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1.
长江河口生态系统鱼类浮游生物生态学研究进展   总被引:12,自引:0,他引:12  
鱼类浮游生物群落结构的时空分布和动态变化与其所处水域的环境因子有密切的关系,它的变动受环境因子的变化和时空异质性的制约,而其鱼类浮游生物群落结构的变动最具代表性。研究证明,鱼类浮游生物群落结构对鱼类资源的补充,延续和维持生态平衡具有重要的意义,但尚无系统报道。本文就长江口鱼类浮游生物群落的研究做了阐述。三峡工程建设之后,通过改变长江径流来改变长江口水域的温度、盐度及其他非生物因子,同时由于非生物因子的变化,也引起生物因子的改变,从而使鱼类浮游生物优势种的组成和群落结构的生态性质发生了一定的变化,可以影响到长江口鱼类资源的补充,进一步改变长江口水域生态系统的平衡。  相似文献   

2.
海洋鱼类早期摄食行为生态学研究进展   总被引:3,自引:0,他引:3  
鱼类的早期阶段是指仔、稚、幼鱼期。鱼类早期生长的细微差别对其存活以及整个生活史阶段的生长,有着不可估量的影响。20世纪60年代以来,围绕着决定鱼类早期存活的生态学因子所展开的鱼类早期生活史研究,在国际上受到了普遍重视[1];近二三十年以来,随着鱼类人工繁育技术的进展,  相似文献   

3.
河口浮游动物生态学研究进展   总被引:7,自引:0,他引:7       下载免费PDF全文
河口位于河流与海洋的交汇处,是二者相互作用的复杂区域,其营养物质丰富,生物生产力大,生态环境多变。河口范围通常划分为三段:河口上游段,主要为淡水控制,每天经受潮汐的影响;河口中游段,发生咸淡水混合;河口下游段,与开阔的海洋自由相通。河口是一种独特的生态系统,理化环境与河流和海洋均有差异[1~4]。河口是水产资源的宝库,是渔业的重要基地。  相似文献   

4.
大洋性柔鱼类资源中长期预报研究进展   总被引:2,自引:0,他引:2  
柔鱼类分布广泛,资源丰富,已成为人们重要的开发和利用对象,如何持续和合理开发该资源已成为大家关注的重要话题。柔鱼类具有短生命周期、产完卵即死亡的特性,其特殊的生活史特性使得传统的资源评估方法无法很好的对其资源量进行准确评估和预测。因此,如何开展大洋性柔鱼类的资源中长期预报显得尤为重要。本文总结概括了大洋性柔鱼类中长期预报的基本概念、三种主要的大洋性柔鱼类生活史、影响大洋性柔鱼类资源(补充)量的主要环境因子,并介绍了目前使用的主要柔鱼类中长期预报模型,展示了大洋性柔鱼类中长期预报的发展历程及所取得的进展。同时,对柔鱼类中长期预报模型中存在的问题进行了探讨,并对其未来主要的研究方向进行了展望。  相似文献   

5.
根据收集到的有关钱塘江河口防洪、御潮、灌溉、航运、供水、旅游等方面的资料,分析、计算了该河口防洪御潮资源和水资源、滩涂、岸线及涌潮资源等的储存量。并提出了对这些资源开发和保护的初步设想,为促进钱塘江河口两岸经济可持续发展提供科学决策的依据。  相似文献   

6.
西沙群岛重要岛礁鱼类资源调查   总被引:10,自引:1,他引:10  
为摸清岛礁海域鱼类资源种类及分布 ,合理安排渔船生产 ,2 0 0 3年 5月采用延绳钓和底层刺网在西沙群岛的浪花礁、东岛、永兴岛、华光礁、金银岛、玉琢礁和北礁等 7座珊瑚礁水域进行了 1个航次的鱼类资源调查。 2种作业投入的捕捞努力量分别为延绳钓 3 740钓、底层刺网 14 480m ,单次作业努力量延绳钓 80~ 3 2 0钓、底层刺网 12 0~ 80 0m。捕获鱼类 177种 ,渔获量 3 70 0尾 2 767.0 0kg ,其中延绳钓 3 3种计 77尾 1711.5 5kg ,底层刺网共 15 3种计 3 62 3尾 10 5 5 .45kg。按岛礁平均 ,渔获率和单位捕捞努力量渔获量 (CPUE)延绳钓为 2 .0 6尾·(10 0钓 ) -1、45 .76kg·(10 0钓 ) -1,底层刺网为 2 5 0 .2 1尾·(1km) -1、72 .89kg·(1km ) -1。捕获的主要经济种类有鲨鱼、裸胸鳝、石斑鱼、笛鲷、裸颊鲷、鹦嘴鱼和绯鲤等。北礁、金银岛和玉琢礁的鱼类资源比较丰富 ,开发潜力较高 ;浪花礁、东岛、华光礁和永兴岛次之 ,也有一定的生产价值。  相似文献   

7.
海洋链霉菌由于其独特的生理和代谢功能,成为海洋微生物活性物质的主要来源。对2010-2013年初的海洋放线菌天然产物的统计表明,研究最多的是链霉菌放线菌,占海洋放线菌新天然产物的60%。本文综述了自1976年第一个海洋链霉菌天然产物到2016年6月的40年间报道的547个海洋链霉菌天然产物的结构、生物活性及其微生物来源。其结构包括含氮化合物(如生物碱)、聚酮、萜类、甾体等,其中含氮化合物是主要类型, 占海洋链霉菌天然产物总数的61%;而67%的海洋链霉菌天然产物表现出细胞毒、抑菌、抗疟和抗寄生虫等生物活性。  相似文献   

8.
船舶的微生物腐蚀与防护技术*   总被引:2,自引:0,他引:2  
王毅  张盾 《海洋科学集刊》2016,51(51):58-68
海洋环境中的微生物腐蚀已被公认为是海洋工程金属构筑物的腐蚀破坏的重要形式。航行在海洋中的船舶不仅受到海水腐蚀的影响,各个部件还会受到微生物腐蚀的影响。严重的微生物腐蚀会导致管路阻塞、部件失效和腐蚀穿孔,不仅影响船舶设备正常运行,也严重威胁船舶安全。本文系统分析了船舶微生物腐蚀发生的位点和危害、不同位点的腐蚀微生物群落结构特征、船舶材料的微生物腐蚀以及不同防护技术的适用范围,并在此基础上提出对船舶微生物腐蚀研究工作的建议。  相似文献   

9.
河口水流是河口生态环境、河道演变、物质输运等物理过程的根本动力。由于径流、潮波、地形以及气象等因素的影响,河口水流呈现复杂的三维结构。其中既包括淡水注入形成的余流,也包括周期性的潮流、风生流、斜压流及河口非线性作用导致的流动等。为探究河口水流的组成及其潮内变化,基于瓯江口实测资料,利用主成分分析(Principal Component Analysis, PCA)法对河口水流进行分解,探讨了PCA法对河口水流的分解性能及斜压分潮流的高频特征。研究认为,PCA法在河口水流结构研究中既可采用原始数据操作亦可用标准化的数据进行计算。PCA法可分解出斜压成分(河口重力环流型结构),但不能将正压成分(径流和潮流)分开,径流和潮流二者综合作用的结果体现在主成分的得分之中。主成分的取舍应根据水流结构和累计解释方差综合判断,不宜仅依据累计解释方差。河口斜压流动具有明显的高频特征,近似呈1/4日分潮的周期。  相似文献   

10.
研究了2010年冬季胶州湾23个大面站浮游植物的群落结构特征。共检出浮游植物5门44属69种,平均细胞丰度为222.8 cells/mL,其中硅藻在物种数量和细胞丰度上占绝对优势。主要优势种为柔弱几内亚藻Guinardia delicatula、扭链角毛藻Chaetoceros tortissimus、诺氏海链藻Thalassiosira nordenski?ldii和尖刺伪菱形藻Pseudo-nitzschia pungens。调查期内浮游植物表层细胞丰度的平面分布趋势为北部高于南部,垂直分布则为各水层之间细胞丰度相差不大。表层浮游植物的Shannon-Wiener指数和均匀度指数的分布显示胶州湾东南至湾口海域浮游植物群落更加均匀稳定。与环境因子的相关分析表明浮游植物细胞丰度与铵盐、硝酸盐、亚硝酸盐、硅酸盐呈显著的正相关。  相似文献   

11.
九龙江口鱼类浮游生物的生态   总被引:3,自引:3,他引:3  
江素菲  陈枫 《台湾海峡》1993,12(4):351-358
1987年3月到1988年2月在九龙江口的5个固定站位上,逐月进行鱼卵和仔,稚鱼调查的资料。结合1983年至1984年的鉴定资料进行分析,结果表明,该海区的鱼类生态结构系由淡水,半咸水,沿岸和海水鱼类等4种生态类型组成。鱼类主要产卵期为3-9月,盛期为5-8月。鱼卵数量以河口上游最多。种数则以河口下游较多。仔,稚鱼相对集中于河口中游,其数量和种数均为最多。在九龙江口放流,增殖或引进鱼类新种成功的机  相似文献   

12.
长江口鱼卵仔鱼资源现状的调查与分析   总被引:4,自引:0,他引:4  
根据2003年5月至2004年11月长江口海域7个航次、115个站次的鱼卵仔鱼调查采样资料分析,共鉴定出该海域的鱼卵仔鱼51种,隶属10目27科45属;其中,5种仅鉴定到科,4种仅鉴定到属,还有两种未能鉴定。在长江口门附近鱼卵较为集中,绝大部分为凤鲚鱼卵,占鱼卵总数的95.7%,其它小部分分别为鮻、斑点马鲛、长蛇鲻、中华小公鱼、小带鱼以及鲆科的鱼卵。中华小公鱼的仔鱼出现次数最多,占仔鱼总次数的38.4%;凤鲚、虎鱼科、棘头梅童鱼、鮻和斑鱼祭的仔鱼分别占仔鱼总次数的19.7%、14.4%、6.6%、6.2%和3.5%。长江口门内分布的主要仔鱼种类为凤鲚、赤鼻棱鱼是、中华小公鱼等;长江口门以外分布的主要仔鱼种类为凤鲚、鮻、鲆科、小黄鱼和长蛇鲻等;其中凤鲚、中华小公鱼等的仔鱼和鱼卵较多。5月鱼卵仔鱼的种类和数量较多,2月和11月的较少。与历史同期相比,该海域部分种仔鱼类已经消失,棘头梅童鱼等经济种类的鱼卵仔鱼资源补充量急剧下降,表明长江口海域经济种类仔鱼资源已受到衰竭的威胁。  相似文献   

13.
For many years, estuarine science has been the ‘poor relation’ in aquatic research - freshwater scientists ignored estuaries as they tended to get confused by salt and tides, and marine scientists were more preoccupied by large open systems. Estuaries were merely regarded by each group as either river mouths or sea inlets respectively. For the past four decades, however, estuaries (and other transitional waters) have been regarded as being ecosystems in their own right. Although often not termed as such, this has led to paradigms being generated to summarise estuarine structure and functioning and which relate to both the natural science and management of these systems. This paper defines, details and affirms these paradigms that can be grouped into those covering firstly the science (definitions, scales, linkages, productivity, tolerances and variability) and secondly the management (pressures, valuation, health and services) of estuaries. The more ‘science’ orientated paradigms incorporate the development and types of ecotones, the nature of stressed and variable systems (with specific reference to resilience and redundancy), the relationship between generalists and specialists produced by environmental tolerance, the relevance of scale in relation to functioning and connectivity, the sources of production and degree of productivity, the biodiversity-ecosystem functioning and the stress-subsidy debates. The more ‘management’ targeted paradigms include the development and effects of exogenic unmanaged pressures and endogenic managed pressures, the perception of health and the ability to manage estuaries (related to internal and external influences), and the influence of all of these on the production of ecosystem services and societal benefits.  相似文献   

14.
DNA条形码技术是利用一段较短的DNA序列实现快速准确物种鉴定的工具。本研究采用传统形态学和DNA条形码技术相结合,对长江口及其邻近水域的鱼类浮游生物种类进行准确鉴定,并对部分种类仔稚鱼进行了形态学描述。结果表明:2016年春、夏季和2017年夏季共获得鱼类浮游生物55种,隶属9目19科。其中鲈形目种类数最多,为35种。鱼类浮游生物在类群上季节变化不明显,但在种类上有明显的季节变化。仅有凤鲚(Coilia mystus)、日本鳀(Engraulis japonius)和小黄鱼(Larimichthys polyactis)在春、夏季同时出现。首次描述了龙头鱼(Harpadon nehereus)仔、稚鱼阶段的形态特征;对龙头鱼、前鳞龟鰉(Chelon affinis)、四指马鲅(Eleutheronema tetradactylum)、少鳞鱚(Sillago japonica)和日本须鳎(Paraplagusia japonica)这5种仔、稚鱼的可量性状、鳍的发育、黑色素的分布等情况进行了描述,绘制了仔、稚鱼形态图。以上研究可为河口鱼类育幼场的研究提供科学依据,也为鱼类早期发育阶段分类资料的积累探索新途径。  相似文献   

15.
九龙江口水体中各形态磷的行为   总被引:12,自引:1,他引:12  
陈淑美  卢美鸾 《台湾海峡》1997,16(3):299-305
199御3月至1996年2月,逐月从九龙江口的淡水端到入海端的全段河口区采取表层水样。测定并计算水体溶解态和颗粒态的磷:DIP,DOP,DTP,PIP,POP,PTP和TP。结果表明,河流为九龙江口带来大量的磷。其主要以无机态的PIP,DIP形式存在。  相似文献   

16.
The spectral absorption properties of chromophoric dissolved organic matter (CDOM) and their distributions in two Chinese estuaries, the Yangtze River Estuary and the Jiulong River Estuary, were studied during August 2003 (wet season) and during different seasons between 2003−2005, respectively. The CDOM concentrations (a355) of fresh end members in the Jiulong River Estuary varied seasonally, while its quality remained relatively stable. However, the a355 of the marine end members exhibited less variability. Application of a conservative mixing model indicated that CDOM behaved conservatively in the Yangtze River Estuary. No photobleaching removal was observed at high salinity region of this estuary. Although CDOM showed conservative behavior for many cruises in the Jiulong River Estuary, there was evidence for removal in the low salinity regions during some cruises. Laboratory mixing experiments and a salt addition experiment suggested that particle sorption of CDOM maybe the possible reason for the removal. These results showed that absorption properties of CDOM can be used as a tool to observe the quantitative and qualitative dynamics of DOM during estuarine mixing.  相似文献   

17.
An experimental approach was used in determining which factors, natural or man made, had the greatest impact on estuarine microplankton ecology. In microcosms, filled with natural water of <5‰, 10‰, 18‰ and > 26‰ salinity, the impact of high organic load (glucose), shading, Cu and a heavy metal mixture on the microplankton populations was monitored. Naturally occurring perturbations were of much greater impact to estuarine ecology than the addition of heavy metals in concentrations five to ten times that which are known to occur in moderately polluted estuaries.  相似文献   

18.
On the ecology of meiofauna in an organically polluted estuarine mudflat   总被引:1,自引:0,他引:1  
The structure, distribution and seasonal changes of the benthic meiofauna in an organically polluted, tidal, brackish-water mudflat in the Ems-Dollart estuary were analysed. Towards the outfall of polluted fresh water, macrofauna disappeared, numbers of meiofauna increased but the diversity of the meiofauna decreased. In the area surrounding the outfall the numbers and biomass of nematodes and oligochaetes increased rapidly in spring and remained high until autumn (c. 13 × 106 individuals m−2; c. 2gCm−2). The benthic fauna comprised small numbers of species, dominated by a few fast-growing diatom-feeding nematodes (Eudiplogaster pararmatus and Dichromadora geophila) and oligochaetes (Amphichaeta sannio and Paranais litoralis). Eudiplogaster pararmatus exhibits brood care and it tolerates low salinities. Dichromadora geophila which is oviparous, behaved similarly regarding tolerances, life cycle and feeding but this species was less successful than Eudiplogaster in colonizing the mudflats near the outfall. The success of the two naidid oligochaete species results from their method of reproduction by means of binary fission.Most organisms fed on benthic diatoms. In spite of intensive mineralization in the mudflat, only one bacteria-feeding organism was found in abundance (the nematode Leptolaimus papilliger). The absence of macrofaunal organisms, e.g. Nereis diversicolor, is probably also responsible for the development of high densities of meiofauna in the upper sediment layers of the mudflats in the vicinity of the outfall.The heavy load of organic waste entering the Dollart reduced the diversity within the benthic ecosystem, but nevertheless a simple system remained, based on the recurrent reoxidation of the sediment surface.  相似文献   

19.
A laboratory system was used to test the effect of water flow on the resuspension of mud and sand sediments and, specifically, benthic diatoms from the Ems estuary, The Netherlands. Current velocities generated by two rotating cylinders in a cylindrical tank were determined by a small float and a laser Doppler velocimeter. At low angular velocities, the amount of suspended matter increased linearly with angular velocity and the float current velocity. However, at higher angular velocities, the increase in current velocity was less because of the strong turbulence: concomitantly, the current velocity boundary layer (δ) became thinner and the suspended matter concentration increased rapidly. The dominant diatom species from the sandy sediment were suspended in two distinct groups, one of which consisted of the species Navicula aequorea, Navicula salinicola, Ophephora martyi and Opephora pacifica, and was more exclusively bound to sand grains than the other. The benthic diatom species inhabiting the silty sediment did not show this difference. The most important shortcoming in the experiments was the inability to determine the radial and vertical velocity components. This precluded reliable calculations of the shear stress. The data presented emphasize the importance of finding a method to determine the shear stress under experiments and field conditions so that direct comparisons can be made. Despite this it is assumed that, just as under the experimental conditions discussed, under natural conditions in shallow waters resuspension starts at current velocities as low as ca. 10 cm s−1.  相似文献   

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