捕捞诱导鱼类生物学特征进化研究进展

随着捕捞强度加大,渔业生物为了应对捕捞压力、维持种族繁衍,逐渐产生适应性进化,这一过程称为捕捞诱导进化(Fishing-induced evolution,FIE),通常表现为渔业生物个体变小、性成熟提前,个体对捕捞的敏感性增强,进一步导致渔业种群结构简单、生态系统稳定性下降和渔业经济效益降低。认知捕捞诱导的渔业生物适应性进化,掌握捕捞对渔业种群的作用机制,有利于制定科学合理的渔业资源养护与管理策略。虽然FIE方面已进行了大量研究,但FIE在生理、生态及基因层面上对渔业生物的具体影响过程尚未明确,尤其是在气候变化、多物种相互作用等的动态环境中,FIE的作用方式更为复杂。作者综述了鱼类FIE的主要研究方法,总结了捕捞对大个体的选择性在鱼类生长、性成熟和行为方面的影响,并分析了这种影响对渔业种群恢复与管理产生的效应,以及今后需要解决的关键科学问题,旨在为FIE的进一步深入研究和渔业资源的科学管理提供帮助。     

秘鲁鳀资源变动及与海洋环境要素的关系研究进展

秘鲁鳀(Engraulis ringens)是一种小型中上层鱼类。作为重要的商业性鱼类之一,秘鲁鳀的捕捞产业曾形成了世界上最大的单鱼种渔业,但其产量的年间差异非常大,上升流流场结构变化是其产量变化的重要影响因素。上升流对秘鲁鳀捕捞量的作用机制可归纳为低纬度的地理位置、适宜的水温结构、低溶解氧、高能量传递效率的食物网以及复杂的海洋环境要素变化五个方面。秘鲁鳀渔业生物学的多个方面都显著地受到了海洋环境变化的影响。此外,与气候相关的大尺度海洋生态系统周期性变化(regime shift)也影响到了秘鲁鳀的资源变动。本研究认为,今后在加强对长时间尺度生态系统周期性变化的研究同时,也应注重结合海洋环境变化、捕捞因素及种群的内部动力过程这三者之间的关系,结合基于个体的海洋动力学,建立秘鲁鳀资源评估及预测的模型,为合理开发和管理提供基础。     

过度捕捞使海洋系统生态退化

＂过度捕捞＂是指人类的捕鱼活动导致海洋中生存的某种鱼类种群不足以繁殖并补充种群数量。现代渔业捕获的海洋生物已经超过生态系统能够平衡弥补的数量,结果使整个海洋系统生态退化。     

澳大利亚：均衡多样化渔业对生态系统有利

澳大利亚一个国际研究小组近日在《Science》杂志上撰文指出,均衡性的多样化捕捞既能满足渔业生产的需要,又能保护好渔业环境。据这篇题为《反思选择性渔业的后果》一文的阐述,增加对种群数量和个体大小均日益减小的鱼类的选择性捕捞,无论对渔业生产还是环境保护都是有害无益的。     

海洋鱼类摄食生态与食物网研究进展

首先总结归纳了海洋鱼类摄食生态与食物网研究中的实验方法,主要包括胃含物分析法、碳氮稳定同位素法、特定化合物同位素法等实验方法的发展历史和应用现状；随后介绍了海洋鱼类摄食生态与食物网最新研究进展和取得的成绩,主要包括海洋鱼类摄食生态中食物组成、摄食方式、摄食量和食物用于机体各种生命活动分配方式,以及海洋食物网研究中以传统胃含物分析法为基础、以简化食物网为核心,碳氮稳定同位素技术和生态系统模型的应用发展；最后,着重分析了我国海洋鱼类摄食生态和食物网研究中有待解决的问题,并对该领域今后的发展趋势进行了展望。     

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.     

生态系统的渔业管理(ENBEM)现状及发展方向

本文就生态系统的渔业管理(EBFM)现状及未来发展进行了探讨,大部分观点和论据出自美国、新西兰和加拿大.其中美国和新西兰在实施单一种类管理降低过度捕捞方面一直处于世界前列.目前世界上关于EBFM有三种不同的观点:第一种观点认为EBFM是在传统单一种类管理中简单地加入了对混获、草食性种类和生物栖息地修复的关注;第二种观点认为EBFM是以营养连通性为中心,其最终目标是使用生态系统模型来解释种类间相互作用;第三种观点认为EBFM涵盖社会的广泛影响,如管理海洋生态系统时带来的土地利用、国民经济政策和人口增长等问题.由于第三种观点涉及面太大,本文主要探讨前两种观点.     

渔业简讯

推进世界渔业的可持续发展渔业是指包括在内陆和海洋水域捕捞野生鱼类,以及经放养增殖和水产养殖而获得鱼类产品的产业。渔业在世界食品经济中有着重要作用。目前全球有4000多万人从事捕捞渔业和养殖渔业。鱼类是含有丰富蛋白质、重要脂肪酸和维生素、矿物质的人类食物来源。鱼     

影响大亚湾鱼类生产力的主要生物类群

<正> 鱼类食物关系或食物链(网)是海洋生态系统中一个非常重要的因素。它关系到物质循环过程和各级生产力,特别是终级生产力的水平。在渔业生产中,最关心的是终级生产力产品的数量与质量及其变动情况。因此,这个问题的研究不仅具有理论意义且有实用意义。以往的研究中,由于渔业发展的历史是从北部水域开始的,食物关系的研究也就停留在少数几种占主导位置的捕捞对象上进     

海洋捕捞业与海洋生物多样性的持续有效发展——基于海洋生物经济学模型的分析

海洋捕捞业的经济有效性和海洋生物种群的保护是当前海洋渔业经济研究的重点,应该将相关海洋物种的捕捞和繁殖规律统筹考虑,提高海洋渔业资源的利用效率.通过对Flaaten的生物经济学模型的数理分析比较,提出经济鱼种的价格上涨并不会导致该鱼种生物种群存量下降,如果管理措施合理,鱼类种群存量依然存在上升的可能;并由此指出海洋捕捞必须考虑种群间相互关系,利用合理的生物经济学模型、建立明晰的海洋捕捞权等措施有助于海洋生物经济的持续有效发展.     

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。     

Gear restrictions create conservation and fisheries trade-offs for management

Gear-based management for coral reef fisheries is often overlooked in the scientific literature. Empirical studies have demonstrated the conservation benefits of gear-restricted areas (i.e. prohibiting fishing gears), which can support greater biomass than unrestricted areas and protect species that play key functional roles. However, population dynamics of functional feeding groups of reef fishes under specific gear-restriction regimes remains uncertain. Here, we constructed a multi-species, length-based fisheries model to observe relative biomass and catch of reef fishes under various gear-restriction management scenarios. We used fishery-dependent and fishery-independent data to determine the catchability of functional groups and selectivity of size classes for hook-and-line, net and spear fishing, which are widely used gear types on coral reefs globally. Our model revealed trade-offs involved with gear-restriction management such that no single management strategy was able to maximize biomass or catch of all functional groups simultaneously. Also, we found that spear fishing (i.e. prohibiting hook-and-line and net fishing) maintained the highest total biomass summed across functional groups, whilst hook-and-line fishing (i.e. prohibiting net and spear fishing) and a ban on spears maintained the lowest biomass. However, hook-and-line fishing generated the highest catch-per-unit-effort. Our model results were primarily driven by differential growth rates, maximum per capita production of recruits, and catchability of functional groups targeted by each fishing gear. We demonstrate that gear restrictions can be a critical management tool for maintaining biomass and catch of certain functional groups but will likely require additional management to protect all key functional feeding groups of coral reef fishes.     

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.     

澳洲鲭太平洋群系的资源评估与管理策略

澳洲鲭是西北太平洋重要的经济种类,了解和掌握澳洲鲭太平洋群系资源开发状况对确保其可持续利用具有重要的意义。根据日本中央水产研究所提供的1995—2015年澳洲鲭太平洋群系的生产统计和资源调查资料,利用基于年龄结构的实际种群模型和单位补充量产量模型等进行资源量评估,分析澳洲鲭太平洋群系资源利用情况及其管理策略。结果显示,历年澳洲鲭太平洋群系资源量虽有波动但仍保持在较高水平,2015年资源量最高约为65万t;年平均捕捞死亡系数呈波动下降趋势,2015年捕捞死亡系数只有0.15,近五年平均捕捞死亡系数Fcur=0.33,单位补充量亲体量是未开发时的32.7%,不存在生长型捕捞过度,也不存在补充型捕捞过度,处于可持续开发状态。研究还探讨了水温变化引起自然死亡波动以及不同开捕年龄对澳洲鲭太平洋群系资源状况的影响。研究表明,该渔业目前开发和利用程度合理,建议使用F0.1做为管理参考点进行渔业资源的管理。     

"丢弃渔具"研究进展

废弃、遗失或以其他方式丢弃的渔具(abandoned, lost or otherwise discarded fishing gear, ALDFG)是海洋生态环境及渔业最为严重的危害之一,世界各国及国际组织对其引发的问题日益关注。本文介绍了ALDFG对海洋生态及渔业的危害、ALDFG产生的主要原因、各国及相关国际组织为减少ALDFG所提出的措施及常用的ALDFG调查和评估方法。发现ALDFG的研究多采用统计模型量化ALDFG,或结合统计检验等评估ALDFG的危害性(幽灵捕捞)和通过经济学层面评估清除ALDFG带来的生态及经济效益等。建议：①通过问卷调查与水下实地调查等评估国家管辖海域ALDFG量和危害程度,并结合海洋动力学模型及渔具水动力性能等分析ALDFG移动轨迹;②开发新材料,改进渔具及属具设计方法,减少ALDFG;③通过水下实地调查,确定ALDFG的物理变化过程、幽灵捕捞能力的变化等;④观察ALDFG清除后对海洋生态系统多样性及渔业资源的积极作用,并结合经济模型分析ALDFG清除后产生的社会及经济效益。     

Population trends of bycatch species reflect improving status of target species

Synthesis studies of fish stocks worldwide suggest improving status of mainly target species that are fully assessed. Other analyses, primarily based on catch data alone, but which include a wider range of species as well as bycatch, present a different view. Catch‐only analyses could be more robust if fishery‐independent data were used and discards accounted for. We develop a model that uses only survey biomass at length and landings data to estimate fishing mortality, spawning stock biomass (SSB) and discards. An analysis of species from the North Sea shows the model results compare well with most fully assessed stocks. When applied to bycatch species with limited data, trends in fishing mortality and SSB typically reflect those of the target species. In the last decade, mean fishing mortality rates have tended to decline, while mean SSB has increased. Despite increasing SSB, recent mean recruitment appears to have been lower than previously which may limit future biomass recovery. Species usually associated with more northerly distributions appear to show the greatest effect of weaker recruitment, which may be linked to climate. Estimated discards have tended to decline in magnitude as a result of reduced fishing mortality and associated lower total catches. The model offers a simple way to use both landings and survey data to obtain more detailed population trends for data limited species.     

Modelling the effects of reserve size and fishing mortality for Caribbean queen conch Strombus gigas

相似文献   

南极磷虾生物量估算方法

南极磷虾是南大洋生态系统食物网中的关键种,在南大洋中上层生态系统中起着至关重要的连接作用,其资源的养护和持续利用受到国际社会日益关注。磷虾研究已有90多年的历史,其生物量及其分布一直是研究的重点。生物量评估方法也在不断发展,从早期的浮游动物干重法、生产量与生物量比例系数转换法,到网具采样法以及现在流行的声学法,评估手段也变得更为高效。本文通过系统梳理磷虾生物量的主要评估方法,分析其优缺点,并着重从磷虾目标强度模型(TS)参数的海上实测、声学数据中磷虾信号的提取,磷虾单位平方海里声学反射系数(NASC)的计算,基于渔船声学数据修正磷虾渔业单位捕捞努力量渔获量(CPUE),基于渔船声学数据的磷虾集群、洄游和渔场形成机制研究等5个方面对现行生物量声学评估法提出改进建议,提高资源评估的精度,以期为磷虾生物资源的开发与管理提供科学依据。     

Kittiwake breeding success in the southern North Sea correlates with prior sandeel fishing mortality

1. In the North Sea, sandeels provide a vital food source for breeding seabirds, but are also the target of an industrial fishery. GPS tracking suggests that the most productive fishing grounds overlap with foraging areas of black‐legged kittiwakes from eastern England, raising the prospect that the fishery could affect the birds. Rising sea temperatures also threaten sandeels, so kittiwake food supplies could be affected by local and larger‐scale processes.
2. Drivers of kittiwake breeding success at Flamborough Head and Bempton Cliffs Special Protection Area, the UK's largest colony, and one of the closest to the sandeel fishing grounds, were examined. Relationships between sandeel stocks, sea surface temperature and kittiwake breeding success were analysed with generalized linear mixed models and generalized linear models, with model performance assessed using the Akaike Information Criterion and R².
3. Higher kittiwake breeding success was associated with higher sandeel spawning stock biomass (SSB; biomass of sexually mature fish) the preceding winter (R² = 21.5%) and lower sandeel fishing mortality two years previously (R² = 22.3%). After temporal trends were removed, only the fishing mortality effect remained. Models with multiple predictors supported the importance of fishing mortality. Higher sandeel SSB was associated with lower temperatures (R² = 15.2–38.6%) and lower sandeel fishing mortality (R² = 24.2–26.1%).
4. Hence, lower temperatures and fishing mortality were positively associated with sandeel biomass, and higher sandeel biomass and lower fishing mortality were positively associated with kittiwake productivity. In light of worsening environmental conditions and declining sandeel and kittiwake populations, careful consideration should be given to the requirements of sandeel‐dependent predators when making fishery management decisions.

     

Selectivity matters: Rules of thumb for management of plate‐sized,sex‐changing fish in the live reef food fish trade

Effective management of fisheries depends on the selectivity of different fishing methods, control of fishing effort and the life history and mating system of the target species. For sex‐changing species, it is unclear how the truncation of age‐structure or selection of specific size or age classes (by fishing for specific markets) affects population dynamics. We specifically address the consequences of plate‐sized selectivity, whereby submature, “plate‐sized” fish are preferred in the live reef food fish trade. We use an age‐structured model to investigate the decline and recovery of populations fished with three different selectivity scenarios (asymptotic, dome‐shaped and plate‐sized) applied to two sexual systems (female‐first hermaphroditism and gonochorism). We parameterized our model with life‐history data from Brown‐marbled grouper (Epinephelus fuscoguttatus) and Napoleon fish (Cheilinus undulatus). “Plate‐sized” selectivity had the greatest negative effect on population trajectories, assuming accumulated fishing effort across ages was equal, while the relative effect of fishing on biomass was greatest with low natural mortality. Fishing such sex‐changing species before maturation decreased egg production (and the spawning potential ratio) in two ways: average individual size decreased and, assuming plasticity, females became males at a smaller size. Somatic growth rate affected biomass if selectivity was based on size at age because in slow growers, a smaller proportion of total biomass was vulnerable to fishing. We recommend fisheries avoid taking individuals near their maturation age, regardless of mating system, unless catch is tightly controlled. We also discuss the implications of fishing post‐settlement individuals on population dynamics and offer practical management recommendations.