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1.
印度洋鲣鱼围网资源渔场时空变化及其与ENSO的关系 总被引：1，自引：0，他引：1
鲣鱼是印度洋重要的金枪鱼种类之一,其资源丰度与海洋环境关系密切。本研究根据1980-2010年印度洋鲣鱼围网生产统计数据以及海洋环境与厄尔尼诺-南方涛动（ENSO）指数等,对印度洋鲣鱼围网资源渔场时空分布,以及厄尔尼诺年和拉尼娜年等不同尺度气候条件下鲣鱼资源渔场时空变动及其与海洋环境因子的关系进行分析。研究结果表明,1980-2010年印度洋鲣鱼围网渔获量基本保持不断增加的趋势,但CUPE值变化幅度较大,最低仅为0.68 t/d（1997年）,最高达到1.58 t/d（2002年）。同时鲣鱼资源丰度（CPUE）与Ni?o3.4区指数存在显著的负相关关系,即厄尔尼诺年,鲣鱼CPUE 随之下降,拉尼娜年,CPUE 随之上升。ENSO现象对鲣鱼渔场时空分布也有显著影响,厄尔尼诺发生时,鲣鱼围网作业渔场重心会向东、向北移动,而拉尼娜年则向西、向南移动。 相似文献
2.
鲣Katsuwonus pelamis广泛分布于各大洋热带和亚热带海域,其中以中西太平洋资源量最为丰富。综合评价环境因子对鲣鱼资源量的影响,构建科学的资源预报模型可为我国可持续合理开发该鱼种提供参考。本研究利用1998—2013年中西太平洋渔获量数据,以单位捕捞努力量渔获量(CPUE)为资源相对丰度指标,利用灰色关联方法分析鲣鱼资源相对丰度与环境因子之间的关联度,选取合适的环境因子,并基于不同环境因子构建不同的灰色预测模型对鲣鱼资源相对丰度进行预测,比较选择最优模型。结果表明, 中西太平洋鲣鱼的产量逐年递增,而CPUE在年间有着较大的波动。灰色关联分析认为,海表面温度与CPUE的平均关联度最大,其次为Nino3.4区海表温度距平值,其他的环境因子与CPUE的关联度较小。基于多环境因子的预测模型中,包含所有因子(海表面温度、海表面高度、叶绿素质量浓度a和Nino3.4区海表温度距平值)的模型M1有着最佳的拟合效果,实际值与预测值的相对误差为6.475 2,相关系数为0.687 4;而基于单一环境因子的预测模型中,去除11月SST数据的模型S2有着最佳的拟合效果,实际值与预测值的相对误差为7.419 2,相关系数为0.791 0。相比多环境因子的预测模型,单一环境因子预测模型有着较高的稳定性,实际值与预测值直接相关性也较高,可以作为中西太平洋鲣鱼资源相对丰度预报的最优模型。 相似文献
3.
鲣是大洋中重要经济种类，主要分布于太平洋中西部海域，其渔场和资源丰度易受海洋环境因子影响。根据1995-2014年中西太平洋金枪鱼围网船队在主要作业海域（15°S~10°N，120°E~155°W）的生产数据，结合弱、中、强拉尼娜条件下的海表温度（SST）和海面高度（SSH）数据，运用算术平均法（AM）建立基于SST和SSH的栖息地指数综合模型。结果表明，在栖息地综合指数（HIS）大于0.6的海域，各拉尼娜时期作业比重均在60%以上。利用弱拉尼娜（2005年12月-2006年3月）、中拉尼娜（2011年10月-2012年3月）和强拉尼娜（2010年6月-2011年4月）数据进行模型验证，分析认为作业渔场主要分布在HSI大于0.6的海域，作业次数所占比重分别为53.9%、66.5%、63.6%。在中西太平洋区域，随着拉尼娜强度的增加，资源丰度上升，其渔场分布向东北和东南方向扩散。研究表明，基于SST和SSH各强度拉尼娜时期的栖息地模型均可较好预测中西太平洋鲣渔场，并为以后拉尼娜期间中心渔场的分析提供参考。 相似文献
4.
中西太平洋金枪鱼围网高产渔区年间变化及其原因分析 总被引：1，自引：1，他引：0
金枪鱼类是中西太平洋海域重要的经济鱼种,其中鲣产量约占到总产量的50%。本研究利用1995-2010年16年的中西太平洋（20°S~20°N,120°E~155°W）鲣围网生产统计数据和Niño3.4海区（5°S~5°N,120°~170°W）海表温度异常数据,对这16年鲣产量最高的十大渔区（5°×5°）进行时空格局分析,讨论渔场分布差异及CPUE与ENSO指数的关系。结果表明:16年间十大作业渔区主要分布在5°S~5°N、130°~175°E区域,这十大渔区产量占总产量的比重达47.5%,其中5°S~0°、155°~160°E,0°~5°N、130°~135°E,0°~5°N、135°~140°E及5°S~0°、160°~165°E等4个渔区产量占高产渔区产量的比重均超过10%,是中西太平洋重要的鲣产区。高产渔区的分布受海表温度影响较大,在厄尔尼诺时期,高产渔区分布明显偏东,主要分布在155°~180°E海域;在拉尼娜时期,高产渔区分布明显偏西,主要分布在130°~160°E海域。 相似文献
5.
中西太平洋金枪鱼围网技术及存在的问题 总被引：3，自引：0，他引：3
金枪鱼围网产量约占全球金枪鱼捕获量的70%,发展金枪鱼围网渔业具有广阔的前景.本文根据中鲁远洋渔业股份有限公司金枪鱼围网渔船的作业情况,分析了围网作业中的一些捕捞技术,并探讨了在发展该项目中存在的问题. 相似文献
6.
大西洋金枪鱼渔业现状分析 总被引：4，自引：0，他引：4
本文采用大西洋国际金抢鱼保护委员会ICCAT的报告和统计常设委员会（SCRS）数据库，统计分析了1978-2002年大西洋金抢鱼的渔获种类及渔具渔法。结果表明：按种类分黄鳍金枪鱼（占28％）、鲣鱼（22％）、长鳍金枪鱼（15％）、大眼金枪鱼（11％）、其他种类（8％）；按渔具分围网（42％）、延绳钓（29％）、饵钓（22％）、其它渔具（7％）。同时分析了不同海域的渔获种类、渔获量波动情况和原因。 相似文献
7.
《Marine Policy》2014
The use of drifting fish aggregating devices (FADs) has become the dominant practice in tropical tuna purse seine fishing. However, just as FADs can increase fishing efficiency, their use has been associated with several negative ecosystem impacts, and moves are being made to manage the use of FADs. In the evaluation of potential management options it is important to consider how fishers will respond to the introduction of control measures, which first requires an understanding of fishery and fleet dynamics. This paper addresses this need by characterising the past and present use of FADs in the Indian Ocean tropical tuna purse seine fishery. The paper describes historical trends in fishing practices, summarises spatiotemporal patterns in the use of FADs and establishes and attributes variation in FAD fishing strategies within the fleet. It also provides an overview of current FAD management policies in the Indian Ocean and examines the observed effects of existing measures on the behaviour of the purse seine fleet. Using this comprehensive understanding, the potential impact on the purse seine fleet of a number of plausible FAD management options are discussed and inferences are drawn for the future sustainability of tropical tuna purse seine fishing in the Indian Ocean. 相似文献
8.
采用2016—2017年中国印度洋围拖网生产数据和同期的海表温度、叶绿素、表层海流和海面高度数据, 绘制了阿拉伯海鲐鱼Scomber australasicus围网月平均单位捕捞努力量渔获量(CPUE)和环境因子空间叠加图, 分析鲐鱼渔场与海洋环境因子之间关系, 采用频次分析和经验累积分布函数计算鲐鱼渔场最适宜的海洋环境区间。结果表明, 该海域月平均CPUE呈现先减少后增加的趋势; 围网渔场渔汛主要在东北季风期间, 从10月到翌年3月; 作业渔场重心分布在59°—62°E、13°—17°N, 具有明显的月变化, 基本呈现西南移动趋势。空间上, CPUE 分布在西边界流速较大的海域右侧, 在海流最大值和最低值中间区域。在印度洋东北季风期间, 阿拉伯海围网鲐鱼渔场适宜海表温度在25~28℃; 叶绿素浓度在0.2~0.5mg·m -3; 表层海流在0.05~0.25m·s -1; 海表高度0.2~0.35m。 相似文献
9.
The simulation of the geometry of a tuna purse seine under current and drift of purse seiner 总被引：4，自引：0，他引：4
It was necessary to obtain a more practical interactive precise model of the three-dimensional (3-D) geometry during purse seine operations considering movements of fishing vessel and details of the sea condition. The changes in the shape of a purse seine from shooting to pursing during pelagic skipjack fishing was recorded in the Southwest Pacific Ocean by photographs of the scanning sonar with in situ measurements of water flow by a current meter. The modeling of 3-D geometry during purse seining was established using finite element methods, as resultant force vector from flow drag, buoyancy, sinking force, tension of pulling or pursing acting on net panels in connection with drift of fishing vessel with time elapsed from the start of shooting to the end of pursing. The simulation results were matched closely by field measurements as a heart-like shape in upper net near floatline and a water-drop shape in purse line following drift of ship towards inside net circle during pursing. This model of a purse seine can be extended to almost any kind of purse seine generating real fishing parameters and to modeling fish capture process. 相似文献
10.
中西太平洋金枪鱼围网渔业鲣鱼资源的时空分布 总被引：7，自引：0，他引：7
利用灰色关联度方法及渔业地理信息系统软件Marine Explorer4.0对1990~2001年中西太平洋金枪鱼围网渔业鲣鱼资源的时空变化进行了研究,结果表明,12年间中西太平洋鲣鱼产量的空间分布可归为3类:1990、1991、1995和1996年的为第一类,鲣鱼产量的主要分布区位于西部海域;1998、1999和2001年的为第二类,鲣鱼产量的主要分布区比第一类偏东20个经度;1992、1993、1994、1997和2000年的为第三类,鲣鱼产量的主要分布区的范围比前两类广。单位捕捞努力量的鲣鱼渔获量高分布区与产量空间分布区基本相似。灰色关联度的分析表明,12年中,1998、2000、1994、1995和1999年5年的鲣鱼资源丰度较高,1990、1991、1997和2001年4年的鲣鱼资源丰度较低,1996、1992和1993年3年的鲣鱼资源丰度处于中等水平。 相似文献
11.
《Marine Policy》2014
Several tuna regional fisheries management organizations (t-RFMOs) have adopted retention requirements for skipjack, bigeye and yellowfin tunas caught by purse seine vessels to reduce discards, create disincentives to catch small fish, and incentivize the development and adoption of more selective technologies. Although retention policies in the t-RFMOs have been limited to target tunas in purse seine fisheries, some have advocated for an expansion of those policies, and t-RFMOs could consider expanding retention policies to a greater number of species and/or to other gear types. This paper discusses the benefits and costs of broader retention policies for purse seine and longline tuna fisheries in the western and central Pacific Ocean (WCPO). Using bycatch data from observers and logbooks from the U.S. purse seine and longline fleets operating in the WCPO, this paper documents the types and magnitude of fish discarded. For the purse seine fishery, this information was used to estimate direct impacts of having to off-load at the initial point of landing in key Pacific Island ports. For the longline fishery, estimates of direct impacts were limited to Honolulu and Pago Pago, American Samoa, the two primary ports where U.S. catch is landed. Expanding retention policies beyond the target tunas and to other gear types would further reduce discarding and possibly provide stronger incentives to develop and use more selective techniques. Beyond impacts to the ecosystem and fisher behavior, adopting broader retention policies may have other implications, and this paper explores those implications on vessels, processors, and communities. In general, as is the case with most direct interventions on fishing operations, there will be both benefits and costs, and the magnitude of those impacts will depend on the scope and extent of any expanded retention policy. 相似文献
12.
中西太平洋是全球主要的鲣鱼（Katsuwonus pelamis）围网作业渔场,渔场极易受到海洋环境的影响,但渔场分布在众多岛国的管辖海域,如何科学指导企业准确入渔是重要的研究课题。本文根据1995-2012年中西太平洋鲣鱼围网捕捞生产统计数据,选取产量最高的22个海区（5°×5°）,结合Niño3.4区海表温度距平值（SSTA）和作业海域表温（SST）,研究中西太平洋鲣鱼围网渔场的空间分布规律,同时,以各海区捕捞努力量（作业次数）所占的百分比为入渔指标,建立基于环境因子的入渔决策模型。研究认为,中西太平洋鲣鱼捕捞努力量在纬度方向上主要分布于5°S~5°N,其累计捕捞努力量占所有作业海区的87.4%,其中以130°~140°E经度范围为最高,其捕捞努力量占22个海区的45.08%。入渔指标与Niño3.4区的SSTA、作业海域SST均符合正态模型（P<0.01）,Niño3.4区的SSTA最适值为0.25℃,作业海域SST最适值在29.5℃左右。对预测和实际排名前十的海域进行统计发现,预测值与实际值基本一致。研究认为,所建立的入渔预测模型可有效指导企业的渔业生产,为提高企业生产效率提供支撑。 相似文献
13.
Biodiversity and environmental characteristics of the bycatch assemblages from the tropical tuna purse seine fisheries in the eastern Atlantic Ocean 
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下载免费PDF全文 Nerea Lezama‐Ochoa Hilario Murua Jon Ruiz Pierre Chavance Alicia Delgado de Molina Ainhoa Caballero Igor Sancristobal 《Marine Ecology》2018,39(3)
The impact of human activities such as fishing has been identified as a main factor in diversity loss in the open ocean. This paper studies the diversity patterns and environmental characteristics of the bycatch assemblages in Fish Aggregating Devices (FADs) and Free School sets (sets made on schools of tuna) from the tropical tuna purse seine fishery in the eastern Atlantic Ocean (35°W–15°E and 20°N–15°S). Data were collected from scientific observer programmes carried out between 2003 and 2011 on board Spanish and French fleets. The results showed different structure and diversity patterns of the bycatch assemblages depending on the fishing mode, with higher number of species and diversity found in FAD sets than in Free School sets. Bycatch assemblages showed preferences for specific oceanographic characteristics of the Atlantic Ocean, such as the equatorial and seasonal coastal upwelling systems, the Cape Lopez front system and the Guinea dome. The type of set and sea surface temperature play an important role to describe the diversity patterns of these species. These results confirm the importance of integrating different methods to study the marine ecosystem towards the correct implementation of the Ecosystem Approach to Fishery Management (EAFM). 相似文献
14.
关于我国金枪鱼围网渔业发展问题的几点探讨 总被引：7，自引：1，他引：7
本文通过对联合国粮农组织公布的1989－1998年金枪鱼渔获量的分析，清晰了我国发展金枪鱼围网渔业的趋势，并着重对于围网生产密切相关的渔场选择、捕捞技术进行了几点探讨，还对开发科研工作谈了个人看法。 相似文献
15.
西北太平洋环境变化对柔鱼冬春生群体资源丰度年间变化的影响 总被引：5，自引：0，他引：5
The neon flying squid Ommastrephes bartramii is an economically important species in the Northwest Pacific Ocean. The life cycle of O. bartramii is highly susceptible to climatic and oceanic factors. In this study, we have examined the impacts of climate variability and local biophysical environments on the interannual variability of the abundance of the western winter-spring cohort of O. bartramii over the period of 1995–2011. The results showed that the squid had experienced alternant positive and negative Pacific Decadal Oscillation(PDO) over the past 17 years during which five El Ni?o and eight La Ni?a events occurred. The catch per unit effort(CPUE) was positively correlated with the PDO index(PDOI) at a one-year time lag. An abnormally warm temperature during the La Ni?a years over the positive PDO phase provided favorable oceanographic conditions for the habitats of O.bartramii, whereas a lower temperature on the fishing ground during the El Ni?o years over the negative PDO phase generally corresponded to a low CPUE. The same correlation was also found between CPUE and Chl a concentration anomaly. A possible explanation was proposed that the CPUE was likely related to the climateinduced variability of the large-scale circulation in the Northwest Pacific Ocean: high squid abundance often occurred in a year with a significant northward meander of the Kuroshio Current. The Kuroshio Current advected the warmer and food-rich waters into the fishing ground, and multiple meso-scale eddies arising from current instability enhanced the food retention on the fishing ground, all of which were favorable for the life stage development of the western squid stocks. Our results help better understand the potential process that the climatic and oceanographic factors affect the abundance of the winter-spring cohort of O. bartramii in the Northwest Pacific Ocean. 相似文献
16.
Data collected from a longline fishery in the Indian Ocean were used to evaluate the performance of a deterministic habitat-based
standardization (detHBS) method for catch per unit effort (CPUE) standardization. The habitat preference indices of the yellowfin
tuna (Thunnus albacares) were estimated for different depth, temperature, and dissolved oxygen (DO) classes. The detHBS was applied for standardizing
the yellowfin tuna CPUE based on the habitat preference indices of the yellowfin tuna. Nominal CPUE and normalized nominal
CPUE were compared with the standardized CPUE and normalized standardized CPUE, respectively, using Wilcoxon tests. The results
showed that (1) there was significant difference between nominal CPUE and standardized CPUEs (p < 0.01); (2) there was no significant difference between normalized nominal CPUE and normalized standardized CPUEs estimated
using the data set of depth, temperature, and DO (p > 0.01). This study suggests that detHBS effectively improved the precision of CPUE standardization, and the depth data set
was the optimum data set in standardizing CPUE. 相似文献
17.
基于神经网络的南太平洋长鳍金枪鱼渔场预报 总被引：2，自引：1，他引：1
南太平洋长鳍金枪鱼是我国远洋渔业的重点捕捞对象;对南太平洋长鳍金枪鱼进行准确的渔场预报;可以提高捕捞效率;提高渔业的生产能力。本研究根据1993-2010年南太平洋长鳍金枪鱼的延绳钓生产数据以及海洋卫星遥感数据（海水表面温度;SST;海面高度;SSH）和ENSO（El Niño-Southern Oscillation）指标;采用DPS（data processing system）数据处理系统中的BP人工神经网络模型;以渔获产量（单位时间的渔获尾数）和单位捕捞努力量渔获量（CPUE;Catch per unit of effort）分别作为中心渔场的表征因子;并作为BP模型的输出因子;以月、经度、纬度、SST、SSH和ENSO指标等作为输入因子;分别构建4-3-1;5-4-1;5-3-1;6-5-1;6-4-1;6-3-1等BP模型结构;比较渔场预报模型优劣。研究结果表明;以CPUE作为输出因子的BP人工神经网络结构总体上较优;其中以6-4-1模型结构为最优;相对误差只有0.006 41。研究认为;以CPUE为输出因子的6-4-1结构的人工神经网络模型;能够准确预报南太平洋长鳍金枪鱼的渔场位置。 相似文献
18.
An enhanced version of the spatial ecosystem and population dynamics model SEAPODYM is presented to describe spatial dynamics of tuna and tuna-like species in the Pacific Ocean at monthly resolution over 1° grid-boxes. The simulations are driven by a bio-physical environment predicted from a coupled ocean physical–biogeochemical model. This new version of SEAPODYM includes expanded definitions of habitat indices, movements, and natural mortality based on empirical evidences. A thermal habitat of tuna species is derived from an individual heat budget model. The feeding habitat is computed according to the accessibility of tuna predator cohorts to different vertically migrating and non-migrating micronekton (mid-trophic) functional groups. The spawning habitat is based on temperature and the coincidence of spawning fish with presence or absence of predators and food for larvae. The successful larval recruitment is linked to spawning stock biomass. Larvae drift with currents, while immature and adult tuna can move of their own volition, in addition to being advected by currents. A food requirement index is computed to adjust locally the natural mortality of cohorts based on food demand and accessibility to available forage components. Together these mechanisms induce bottom-up and top-down effects, and intra- (i.e. between cohorts) and inter-species interactions. The model is now fully operational for running multi-species, multi-fisheries simulations, and the structure of the model allows a validation from multiple data sources. An application with two tuna species showing different biological characteristics, skipjack (Katsuwonus pelamis) and bigeye (Thunnus obesus), is presented to illustrate the capacity of the model to capture many important features of spatial dynamics of these two different tuna species in the Pacific Ocean. The actual validation is presented in a companion paper describing the approach to have a rigorous mathematical parameter optimization [Senina, I., Sibert, J., Lehodey, P., 2008. Parameter estimation for basin-scale ecosystem-linked population models of large pelagic predators: application to skipjack tuna. Progress in Oceanography]. Once this evaluation and parameterization is complete, it may be possible to use the model for management of tuna stocks in the context of climate and ecosystem variability, and to investigate potential changes due to anthropogenic activities including global warming and fisheries pressures and management scenarios. 相似文献
19.
On 1 December 2007, eight ‘Small Island Developing States’ in the Western and Central Pacific Ocean implemented a management regime restricting the total number of days fished by tuna purse seine vessels within their waters, commonly referred to as the Vessel Day Scheme (VDS). The VDS is seen as one component of management arrangements to reduce fishing mortality on bigeye and yellowfin tuna, constrain fishing effort, and increase the rate of return from access fees by Distant Water Fishing Nations. 相似文献
20.
黄鳍金枪鱼索饵水层影响延绳钓捕捞效率,而黄鳍金枪鱼索饵水层分布受水温垂直结构的影响,因此本文采用GAM模型分析次表层环境变量对延绳钓黄鳍金枪鱼渔获率的影响,评估黄鳍金枪鱼垂直水层分布对中西太平洋黄鳍金枪鱼延绳钓单位捕捞努力量渔获量(Catch Per Unite Effort, CPUE)的作用。模型结果表明,环境因子对热带中西太平洋延绳钓黄鳍金枪鱼渔获率空间分布影响明显。黄鳍金枪鱼延绳钓CPUE在2012年之后快速增多,高渔获率月份出现在北半球夏季,空间上在10°S,140°E附近区域。温跃层上界温度和深度、温跃层下界深度、18℃等温线深度、△8℃等温线深度及其和温跃层下界深度的深度差对延绳钓渔获率影响较大,是影响热带中西太平洋黄鳍金枪鱼延绳钓渔获率的关键环境因子。随着温跃层上界温度和深度值变大,延绳钓CPUE逐渐递增,对延绳钓CPUE影响密切的温度和深度分别为27～28℃和70～90 m。温跃层下界深度对延绳钓CPUE影响在250～280 m时最大;之后随着下界深度的变大,CPUE快速下降。18℃等温线深度对延绳钓CPUE影响呈现先震荡后递增的趋势,影响密切的区域在230 m深度上下。△8℃等温线深度与温跃层下界深度的差值对热带中西太平洋黄鳍金枪鱼延绳钓CPUE影响呈现先快速递减后缓慢增加的趋势,在深度差为70 m上下时影响最密切。研究结果揭示,在黄鳍金枪鱼活动水层受限或栖息水层和延绳钓作业深度相吻合时,延绳钓渔获率最高。依据黄鳍金枪鱼垂直活动水层调整延绳钓投钩,可以提高渔获率。因此,采用延绳钓CPUE进行渔场和资源评估时要考虑金枪鱼适宜垂直活动空间。 相似文献