中国近海鱼类生活史型与生态学参数地理变异

根据1985－1986年东海北部近海调查材料及其它有关文献，对43种鱼计74个种群或群体的生活史选择型及其生态参数进行了比较研究。结果表明，分布于我国近海的主要鱼类大多偏于r选择型。对r－K选择鱼种的资源特征及其对捕捞的反应作了阐述。各鱼种的种群生态学参数在种间和空间分布均表现出地理变异。     

海洋渔业对海洋生态系统的影响

海洋捕捞渔业生产为人类的生存和发展作出了重要贡献,但同时对海洋生态系统及其持续发展也造成了许多不利的生态影响,且随着渔捞技术的进步和渔捞努力量的加大,这种影响将继续加大。海洋渔业活动可以引起海洋物种品质的下降,明显影响自然海域海洋生物的生物量,破坏海洋生物栖息地,使海洋生物群落结构发生改变,影响到食物链的传递,导致某些海洋生物种类的消失和灭绝,从而在各个水平上使海洋生物多样性降低,使生态系统的结构和功能遭到一定程度的破坏。强烈的海洋渔业活动可能造成海洋生物种类的系列性枯竭。     

台湾海峡上升流区底栖生物数量动态的初步研究

不同季节底梄生物数量的动态由其组成种的种群特点所决定。在一些生命周期短(一年左右)、生长速度快(新生个体当年可以长成)的种处于优势的情况下,生物数量的季节变化就比较显著;而生命周期长、其种群由多个年龄组的个体构成的种占优势的情况下，一年之中种群数量就相对稳定。另一方面,底栖生物数量的急剧改变又决定于经济种的捕食活动和优势种的生物学过程。台湾海峡系经济鱼、虾类的集中分布区,尤以上升流区范围内的集群最密集。为了便于深入研究上升流与经济鱼、虾类资源的关系,本文着重探讨上升流范围内底栖生物数量的动态特点。     

台湾海峡及其邻近海域鱼类生活史特征及其变化研究

世界范围内,海洋渔业资源广泛面临着过度捕捞的压力.鱼类的不同生活史特征可表征不同的生活史对策,其变化可揭示鱼类种群对渔业捕捞压力的响应.台湾海峡及其邻近海域的主要渔场30多年来面临着过度捕捞的压力,导致了鱼类群落结构发生改变.本研究分析了该海域51种主要经济鱼类的生态参数,系统研究了其生活史特征及其变化.采用主成分分析法可将51种鱼类分成5个不同的生活史对策组,分组结果表明超过60%的鱼类被归纳入第5组,即近r对策组,且多为中上层鱼类.在此基础上收集相关历史数据,对其中25种经济鱼类进行生活史变化分析,讨论不同鱼类种群对渔业开发的响应.分析结果表明,在长期的渔业开发活动下多数鱼类表现出小型化、低龄化、早熟和生长率加快等趋势.此外,本研究计算了每种鱼类的开发率以进一步研究渔业捕捞压力对鱼类种群的影响,发现其中4种底层和近底层鱼类的生活史特征变化显著,提示某些物种可能对捕捞压力更敏感.本研究可为渔业管理和保护提供重要的科学依据.     

我国海洋浮游动物染色体研究进展

海洋浮游动物是海洋生态系统中非常重要的一大生态类群 ,种类组成繁杂、数量大、分布广 ,有着极其重要的生态学研究意义[1]。过去 ,这类动物的生物多样性研究重点主要在物种多样性的丰度和数量表达及其与环境因子的关系方面 ,积累了大量资料 ,但是在遗传多样性研究方面的资料则十分匮乏。我国海洋南北地理跨度较大 ,各海域地理环境、生态条件不尽相同 ,不仅有着各自的浮游动物群落面貌和特征 ,其共有种在各自栖息的环境条件中经自然选择以及在遗传漂移过程中常出现遗传趋异 ,有的种群可能已完全适应其生态环境 ,产生了独特的基因型和遗传结…     

适用于短生命周期种类资源评估模型的研究现状与展望

近几十年来随着传统鱼类资源衰退,短生命周期种类的资源量和捕捞产量出现了增长,并已成为世界海洋捕捞业的重要捕捞对象,为使渔业资源可持续利用,必须制定合理的渔业管理计划,实现对渔业资源的科学管理。对渔业资源进行科学的评估是制定渔业管理计划的基础,渔业资源评估模型则是进行渔业资源评估的重要工具,对短生命周期种类资源进行科学评估和管理是一个极为重要的课题。但是短生命周期种类具有生命周期短、生长快、资源丰富以及产卵种群多的特点,资源量极易受海洋环境影响的独特的生活史特征,使得世界各国对短生命周期种类资源评估和管理的研究处在发展初期。本文首先介绍了短生命周期种类的生物学特点,接着简要介绍了传统资源评估模型的分类,最后详细阐述了目前应用于短生命周期种类的资源评估模型与方法,同时,本文对渔业资源评估模型中存在的问题进行了探讨,并对其未来的发展进行了展望。     

对黄、东海水母暴发机理的新认知

基于大量实验结果和大规模海上考察和综合分析,从基础生物学和生态学的角度,对中国近海水母暴发的机理提出一种新的理论模式:水母生活史中的大部分时间以水螅体的形式生活在海底;水母种群的暴发是水螅体对环境变异的一种应激反应,是为了逃避动荡环境、扩大分布范围、寻求新的生存空间,为种群繁衍需求更多的机会的一种生存策略。导致水母种群暴发的关键过程是海洋底层温度的变动和饵料数量的变化,全球气候变化和富营养化是中国近海水母暴发的最重要诱发因素。水母暴发是全球变化下海洋生态系统演变的一种综合体现。     

甲藻孢囊研究进展

孢囊的形成是某些海洋甲藻生活史中的重要阶段,尤其是甲藻在不良环境条件下使个体度过逆境的阶段,它对种群的保存和延续有重要的意义.孢囊被普遍认为是赤潮发生的"种源"以及外来种类的主要来源之一,它对赤潮的发生、延续和消亡过程有着重要的作用.大多数的甲藻孢囊具有含孢粉类似物的抗性细胞壁,可以长期保存在底部的沉积物中,所以被广泛地应用于中世纪以来的沉积物生物地层学和古生态学的考察中.对甲藻孢囊的研究,目前是海洋生态学、海洋地质学、海洋环境学的研究热点.本文阐述了国内外近些年来对甲藻孢囊研究的主要进展,内容主要集中在甲藻孢囊的研究方法、形态分类、空间分布、原位动力学以及孢囊与海洋环境关系方面的研究.     

中国近海带鱼肌浆蛋白电泳图谱的初步分析

带鱼是我国海洋渔业近二十年来首要的捕捞对象,产量约占世界带鱼总产量的3/4。种群是鱼类数量变动的基本单元。以往从形态和生态学等方面,对带鱼种群进行过一些研究,结果不甚一致,特别是近几年来,出现了中国近海带鱼存在不同的种或亚种的报道。因而,进一步探讨带鱼的种群和分种的问题,仍然是渔业生产和鱼类分类上     

中国近海渔业资源结构特点及演替的研究

渔业资源是一种不断变化和更新的生物资源,如能合理地开发和利用可望取得良好的经济、社会和生态效益及永续利用的目的。然而由于人类的过度的开发和利用,加之生态环境的日趋恶化,使得许多渔业资源遭到破坏而严重衰退。近十多年来我国渔业与世界渔业发展的总趋势相似,随着捕捞强度的盲目增加,使得许多传统渔业资源遭到不同程度的破坏,主要捕捞对象替代频繁,其结构发生了显著的变化,总趋势是:经济价值高的、个体大的、年龄结构复杂的和在生态系统中营养层次高的类群逐渐被经济价值低的、个体小的、年龄结构简单的和营养层次低的类群所替代;底层鱼类所占比例日益减少,中、上层鱼类及虾、蟹类比例逐年增加。 对渔业资源结构特点和演替规律的研究一直受到国内外学者的重视,许多国家为了保护其近海渔业资源和本国的渔业权益,纷纷宣布建立渔业保护区和专属经济区,并采取了一系列的保护措施,因此近年特别着重研究建立保护区后的渔业资源结构的变化( Gunnar,1989; Megrey and Wespestaa,1990; Pinhorn and Halliday,1990)。我国学者也有许多渔业资源方面的研究报告(中国海洋渔业资源编写组,1990;邓景耀等,1991；孙宗烨等,1987;宋海棠等,1990;罗秉征等,1992;1993)。本文探讨了近40年来我国近海渔业资源结构的特点及其演变规律及趋势,并对我国不同海区渔业资源的演变进行了比较,进而分析了我国海洋渔业资源变化的原因,旨在为更加合理地利用我国的海洋渔业资源,并为其持续发展提供科学依据。     

中国沿海小黄鱼种群动力学及其空间异质性研究

小黄鱼是我国近海四种最重要的经济鱼类之一，在过去的几十年中小黄鱼种群及其两个地理亚种群经历了巨大的变化。小黄鱼的种群动力学研究，对于维持这一重要渔业的可持续管理是至关重要的。目前仅有的两个小黄鱼种群动力学模型只涵盖了较短的时间，且没有关注其空间差异。本文研究了1968年至2015年间黄渤海和东海小黄鱼的种群动力学模型，包含和不包含空间分层结构的两种贝叶斯模型被用于分析其种群动力学的大尺度空间异质性。本文分析了不同的假设，来研究小黄鱼种群动力学潜在的变化趋势。研究结果表明小黄鱼种群动力学特征具有明显的时间和空间变化。种群的增长速度从20世纪八十年代开始增加，而可捕系数从1981年到2015年增加了两倍多。与黄渤海亚种群相比，东海的小黄鱼亚种群生长速度更快，遭受的捕捞压力也更大。基于最大可持续产量MSY的参考点表明，无论是整个小黄鱼种群还是两个亚种群，近年来都有非常高的过度捕捞风险。因此我国小黄鱼的渔业管理急需更加保守的管理策略，同时考虑其地域差异。本文所用的方法可以应用于其他种类的资源评估和渔业管理，尤其是具有空间异质性和数据有限的种类。     

An Application of the Bayesian Hierarchical Approach to Refining the Information on Main Life History Parameters for Small Yellow Croaker,Larimichthys polyactis,off the Coast of China

Small yellow croaker, Larimichthys polyactis, is a commercially important species in China. The uncertainty in its main life history parameters has not bee     

The year-class phenomenon and the storage effect in marine fishes

Factors contributing to population growth through strong year-class formation have driven a century of directed research in fisheries science. A central discovery of Hjort's paradigm was that multiple generations overlap and longevity is matched with frequency of strong recruitments. Here, I elaborate on this tenet by examining how intra-population modalities in spawning and early habitat use favour population resiliency. A modern theory that has application is the storage effect [Warner, R.R., Chesson, P.L., 1985. Coexistence mediated by recruitment fluctuations – a field guide to the storage effect. Am. Nat. 125, 769–787], whereby spawning stock biomass accumulates each year so that when early survival conditions are favourable, stored egg production can result in explosive population growth. I review two early life history behaviours that contribute to the storage effect: split cohorts (i.e., seasonal pulses of eggs and larvae) and contingent behaviour (i.e., dispersive and retentive patterns in early dispersal). Episodic and pulsed production of larvae is a common feature for marine fishes, well documented through otolith microstructure and hatch-date analyses. In temperate and boreal fishes, early and late spawned cohorts of larvae and juveniles may have differing fates dependent upon seasonal and inter-annual fluctuations in weather and climate. Often, a coastal fish may spawn for a protracted period, yet only a few days' egg production will result in successful recruitment. In these and other instances, it is clear that diversity in spawning behaviour can confer resilience against temporal variations in early survival conditions. Although many factors contribute to intra-population spawning modalities, size and age structure of adults play an important role. Contingent structure, an idea dating to Hjort (herring contingents) and Gilbert (salmon contingents), has been resurrected to describe the diversity of intra-population modalities observed through otolith microchemical and electronic tagging approaches. Retentive and dispersive behaviours confer resiliency against early survival conditions that vary spatially. Examples of contingent structure are increasingly numerous for diadromous fishes. Here, a nursery habitat associated with a contingent behaviour may make a small contribution in a given year, but over a decade contribute significantly to spawning stock biomass. For flatfish and other marine fishes, contingent structure is probable but not well documented. Proximate factors leading to contingent structure are poorly known, but for diadromous fishes, time of spawning and early life history energetic thresholds is hypothesized to lead to alternative life cycles. Here again time of spawning may lead to the storage effect by hedging against spatial variance in early vital rates. Managing for the storage effect will be promoted by conservation of adult age structure and early habitats upon which both strong and weak year-classes rely.     

Variable spatial structure of schooling pelagic fish off Namibia: implications for acoustic surveys

Schools of horse mackerel Trachurus trachurus capensis, sardine Sardinops sagax and round herring Etrumeus whiteheadi were surveyed by conventional echo-integration along systematic transects. The transects were surveyed twice, in opposite directions. Clupeoid biomass was concentrated in a few dense aggregations, whereas horse mackerel were less dense and distributed over larger areas. The influence of aggregation patterns of the different species on the precision of the acoustic estimates was analysed with respect to spatial variability and diurnal effects. Isotropic variograms computed from values of acoustic back-scattering strength showed little or no structure for all three species. Indicator variograms showed relatively large structures (>15 miles) for all three species at the lowest cut-off level, confirming the influence of high values on the variograms. The autocorrelation range decreased with an increase in cut-off value for horse mackerel, whereas variograms of sardine and round herring showed no structure at larger cut-off values. There were large variances in estimated biomass for sardine (77%) and round herring (90%) between surveys, whereas biomass estimates of horse mackerel were relatively similar between surveys.     

桁拖网渔具刚性栅栏对鱼类的分隔效率研究

东海捕虾桁拖网选择性能不佳,对渔业资源的保护和渔业的合理管理带来了负面的影响.刚性栅栏是实现拖网渔具种类选择性捕捞的主要装置,本文根据在吕四渔场开展刚性栅栏海上生产试验,结合SELECT模型分析不同栅条间距(15、20和25mm)的刚性栅栏对短吻舌鳎、小黄鱼和棘头梅童鱼的分隔效率.结果表明,随着栅条间距的增大,栅栏对鱼类的重量分隔率逐渐减小,分隔栅栏对鱼类的50%选择体长(L50S))逐渐增大;对于短吻舌鳎,个体接触分隔栅栏的概率可使用常数来表示,即接触概率与个体尺寸无关,接触概率在0.2-0.4之间,并随着栅条间距的增大而增大(不显著,P>0.05):对于小黄鱼和棘头梅童鱼,所有进入网囊的个体都将接触刚性栅栏;不同鱼类接触栅栏概率的显著差异说明不同鱼类在网囊中的不同行为习性.     

Comparative studies on some genetic characteristics among four large yellow croaker (Pseudosciaena crocea) populations

The genetic structure was compared among four large yellow croaker (Pseudosciaena crocea) populations, an important aquaculture species in China. RAPD and ISSR results show that the genetic distances between domestic stocks and their wild counterparts are significantly larger than those between the three wild stocks. The sequence of mtDNA cyt b shows that the three wild populations share the same sequence, with differences in the four bases from the cultured stock: two transitions [57(C-T), 291(G-A)] and two transversions [66(C-G),223(A-C)]. Cluster analysis reveals that the domestic stock has diverged from its parental wild stock [Min—Yuedong (Fujian Province—eastern Guangdong Province, China) stock]. Results demonstrate that 20 a of domestication of the Pseudosciaena crocea stock has resulted in significant genetic changes.     

我国大黄鱼的出口贸易结构和国际竞争力

我国是全球最大的大黄鱼养殖国和出口国。为提升我国大黄鱼的产业发展和国际贸易水平,文章分析我国大黄鱼的出口贸易结构,分别采用显性比较优势指数、出口产品质量升级指数和贸易竞争力指数分析我国大黄鱼的国际竞争力,并在分析影响因素的基础上提出建议。研究结果表明:2008—2017年我国大黄鱼的出口规模总体稳定,出口额增长,出口量下降;我国大黄鱼的出口市场集中在亚洲国家和地区;我国大黄鱼的比较优势极强但正在减弱,以出口价格反映的产品质量偶有下降但总体提升,相对于国际市场同种产品的竞争优势较强,总体来看国际竞争力较高,但仍有提升的空间;影响我国大黄鱼出口贸易结构和国际竞争力的因素主要包括地区饮食习惯、相关行业发展、国际贸易壁垒和产业发展空间,未来我国大黄鱼的生产和贸易应充分发挥产业比较优势、合理规划产业发展空间、积极开拓新兴出口市场和有效应对国际贸易壁垒。     

我国大黄鱼产业的集聚水平研究

大黄鱼是我国近海主要的经济鱼类之一。为促进我国大黄鱼产业的可持续发展,文章从产业集聚的角度研究大黄鱼产业的发展规律,采用区位熵和空间基尼系数方法测度2011—2020年大黄鱼养殖产业和捕捞产业的集聚水平。研究结果表明：根据空间基尼系数的测算结果,大黄鱼养殖产业的集聚水平高于其捕捞产业;福建大黄鱼养殖产业的集聚水平相对于...     

黄海南部小黄鱼洄游分布及种群结构特征

Monthly fishery survey data of the small yellow croaker Larimichthys polyactis in the southern Yellow Sea from2003 and 2013 were employed to evaluate the variation in the resource distribution and biological characteristics(especially body length and sex ratio) in the population on a decadal scale.The results indicated that the small yellow croaker migrated from the Shawai fishing ground to the Dasha fishing ground in spring and was mainly distributed in the central and western parts of the Dasha fishing ground in April and May.Larimichthys polyactis in the Dasha fishing ground migrated eastward to offshore wintering grounds in autumn and reached the central Dasha fishing ground in October and November.The small yellow croaker entered the western waters of the Shawai fishing ground in winter.A large number of age 0+ fish occurred in the Shawai and Jiangwai fishing grounds in October of 2003 and 2013.The body lengths of the spawning stock and wintering stock in 2013 were larger than those in 2003,and the monthly sex ratios(female to male) were significantly less than 1 in both years.The monthly distribution of this fish in the southern Yellow Sea was consistent with a previous finding that "the stock migrated between the wintering grounds in the west of Jeju Island and the Lüsi spawning grounds" but tended to move more northward,with the spawning grounds extending outward.In the past decade,body length variation experienced a decline after an increase,rather than a steady decrease.The sex ratio in the single-stick stow net showed a tendency to increase over the decade,but was either less than or more than 1 depending on the fishing gear;therefore,further studies should be conducted to determine the sex structure.     

鱼类游泳运动的研究——Ⅰ、三种海洋鱼类游泳的运动学特性

作者提出鲭鱼(Scomber scombrus L.)、绿青鳕(Pollachius virens(L))和鲱鱼(Clupea harengus L.)的游泳运动学特性。实验表明,这三种鱼类的游泳速度与摆尾频率成线性关系。当泳速大于三倍体长/秒(BL/S)时,单位游距几乎不随游速变化,其平均值分别为:鲭鱼0.90体长(BL)、绿青鳕0.88BL、鲱鱼0.70BL。其摆尾幅度都不随游速变化,平均值在0.21～0.23BL之间,各种鱼之间无显著差别。作者认为,鱼类游泳的单位游距与鱼类的体型、肌肉及游泳推进性能有关,而单位游距的差异是身体—尾鳍式游泳的鱼类之间最大游速差异的主要原因。