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61.
利用2012年9月1—6日采自马卡诺夫海盆3个站位和楚科奇深海平原1个站位的分层浮游动物样品,研究了浮游动物在0—1 000 m水层的垂直分布以及地理差异。结果表明,浮游动物在上层分布密集而在深层比较稀少。4个站位在0—50 m、50—100 m和100—200 m水层的平均丰度分别为265.0、360.7和231.2 ind·m-3,而在200—500 m和500—1 000 m的丰度只有64.4和36.9 ind·m-3。在数量上占优势的种类中,植食性为主的拟长腹剑水蚤(Oithona similis)、北极哲水蚤(Calanus glacialis)和极北哲水蚤(Calanus hyperboreus)集中在200 m以浅的水层。虽然在200m以下杂食性种类矮小微哲水蚤(Microcalanus pygmaeus)、隆剑水蚤(Oncaea spp.)和细长长腹水蚤(Metridia longa)的丰度明显降低,但是占浮游动物总丰度的比例却明显更高。两个调查海区浮游动物种类组成相似,但是楚科奇深海平原大型桡足类极北哲水蚤的丰度较高,而小型桡足类丰度较低?垂直分布上差异主要在于500—1 000 m水层,马卡诺夫海盆站位丰度为22.7—92.6 ind·m-3,而楚科奇深海平原只有1.6 ind·m-3。深海区浮游动物丰度的地理差异说明生物泵的作用存在空间异质性。类似地理差异产生的原因在于楚科奇深海平原存在数量较多的极北哲水蚤,它们在春季融冰前就上升到表层摄食冰藻,显著降低了有机物的垂直通量。 相似文献
62.
Delphine Bonnet Anthony Richardson Andrew Hirst Martin Edwards Rabea Diekman Luis Valdes Juan Carlos Molinero Wulf Greve Aitor Albaina Serena Fonda Umani Antonina dos Santos Susan Robinson 《Progress in Oceanography》2005,65(1):1-53
We review current knowledge and understanding of the biology and ecology of the calanoid copepod Calanus helgolandicus in European waters, as well as provide a collaborative synthesis of data from 18 laboratories and 26 sampling stations in areas distributed from the northern North Sea to the Aegean and Levantine Seas. This network of zooplankton time-series stations has enabled us to collect and synthesise seasonal and multi-annual data on abundance, body size, fecundity, hatching success and vertical distribution of C. helgolandicus. An aim was to enable comparison with its congener Calanus finmarchicus, which has been studied intensively as a key component of European and north east Atlantic marine ecosystems. C. finmarchicus is known to over-winter at depth, whereas the life-cycle of C. helgolandicus is less well understood. Overwintering populations of C. helgolandicus have been observed off the Atlantic coast between 400 and 800 m, while in the Mediterranean there is evidence of significant deep-water populations at depths as great as 4200 m. The biogeographical distribution of C. helgolandicus in European coastal waters covers a wide range of habitats, from open ocean to coastal environments, and its contribution to mesozooplankton biomass ranges from 6% to 93%. Highest abundances were recorded in the Adriatic and off the west coast of Spain. C. helgolandicus is generally found in 9-20 °C water, with maximum abundances from 13-17 °C. In contrast, C. finmarchicus is found in cooler water between 0 and 15 °C, with peak abundances from 0 to 9 °C. As water has warmed in the North Atlantic over recent decades, the range of C. helgolandicus and its abundance on the fringes of its expanding range have increased. This review will facilitate development of population models of C. helgolandicus. This will not only help answer remaining questions but will improve our ability to forecast future changes, in response to a warming climate, in the abundance and distribution of this important species. 相似文献
63.
Cecilie Broms Webjrn Melle 《Deep Sea Research Part II: Topical Studies in Oceanography》2007,54(23-26):2760
Seasonal development of Calanus finmarchicus was studied in relation to the physical environment and phytoplankton bloom dynamics in the Norwegian Sea during eight basin-scale surveys from March to August 1995. Our main objective was to gain new knowledge about the life cycle of C. finmarchicus and its adaptation to the physical and biological environment of the Norwegian Sea. Time of spawning, estimated by temperature-dependent back-calculations from the occurrences of copepodite stage 1 (CIs), varied by water mass and occurred mainly during the phytoplankton pre-bloom and bloom periods. Recruitment to CI of the year's first generation (G1) generally occurred during the bloom and late bloom. The seasonal development of C. finmarchicus was progressively delayed from Coastal to Atlantic and to Arctic water, and from south to north within Atlantic and Arctic waters. This delay was partly linked to the phytoplankton bloom development that followed the same pattern, but development of C. finmarchicus also showed an increasing tendency to lag behind the phytoplankton development in colder waters. This may explain why C. finmarchicus are less successful in colder water. The consumption of nitrate was used as proxy for the seasonal history of phytoplankton development to aid interpretation of the lifecycle of C. finmarchicus. This approach allows us to align phytoplankton bloom and copepod development sequences despite temporal and geographical variation in bloom development, which otherwise tend to cause variability in quasi-synoptic and large-scale data. Two generations of C. finmarchicus were found in southern and northern regions of Coastal Water, and in southern Atlantic Water. In northern Atlantic Water and in Arctic Water, one generation was observed. 相似文献
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65.
Annual variation in Calanus sinicus abundance and population structure in the northern boundary area of the Yellow Sea Cold Water Mass 总被引：1，自引：0，他引：1
The Yellow Sea Cold Water Mass （YSCWM） was suggested as an over-summering site of the dominant copepod species Calanus sinicus in coastal Chinese seas. Population abundance and structure were investigated by monthly sampling along three transects across the northern boundary of the YSCWM during 2009-2010. Results show that thermal stratification existed from June to October and that the vertical thermal difference increased with depth. Generally, total abundance was lowest in October and highest in June, and the female/male sex ratio was highest in February and lowest in August. Evident spatial differences in abundance were observed during the existence of the YSCWM. In June, total abundance averaged 158.8 ind/m~ at well-stratified stations, and 532.1 ind/m3 at other stations. Similarly, high abundances of 322.0 and 324.4 ind/m3 were recorded from July to August inside the YSCWM, while the abundance decreased from 50.4 to 1.9 ind/m3 outside the water mass. C. sinicus distribution tended to even out over the study area in September when the YSCWM disappeared. We believe that the YSCWM may retard population recruitment in spring and preserve abundant cohorts in summer. The summer population was transported to neritic waters in autumn. In addition to low temperatures, stable vertical structure was also an essential condition for preservation of the summer population. C. sinicus can survive the summer in marginal areas in high abundance, but the population structure is completely different in terms of C5 proportion and sex ratio. 相似文献
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67.
极地海区浮游动物对全球气候变化的响应极其敏感,其群落结构已成为研究全球变化对海洋生态系统影响的重要指标,而DNA条形码则是浮游动物种类鉴定的有效工具。采用线粒体细胞色素c氧化酶第一亚基编码基因(mtCOI)特异扩增测序的方法,分析了南大洋32种常见浮游动物的94条DNA条形码序列,其长度分布在830碱基到1050碱基之间。发现南极常见浮游动物种内遗传差异均值为0.67%,分布在0—2.6%之间;同属近源种间遗传差异均值为14.3%,分布在0.1%—29.3%之间。哲水蚤属的近缘哲水蚤(Calanus propinquus)和C.simillimus遗传相似度非常高。考虑到上述两者在形态和遗传上的相似性,本研究认为两种可能为同种异名,有待开展深入研究确认C.simillimus种的地位。除了哲水蚤属的两种外,所有样品种内、种间遗传差异显著,且同种的不同样品都聚到一起形成单系群。结果表明mtCOI序列可以作为DNA条形码实现南极浮游动物常见种的准确鉴定(水母和海樽等胶质浮游动物的有效性未验证)。以上结果也得到了示踪向量分析的证实。本研究新增的DNA条形码数据以及新提供的兼并引物必将推动南极浮游动物环境样品的宏基因组学研究。 相似文献
68.
Calanus sinicus is a calanoid copepod widely distributed in coastal waters of China and Japan, and oversummering strategies may have major impacts on their population dynamics which in turn affect local marine food web structure. The abundance, stage composition, and sex composition of the planktonic copepod C. sinicus were studied from August to October 2002 in the southern Yellow Sea to understand how its population recovers from the over-summering state. Results showed that C. sinicus had low reproduction in August due to high temperature, except in waters near the Cheju Island with rich food and moderate bottom temperature, but the reproduction rates here decreased in September–October as food availability declined. When temperature dropped in September–October, C. sinicus actively propagated in coastal shallow waters. However, reproduction rates of C. sinicus individuals inhabiting the Yellow Sea Cold Water Mass(YSCWM) remained low during the three months of the study. The percentage of C. sinicus females was high during the reproductive period, which suggests that the sex composition of adult C. sinicus may reflect whether or not the population is in the reproductive mode.Numerous fifth copepodite stage(CV) C. sinicus aggregated in the YSCWM in a suspended developmental stage during the three months of this study, and they potentially served as the parental individuals for population development when conditions became optimal for reproduction later in the year. 相似文献
69.
初夏南黄海浮游动物功能群丰度年际变化 总被引：2，自引：1，他引：1
利用1959年和2000—2009年6月份在南黄海海域进行的7个航次海洋调查采样样品,并结合同步温盐资料及海温长期变化数据,研究了不同浮游动物功能群丰度的年际变化。结果表明:大型甲壳类和毛颚类功能群丰度高且波动幅度较大,在1959年和2000—2009年两个时期无明显差异,最低值分别出现在2003年和2000年;而中华哲水蚤为优势种的大型桡足类功能群丰度在2000—2009年显著高于1959年,波动范围分别在2035—24500和912—1330ind/m2之间;小型水母和海樽类功能群丰度一般较低,但是在2007年出现暴发式增加,平均丰度分别是其它年份中最高平均丰度的4.8倍和88.5倍。大型甲壳类和毛颚类分别在东部冷水团区和中部锋面区波动幅度最大,小型水母和海樽类则是在西部浅水区波动幅度最大。分析认为桡足类丰度增加与营养盐浓度升高和鱼类过度捕捞有关,而胶质生物种群剧烈波动与气候变化引起的环境变异相关。 相似文献
70.
Dag Slagstad Kurt S. Tande 《Deep Sea Research Part II: Topical Studies in Oceanography》2007,54(23-26):2702
Very high concentrations of overwintering Calanus finmarchicus were found in the eastern Lofoten Basin of the Norwegian Sea close to the shelf break in January 2001–2002. A coupled 3D hydrodynamic and ecological model was used to study the formation of this deep overwintering aggregation and its stability. The ecological model includes nutrients, phytoplankton and microzooplankton in addition to a stage-structured model of C. finmarchicus. Using a Eulerian approach, the model was initiated with an overwintering stock evenly distributed in the oceanic regions of the Norwegian Sea, i.e. where depths>600 m. Spawning and development of the new generation take place in response to vertical mixing and phytoplankton development. Animals are assumed to begin their descent to overwintering depths of 700–1000 m as late stage Vs. Model results show that, in late summer, high concentrations of animals were found at overwintering depths near the shelf break north of the North Sea, off the northeastern Vøring Plateau and in the eastern Lofoten Basin along the slope of the Barents Sea shelf. They remained there for months due to deep eddies and southward, deep currents along the Norwegian shelf. The simulation experiments indicate that the combined effect of deep anticyclonic circulation and vertical migration behavior of the animals may explain the high concentrations of overwintering C. finmarchicus found in field surveys in the Eastern Lofoten Basin, close to the shelf break. 相似文献