胶州湾不同季节浮游动物昼夜垂直移动规律初步研究

在胶州湾内设置连续站(36°5'54″N,120°15'20″E),分别于2006-2007年分春季、夏季、秋季、冬季四季进行垂直分段拖网,研究了胶州湾浮游动物垂直移动的规律。结果显示,浮游动物在不同季节显示不同的垂直迁移行为。同时,对该海域出现的优势种类的垂直移动规律进行了研究并分类,发现不同物种同一季节迁移方式不同,对于同一种类,在不同季节也表现出不同的迁移规律。因此,浮游动物垂直迁移规律不是一成不变的,由外界环境因子和内在因素共同作用决定。不同季节影响浮游动物垂直迁移的关键因子不同,其中春季、夏季、秋季三季主要影响因子是光照,冬季除了光照,还有温度、盐度和浮游植物密度。总体与温度和浮游植物密度正相关,与盐度负相关。对于不同种类,影响其垂直迁移的主要因子也不尽相同。     

基于声学仪器与粒径分析仪研究东海浮游动物昼夜垂直迁移过程

浮游动物的昼夜迁移活动与其种群变动和摄食节律紧密联系,浮游动物昼夜移动的研究已经成为种群动力学研究的一个重要组成部分。2013年夏季在浙江东部近海,结合声学多普勒流速剖面仪(ADCP)和激光粒径分析仪(LISST-100)等仪器进行了一次定点周日连续观测。通过声学反演方法,得到后向散射强度剖面的时间变化,结合LISST-100得到的水体悬浮物粒径谱,研究了浮游动物垂直迁移及其习性。分析发现了可能是精致真刺水蚤的一次昼夜垂直迁移过程,其在夜间进入跃层附近进食,白天蛰伏于底层低温高盐的台湾暖流水中,垂向迁移速度达到了0.05 m/s。LISST-100观测还发现在夜间跃层边界处大粒径颗粒聚集和100～150 μm大小的颗粒物的减少,水体中不同粒径的悬浮颗粒物有明显的昼夜变化节律,推测水体中不同层次生物群落结构存在昼夜差异。     

不同环境因子对毛颚动物的影响和毛颚动物生态研究综述

毛颚动物又称箭虫,是海洋中的次级生产力代表之一。毛颚动物的呼吸受温度影响较大,因此其丰度会受到水温的调节作用。盐度>25时,毛颚动物种类多丰度低,但也有一些耐高盐的种类可在高盐环境中有高丰度。许多研究表明,海流和海洋锋对毛颚动物分布产生显著影响,海流可将毛颚动物携至不同水层甚至不同气候带。毛颚动物有迁移现象并呈垂直分布,这与捕食相联系,不同毛颚动物之间遵循空间、时间、食物型分离的生态规则,以减少种间竞争。毛颚动物对其捕食对象的摄食压力较大,此外,还产生可快速下沉的粪粒,在有机物向下输送过程有一定作用。     

南沙群岛渚碧礁春季浮游动物群落特征

根据2002年5月的调查资料,对南沙群岛渚碧礁浮游动物的群落结构、平面分布、垂直分布和昼夜变化等进行了研究分析。浮游动物鉴定有72种,其中挠足类种数最多,其次是浮游幼虫、毛颚类。浮游动物种类中多数是终生浮游生物,少数是阶段性浮游生物,个别是暂时性浮游生物。渚碧礁浮游动物群落的热带特征非常显著,多数种类属于热带外海生态类群,少数属于暖水沿岸生态类群。优势种相当突出,其中奥氏胸刺水蚤Centropagesorsinii占主导地位。渚碧礁浮游动物平均密度达840个·m-3,礁坪区与湖内的浮游动物数量分布差异很大,湖为礁坪的7倍多,两者的优势种也有明显差异。浮游动物垂直分布不均匀,主要密集于5—10m水层,因种类不同其垂直分布也有差异。礁坪的浮游动物种类和数量昼夜变化显著,均呈白天减少、夜晚增加。浮游动物的数量分布与环境因子和浮游动物生态习性有关。     

浮游动物的昼夜垂直迁移

浮游动物的昼夜垂直迁移（ＤＶＭ———ＤｉｅｌＶｅｒｔｉｃａｌＭｉｇｒａｔｉｏｎ）是指浮游动物以２４ｈ为周期有规律地分布在不同水深的现象。它表现为不同的形式 :（１）大多数种类白天在水体深层 ,晚上上升到表层（Ｎｏｃｔｕｒｎａｌｍｉｇｒａｔｉｏｎ） ;（２）有的种类傍晚和拂晓在表层 ,其他时间在深水 ,叫做“晨昏迁移（Ｔｗｉｌｉｇｈｔｍｉｇｒａ ｔｉｏｎ）” ;（３）少数种类白天在表层 ,晚上在深水 ,叫做“反向迁移（Ｒｅｖｅｒｓｅｍｉｇｒａｔｉｏｎ）”。这些表现形式不是绝对的 ,而是一个连续分布的谱。浮游动物垂直…     

水母伞径和饵料密度对海月水母(Aurelia sp.1)捕食率的影响

海月水母在全球范围内大量暴发,严重危害海洋生态系统的健康以及鱼类资源的可持续利用。本文以卤虫无节幼体为饵料,初步研究了水母伞径和饵料密度对海月水母个体捕食率的影响以及海月水母的昼夜捕食节律。研究结果表明,海月水母的伞径对其捕食率的影响极显著(P<0.01),在1—8cm范围内,随着伞径的增加个体捕食率线性增加,两者之间的关系式为y=0.044x+0.125(R2=0.9036)。饵料密度对海月水母捕食率的影响显著(P<0.05),在0.25—26.11mgC/L范围内,随饵料密度的增加个体捕食率呈线性增加趋势,关系式为y=0.508x(R2=0.958)。在饵料充足时,海月水母没有昼夜捕食节律。在高饵料密度下海月水母出现过剩捕食,但是捕食行为依然活跃。上述结果既为量化评估海月水母对浮游动物群体的捕食压力提供了基础参数,同时水母过剩捕食行为说明依据生物量和代谢率的推算结果可能低估自然海域水母队浮游动物的捕食压力。     

真刺唇角水蚤对鱼卵和仔鱼的捕食

鱼类幼体的死亡常常被归因于食物的缺乏,实际上,以桡足类为主的浮游动物对鱼卵和仔鱼的捕食是其死亡的最主要原因之一,也是影响鱼类资源补充的主要因素;所以,研究桡足类对鱼卵和仔鱼的捕食不仅对海洋食物链研究而且对研究鱼类资源补充和产量的估算,也具有重要的意义。有关这方面的实验国内尚未见专门报道,本文为厦门港     

甲藻塔玛亚历山大藻昼夜垂直迁移特性的研究

分离于香港海域的塔玛亚历山大藻单克隆藻株的昼夜垂直迁移特性的实验研究于１９９４年９月－１９９５年４月在暨南大学水生生物研究所的人工培养柱里进行。结果表明，该藻具有显著的趋光生和节律性昼夜垂直迁移行为。其昼夜垂直迁移的一般规律为光开始后立即向上迁移，向下迁移则从光照结束前２ｈ左右开始，直至光结束后１ｈ左右才在底部形成细胞的最大分布，但在连续光照或无光照的第２或第３天以后，这种规律性的昼夜垂直迁移即完     

烟、威海区鲐鱼渔场中浮游动物的昼夜垂直分布

本文所报告的是在烟、威海区鮐魚漁汛期所进行的两次定点周日调查的结果。分析的种类主要的是鮐魚的食物,包括细长脚(虫戍)(Themisto gracilipes Norman)强壮箭虫(Sagitta crassa Tokioka)太平洋哲镖溞(Calanus pacificas Brodsky)和十足目幼虫(Decopod larva)等。 从分析得到以下初步结果: 一、所调查的浮游动物的垂直分布表现有明显的周日变化,说明它们都有周日垂直移动。 二、上述浮游动物表现有午夜下沉和黎明上升现象,其中以太平洋哲镖水蚤和强壮箭虫表现得较明显。 三、参攷着本海区在调查期间的温度垂直分布情况来看,这些动物的垂直移动在温跃层处受到水文情况变化的影响。 四、在分析的资料中还发现一些其他浮游动物如腹针剌镖水蚤有周日垂直移动现象,一些底部生活的动物如钩虾亚目端足类,细螯虾(Leptochela gracilis Stimpson)和多毛类环节动物等在夜间进入水层中,最高分布到5M(钩虾亚目和多毛类)或OM水层(细螯虾)。这些动物在鮐魚胃含物中也有出现。 本文讨论了所调查的动物的昼夜垂直分布和鮐魚摄食情况的关系。 本文还计算了各类浮游动物的垂直移动幅度D(分布中心的移动)和垂直移动中的活动量A(D×生物量,本文所用为相对数值)。并用它们来比较各种动物的垂直移动强度,以及这些动物在全部浮     

浮游动物连续采集或计数工具的简介

到２０世纪７０年代 ,大尺度的生物地理分布已经比较清楚 ,浮游动物的生态学开始研究物理环境对浮游动物的影响。在较短时间内（１ａ以内） ,环境因子是在中、小尺度（分别为１００～１０００ｍ和１０～１００ｍ）对浮游动物种群（群落）产生影响的。因此研究浮游动物中、小尺度的分布 ,同时观测物理因子成为海洋调查的重要内容之一。国际上通用的浮游动物采集网具为Ｂａｎｇｏ网。在我国的海洋浮游动物调查中 ,使用浮游动物网（浮游动物大型网、中型网）采集浮游动物。用水平拖网和垂直拖网的方式研究浮游动物的生物量和丰度 ,垂直分层拖网…     

Diel Vertical Migration of the Marine Cladoceran Podon Leuckarti: Variations with Reproductive Stage

Diel vertical migration (DVM) of the marine cladoceran Podon leuckarti was investigated with reference to their reproductive stages and size. Males and females, except for gamogenic females with an advanced resting egg (GA), aggregated at the near-bottom layer or at the surface during the day and dispersed into the water column at night. Both the near-bottom aggregation and the surface aggregation during daytime are suggested to be behavior that reduces the predation risk from visual predators. However, GA aggregated in the near-bottom layer during daytime and avoided the surface layer. The near-bottom aggregation might be more effective behavior for GAs to reduce risk of visual predation than the surface aggregation because of the conspicuous resting egg they carried. These results show that carrying an advanced resting egg influenced the DVM of P. leuckarti.     

基于ADCP回声的黑潮-亲潮混合区浮游动物昼夜垂直迁移研究

利用深海潜标所搭载的声学多普勒流速剖面仪(acoustic doppler current profiler,ADCP)得到的后向散射强度Sv,研究了黑潮-亲潮混合区浮游动物的垂向分布、其昼夜垂直迁移(diel vertical migration;DVM)的基本特征、多时间尺度变化及对反气旋式中尺度暖涡的响应.结果表...     

河口鱼类早期资源生态学研究进展*

河口是咸淡水交汇的水域,有大量的营养物质,是初级生产力和浮游生物最丰富的水域,为鱼类及其幼鱼的生长提供了丰富的饵料基础。本文综述了国内外有关河口鱼类早期资源(鱼类浮游生物)生态学研究的若干最新研究进展,内容包括：河口鱼类浮游生物的生态类型、种类组成和时空分布,温度、盐度、混浊度、食物、其他动物捕食等环境要素,厄尔尼诺和拉妮娜现象等气候现象,和大型工程建设、过度捕捞和污染等人为因素对河口鱼类浮游生物群落结构影响的研究。     

Individual-based models of copepod populations in coastal upwelling regions: implications of physiologically and environmentally influenced diel vertical migration on demographic success and nearshore retention

We link a two-dimension coastal upwelling circulation hydrodynamic-ecosystem (NPZ) model with an individual-based model (IBM) for an intermediate sized (ca. 2.5 mm) copepod capable of diel vertical migration (DVM) at larger sizes. The NPZ model is that of Franks, Wroblewski and Flierl (1986), with the zooplankton state variable parameterized for macrozooplankton. IBM simulations are done with different scenarios for behavioral responses; the interaction of the organisms with the circulation is evaluated by examining growth/development, reproduction, survival and distribution. Since ocean productivity in coastal upwelling systems is greatest nearshore, zooplankton production is favored by nearshore retention. Model results, using an idealized, intermittently wind-forced, upwelling circulation, indicate that non-migrating copepods are flushed from the nearshore system in offshore zonal surface flow; highest population abundances occur offshore, in a region of relatively low food resources. Conversely, migrating copepods interact with the stratified zonal flow within the upwelling system and are retained nearshore when the amplitude of the DVM is sufficient to place the individuals in near-bottom onshore flow during the day. Environmental features, like deep-extending food resources, and physiological controls, like satiation or body size, that permit copepods to remain deeper, or spend more time away from the surface, favor nearshore retention. Diel vertical migration is one mechanism, which may permit animals to exploit favorable habitats located nearshore in upwelling systems.     

Food web and fish stock changes in central Chile: comparing the roles of jumbo squid (Dosidicus gigas) predation,the environment,and fisheries

We analyzed recent food web and fish stock changes in the central Chile marine ecosystem, comparing the roles of jumbo squid (Dosidicus gigas) as predator, the environment, and fishing. To accomplish this we used food web modeling and the Ecopath with Ecosim software (EwE). The principal fish stocks have experienced wide decadal fluctuations in the past 30 years, including stock collapses of horse mackerel (Trachurus murphyi) and hake (Merluccius gayi), and there was a large influx of jumbo squid during the mid-2000s. We used two EwE models representing the food web off central Chile to test the hypothesis that predation by jumbo squid has been significant in explaining the dynamics of the main fishing resources and other species in the study area. Results indicate that predation by jumbo squid on fish stocks is lower than that of other predators (e.g. hake) and the fishery. Long-term fluctuations (1978–2004) in the biomass of the main fish stocks (as well as other components of the food web) seem to be related to fishing and to variation in primary production, rather than to predation by jumbo squid alone. Jumbo squid seems to play a role as predator rather than prey in the system, but its impacts are low when compared with the impacts of other predators and fishing. Therefore, we conclude that jumbo squid predation on its prey was not the primary force behind the collapse of important fish stocks off central Chile. Future efforts should be directed to better understanding factors that trigger sudden increases in jumbo squid abundance off central Chile, as well as modeling its trophic impacts.     

Diel vertical migration of medusae in the open Southern Adriatic Sea over a short time period (July 2003)

Diel vertical migration (DVM) of medusae was investigated at a fixed station in the oligotrophic Southern Adriatic Sea at several depths during summer (July) 2003. We hypothesized that medusan DVM is considerably influenced by environmental variables such as hydrographic features, light intensities, and potential prey densities. We used short-term repetitive sampling as an approach to detail these relationships. Of the 26 species collected, the highest abundance was in the layer between the thermocline (15 m) and 100 m depth, where Rhopalonema velatum predominated, reaching the maximum count of 93 individuals per 10 m³. Seven species were observed over a wide depth range: Solmissus albescens (15–1200 m), R. velatum (0–800 m), Persa incolorata (50–1200 m), Octophialucium funerarium (200–1200 m), Arctapodema australis (200–1200 m), Amphinema rubra (100–800 m), and Rhabdoon singulare (15–600). According to the medusan weighted mean depth (WMD) calculations, the longest DVMs were noted for the deep-sea species S. albescens , O. funerarium , and A. australis . The shallowest species, Aglaura hemistoma , was primarily non-migratory. Certain medusan assemblages were associated consistently with a particular depth layer characterized by a particular light intensity. The interplay of environmental factors and trophic relationships explains some of the features of medusan migratory patterns. These findings thus contribute to understanding the variables that determine patterns of medusan vertical migratory behavior.     

海洋浮游微食物网结构及其影响因素

微食物环是海洋生态系统中重要的物质和能量过程,是传统食物链的有效补充。微食物环研究是当前海洋生态学研究的热点之一,但对其结构的系统研究较少,海洋微食物网结构在2000年才被Garrison提出。尽管微食物网各个类群的丰度在不同海洋环境中有相对变化,但是这些变化都处于一定的范围之内,其丰度结构约为纤毛虫10 cell ml-1、鞭毛虫103 cell ml-1、微微型真核浮游生物104 cell ml-1、蓝细菌104-5 cell ml-1、异养细菌106 cell ml-1、病毒107 particle ml-1。海洋浮游食物链中捕食者和饵料生物粒径的最佳比值为10:1,实际研究中该比值会略低,例如纤毛虫与其饵料的粒径比值为8:1,鞭毛虫为3:1。Pico和Nano浮游植物的丰度比（Pico:Nano）是研究微食物网结构的指数之一,该指数具有不受研究尺度影响的优点,可用于研究区域性和全球性微食物网结构。近年来,学者们从多角度对海洋微食物网的结构开展了研究,不同海区微食物网各类群丰度、生物量的时间和空间变化研究有很多报道,微食物网的结构可受空间、季节、摄食、营养盐等多种因素影响。在对不同空间微食物网的研究中,学者往往研究不同物理性质的水团中各类群生物丰度的不同,以此来表征微食物网结构的不同;同一海区微食物网结构的季节变化也是使用各个类群丰度和生物量的变化来表示,该变化主要受水文环境因素影响。摄食者对微食物网各类生物的影响通过三种途径：1. 中型浮游动物摄食;2. 中型浮游动物摄食微型浮游动物,通过营养级级联效应影响低营养级生物;3. 中型浮游动物通过释放溶解有机物、营养盐影响细菌和低营养级生物。浮游植物通过产生化感物质和溶解有机物影响微食物网结构,而营养盐的浓度及变化则可以对微食物网产生直接或间接影响。     

Impact of shorebird predation on intertidal macroinvertebrates in a key North African Atlantic wintering site: an experimental approach

Shorebirds, as migratory aquatic birds and top predators in intertidal ecosystems, can be affected by global environmental changes and escalations in local impacts on coastal lagoons and estuarine trophic networks. Many shorebirds winter in North African Atlantic coastal sites, most likely because these locations provide constant and reliable food supplies with less energy costs in comparison with the wintering sites of northern Europe. Although more information is available for other important southern coastal sites (e.g. Saharan Atlantic coastal desert and Guinean mangroves coast), very little information is available for the North African Atlantic coast. Here, we focus on the impact of shorebird predation on benthic macroinvertebrates in a major wintering site in this area—Sidi Moussa coastal lagoon, Morocco—using an exclosure experiment. For most of the macroinvertebrate species there was no significant effect of the exclusion of shorebird predation. Overall, our results do not show evidence that predation by shorebirds influenced the overall standing biomass of the benthic community. This may indicate that the benthic productivity is high enough to provide constant and reliable food supplies for non-breeding shorebirds.     

Catch, survey and life-history data for shrimp (Pandalus borealis) off Jan Mayen

The Jan Mayen area has an extreme environment with low temperatures and infrequent, but abrupt temperature changes. The shrimp population here is considered to be on its edge of distribution. The life-history parameters are in the same range as in other high-latitude shrimp populations and are characterized by slow growth, large size at maturation and extended longevity. Irregular and sporadic commercial exploitation limit fishing mortality and give the population life-history parameters not previously seen in other areas. The Jan Mayen shrimp are large compared to, e.g., the Barents Sea shrimp and can reach a maximum carapace length (L_max) of 37 mm and an age of 10–11 years. The large size at sex transformation (L₅₀, >24 mm) and analyses of length–frequency distributions indicate that the shrimp may be 6–7 years of age before changing sex. The change in L_max and L₅₀ observed during the study period is probably caused by increased natural mortality due to sudden temperature changes or due to increased predation, rather than increased growth rates. The life-history strategy of shrimp in the Jan Mayen area can be explained by factors such as depth, temperature and population density variations caused by fluctuation in recruitment and mortality.The shrimp fisheries in the Jan Mayen area began in the late 1970s and reached an annual landing of 2000 tonnes in 1985, and since then landings have oscillated around 500 tonnes depending on a combination of factors. The survey indices of stock biomass varied between 3000 and 6600 tonnes. For most years, the highest shrimp densities are at a depth of 200–299 m, while large shrimp (and therefore also female shrimp) are dominant at depths greater than 300 m.Fish community data were studied as the composition of the demersal fish community is an integrated response to environmental conditions and as predation affects the shrimp stock. Polar cod and capelin are the most abundant fish species in the study area. A high number of blue whiting was registered in 1979, but the number declined in 1980 and 1981 as temperature decreased. During the surveys in 1994 and 1995, no blue whiting was registered. A few individuals were found again in the 1999 samples. The number of Greenland halibut has declined from the beginning of the 1980s to the 1990s.