种群模拟在渔业资源评估中的研究现状及展望

随着渔业资源评估理论、数理统计方法和计算机技术的进步, 资源评估模型朝着多样化和复杂化不断发展, 其中种群模拟技术是检测模型适用性和局限性的重要手段。该技术由种群仿真理念发展而来, 通过模拟“真实”种群的方式, 对资源评估结果和管理策略进行有效的评价和预测, 并凭借可结合海洋环境因子、鱼类洄游空间分布以及多鱼种渔业进行资源评估的特性, 已成为开发新资源的重要评估方法之一。为此, 本文对种群模拟的结构和发展过程进行了回顾, 对该技术的核心组成部分操作模型和常见的四类误差(过程误差、观测误差、模型结构误差和管理误差)展开分类讨论。此外, 本文还结合近年来迅速发展的数据缺乏和数据适中模型的特点, 根据实际应用案例对种群模拟的作用和使用前景进行梳理, 并就种群模拟技术发展中存在的主要问题和潜在解决办法提出分析和建议。     

EwE模型在评价渔业水域生态系统中的应用

渔业影响了水域生态环境,如过度捕捞、鱼类生存环境变迁等都使得原有渔业水域生态系统越来越脆弱。科学开发有限得渔业资源需要正确的理论指导。构建生态系统模型可以更完整地认识水域生态系统得结构和功能。Ecopath with Ecosim(EwE)模型是以生态系统中的能量流动和物质平衡为理论基础,融合了生态学的相关基础理论知识,主要用于探讨生态学的基本问题、评估渔业对生态系统的影响、提出渔业管理政策、评估海洋保护区域的效果和位置确定、评估环境变化对渔业的影响。该模型为海洋渔业和淡水渔业提供了分析和管理工具.     

EwE模型在评价渔业水域生态系统中的应用

渔业影响了水域生态环境,如过度捕捞、鱼类生存环境变迁等都使得原有渔业水域生态系统越来越脆弱。科学开发有限的渔业资源需要正确的理论指导。构建生态系统模型可以更完整地认识水域生态系统的结构和功能。Ecopath with Ecosim（EwE）模型是以生态系统中的能量流动和物质平衡为理论基础,融合了生态学的相关基础理论知识...     

基于个体生态模型在渔业生态中应用研究进展

近年来, 基于个体的生态模型(individual-based model, IBM)被广泛应用到海洋生态环境中, 被认为可能是研究鱼类生态过程的唯一合理手段。基于个体生态模型以众多的生物个体为模拟对象, 考虑个体之间的差异、环境条件的时空变化对个体发育的影响,这一研究为基于生态系统的渔业管理, 以及资源补充量预测分析提供了科学的研究方法和手段。本文主要介绍了IBM的基本概念, 以及在渔业上的研究方法和技术, 总结了IBM在鱼类输运、生长死亡和捕食相关的应用研究现状以及IBM在渔业上未来发展趋势, 并对IBM在渔业上应用的问题和不足进行了分析和讨论。本论文的总结与分析将为国内开展我国近海鱼类早期生活史的研究, 以及基于生态系统的渔业资源评估管理提供参考。     

实际种群分析法在绿鳍马面鲀资源评估中的应用和改进

从８０年代初年起,应用实际种群分析法和计算机编程每年对东海绿鳍马面Ｔｕｎ资源量及产量作估算和预报,在１０多年的工作中,利用计算机运算速度不断提高的优势,对评估方法逐步作了改进,根据捕捞方程采用迭代法直接求算捕捞死亡系数Ｆ值,利用反复迭代取消了初始值的估算,使得估算精度和计算便利性都有所提高。实践表明,评估预报结果对渔业生产和管理部门有一定的参考价值。     

应用贝叶斯状态空间剩余产量模型框架评估印度洋大眼金枪鱼的资源状况

根据1950―2016年的渔获量数据及1955―2016年的单位捕捞努力量(Catch Per Unit Effort,CPUE)数据,采用贝叶斯状态空间剩余产量模型框架JABBA(Just Another Bayesian Biomass Assessment)对印度洋大眼金枪鱼(Thunnus obesus)的资源状况进行评估,分析了渔船效应、CPUE数据尺度对评估结果的影响。结果表明,模型拟合效果对于不同时间跨度下CPUE数据的选择比较敏感。当选用时间跨度为1979―2016年的CPUE数据且考虑渔船效应时,模型拟合效果最好。2016年大眼金枪鱼的资源量为812 kt,最大可持续产量(Maximum Sustainable Yield,MSY)为163 kt,远高于同年渔获量86.81 kt,其资源量具有82.50%的概率处于"健康"状态。当总允许可捕量为69.45～104.17 kt时(2016年渔获量的80%～120%),未来10年大眼金枪鱼的资源量仍高于B_(MSY)(达到MSY所需的生物量)。回顾性分析结果表明,该资源评估结果存在一定程度的回顾性问题,捕捞死亡率和资源量分别存在被低估和高估的现象。将来需要在模型结构设定、CPUE数据选择及模型参数的先验分布设置等方面进一步优化。     

利用贝叶斯动态产量模型评估印度洋长鳍金枪鱼资源状态

印度洋长鳍金枪鱼(Thunnusalalunga)的生物学信息相对较少,渔业数据存在较多问题,致使其资源评估结果仍存在较大的不确定性,从而影响了渔业管理的科学性。为此,本研究基于印度洋长鳍金枪鱼的渔业捕捞、标准化CPUE (catch per unit effort)数据及相关种群假设,利用贝叶斯动态产量模型对该种群进行了资源评估研究,结果显示:(1)渔获量的观测误差对模型参数估计、资源状态的判断及渔业管理具有重要影响,渔获量观测误差的增大使模型评估的过度捕捞概率上升,导致总可捕量(total allowable catch, TAC)减少;(2)动态产量模型形状参数、r的先验分布和资源丰度指数的选择均会影响资源评估的质量,本研究显示, Fox模型的资源评估结果比Schaefer模型的评估结果更合理,r先验分布范围的增大使模型评估的资源状态变好,使用西南海域标准化CPUE时的评估结果相对较好;(3)设置某些年份的资源量比例(φ、P2017)范围有助于提高数据缺乏下渔业资源评估的质量;(4)评估结果表明印度洋长鳍金枪鱼发生资源型与捕捞型过度捕捞的概率分别为34%、50%,两种过度捕捞同时...     

时滞差分模型与剩余产量模型的应用比较以南大西洋长鳍金枪鱼为例

将剩余产量模型和时滞差分模型分别应用于南大西洋长鳍金枪鱼（Thunnus alalunga）渔业数据,结果表明,比起剩余产量模型,时滞差分模型拟合的单位捕捞努力渔获量（catch per unit effort,CPUE）曲线能够更好地捕捉到CPUE随着时间的波动。赤池信息量准则（Akaike information criterion,AIC）的结果显示,时滞差分模型比Schaefer模型的评估效果要好。时滞差分模型评估的最大可持续产量（maximum sustainable yield,MSY）中值为22 490 t,80%置信区间为21 756~23 408 t;剩余产量模型评估的MSY中值为27 520 t,80%的置信区间为26 116~28 959 t。生物学参考点的结果表明目标群体在1985年以前资源状态较好;1985年~2005年的20年里处于过度捕捞状态;2005年后资源状况得到改善,但仍需加强管理。比起剩余产量模型,时滞差分模型给出了更为有效且保守的评估结果。     

渔业数据失真对两种非平衡剩余产量模型评估结果的影响比较

为了研究渔业数据失真对两种非平衡剩余产量模型评估结果的影响,以南大西洋长鳍金枪鱼渔业产量和单位捕捞努力量渔获量(CPUE)数据作为基础数据,加入5种不同程度[变异系数(CV)=1%、5%、10%、20%和30%]的随机误差,模拟了(1)无数据失真,(2)仅产量数据失真,(3)仅CPUE数据失真,(4)产量和CPUE数据均失真等4种情况。利用基于ASPIC的非平衡剩余产量模型(ASM)和基于贝叶斯状态空间建模方法的非平衡剩余产量模型(BSM)分别评估了最大可持续产量(MSY)、B_(MSY)、F_(MSY)、B_(2011)/B_(MSY)、F2011/F_(MSY)等5种生物学参考点和管理指标。结果显示,在无数据失真情况下,ASM和BSM评估的MSY分别为2.866×10~4 t和2.836×10~4 t,B_(2011)/B_(MSY)分别为1.366和1.324,F2011/F_(MSY)分别为0.627和0.667,均相差不大,表明该渔业目前状态良好,ASM得到了较大的B_(MSY)(31.48×10~4 t)和较小的F_(MSY)(0.091);数据失真对ASM评估的B_(MSY)和F_(MSY)分别产生了严重的过低估计和过高估计,且CPUE数据失真产生的影响要比产量数据失真大;随着随机误差的增大,BSM评估的生物学参考点和管理指标的绝对百分比偏差有增大趋势;与ASM相比,BSM能够更好地处理渔业数据中存在的随机误差,除了MSY以外,BSM评估的生物学参考点和管理指标绝对百分比偏差均要比ASM的评估结果低,尤其是B_(MSY)和F_(MSY)。因此,在使用存在较大随机误差的渔业数据进行资源评估时,BSM具有一定的优势。     

环境DNA技术在象山港水域鱼类多样性调查中的应用与评估

通过对象山港水域环境DNA(eDNA)样品的采集和高通量测序分析,并结合渔业资源调查数据,阐述象山港主要鱼类群落的种类组成和多样性特征,探讨了环境DNA技术在典型海域鱼类多样性研究中的应用前景.结果显示,共从象山港水域环境DNA样品中检测到26个常见鱼类物种,隶属于辐鳍鱼纲(Actinopterygii)的7个目中的2...     

基于系统动力学模型的渔业资源增殖放流效应分析

文章从系统动力学角度出发,着眼于动态系统的整体统筹,综合考虑渔业、生态和社会三方面要素,对山东省中国对虾（Penaeus chinensis）增殖放流渔业进行了系统动力学建模仿真,并通过对预测结果的比较分析,探讨了合理的放流量、捕捞努力量等决策变量,以期为渔业决策者提供有益的参考。文中提出的方法亦可用于对渔业资源生物量、产量、社会效益、生态效应的评估和预报。     

Estimating uncertainty in fish stock assessment and forecasting

A variety of tools are available to quantify uncertainty in age‐structured fish stock assessments and in management forecasts. These tools are based on particular choices for the underlying population dynamics model, the aspects of the assessment considered uncertain, and the approach for assessing uncertainty (Bayes, frequentist or likelihood). The current state of the art is advancing rapidly as a consequence of the availability of increased computational power, but there remains little consistency in the choices made for assessments and forecasts. This can be explained by several factors including the specifics of the species under consideration, the purpose for which the analysis is conducted and the institutional framework within which the methods are developed and used, including the availability and customary usage of software tools. Little testing of either the methods or their assumptions has yet been done. Thus, it is not possible to argue either that the methods perform well or perform poorly or that any particular conditioning choices are more appropriate in general terms than others. Despite much recent progress, fisheries science has yet to identify a means for identifying appropriate conditioning choices such that the probability distributions which are calculated for management purposes do adequately represent the probabilities of eventual real outcomes. Therefore, we conclude that increased focus should be placed on testing and carefully examining the choices made when conducting these analyses, and that more attention must be given to examining the sensitivity to alternative assumptions and model structures. Provision of advice concerning uncertainty in stock assessments should include consideration of such sensitivities, and should use model‐averaging methods, decision tables or management procedure simulations in cases where advice is strongly sensitive to model assumptions.     

小型中上层海洋鱼类资源评估研究进展

小型中上层海洋鱼类是重要的渔业资源,目前其捕捞产量约占到全球海洋渔获量二分之一。小型中上层海洋鱼类具有生命周期短、生长速度快、分布不均匀、易受环境因素影响等生物学特点,近年来,一些小型中上层海洋鱼类渔获量出现下降趋势,为保证其资源的可持续利用,对其进行准确的资源评估研究和制定合理有效的管理策略显得尤为重要。以文献计量统计分析为基础,对20多年来应用于小型中上层海洋鱼类资源评估的模型方法以及所需数据类型进行归纳与回顾,同时对模型中重要的参数估计、不确定性来源进行总结。分析认为,由于缺乏完整、准确的生物学信息导致无法对小型中上层海洋鱼类使用传统的资源评估方法进行评估,因此,其资源评估研究仍处在发展阶段。建议今后研究中应开展以下工作:1)努力提高现有模型的评估精度,尽可能考虑更多影响因素; 2)要进行长期系统的渔业资源独立调查; 3)充分利用体长等易获得数据,开发体长结构模型和基于生态系统的评估模型,降低模型选择的局限性。     

A novel spatiotemporal stock assessment framework to better address fine‐scale species distributions: Development and simulation testing

Characterizing population distribution and abundance over space and time is central to population ecology and conservation of natural populations. However, species distribution models and population dynamic models have rarely been integrated into a single modelling framework. Consequently, fine‐scale spatial heterogeneity is often ignored in resource assessments. We develop and test a novel spatiotemporal assessment framework to better address fine‐scale spatial heterogeneities based on theories of fish population dynamic and spatiotemporal statistics. The spatiotemporal model links species distribution and population dynamic models within a single statistical framework that is flexible enough to permit inference for each state variable through space and time. We illustrate the model with a simulation–estimation experiment tailored to two exploited marine species: snow crab (Chionoecetes opilio, Oregoniidae) in the Eastern Bering Sea and northern shrimp (Pandalus borealis, Pandalidae) in the Gulf of Maine. These two species have different types of life history. We compare the spatiotemporal model with a spatially aggregated model and systematically evaluate the spatiotemporal model based on simulation experiments. We show that the spatiotemporal model can recover spatial patterns in population and exploitation pressure as well as provide unbiased estimates of spatially aggregated population quantities. The spatiotemporal model also implicitly accounts for individual movement rates and can outperform spatially aggregated models by accounting for time‐and‐size varying selectivity caused by spatial heterogeneity. We conclude that spatiotemporal modelling framework is a feasible and promising approach to address the spatial structure of natural resource populations, which is a major challenge in understanding population dynamics and conducting resource assessments and management.     

华南沿海贝类体镉的调查与膳食暴露评估

根据2009年对广东、广西沿海主要贝类养殖区太平洋牡蛎（Crassostrea gigas）、翡翠贻贝（Perna viridis）、文蛤（Meretrix meretrix）和菲律宾蛤仔（Ruditapes philiparum）等贝类体镉（Cd）的调查结果,采用随机模拟的概率评估方法,对贝类体Cd的膳食暴露量进行了评估,对评估的不确定性和变异性进行了定量分析和讨论。结果表明,调查海域贝类w（Cd）存在显著性差异,所有样品中w（Cd）均低于无公害水产品中有毒有害物质限量标准值。将评估结果与WHO/FAO的食品添加剂联合专家委员会推荐的Cd的暂定每周耐受摄入量（PTWI）相比,贝类体Cd的膳食暴露量低于PTWI值,但在P95的高百分位水平下,贝类Cd的膳食暴露量占PTWI的比例较高（29.1%-57.4%）。建议采取相应措施,降低贝类体Cd的膳食暴露量。     

电子鼻技术的研究进展及其在水产品鲜度评价中的应用

水产品的质量管理是水产加工企业的重要环节。传统上，水产品的鲜度主要是采用感官评价或气相色谱分析的方法进行的。这些方法费时昂贵，而且不便于对产品质量的适时监测。因此，高效、快捷的水产品质量监测技术的研究受到了很大关注。利用电子鼻测水产品的鲜度，被公认是一种快速、可靠、可实现自动检测、而且对水产品无任何伤害的新型技术。本文阐述了电子鼻的工作原理和化学传感器技术的研究进展，并且讨论了电子鼻技术在水产品鲜度评价中的应用和未来发展前景。     

The fishery of the Ea Kao reservoir, southern Vietnam: a fishery based on a combination of stock and recapture, and self-recruiting populations

The present paper describes the fishery of the Ea Kao reservoir in south Vietnam. Historical data on the total production and total numbers of fish stocked were available from 1983 to 1996, and this information, together with the results of monthly monitoring of the fishery from June 1996 to December 1998, was used in the present study. A number of gears are used in the Ea Kao fishery, the most important being gill, lift and integrated nets, and beach seines. The fishery of Ea Kao is based on the annual stocking of advanced fry/early fingerlings of 0.3–1.0-g bighead carp, Hypophthalmichthys nobilis (Richardson), silver carp, Hypophthalmichthys molitrix (Cuvier & Valenciennes) and rohu, Labeo rohita Hamilton, as well as the self-recruiting indigenous species Toxabramis houdemeri Pellegrin and two exotic species, i.e. Nile tilapia, Oreochromis niloticus (L.), and common carp, Cyprinus carpio L. On average, the regularly stocked species contribute to 78% of total production, which has been around 400–450 kg ha⁻¹ in the last few years. The monthly peak catches of stocked species tend to coincide with the rainy season from May to October and the catches of self-recruiting species peak between February and April. A significant relationship ( P < 0.001) exists between the stocking density in year n (SD, n ha⁻¹) and the yield of stocked fish in year n + 1 ( Y , kg ha⁻¹):     

Harvest models and stock co‐occurrence: probabilistic methods for estimating bycatch

A primary goal of ecosystem‐based fishery management is to reduce non‐target stock impacts, such as incidental harvest, during targeted fisheries. Quantifying incidental harvest has generally incorporated fishery‐dependent catch data, yet such data may be biased by gear non‐retention, observation difficulties, and non‐random harvest patterns that collectively lead to an impartial understanding of non‐target stock capture. To account for such issues and explicitly recognize the combined influence of ecological and harvest factors contributing to incidental capture within targeted fisheries, we demonstrate a probabilistic modelling framework that incorporates: (i) background rates of target and non‐target stock co‐occurrence as the primary ecological basis for incidental harvest; (ii) the probability of harvesting at localities exhibiting co‐occurrences; (iii) the probability of selecting for non‐target species with fishery gear; and, (iv) as a function of harvest effort, the overall probability of incidental capture for any non‐target stock contained in the species pool available for harvest. To illustrate application of the framework, simulation models were based on fishery‐independent data from a freshwater fishery in Ontario, Canada. Harvest simulations of empirical stock data indicated that greatest species‐specific capture values were over 4000 times more likely than for species with lowest values, indicating highly variable capture probabilities because of the combined influence of stock heterogeneity and harvest dynamics. Estimated bycatch–effort relationships will allow forecasting incidental harvest on the basis of effort to evaluate future shifts in fishing activity against specific ecosystem‐based fishery management objectives, such as reducing the overall probability of bycatch while maintaining target landings.