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1.
The relationships between fishing ground locations of Pacific saury (Cololabis saira) and the two Oyashio fronts, the offshore front between 146oE and 155oE 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.  相似文献   

2.
北太平洋秋刀鱼生活史和资源渔场研究进展   总被引：1，自引：0，他引：1  
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。  相似文献   

3.
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.  相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
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   总被引：1，自引：0，他引：1  
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。  相似文献   

7.
西北太平洋秋刀鱼舷提网捕捞技术   总被引：4，自引：0，他引：4  
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。  相似文献   

8.
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   总被引：7，自引：1，他引：7  
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。  相似文献   

9.

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.

  相似文献   

10.
We examined interdecadal variations in potential fishing grounds for the Pacific saury, Cololabis saira, off the southeastern coast of Hokkaido, Japan, for the early fishing season of August–September. We applied linear trend analysis to a time series of several oceanographic variables for 1993–2014. Trends in the appearance frequency of sea surface temperatures (SST) of 12–18 °C during August–September indicated an interdecadal reduction in the potential fishing area off the Hokkaido coast. There were localized significant increases of both SST and the sea level anomaly along the Kuril–Kamchatka Trench off the Hokkaido coast. The localized trends coincided with decadal decreases of satellite‐based chlorophyll concentrations after 2002. Analysis of mesoscale eddies revealed that the localized trends were related to clockwise (counterclockwise) eddies that appeared more frequently (less frequently) near the trench in recent years. Moreover, the Oyashio transport on the slope between the coast and the trench decreased significantly and completely disappeared in some recent summers. Interactions between the Oyashio and mesoscale eddies resulted in an interdecadal shift in the cold‐water intrusion along the main stream of the Oyashio from the along‐slope direction to the offshore direction in the upstream region of the Hokkaido coast, and large areas of favorable potential fishing grounds near the Hokkaido coast have disappeared in recent years.  相似文献   

11.
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.  相似文献   

12.
Pacific saury (Cololabis saira) has a short life span of 2 years and tends to exhibit marked population fluctuations. To examine the importance of sea surface temperature (SST) and mixed layer depth (MLD) as oceanographic factors for interannual variability of saury recruitment in early life history, we analyzed the relationship between abundance index (survey CPUE (catch per unit of effort)) of age‐1 fish and the oceanographic factors in the spawning and nursery grounds of the previous year when they were born, for the period of 1979–2006, in the central and western North Pacific. Applying the mixture of two linear regression models, the variability in the survey CPUE was positively correlated with previous year's winter SST in the Kuroshio Recirculation region (KR) throughout the survey period except 1994–2002. In contrast, the survey CPUE was positively correlated with the previous year's spring MLD (a proxy of spring chlorophyll a (Chl‐a) concentration) in the Kuroshio‐Oyashio Transition and Kuroshio Extension (TKE) during 1994–2002. This period is characterized by unusually deep spring MLD during 1994–1997 and anomalous climate conditions during 1998–2002. We suggest that saury recruitment variability was generally driven by the winter SST in the KR (winter spawning/nursery ground), or by the spring Chl‐a concentration (a proxy of prey for saury larvae) in the TKE (spring spawning/nursery ground). These oceanographic factors could be potentially useful to predict abundance trends of age‐1 saury in the future if the conditions leading to the switch between SST and MLD as the key input variable are elucidated further.  相似文献   

13.
Effects of oceanic-climate changes on the abundance of Pacific saury (Cololabis saira) in the northwestern Pacific during the last half century were investigated. Abundance indices of both large and medium size groups exhibit interannual–decadal variations, but their patterns were different. The large and medium size groups of saury are corresponding to the recruitments of winter- and spring-cohort, respectively. The abundance of large size group saury was significantly correlated with the winter sea surface temperature (SST) in the Kuroshio region, whereas the medium size group saury showed high correlations with SST in the Kuroshio–Oyashio transition zone and the Oyashio region, indicating that the two size groups are affected by subtropical and subarctic environment, respectively. Significant negative correlation between the abundance index and the southern oscillation index (SOI) suggested that El Niño-southern oscillation (ENSO) events have marked impacts on the large size group saury. Subtropical high pressure index and far east zonal index also show high correlations with the abundance of both large and medium size group saury, indicating a linkage between large-scale atmospheric circulation and the abundance of saury. These correlations demonstrate that the abundance of Pacific saury is directly affected by the SST fields through large-scale atmosphere–ocean interactions from the equatorial Pacific to mid- and high-latitude areas such as El Niño events.  相似文献   

14.
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。  相似文献   

15.
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 unit effort, CPUE)的适宜性指数(suitability index, SI)与各海洋环境变量之间的 SI 模型, 结合提升回归树模型(boosting regression tree, BRT)进行权重分析, 建立以月份为周期的秋刀鱼栖息地适宜性指数(habitat suitability index, HSI)模型。结果表明, (1) GAM 能较好地拟合适宜性指数与环境变量的关系, 获得最优环境变量参数值;(2) 环境变量对 CPUE 影响权重的前 3 位分别为海表温度梯度、海表温度和混合层深度, 其中, 在秋季 9—11 月海表温度梯度的权重值均为最高;(3) HSI 模型的检验和评价总体准确率分别为 82.0%和 73.2%, 秋季可达 87.7%和 77.9%, 在盛渔期 10 月, 预测准确率达 89.4%;(4) HSI 高值区与秋刀鱼实际渔场在空间分布基本一致。研究表明该模型适用于秋刀鱼的渔情预报, 并在每天的速报中具有明显优势。  相似文献   

16.
西北太平洋公海秋刀鱼夏季索饵场浮游动物的分布   总被引：1，自引：1，他引：1  
朱清澄  夏辉  花传祥  许巍 《水产学报》2008,32(6):890-898
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。  相似文献   

17.
ABSTRACT:   Stable carbon and nitrogen isotope ratios were determined in the baleen plates of 17 common minke whales Balaenoptera acutorostrata from the north-western Pacific Ocean off Japan, as well as prey species (krill Euphausia pacifica , Japanese anchovy Engraulis japonicus and Pacific saury Cololabis saira ) collected in the stomach contents, to investigate the trophic relationship between the minke whales and their prey. A few δ15N-depleted peaks occurred along the length of baleen plates for 10 males irrespective of stomach content (anchovies and sauries). Similar δ15N-depleted peaks were also found for one female and two immature individuals. It was likely that these δ15N-depleted peaks formed in early summer. The stable nitrogen isotope ratio (δ15N) values in Pacific saury (9.3 ± 1.4‰) did not differ significantly from that in Japanese anchovy (8.8 ± 0.9‰). In contrast, δ15N in krill (7.2 ± 0.5‰ in July and 8.0 ± 0.2‰ in September) were significantly lower than in the Pacific saury. Thus, these peaks may reflect the dietary change from krill to fishes in the feeding migration of the whales. Growth rate of the baleen plate was estimated to be 129 mm/y, and it appeared that a dietary record of about 1.4 years remained in the baleen plate. For two immature whales, the maximum value of δ15N occurred at the tip of baleen. This δ15N enrichment may possibly be useful for discriminating weanlings and older whales.  相似文献   

18.
王靓  花传祥  朱清澄  李非 《中国水产科学》2020,27(11):1379-1392
小型中上层鱼类是北太平洋海域重要的渔业资源,具有生命周期短、生长速度快、高集群性等特点,其资源年间波动显著,且受气候-海洋变化的影响。本文围绕秋刀鱼（Coloabis saira）、鲣（Katsuwonus pelamis）、鲐（Scomber japonicus）、鳀（Engraulis japonious）、竹䇲鱼（Trachurus japonicus）、沙丁鱼（Sardinops sagax）6种主要的小型中上层鱼类,回顾了厄尔尼诺-南方涛动（El Niño/La Niña-southern oscillation,ENSO）、太平洋年代际振荡（the Pacific decadal oscillation,PDO）、黑潮-亲潮（Kuroshio-Oyashio,KR-OY）等关键气候-海洋指数的特点及对鱼类栖息地环境和资源变动的影响。概括了气候-海洋变化对小型中上层鱼类的洄游分布和资源丰度的直接影响过程,以及对亲体繁殖产卵、仔稚体成活率和资源量波动间接的滞后影响过程。建议：（1）在多种气候-海洋指数基础上添加种群动态过程、捕捞方式系数、自然死亡率等参数构建生物量动态模型,揭示气候-海洋变化对渔业资源量的影响过程;（2）结合北太平洋涛动（North Pacific oscillation,NPO）、北极涛动（Arctic oscillation,AO）、北太平洋环流振荡（North Pacific gyre oscillation,NPGO）等其他北太平洋主要气候,基于物理海洋模型及空间耦合水动力学模型研究大尺度海流、中尺度涡旋对小型中上层鱼类影响。  相似文献   

19.
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。  相似文献   

20.
We explored the seasonal potential fishing grounds of neon flying squid (Ommastrephes bartramii) in the western and central North Pacific using maximum entropy (MaxEnt) models fitted with squid fishery data as response and environmental factors from remotely sensed [sea surface temperature (SST), sea surface height (SSH), eddy kinetic energy (EKE), wind stress curl (WSC) and numerical model‐derived sea surface salinity (SSS)] covariates. The potential squid fishing grounds from January–February (winter) and June–July (summer) 2001–2004 were simulated separately and covered the near‐coast (winter) and offshore (summer) forage areas off the Kuroshio–Oyashio transition and subarctic frontal zones. The oceanographic conditions differed between regions and were regulated by the inherent seasonal variability and prevailing basin dynamics. The seasonal and spatial extents of potential squid fishing grounds were largely explained by SST (7–17°C in the winter and 11–18°C in the summer) and SSS (33.8–34.8 in the winter and 33.7–34.3 in the summer). These ocean properties are water mass tracers and define the boundaries of the North Pacific hydrographic provinces. Mesoscale variability in the upper ocean inferred from SSH and EKE were also influential to squid potential fishing grounds and are presumably linked to the augmented primary productivity from nutrient enhancement and entrainment of passive plankton. WSC, however, has the least model contribution to squid potential fishing habitat relative to the other environmental factors examined. Findings of this work underpin the importance of SST and SSS as robust predictors of the seasonal squid potential fishing grounds in the western and central North Pacific and highlight MaxEnt's potential for operational fishery application.  相似文献   

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