次为桡足类、箭虫类、虾类、端足类、浮蚕类。在浮游动物中,桡足类和箭虫类占绝对优势,出现频率分别达到100%和93.3%,平均生物量为298.56mg/m^3和118.09 mg/m^3,其和占总生物量的高达96.88%,严重影响了总生物量的空间分布,分析认为与中心渔场分布的关系最为显著,因此可将其生物量大小作为确定秋刀鱼中心渔场的重要指标。