基于连续型时滞差分模型的南大西洋长鳍金枪鱼资源评估

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B₂₀₁₁/B     

基于贝叶斯方法的南大西洋长鳍金枪鱼渔业的风险评估与管理

使用ASPIC与CEDA软件对南大西洋长鳍金枪鱼的产量和标准化的CPUE数据进行分析,得到了环境容量K、可捕系数q和内禀增长率r的点估计。以此作为3个参数的先验信息,应用MCMC算法计算3个参数的后验概率分布。根据种群参数的后验概率,设定不同的捕捞策略,对该群体进行风险评估。结果表明,1985—2005年南大西洋长鳍金枪鱼经历了轻度的过度捕捞,2005年之后开始恢复,目前这个群体的资源状态较好,仍需加强管理使其可持续发展。建议产量控制在27 970t以内,捕捞死亡率控制在0.15左右。     

大西洋热带海域长鳍金枪鱼渔场预报模型的比较

为提高大西洋热带海域长鳍金枪鱼(Thunnus alalunga)渔场预报的准确率,对K最近邻(k nearest neighbor,KNN)、逻辑斯蒂回归(logistic regression,LR)、决策与分类树(classfication and regression tree,CART)、梯度提升决策树(gr...     

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

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。     

基于神经网络的南太平洋长鳍金枪鱼渔场预报

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。     

评估不同评估配置应对年龄空间结构的表现:基于印度洋长鳍金枪鱼的模拟研究

不同种群结构或种群分布的空间异质性是导致模型错误的一个重要因素,并在渔业资源评估中对参数估计有重要影响。本文根据状态相关的洄游率与区域相关的捕捞死亡率,利用合成模型,模拟了印度洋长鳍金枪鱼年龄空间结构的异质性,并生成了资源评估数据。基于这些数据,本文研究了用于空间异质资源评估模型的不同空间配置、选择曲线及CPUE（Catch Per Unit Effort）使用场景的表现。本文结果表明：（1） 尽管同操作模型一致的空间动态配置能在所有模拟场景中对相对产卵生物量、相对死亡系数、最大可持续产量提供准确、无偏估计,但若由于知识与数据限制,使空间动态配置与操作模型不一致,则其表现可能相当差;（2） 对于空间配置,边界划分必须正确,但对于非空间配置,不管边界划分正确与否,只要划分的区域能合理反映现场数据的变化,并能通过增加空间参考参数从而能有效减少忽略空间结构的影响即为合理;（3） 尽管区域作为渔业的方法及灵活的时变选择曲线是一个较好备选方法,可用于解决空间结构问题,但这些方法并不能完全消除由空间结构而引起模型错误导致的影响,从而使模型的参数估计具有很大的不确定性、相同评估模型不同参数的估计质量不一致、相同评估配置的评估质量在不同模拟场景下存在很大的差异;（4） 尽管采用多个CPUE指数一般可以避免最差的参数估计,但没有更好的选择或生成CPUE指数的方法可以用于显著提高资源评估质量,因为忽略空间结构将导致所有资源评估模型预测的CPUE所包含的信息通常不同于观测的CPUE。对比不同建模者的模型配置的评估结果,除了与操作模型完全匹配的空间配置外,其他模型配置的表现均与具体案例有关。从这个意义上讲,本文研究结果不仅对当前印度洋长鳍金枪鱼资源评估有益,也将增加对空间结构配置效果的理解。     

基于随机森林的印度洋长鳍金枪鱼渔场预报

为了提高远洋渔场预报水平和满足渔业生产的需要,提出了一种基于随机森林建立印度洋长鳍金枪鱼(Thunnus alalunga)渔场预报模型的方法。选取2002-2009年各个月份印度洋5°×5°格点渔业环境和时空数据(包括海表温度、叶绿素a浓度、表温距平、叶绿素a浓度距平、海表温度梯度强度和海面高度异常等数据)作为预测变量,利用长鳍金枪鱼的CPUE(Catch per unit effort,单位:尾/千钩数)的三分位点将渔区划分为高CPUE、中等CPUE和低CPUE三种类型,作为响应变量,对数据进行训练。结果表明,当随机森林中决策树达到100以上时,袋外数据OOB(out-of-bag)的分类误差率趋于平稳。将训练得到的随机森林用于2010年印度洋长鳍金枪鱼分月渔场的预测,其概率等值面图与实际生产的渔场分布进行叠加比较,显示高CPUE渔场概率分布与实际渔场的位置及范围变化情况符合。通过ROC(Relative Operating Characteristic)分析,高CPUE、中等CPUE和低CPUE的AUC(Area Under ROC Curve)分别达到0.847、0.743和0.803,表明预测精度较高。最后对中等CPUE渔区预测精度相对较低的原因进行了分析。     

热带大西洋大眼金枪鱼和黄鳍金枪鱼渔场温跃层的时空变化特征

采用2007 ～2011年Argo浮标剖面温度资料研究了大西洋黄鳍金枪鱼(Thunnus albacares)和大眼金枪鱼(Thunnus obesus)延绳钓主要作业渔场温跃层的时空变化特征.研究结果表明热带大西洋黄鳍金枪鱼、大眼金枪鱼延绳钓主要作业渔场温跃层的上界深度和温度存在着明显的季节性变化.温跃层上界深度呈现出冬深夏浅的季节性变化特征,大致呈纬向带状分布,12月至翌年4月份,15°N以北海域温跃层上界深度超过80 rn,同期10°S以南海域的多低于50 m;6～10月份的则相反.在赤道纬向区域温跃层上界温度在27℃以上,往南北两侧30°区域温度值依次递减至20℃及以下.温跃层下界深度和温度没有明显的季节性变化.温跃层下界深度高值区域的空间分布呈现“W”形状,深度值在220 m以上.在25°S以南,从南美洲到非洲西沿岸海域并延伸到安哥拉外海,以及10°N非洲西海岸外海,在1a中的大部分月份里,温跃层下界深度浅于150 m.在15°N以北和15°S以南区域下界温度大于15℃,在这之间的纬向区域下界温度低于14℃.全年在大西洋西部的5 °～ 15°N和5 °～15°S区域的温跃层厚度最大,在80～150 m之间,冬季和夏季呈现相反的分布特征;温跃层强度高值在5°S～ 15°N纬向区域,尤其是大西洋东部,介于0.15 ～ 0.25℃/m之间.根据文中揭示的大西洋金枪鱼延绳钓主要作业渔场区温跃层的时空变化特征,作者建议晚上大眼金枪鱼和黄鳍金枪鱼投钩深度应该在温跃层上界深度分布的附近水域;白天捕捞黄鳍金枪鱼投钩深度应该在温跃层下界深度分布的水域附近,大眼金枪鱼投钩深度要比黄鳍金枪鱼的更深.     

应用贝叶斯方法对有效信息较少的渔业资源进行资源评估-以印度洋长鳍金枪鱼的资源评估为例

众所周知,对有效信息较少的渔业资源进行资源评估面临很大的挑战,而贝叶斯方法在数据数量较少、质量较差的情况下能利用其它种群高质量的数据或已知的先验信息提高资源评估结果的可靠性。由于印度洋长鳍金枪鱼的数据质量较差而数据量有限,长鳍金枪鱼的资源评估结果存在很大的不确定性,为此,本文以印度洋长鳍金枪鱼的资源评估为例,以调查贝叶斯方法在有效信息较少的资源评估中的优势。本文根据不同的先验假设与捕捞数据系列,共构建了8个贝叶斯动态产量模型,以评估长鳍金枪鱼资源。结果表明:(1)分析参数的后验分布能提高捕捞数据系列选择与参数假设的合理性; (2) 利用种群统计学方法为内禀增长率(r)构建有信息先验,能提高资源评估结果的可靠性。与传统方法相比,当基于贝叶斯框架时,能将已知的知识表示为先验信息并能分析参数的后验分布,从而在数据较少或数据质量较差的情况下,能利用各种信息提高参数估计的合理性与资源评估的可靠性。因此,对数据量较少或数据质量较差情况下的渔业资源评估而言,贝叶斯方法非常有效,如本文所示的印度洋长鳍金枪鱼的资源评估。     

大西洋中部金枪鱼延绳钓渔场黄鳍金枪鱼(Thunnus albacares)生物学特性的初步研究

根据 2 0 0 1年 6月 1 6日— 1 0月 2 7日大西洋中部金枪鱼延绳钓渔场现场所作的生物学测定数据 ,应用统计与回归的方法分别对黄鳍金枪鱼 (Thunnusalbacares)的性腺成熟度、摄食等级、摄食种类、性比、叉长分布、叉长与纯重的关系、叉长与原条鱼重的关系、原条鱼重与纯重的关系等进行了研究。结果表明 ,( 1 )性腺成熟度Ⅵ级占的比例最高 ,为 47.0 6%。 ( 2 )摄食等级以 1级为主 ,其次为 0级 ,分别占 45 .45 %和 1 8.1 8%。 ( 3)胃含物中以鱿鱼出现的频率为最高 ,占 44 44% ,其次是沙丁鱼和杂鱼 ,分别占 2 7.78%和 2 5 .0 0 %。 ( 4 )雄性与雌性的性比约为 1 .43比 1。 ( 5 )优势叉长为 1 .31— 1 .47m ,占 31 .44% ,平均叉长为 1 39m。 ( 6)不分性别、雄性和雌性黄鳍金枪鱼叉长 (FL)与纯重 (DW)的关系可表达为 :DW =5 .6632× 1 0 - 6FL3 1 951 。( 7)不分性别、雄性和雌性黄鳍金枪鱼叉长 (FL)与原条鱼重 (RW)的关系分别为 :RW =8.5 0 72× 1 0 - 6FL3.1 390 、RWM=1 .1 2 2 9× 1 0 - 5 FLM3.0 847、RWF=7.1 71 1× 1 0 - 6FLF3 1 72 1 。 ( 8)不分性别、雄性和雌性黄鳍金枪鱼原条鱼重 (RW)与纯重 (DW)的关系分别为 :RW =1 .1 339DW、RWM =1 .1 32 0DWM、RWF=1 1 399DWF。     

应用CEDA和ASPIC软件包对巴基斯坦国的多齿蛇鲻(Saurida tumbil)渔业的最大持续产量的初步研究

The catch and effort data analysis(CEDA) and ASPIC(a stock assessment production model incorporating covariates) computer software packages were used to estimate the maximum sustainable yield(MSY) from the catch and effort data of Greater lizardfish Saurida tumbil fishery of Pakistan from 1986 to 2009. In CEDA three surplus production models of Fox, Schaefer and Pella-Tomlinson were used. Here initial proportion(IP) of 0.5 was used because the starting catch was roughly 50% of the maximum catch. With IP = 0.5, the estimated MSY from Fox model were 20.59 mt and 38.16 mt for normal and log-normal error assumptions, while the MSY from Schaefer and Pella-Tomlinson were 60.40, 60.40 and 60.40 mt, for normal, log-normal and gamma error assumptions respectively. The MSY values from Schaefer and Pella-Tomlinson models of three error assumptions were the same. The R2 values from those three models were above 0.6. When IP = 0.5, the MSY values estimated from ASPIC from Fox were 132 mt, and from logistic model were 69.4 mt, with R2 value above 0.8. Therefore we suggest the MSY of S. tumbil fishery from Pakistan to be 60–70 mt, which is higher than the latest catch, thus we would recommend that the fishing efforts for this fishery may be kept at the current level.     

大西洋金枪鱼渔业开发概况及中国远洋金枪鱼船队的利用前景

基于养护大西洋金枪鱼国际委员会提供的数据,文章分析了大西洋金枪鱼渔业的开发概况、主捕鱼种的利用情况和主要渔业国概况。同时,文章还简要分析了中国金枪鱼船队在大西洋的发展概况,并对中国金枪鱼船队的发展前景作了简要探讨。     

Photosynthesis versus irradiance relationships in the Atlantic sector of the Southern Ocean

Eleven incubation experiments were conducted in the South Atlantic sector of the Southern Ocean to investigate the relationship between new production (ρNO^–₃), regenerated production (ρNH⁺₄), and total carbon production (ρC) as a function of varying light. The results show substantial variability in the photosynthesis–irradiance (P vs E) parameters, with phytoplankton communities at stations that were considered iron (Fe)-limited showing low maximum photosynthetic capacity (P^B_max) and low quantum efficiency of photosynthesis (α^B) for ρNO₃, but high P^B_max and α^B for ρNH₄, with consequently low export efficiency. Results at stations likely relieved of Fe stress (associated with shallow bathymetry and the marginal ice zone) showed the highest rates of P^B_max and α^B for ρNO₃ and ρC. To establish the key factors influencing the variability of the photosynthetic parameters, a principal components analysis was performed on P vs E parameters, using surface temperature, chlorophyll-a concentration, ambient nutrients, and an index for community size structure. Strong covariance between ambient nitrate (NO₃) and α^B for ρNO₃ suggests that Fe and possibly light co-limitation affects the ability of phytoplankton in the region to access the surplus NO₃ reservoir. However, the observed relationships between community structure and the P vs E parameters suggest superior performance by smaller-sized cells, in terms of resource acquisition and Fe limitation, as the probable driver of smaller-celled phytoplankton communities that have reduced photosynthetic efficiency and which require higher light intensities to saturate uptake. A noticeable absence in covariances between chlorophyll-a and α^B, between P^B_max and α^B, and between temperature and α^B may have important implications for primary-production models, although the absence of some expected relationships may be a consequence of the small dataset and low range of variability. However, significant relationships were observed between ambient NO₃ and α^B for ρNO₃, and between the light-saturation parameter E_k for ρNO₃ and the phytoplankton community’s size structure, which imply that Fe and light co-limitation drives access to the surplus NO₃ reservoir and that larger-celled communities are more efficient at fixing NO₃ in low light conditions. Although the mean P^B_max results for ρC were consistent with estimates of global production from satellite chlorophyll measurements, the range of variability was large. These results highlight the need for more-advanced primary-production models that take into account a diverse range of environmental and seasonal drivers of photosynthetic responses.     

数据缺乏条件下的渔业资源评估方法研究进展

全球范围内绝大多数渔业处于数据缺乏的状态,而常规的资源评估方法需要准确的生物学信息和完整的渔获数据,通常并不适合此类渔业资源的评估。数据缺乏方法(DLM)正是适用于此类情况的渔业资源评估方法,DLM的研究已经成为渔业资源研究的热点。作者对DLM的近期发展作了简要回顾,重点对主要的DLM方法和数据需求进行了分析比较,指出这些方法的应用需要注意的问题。历史渔获量是大多数DLM方法运用的必要数据(如DCAC、Catch-MSY模型),而关于资源丰度的相对指标和重要生活史参数(如种群内禀增长率、自然死亡系数),则是运用这些方法的必要补充。此外,对运用DLM所需的主要生物学参数的估算方法进行了简介。最后对DLM方法的使用及其在国内渔业中的运用提出了建议。     

Latitudinal changes in siphonophore assemblages across the Atlantic sector of the Southern Ocean

Siphonophores are commonly considered to be useful indicators of water masses and water-mass movement, but their employment as such across the wider Southern Ocean has not so far been attempted. We redress this here using archived samples, collected during January–February 1993 along a transect from Cape Town to the South African National Antarctic Expedition (SANAE) base in Antarctica, and compare the patterns generated with those determined from a prior analysis of whole assemblages at lower taxonomic resolution. Twenty-one species were identified from 18 of the original 53 samples collected, and two distinct assemblages were confirmed as separated by the Sub-Antarctic Front. That to the south was characterised by low diversity and high abundance and was dominated by cold-water specialists, whereas that to the north comprised a larger number of subtropical and temperate species at low abundance. Assemblage structure was strongly influenced by the mixed layer depth, sea surface salinity and chlorophyll a concentration, as well as mesozooplankton biomass. Congruence with the whole-assemblage study was high, indicating that this taxon can be suitably employed as a proxy in studies such as this. The study emphasises the value of archived plankton samples and makes a plea for better curation.     

The ecology and biogeography of tintinnid ciliates in the Atlantic sector of the Southern Ocean

Qualitative and quantitative analyses of the tintinnids retrieved in surface and vertical (down to 1150 m ) samples in the Scotia, Weddell, Bransfield and Bellingshausen areas allow us to define three distinct zones: (A) the Scotia Sea, Bransfield Strait and oceanic waters of the northern-central Weddell Sea, dominated by Codonelopsis gaussi and Cymatocylis affinis/conmllaria; (B) shelf and mostly ice-covered areas of the southernmost Weddell Sea and the Bellingshausen Sea, characterized by Laackmanniella prolongata and Cymatocylis drygalskii; (C) Bransfield-Weddell waters around the tip of the Antarctic Peninsula, where Codonellopsis balechi accounts for 80% of the tintinnids. These areas have (often significantly) different ice regimes, water-column depths, surface salinities, bulk planktonic settling volumes and microplanktonic concentrations. On the other hand, the composition of tintinnid assemblages is very similar on both sides of the Antarctic Peninsula. Causal interpretations for these heterogeneous distribution patterns and probable specific adaptations to the dissimilar environmental settings involved are analyzed.     

Phytoplankton chemotaxonomy in the Atlantic sector of the Southern Ocean during late summer 2009

A chemotaxonomic investigation of surface phytoplankton was undertaken on a research cruise to the Atlantic sector of the Southern Ocean during late austral summer 2009. Based on pigment signatures, several distinct regions emerged that were delineated by physical features. CHEMTAX analysis of high performance liquid chromatography (HPLC) pigment data indicated that diatoms generally dominated communities south of the Antarctic Polar Front (APF), particularly in regions of elevated biomass where chlorophyll-a (chl-a) was >1.5 µg l⁻¹ and diatoms comprised >80% of biomass. Pigment signatures representative of haptophytes-8, indicative of Phaeocystis antarctica, were dominant near the ice shelf. Chl-a concentrations were 0.2–0.6 µg l⁻¹ between the APF and the Subtropical Front (STF) and outputs suggested that chlorophytes, haptophytes-8 and haptophyte-6, in the form of coccolithophores, were the major constituents. Very low chl-a levels (<0.2 µg l⁻¹) were observed north of the STF and the prokaryotes Synechococcus spp. and Prochlorococcus spp. were the dominant groups in these oligotrophic waters.     

关于中国大西洋海洋战略布局的几点思考

随着综合国力的不断增长和海洋力量的不断提升,中国在大西洋的海外利益不断延伸,这对中国的海洋战略提出了新的要求。在《中华人民共和国深海海底区域资源勘探开发法》出台背景下,提前谋划中国的大西洋海洋战略十分必要。文章系统阐述了大西洋的全球战略地位,从政治与外交、军事与安全、经济与贸易、科技与环保等方面分析其对中国的战略意义,探讨大西洋海洋战略布局的目标框架。在此基础上,对中国大西洋战略布局进行现实考量,提出全面构建大西洋伙伴关系,提升大西洋资源调查、勘探和开发能力,中国海警加快融入国际海上搜寻救助体系等建议。