南极磷虾渔业CPUE及其丰度估算适用性

作为一种衡量渔业资源丰度变化的指标,CPUE常用于多种渔业资源评估。南极磷虾作为一种集群性的生物资源,其资源存在着较为明显的时空变化特征,加之该物种本身所具有的特殊性以及渔业特点,这也使得采用CPUE作为衡量该资源丰度指标的有效性存在着较大的不确定性。为此,本实验详细介绍了4种南极磷虾渔业CPUE的常用估算方法,并总结了这些方法所具有的特点、优势以及劣势,在此基础上从时空尺度和环境影响因素等方面对南极磷虾渔业CPUE估算的影响进行了分析。最后,实验就CPUE作为评估南极磷虾资源丰度的适用性及可行性进行了探讨。近年来,南极磷虾渔业日益受到全球的关注,但如何将渔业调查数据纳入到南极磷虾资源评估当中,一直未得到统一的结论,从而导致基于生态系统的南极磷虾渔业管理进展缓慢,本研究结果可为更好地开展南极磷虾资源评估和丰度估算提供思路。     

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。     

福建省生态渔业资源保护的现状与对策

生态渔业是21世纪发展的方向。作者就福建省生态渔业资源保护的途径作扼要探讨。本文着重介绍福建省发展现状、制约生态渔业发展的主要问题以及加快生态渔业资源保护的对策。     

适用于数据缺乏渔业的资源评估方法研究进展

开展渔业资源评估研究是制定渔业可持续发展策略的重要前提, 而数据有限是全球渔业资源评估面临的普遍挑战。传统资源评估方法具有数据需求量大、要求高等特点, 无法应用于数据缺乏渔业的资源评估中。数据缺乏方法(data-limited method)可结合少量易获得数据和相关历史生物学信息对渔业资源状况、生物学参考点以及资源量等进行评估, 已经成为全球区域性渔业管理组织和资源评估学者的关注热点。本文在分析数据缺乏资源评估方法文献的基础上, 对近几年开发的数据缺乏评估方法模型结构、模型输入输出、假设以及不确定性来源和分析方法等进行了回顾和归纳, 同时对数据缺乏评估方法未来的研究重点和方向进行了展望。分析认为, 数据缺乏渔业资源评估研究仍处于发展阶段, 若渔获量和体长数据均可用, 则应考虑整合了两种类型数据的模型, 如 LIME (length-based integrated mixed effects, 基于体长的综合混合效应)模型和 SSS (simple stock synthesis, 简化资源整合) 模型。建议今后研究中应加强以下几个方面的工作: (1)积极开展长时间、多海域、全覆盖的渔业资源独立科学调查, 以获得具有代表性的样本数据; (2)对现有数据缺乏模型进一步优化, 综合考虑各种因素对评估结果的影响; (3) 进行完整、准确的基础生物学研究, 获得较为准确的历史生物学信息, 从而降低评估结果的不确定性; (4)开展基于渔获量模型和基于体长模型的模拟测试研究, 提高模型对统计偏差和数据质量问题的包容性。     

对我国渔业资源增殖放流问题的思考

我国近海资源严重衰退,渔业水域环境不断恶化,远洋渔业形势也不容乐观,这已经成为我国渔业界的共识.渔业资源增殖放流是恢复渔业资源、提高渔业生产力的有效手段,并已在全世界广泛开展.本文分析了国内外渔业资源增殖放流的发展简况和我国当前增殖放流存在的问题,并提出一些建议,希望能对我国渔业资源增殖放流事业的发展有所裨益.     

基于EnhanceFish模型的鱼类增殖放流策略研究：以中山市南朗水域黄鳍棘鲷增殖放流为例

增殖放流是增殖受损生物资源和维持渔业可持续发展的重要途径,效果评估是增殖放流工作的重要环节。本研究引入EnhanceFish模型,从生态容量、种群结构、经济效益等方面对广东省中山市南朗水域黄鳍棘鲷(Acanthopagrus latus)增殖放流效果进行评估,探讨了EnhanceFish模型在我国渔业资源增殖放流效果评估中的应用潜力。结果显示,中山市南朗水域黄鳍棘鲷最大的放流数量为160万尾,最佳放流规格为全长6 cm,可获最大净现值6.2万元,可适当提高捕捞努力量,增加渔民人均收入;EnhanceFish模型能弥补其他评估方式功能单一的劣势,在生态容量评估中结果更精确,在种群结构评估中考虑更全面,在经济效益评估中更节约成本。因此,EnhanceFish模型在我国渔业资源增殖活动中有一定的应用价值。     

资源生态学研究进展及其在渔业上的应用

本文在概述资源生态学及其发展历程基础上,主要介绍了资源生态学的理论体系基础、研究内容与方法,并结合当前渔业发展实际,具体指出资源生态学在渔业上主要有指导生态渔业发展、推动渔业资源管理和促进渔业环境保护三大应用方向。     

美国切萨比克湾生态修复进展综述及其对长江河口海湾渔业生态修复的启示

长江口其独特的生境构成了水生生物的重要洄游通道、索饵场和产卵场。由于近几十年来长江口生态环境全面衰退,渔业资源量锐减。为重新恢复长江口水生生态系统的平衡,近十余年连续开展长江口水生生态修复工程,目前的研究对生态修复有提高和长期综合研究的需求。本文以与长江口同样经历渔业资源衰退问题的切萨比克湾河口(美国最大的河口海湾)生态修复项目为例,对其项目概况、实施的有效生态修复措施和方法技术进行了综述。以切萨比克湾河口区渔业资源的生态修复为具有典型参考意义的蓝本案例,通过了解其在修复河口理化环境、恢复关键物种资源量、保护与修复重要栖息地、合理利用土地、建立流域尺度综治体系等方面的显著成效,以期在基于生态退化机制的修复、基于生态结构和功能的完整性修复、基于生态流域尺度上的综合修复上获得经验,为长江口渔业生态修复的进一步深化研究和长期保护提供相关资料及启示。     

农业部发布关于加强渔业资源增殖放流工作的通知

近年来,由于环境污染、水工建设、围湖造田以及过度捕捞等原因,我国渔业资源处于严重衰退状态,严重影响到渔业经济的可持续发展。为此,各地组织开展了一些渔业资源增殖放流活动,对扩大天然水域鱼类种群规模,增殖渔业资源,保护水生生物多样性,维护生态平衡起到了重要作用,取得了良好的生态、经济和社会效果。但放流数量与资源增殖的需要还有很大差距,甚至一些地方从未开展过增殖放流活动。同时,由于缺乏统一规范和科学指导,个别地方存在着无序放流、放流品种种质不纯等问题,影响了放流效果。为科学指导和规范渔业资源增殖放流活动,保证生态安…     

日本海洋渔业资源增殖研究及启示

我国海洋渔业同世界其他国家渔业一样，由于捕捞能力过剩、船舶污染等原因导致海洋渔业资源严重衰退，借鉴相关国家的成功经验，为我国渔业资源增殖助力已成为刻不容缓的任务。日本是世界上渔业最发达的国家之一，也是较早开展渔业资源增殖的国家，积累了丰富的渔业资源增殖经验和成熟的技术。在对日本进行海洋渔业资源增殖深入研究的基础上，本文尝试提出我国在进行更有效增殖海洋渔业资源中应该注意的一些方面。     

大水面鳜增殖放流技术及效果评估研究进展

鳜(Siniperca chuatsi Basilewsky)是淡水生态系统中的顶级捕食者, 也是我国传统的渔业对象。多年来由于人类活动的过度干扰导致现阶段湖泊、水库等大水面鳜自然资源衰退严重。增殖放流作为水生生物资源养护和恢复的重要措施在世界各国大量开展。近年来针对鳜增殖放流开展了一系列基础性研究工作, 切实提高了鳜增殖放流的综合效益。本文综述了基于合理放流规格、放流时间、放流地点和放流数量的鳜增殖放流技术, 从经济效益、 生态效应、社会效益 3 个方面系统阐述鳜增殖放流效果评估研究的最新进展, 并对该领域未来的研究方向进行了展望, 以期为我国大水面鳜增殖放流工作提供借鉴和参考。     

Integrating recreational fisheries data into stock assessment: implications for model performance and subsequent harvest strategies

Understanding the impacts of recreational fishing on commercially fished stocks is becoming increasingly relevant for fisheries managers. However, data from recreational fisheries are not commonly included in stock assessments of commercially fished stocks. Simulation models of two assessment methods employed in Australia's Commonwealth fisheries were used to explore how recreational fishery data can be included, and the likely consequences for management. In a data‐poor management strategy for blue eye trevalla, Hyperoglyphe antarctica (Carmichael), temporal trends in recreational catch most affected management outcomes. In a data‐rich age‐structured stock assessment for striped marlin, Kajikia audax (Philippi), estimates of stock status were biased when recreational catches were large or when the recreational fishery targeted different size classes than the commercial fishery and these data were not integrated into the assessment. Including data from recreational fishing can change perceptions of stock status and impact recommendations for harvest strategies and management action. An understanding of recreational fishery dynamics should be prioritised for some species.     

Coupling dynamic energy budget and population dynamic models to inform stock enhancement in fisheries management

Extensive applications of fishery stock enhancement worldwide bring up broad concerns about its negative effects, creating a pivotal need for science-based assessment and planning of enhancement strategies. However, the lack of mechanistic understanding of enhanced population dynamics, particularly the density-dependent processes, leads to compromise in model development and limits the capacity in predicting enhancement effects. Here, we developed an individual-based model based on dynamic energy budget theory and full life-history processes, to understand the mechanism of density dependence in population dynamics that emerge from individual-level processes. We demonstrated the utility of the model framework by applying it to an extensively enhanced species, Chinese prawn (Fenneropenaeus chinensis, Penaeidae). The model could yield projections reflecting the observed trajectory of population biomass and yields. The model also delineated the key effects of density dependence on the vital rates of growth, fecundity and starvation mortality. Regarding the manifold effects of stock enhancement, we demonstrated a dampened shape in population biomass and yields with increasing magnitude of enhancement, and trade-offs between the ecological and economic objectives, that is, pursuing high benefit might compromise the wild population without proper management. Furthermore, we illustrated the possibility of combining stock enhancement and harvest regulation in promoting population recovery while maintaining fisheries yields. We highlight the potential of the proposed model for understanding density dependence in enhancement programme, and for designing integrated management strategies. The approach developed herein may serve as a general approach to assess the population dynamics in stock enhancement and inform enhancement management.     

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.     

Frontiers in modelling social–ecological dynamics of recreational fisheries: A review and synthesis

Recreational fisheries are culturally and economically important around the world. Recent research emphasizes that understanding and managing these systems requires a social–ecological perspective. We systematically reviewed quantitative social–ecological models of marine and freshwater recreational fisheries to summarize their conceptualization of social, ecological, and social–ecological dynamics and identify research frontiers. From a candidate set of 626 studies published between 1975 and 2018, 49 met criteria for inclusion in our review. These studies, though diverse in terms of focal species and processes considered, were geographically limited to a few locations and ignored large regions of the globe where recreational fishing is important. There were also important gaps in the social and ecological processes that were included in published models. Reflecting on these patterns in the context of previous conceptual frameworks, we define five key frontiers for future work: 1) exploring the implications of social and behavioural processes like heuristics, social norms, and information sharing for angler decisions and fishery dynamics; 2) modelling governance with more realistic complexity; 3) incorporating ideas from resilience thinking and complex adaptive systems, including slow variables, destabilizing feedbacks, surprises and diversity; 4) considering key ideas in fisheries systems, including spatial and temporal effort dynamics, catch hyperstability, and stocking; and 5) thinking synthetically about the models that we use to describe social–ecological dynamics in recreational fisheries, via explicit comparisons and formal integration with data. Exploration of these frontiers, while remembering the distinction between model complexity and model usefulness, will improve our ability to understand and sustain recreational fisheries.     

Ecological indicators for coral reef fisheries management

Coral reef fisheries are of great importance both economically and for food security, but many reefs are showing evidence of overfishing, with significant ecosystem‐level consequences for reef condition. In response, ecological indicators have been developed to assess the state of reef fisheries and their broader ecosystem‐level impacts. To date, use of fisheries indicators for coral reefs has been rather piecemeal, with no overarching understanding of their performance with respect to highlighting fishing effects. Here, we provide a review of multispecies fishery‐independent indicators used to evaluate fishing impacts on coral reefs. We investigate the consistency with which indicators highlight fishing effects on coral reefs. We then address questions of statistical power and uncertainty, type of fishing gradient, scale of analysis, the influence of other variables and the need for more work to set reference points for empirical, fisheries‐independent indicators on coral reefs. Our review provides knowledge that will help underpin the assessment of the ecological effects of fishing, offering essential support for the development and implementation of coral reef fisheries management plans.     

海洋牧场生态系统稳定性及其对干扰的响应—研究现状、问题及建议

海洋牧场建设是实现我国近海渔业资源恢复、生态系统和谐发展与蓝碳增汇的重要途径。近年来,在快速发展的同时也面临着诸多问题与挑战,极大制约了产业的健康发展。在海洋牧场建设过程中,关于生境营造和资源增殖的基础理论薄弱,对其生态系统稳定性与抗干扰能力认识不清,尤其对小尺度海洋牧场生态系统的结构及其功能实现过程,以及生态承载力知之甚少。亟需针对其人工鱼礁等生境营造的环境效应和增殖放流的资源补充效应开展理论印证和定量研究,以充分认识这些人为扰动的双重性。本文查阅了相关文献90余篇,简要回顾了国内外关于人工鱼礁生境营造的水动力环境特征、生源要素迁移过程、生物群落构建机制和局地生态系统稳定性评价等方面的研究进展。强调了小尺度海洋牧场生态系统结构的复杂性与动态性,重点关注了鱼礁群布局对牧场海域水动力环境、沉积物和生源要素演变的影响,以及在增殖放流等人为扰动下生物群落的物种共存机制。围绕海洋牧场生态系统稳定性与抗干扰能力等关键问题,从水动力驱动、生源要素表征、生物群落重建及生态系统健康等4个方面探讨了目前研究的不足与发展方向,以为海洋牧场人工鱼礁、海藻床等生境营造以及资源修复模式优化提供参考。     

Global fishery dynamics are poorly predicted by classical models

Fisheries dynamics can be thought of as the reciprocal relationship between an exploited population and the fishers and/or managers determining the exploitation patterns. Sustainable production of protein of these coupled human‐natural systems requires an understanding of their dynamics. Here, we characterized the fishery dynamics for 173 fisheries from around the globe by applying general additive models to estimated fishing mortality and spawning biomass from the RAM Legacy Database. GAMs specified to mimic production models and more flexible GAMs were applied. We show observed dynamics do not always match assumptions made in management using “classical” fisheries models, and the suitability of these assumptions varies significantly according to large marine ecosystem, habitat, variability in recruitment, maximum weight of a species and minimum observed stock biomass. These results identify circumstances in which simple models may be useful for management. However, adding flexibility to classical models often did not substantially improve performance, which suggests in many cases considering only biomass and removals will not be sufficient to model fishery dynamics. Knowledge of the suitability of common assumptions in management should be used in selecting modelling frameworks, setting management targets, testing management strategies and developing tools to manage data‐limited fisheries. Effectively balancing expectations of future protein production from capture fisheries and risk of undesirable outcomes (e.g., “fisheries collapse”) depends on understanding how well we can expect to predict future dynamics of a fishery using current management paradigms.     

An appraisal of stocking strategies in the light of developing country constraints

Stocking, transfer and introduction of fish are commonly used to mitigate loss of stocks, enhance recreational or commercial catches, restore fisheries, or to create new fisheries. However, many stocking programmes are carried out without definition of objectives or evaluation of the potential or actual success of the exercise. The present paper describes a strategic approach to stocking aimed at maximizing the potential benefits. A protocol is discussed which reviews factors such as the source of the fish, the stocking density, the age and the size of fish at stocking, the timing of stocking, and the mechanism of stocking. Finally, the effects of social, cultural and economic constraints on the potential outcome of stock enhancement programmes are discussed.