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1.
基于贝叶斯状态空间产量模型的大西洋黄鳍金枪鱼资源评估 总被引：2，自引：1，他引：1
黄鳍金枪鱼(Thunnus albacares)是全球远洋渔业的重要目标鱼种,要实现有效的管理,对其进行科学的资源评估是必不可少的。本文以大西洋黄鳍金枪鱼为研究对象,根据国际大西洋金枪鱼养护委员会的渔获量和单位捕捞努力量渔获量数据,使用贝叶斯状态空间模型进行资源评估,并探讨不同剩余产量函数和单位捕捞努力量渔获量数据对评估的影响。结果表明,使用美国、委内瑞拉、日本和中国台北4个船队的单位捕捞努力量渔获量数据及Fox剩余产量函数时模型拟合效果最佳。关键参数环境容纳量和内禀增长率的估计中值和95%置信区间分别为178 (140,229)×104 t和0.210(0.159,0.274);当前资源量为72.5×104 t,最大可持续产量为13.7×104 t时,种群既没有遭受资源型过度捕捞,也没有捕捞型过度捕捞发生。敏感性分析表明,当渔获量数据存在误报率(70%、80%、90%、110%、120%和130%)时,生物量的评估结果偏高,而捕捞死亡率的结果偏低,但种群均处于健康状态;预测分析显示,当总允许可捕量设为11×104 t时,资源在2024年前仍基本保持健康状态。本研究与国际大西洋金枪鱼养护委员会现有的评估结果基本一致,且模型较稳健,可以为管理决策提供建议。根据模型结果,建议总允许可捕量为11×104 t或更低,以使资源达到可持续开发水平。 相似文献
2.
《海洋湖沼通报》2020,(1)
南大西洋长鳍金枪鱼群体是全球资源状况维持较好的金枪鱼群体之一,剩余产量模型(Surplus production model, SPM)、年龄结构模型(Age-structured population model, ASPM)和贝叶斯产量模型(Bayesian surplus production model, BSPM)等都已成功运用于该群体的资源评估。连续型时滞差分模型(Continuous delay-difference model, CTD-DM)是在时滞差分模型(Delay-difference model, D-DM)基础上考虑了生物过程充分时间延迟构建起来的模型,比起ASPM需要较少的数据,并且比SPM更具有生物学意义。本文在离散型D-DM基础上构建了CTD-DM,并应用在南大西洋长鳍金枪鱼渔业数据中。结果显示,CTD-DM评估的最大可持续产量(Maximum Sustainable Yield, MSY) 80%置信区间为21510-23118 t (中值22398 t),较ASPM和SPM等MSY评估结果偏保守。相对生物量B_(2011)/B_(MSY)和相对捕捞死亡系数F_(2011)/F_(MSY)分别为1.45和1.04,当前该群体相对资源量水平较好,但是相对捕捞死亡系数较高;BSPM和CTD-DM的风险评估结果显示,当捕捞死亡率均等于0.2时在2025年取得最大持续产量,考虑到当前渔业持保守态度和预防性策略的理念,建议捕捞死亡率应控制在0.15以内。 相似文献
3.
渔业产量和资源生物量数值模型及相关因子的初步研究 总被引：2，自引：0，他引：2
对于渔业的中长期预报计算,是渔业种群补充的关键问题。本文在单位补充量产量和单位补充量生物量模型中加入了亲体一补充模型即密度相关过程,并引入了白色噪音以模拟环境变化。结果表明：本研究(1)可以明确地给出渔业种群崩溃的可能性,估计出达到崩溃时的捕捞死亡率;(2)可以估计最大持续产量的绝对值;(3)引入的白色噪音可以模拟环境变化对产量与捕捞死亡率和产量与亲体生物量关系曲线的影响。虽然亲体补充关系仍多是个假设,补充与亲体之间存在的补偿机制需要进一步的研究。 相似文献
4.
《中国海洋大学学报(自然科学版)》2021,(Z1)
太平洋秋刀鱼(Cololabis saira)资源量波动易受海洋环境,尤其是海表温度(SST)变化的影响。本文假设产卵场最适SST范围(P_s)影响环境容纳量(K),索饵场最适SST范围(P_f)影响内禀自然生长率(r),利用2003—2014年西北太平洋渔业数据,建立了基于海表温度的剩余产量模型(EDSP),评估西北太平洋秋刀鱼资源量。研究显示,根据偏差信息准则(DIC)值,基于产卵场海表温度的剩余产量模型(P_s-EDSP)为最优模型。在P_s-EDSP中,最大可持续产量(MSY)为208.56×10~4 t,B_(MSY)水平的生物量为71.46×10~4 t。西北太平洋秋刀鱼的捕捞死亡率为0.15,低于目标水平和MSY水平的捕捞死亡率(F_(tar),F_(MSY)),当前资源生物量高于B_(MSY)。研究结果表明,目前西北太平洋秋刀鱼未遭遇过度捕捞,在其资源评估和管理中应适当考虑产卵场海表温度环境因素。 相似文献
5.
厦门海域渔业资源评估 总被引：7，自引：0，他引：7
以初级生产力和渔业统计资料为材 ,分别应用Tait沿岸海域生态系能流分析法、营养动态法和Cushing等 3种模式 ,估算厦门沿岸海域的渔业资源自然生产量。同时 ,分别应用Schaefer和Fox两种剩余产量模式估算最大持续产量和最大持续捕捞力量。前 3种模式估算该海域的资源生产量分别为 2 0 1 0 5t,1 8463t和 1 7489t,平均 1 8686t。后两种模式估算最大持续产量平均值分别为 9639t和 91 0 4t。估算的最大持续捕捞力量 :5种作业综合总功率为 1 5976kW ;以厦门机定置渔船单位功率渔捞效率为标准估算的总功率为 2 7351kW ;以厦门机刺网渔船单位功率渔捞效率为标准估算的总功率为 432 1 3kW。 1 997年实际渔获量和捕捞力量均超过了估算的最大持续产量和最大持续捕捞力量。文中还讨论了捕捞力量的调整问题。 相似文献
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东海马鲛鱼(Scomberomorus Niphonius)的种群动态易受海洋环境条件的影响,在其资源评估和管理中需要考虑海洋环境条件的作用。假设马鲛鱼产卵场最适海表温度10～19℃(Suitable SST,Tsui)范围会影响种群环境容纳量(K),因此分别使用产卵季3月最适表温范围比值(Tsui-Mar)、4月最适表温范围比值(Tsui-Apr)和3、4月份最适表温范围比值的平均值(Tsui-Ave)作为剩余产量模型的环境因子,构建三种基于环境因子的剩余产量模型(environmentally dependent surplus production,EDSP),分别为Tsui-MarEDSP、Tsui-Apr-EDSP和Tsui-Ave-EDSP,利用贝叶斯估计模型参数,结果显示Tsui-Mar、Tsui-Apr、Tsui-Ave三个基于环境因子的EDSP模型偏差信息标准(deviance information criterion,DIC)值小于传统的剩余产量模型的DIC值,其中Tsui-Ave-EDSP模型DIC值最小,精度最高,估计的最大可持续产量(maximum sustainable yield,MSY)的范围为8.125×106～8.371×106 t,资源量(biomass)范围是1.429×106～1.455×106 t,从1994年到2015年,马鲛鱼的捕捞死亡率远低于目标死亡率(Ftar)和MSY水平捕捞死亡率(FMSY),种群资源量高于MSY水平资源量(BMSY)。东海马鲛鱼没有被过度捕捞或未发生过度捕捞,基于EDSP模型中的管理参考点更为保守,建议日后东海马鲛鱼的种群评估和管理应考虑产卵场环境条件。 相似文献
7.
三疣梭子蟹(Portunus trituberculatus)是中国东海北部海域重要的经济蟹类,对三疣梭子蟹资源开展评估是其可持续利用的基础。本文运用基于贝叶斯方法的Schaefer剩余产量模型,对东海北部海域的三疣梭子蟹资源进行评估,确定了当前三疣梭子蟹资源的开发利用状态,估算了在不同收获率水平下未来10年三疣梭子蟹的生物量和年总可捕捞量,分析了管理策略实施后三疣梭子蟹资源崩溃的风险。研究显示,在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。使用两种方案估算得到的最大可持续产量(MSY)均约为24×104 t, MSY对应的生物量BMSY均约为252×104 t。在基准方案下,MSY对应的捕捞死亡系数FMSY为0.096;在敏感性分析方案下,MSY对应的捕捞死系数FMSY为0.097。在2001—2020年间,捕捞死亡系数均低于FMSY,且生物量基本在BMSY水平之上,表明近年来三疣梭子蟹未出现过度捕捞的情... 相似文献
8.
本文根据1980—1986年间鱼类生物学参数测定,结合体长分布资料的模拟分析,研究黄、渤海区牙鲆种群年龄结构、死亡动态以及在不同年龄和死亡率条件下世代资源生物量变化的规律。模型分析结果表明,当F=1.0和t_c=6.0a时,单位补充量最大群体产量为1492g。由此认为,现阶段牙鲆资源利用的最佳策略是通过增殖放流,增加资源补充;同时应适当控制捕捞压力,减少渔具对幼鱼资源的破坏并增设繁殖保护区,以追求最大持续产量。 相似文献
9.
剩余产量模型在不同渔业中的应用 总被引：4，自引：0，他引：4
剩余产量模型因其简单和所需数据较少的特点为渔业资源评估广泛采用.本文应用目前常用的四种剩余产量模型对五种渔业下的渔业生物种群及北大西洋箭鱼种群xiphias gladius评估效果作了比较.四种剩余产量模型在渔业1中的评估效果较好,而在渔业2中的效果较差;Schnute模型在充分捕捞的渔业,如渔业3、4、5,尤其是在低生物量的渔业3中评估效果较好,但不适合评估未充分捕捞的渔业.Walters-Hilborn模型(W-H模型)适用于各种渔业,尤其是渔业1、4、5.在过度捕捞渔业中如渔业3、4,模型对参数q的估计较其它参数接近真值.在北大西洋箭鱼(xiphias gladius)渔业的评估中,W-H模型对MSY的估计约为14000吨,接近于Prager(1996)的结果. 相似文献
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限额捕捞试点工作逐步展开,预示着我国海洋渔业管理进入全面有序的管理时代。文章根据2008—2017年南海北部渔港渔业生产抽样调查数据,统计出南海北部金线鱼的产量主要来自刺网,占累计总产量的72.90%。剩余产量模型分析认为南海北部金线鱼的最大可持续产量在168 632.99~31 0518.85 t,平均为251 765.59 t。2017年实施最严格的休渔制度后,当年的捕捞努力量投入和渔业产量均未超过最适值,当前总可捕量可设为158 515 t。文章研究结果可为该鱼种限额捕捞政策实施提供参考。 相似文献
11.
Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
13.
Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
14.
海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
15.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
16.
The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
20.
Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations. 相似文献