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1.
Samples were collected with a plankton net in the four seasonal cruises during 2006-2007 to study the seasonal variability of the zooplankton community in the southwest part of Huanghai Sea Cold Water Mass (HSCWM, Yellow Sea Cold Water Mass). The spatial and temporal variations of zooplankton species composition, biomass, abundance and biodiversity were examined. A total of 122 zooplankton species and 30 pelagic larvae were identified in the four cruises. Calanus sinicus and Aidanosagitta crassa were the most dominant species, and Themisto gaudichaudi and Euphausia pacifica were widely distributed in the HSCWM area. The spatial patterns of non-gelatinous zooplankton (removing the high water content groups) were similar to those of the total zooplankton biomass in autumn, but different significantly in the other three seasons. The seasonal means of zooplankton biomass in spring and summer were much higher than that in autumn and winter. The total zooplankton abundance averaged 283.5 ind./m~3 in spring (highest), 192.5 ind./m~3 in summer, 165.5 ind./m~3 in autumn and 65.9 ind./m~3 in winter (lowest), and the non-gelatinous groups contributed the most total abundance. Correlation analysis suggests that the non-gelatinous zooplankton biomass and abundance had a significant positive correlation in the whole year, but the relationship was insignificant between the total zooplankton biomass and abundance in spring and summer. The diversity index H of zooplankton community averaged 1.88 in this study, which was somewhat higher than historical results. Relatively low diversity in summer was related to the high dominance of Calanus sinicus, probably due to the strongest effect of the HSCWM in this season.  相似文献   

2.
Using the hydroacoustic method with a 200 kHz scientific echo sounding system,the diel vertical migration(DVM) of the sound-scattering layer(SSL) in the Yellow Sea Bottom Cold Water(YSBCW) of the southeastern Yellow Sea was studied in April(spring) and August(summer) of 2010 and 2011.For each survey,13–27 hours of acoustic data were continuously collected at a stationary station.The acoustic volume scattering strength(Sv) data were analyzed with temperature profile data.In the spring of both 2010 and 2011,the SSL clearly showed the vertical migration throughout the entire water column,moving from the surface layer at night to near the bottom during the day.Conductivity,temperature,and depth data indicated that the entire water column was well mixed with low temperature of about 8 C.However,the SSL showed different patterns in the summers of 2010 and 2011.In the summer of 2010(28 C at the surface),the SSL migrated to near the bottom during the day,but there were two SSLs above and below the thermocline at depth of 10–30 m at night.In the summer of 2011(20 C at the surface),the SSL extended throughout the entire water column at night,possibly owing to an abrupt change in sea weather conditions caused by the passage of a Typhoon Muifa over the study area.It was concluded that the DVM patterns in summer in the YSBCW area may be greatly influenced by a strengthened or weakened thermocline.  相似文献   

3.
Giant jellyfish (Nemopilema nomurai) outbreaks in relation to satellite sea surface temperature (SST) and chlorophyll-a concentrations (Chl-a) were investigated in the Yellow Sea and East China Sea (YECS) from 1998 to 2010. Temperature, eutrophication, and match–mismatch hypotheses were examined to explain long-term increases and recent reductions of N. nomurai outbreaks. We focused on the timing of SST reaching 15 °C, a critical temperature enabling polyps to induce strobilation and enabling released ephyra to grow. We analyzed the relationship of the timing with interannual variability of SST, Chl-a, and the timing of phytoplankton blooms. Different environmental characteristics among pre-jellyfish years (1998–2001), jellyfish years (2002–2007, 2009), and non-jellyfish years (2008, 2010) were assessed on this basis. The SST during late spring and early summer increased significantly from 1985 to 2007. This indicated that high SST is beneficial to the long-term increases in jellyfish outbreaks. SST was significantly lower in non-jellyfish years than in jellyfish years, suggesting that low SST might reduce the proliferation of N. nomurai. We identified three (winter, spring, and summer) major phytoplankton bloom regions and one summer decline region. Both Chl-a during non-blooming periods and the peak increased significantly from 1998 to 2010 in most of the YECS. This result indicates that eutrophication is beneficial to the long-term increases in jellyfish outbreaks. Timing of phytoplankton blooms varied interannually and spatially, and their match and mismatch to the timing of SST reaching 15 °C did not correspond to long-term increases in N. nomurai outbreaks and the recent absence.  相似文献   

4.
春、秋季南黄海浮游纤毛虫丰度及生物量的分布差异   总被引:1,自引:0,他引:1  
Seasonal variation of marine plankton spatial distribution is important in understanding the biological processes in the ocean.In this study,we studied spatial distribution of planktonic ciliate abundance and biomass in the central deep area(station depth greater than 60 m) and the coastal shallow area(station depth less than 60 m) of the southern Yellow Sea(32°–36.5°N,121°–125°E) in spring(April) and autumn(October–November) of 2006.Our results showed that both ciliate abundance and biomass in the surface waters were higher in spring((1 490±2 336)ind./L;(4.11±7.81) μg/L) than in autumn((972±823) ind./L;(1.11±1.18) μg/L,calculated by carbon).Ciliate abundance and biomass in the surface waters of the coastal shallow area were similar in spring and autumn.However,in the central deep area,those values were much higher in spring((1 878±2 893) ind./L;(5.99±10.10)μg/L) than in autumn((738±373) ind./L;(0.74±0.76) μg/L).High values of ciliate abundance and biomass occurred in the central deep area in spring and in the coastal shallow area in autumn.Mixotrophic ciliate Laboea strobila was abundant in the central deep area in spring,when a phytoplankton bloom occurred.However,in autumn,L.strobila was abundant in the coastal shallow area.Boreal tintinnid Ptychocyli obtusa was found in spring.Both L.strobila and P.obtusa were concentrated in the surface waters when their abundance was more than 1 000 ind./L.Peaks of these species were in the subsurface waters when their abundance was less than 400 ind./L.This study showed that both high abundance and biomass of ciliates occurred in different areas in southern Yellow Sea seasonally.  相似文献   

5.
北黄海獐子岛海域浮游动物群落年际变化   总被引:1,自引:0,他引:1  
本文比较了海洋普查期间(1959年1-12月)和2009-2010年獐子岛海域附近站位的浮游动物的种类组成、优势种、丰度、生物多样性,结果显示,北黄海区域浮游动物群落物种组成未发生较大的变化,在獐子岛海域以及整个北黄海,中华哲水蚤和强壮箭虫的优势种地位没有发生变化,细足法虫戎也一直出现且为冬春季的优势种;太平洋磷虾在2009-2010年獐子岛海域虽然全年均有出现,但是全年均不是优势种,而在1959年的獐子岛海域,作为优势种出现在4月和11月;1959年与2009年相较,腹针胸刺水蚤在春夏季优势种的地位被沃氏纺锤水蚤所取代。2009年浮游动物丰度(131.26 ind/m3)比1959年(78.90 ind/m3)高;浮游动物多样性指数(H')均在夏秋季高于冬春季节,且年平均多样性指数也有所提高。  相似文献   

6.
采用气相色谱法对秋季黄海颗粒悬浮物和中华哲水蚤的脂肪酸组成及其指示作用进行了研究。结果表明,黄海表层海水中硅藻所占比例要大于甲藻。硅藻在黄海南部浮游植物中所占比重高于黄海北部,甲藻在黄海南北部的差别不大。从脂肪酸组成来看,中华哲水蚤雌体、雄体和桡足幼体都摄食硅藻和甲藻,雌体和雄体摄食的硅藻远多于甲藻,而桡足幼体摄食的甲藻则比雌体和雄体多。雄体和桡足幼体植食性的程度高于雌体,而雌体则可能由于繁殖活动的需要,还摄食了原生动物等其它一些营养丰富的食物。对冷水团内外中华哲水蚤脂肪酸组成研究发现,桡足幼体比雌体积累了更多的脂肪酸以满足度夏过程中的能量需求和后期繁殖的需要。  相似文献   

7.
A spatial and temporal variation in physiochemical parameters in the southeastern Yellow Sea(YS) is investigated in the spring and summer of 2009 to 2011.Nutrient show a strong negative relationship with chlorophyll a(Chl a) concentration in spring,and the subsurface chlorophyll a maxima(SCM) layer was associated with the nitracline in summer.In summer,the SCM was usually found within or above the pycnocline and at the depths of shoals from the open sea to the coastal sea due to tidal and/or topographical fronts in the southernmost study area.High Chl a concentrations were found in the central southern YS,where the YS cold water layer expanded under the pycnocline and encountered water masses during spring and summer.After a typhoon in the summer of 2011,Chl a concentration increased,especially in the central southern YS,where cold waters occurred below the pycnocline.The results suggest that the development of thermohaline fronts may play an important role in the growth and accumulation of phytoplankton biomass in the upper layer of the southeastern YS during spring and summer.  相似文献   

8.
根据2009年8月至2010年6月4个季度月(夏、秋、冬、春季),对位于北黄海獐子岛附近海域所设的13个站进行的大型底栖动物生态调查所获得的资料,对该海域大型底栖动物的种数、密度和生物量的组成及季节变化进行分析研究,采用Shannon-Wiener指数(H’)、物种丰富度指数(D)和物种均匀度指数(J)分析该该海域大型底栖动物的物种多样性;并研究了该海域的次级生产力和P/B值的空间分布和季节变化。结果表明,北黄海獐子岛附近海域大型底栖动物全年总种数、年平均栖息密度和年平均生物量分别为211种、699.415个/m2和98.927 g/m2。各季度的种数(S)、平均密度D (个/m2)和平均生物量B (g/m2)的季节变化分别为: S春季(121)>S秋季(118)>S冬季(89)>S夏季(87),D春季(794.58)>D秋季(766.92)>D夏季(674.62)>D冬季(561.54),B春季(180.271)>B夏季(107.121)>B秋季(70.824)>B冬季(37.493)。全年物种多样性指数H’值、物种丰富度指数D值和物种均匀度指数J值分别为2.976、4.135和0.707,该海域大型底栖动物的夏季、秋季和春节平均密度季节变化不明显,但冬季明显较少。而平均生物量和种数的季节变化比较明显,春季较高,冬季较低。该海域的平均次级生产力为15.335g(AFDW)/(m2.a),相对较高。P/B值的平均值为1.239。  相似文献   

9.
The Yellow Sea Cold Water Mass(YSCWM) is one of the important water mass in the Yellow Sea(YS).It is distributed in the lower layer in the Yellow Sea central trough with the temperature less than 10 C and the salinity lower than 33.0.To understand the variability of the YSCWM,the hydrographic data obtained in April and August during 2009–2011 are analyzed in the southeastern Yellow Sea.In August 2011,relatively warm and saline water compared with that in 2009 and 2010 was detected in the lower layer in the Yellow Sea central area.Although the typhoon passed before the cruise,the salinity in the Yellow Sea central trough is much higher than the previous season.It means that the saline event cannot be explained by the typhoon but only by the intrusion of saline water during the previous winter.In April 2011,actually,warm and saline water(T >10 C,S >34) was observed in the deepest water depth of the southeastern area of the Yellow Sea.The wind data show that the northerly wind in 2011 winter is stronger than in 2009 and 2010 winter season.The strong northerly wind can trigger the intrusion of warm and saline Yellow Sea Warm Current.Therefore,it is proposed that the strong northerly wind in winter season leads to the intrusion of the Yellow Sea Warm Current into the Yellow Sea central trough and influenced a variability of the YSCWM in summer.  相似文献   

10.
用锰纤维富集-射气法测量了北黄海水体的^224 Ra,研究了该海域夏季和冬季2个季节^224 Ra比活度及其垂直分布,并对其进行了比较研究.北黄海夏季^224 Ra 比活度为0.24—3.48Bq/m2,平均值为1.14Bq/m2;冬季^224 Ra比活度为0.37~6.68Bq/m2,平均值为0.94Bq/m2.北黄海的表层水有3个^224 Ra 高值区,分别位于东北部海域、渤海海峡南部和北黄海中北部海区.30m水深将^224 Ra比活度的垂直分布分成上层和下层2层.在0~30m水层,夏季,随着水深增加^224 Ra比活度逐渐增加,比活度变化较小;冬季部分站位由表层向下^224 Ra比活度逐渐降低.30m水深以下,^224 Ra比活度随着水深的增加而增加,而且变化幅度较大.由^224 Ra比活度的垂直分布得出该海域的垂直涡动扩散系数为2.5~43.5cm2/s,夏季北黄海冷水团中心海域底层溶解态化学物质输运补给到上层所经历的时间为9~15d左右.  相似文献   

11.
黄海春季和秋季中华哲水蚤脂类含量及组成分析   总被引:2,自引:0,他引:2  
脂类物质在哲水蚤的休眠、繁殖以及个体发育过程中发挥着重要作用,通过分析2010年11月(秋季)和2011年4月(春季)黄海中华哲水蚤Calanus sinicus的脂类组成,对脂类各组分的生理功能进行了初步探讨。结果表明,春季、秋季中华哲水蚤雌体脂类平均含量占干质量的10.6%和12%,C5期个体脂类含量偏高,占到干质量的17%。中华哲水蚤所含脂类主要由蜡脂和磷脂组成,两种脂类约占总脂的90%,三酰甘油含量约占总脂的6%。结合种群结构对脂类的生理作用进行了初步探讨,发现:(1)蜡脂作为主要的能量储存方式,其含量变化反映出不同发育期、不同季节中华哲水蚤的能量需求变化;(2)磷脂作为结构性脂类在中华哲水蚤个体生长与生殖过程中具有重要作用;(3)三脂酰甘油在中华哲水蚤中的含量不高,但是可能在脂类转化利用过程中发挥作用。  相似文献   

12.
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   

13.
黄海溶解氧垂直分布最大值的成因   总被引:1,自引:0,他引:1  
本文对黄海溶解氧垂直分布中最大值的成因进行了探讨.认为:浮游植物春花期光合作用产生的大量氧,是溶解氧垂直分布最大值得以在春季(5月)形成的基础;而良好的温、密跃层的存在是氧最大值得以形成的必要条件,夏季叶绿素最大值层中较强的光合作用,是氧最大值在夏季得以维持甚至增强的主要原因.提出:黄海春、夏季溶解氧垂直分布中的最大值并非主要由冬季保持而来.  相似文献   

14.
Microzooplankton grazing impact on phytoplankton was assessed using the Landry–Hassett dilution technique in the Western Arctic Ocean during spring and summer 2002 and 2004. Forty experiments were completed in a region encompassing productive shelf regions of the Chukchi Sea, mesotrophic slope regions of the Beaufort Sea off the North Slope of Alaska, and oligotrophic deep-water sites in the Canada Basin. A variety of conditions were encountered, from heavy sea-ice cover during both spring cruises, moderate sea-ice cover during summer of 2002, and light to no sea ice during summer of 2004, with a concomitant range of trophic conditions, from low chlorophyll-a (Chl-a; <0.5 μg L−1) during heavy ice cover in spring and in the open basin, to late spring and summer shelf and slope open-water diatom blooms with Chl-a >5 μg L−1. The microzooplankton community was dominated by large naked ciliates and heterotrophic gymnodinoid dinoflagellates. Significant, but low, rates of microzooplankton herbivory were found in half of the experiments. The maximum grazing rate was 0.16 d−1 and average grazing rate, including experiments with no significant grazing, was 0.04±0.06 d−1. Phytoplankton intrinsic growth rates varied from the highest values of about 0.4 d−1 to the lowest values of zero to slightly negative growth, on average 0.16±0.15 d−1. Light limitation in spring and post-bloom senescence during summer were likely explanations of observed low phytoplankton growth rates. Microzooplankton grazing consumed 0–120% (average 22±26%) of phytoplankton daily growth. Grazing and growth rates found in this study were low compared to rates reported in another Arctic system, the Barents Sea, and in major geographic regions of the world ocean.  相似文献   

15.
黄、东海陆架海域温度垂直结构类型划分与温跃层分析   总被引:4,自引:0,他引:4  
基于黄、东海陆架海域1997—1999年4个季节调查的CTD资料,采用拟阶梯函数逼近法对温度垂直剖面拟合逼近,然后按拟合均方差和跃层强度对黄、东海陆架区的温度垂直结构进行类型划分,共划分为6个类型:三层结构型(T型)、主跃层上位型(U型)、主跃层下位型(L型)、多阶梯状结构型(M型)、异常结构型(A型)和垂直均匀型(H型)。分析结果表明:温度垂直结构类型在黄海区域为:春季呈L型;夏季呈U型;秋季呈T型;冬季呈H型。东海北部春季基本呈T型;夏季西部呈T型,东部呈U型;秋、冬季演变为H型;东海南部春、夏季主要呈L型;秋、冬季除近岸出现逆温类型外,大部分区域呈H型。利用风和潮的混合卷挟模式阐述了各种温度垂直结构的形成机制,最后给出了黄、东海陆架海域的主温跃层特征值的区域分布和季节变化。  相似文献   

16.
北黄海冷水团对獐子岛微微型浮游生物分布的影响   总被引:3,自引:1,他引:2  
Picoplankton distribution around the Zhangzi Island(northern Yellow Sea)was investigated by monthly observation from July 2009 to June 2010.Three picoplankton populations were discriminated by flow cytometry,namely Synechococcus,picoeukaryotes and heterotrophic prokaryotes.In summer(from July to September),the edge of the northern Yellow Sea Cold Water Mass(NYSCWM)resulting from water column stratification was observed.In the NYSCWM,picoplankton(including Synechococcus,picoeukaryotes and heterotrophic prokaryotes)distributed synchronically with extremely high abundance in the thermocline(20 m)in July and August(especially in August),whereas in the bottom zone of the NYSCWM(below 30 m),picoplankton abundance was quite low.Synechococcus,picoeukaryotes and heterotrophic prokaryotes showed similar response to the NYSCWM,indicating they had similar regulating mechanism under the influence of NYSCWM.Whereas in the non-NYSCWM,Synechococcus,picoeukaryotes and heterotrophic prokaryotes exhibited different distribution patterns,suggesting they had different controlling mechanisms.Statistical analysis indicated that temperature,nutrients(NO3–and PO43–)and ciliate were important factors in regulating picoplankton distribution.The results in this study suggested that the physical event NYSCWM,had strong influence on picoplankton distribution around the Zhangzi Island in the northern Yellow Sea.  相似文献   

17.
Study on abundance variation of pteropods in the East China Sea   总被引:5,自引:0,他引:5  
1 Introduction Pteropoda, an order of marine pelagic mollusks, belongstoClassGastropoda,SubclassOpisthobranchia. The speciesofthisorder can be found all over the world buttheyareusuallyabundantinthecontinentalshelfand continental slope area. As fish diets…  相似文献   

18.
Vertical distributions of phytoplankton biomass and community structure were studied in the summer stratified central Yellow Sea (YS) using a submersible spectrofluorometer (Fluoroprobe, bbe Moldaenke, Germany), along with photosynthetic pigments analysis (HPLC-CHEMTAX), and microscope observation. Above all, the results of the dominating group obtained from these methods generally coincided with each other on the transect 35°N. The concentrations of brown algae, green algae and total chlorophyll a (Chl a) biomass were highly correlated between the results of Fluoroprobe observations and pigments analysis (r?=?0.79, 0.91 and 0.82, respectively, n?=?54, p?<?0.01). In the summer stratified central YS, significant differences in phytoplankton compositions on the vertical distribution was observed. On the basis of HPLC-CHEMTAX results, the dominating group of phytoplankton composition generally changed from cyanobacteria to chrysophytes and then to diatoms, from surface to bottom. Interestingly, on the basis of high-resolution observations using Fluoroprobe, a periodic fluctuation of the pycnocline presumably due to the semidiurnal internal tides was observed at an anchor station (35°N, 123°E). In addition, both nutrients and Chl a concentrations at the depth of the subsurface chlorophyll maximum (SCM) seemed to coincide with the rhythm of the pycnocline fluctuation, indicating the latter might have a potential impact on the dynamics of SCM phenomena in the summer stratified central YS.  相似文献   

19.
The seasonal size structure and spatial abundance distributions of Euphausia pacifica populations were investigated in the central part of southern Yellow Sea from August 2009 to May 2010.The abundance and biomass of E.pacifica were higher in spring and summer,and lower in autumn and winter.The mean abundance and biomass(calculated by carbon)were 74.94 ind./m~3 and 8.23 mg/m~3,respectively.Females with total length(TL)ranging between 10 and 19 mm in summer had a substantial contribution to the population biomass,whereas larvae of TL of 3–7 mm in spring were the main contributor to the population abundance.The sex ratio(female:male)showed a female bias in four seasons.Its value peaked in summer,and then decreased in autumn,spring,and winter successively.Cohort analysis revealed that the length-frequency distribution of E.pacifica could be characterized as one group with large animals(mean TL12 mm)accompanied by one or two subgroups of small individuals(mean TL7 mm).Regarding the spatial distribution,juveniles and adults of E.pacifica tend to concentrate in relatively deep water with low temperature(~11℃)and high salinity(32),whereas its larvae showed more abundance in inshore water with rich chlorophyll a,low salinity(32),and warm temperature(11℃),especially in summer and autumn.Associations changed seasonally between stage-specific abundance and environmental factors.  相似文献   

20.
夏季南黄海浮游动物分布及其影响因素分析   总被引:4,自引:1,他引:3  
王晓  王宗灵  蒲新明  刘萍 《海洋学报》2013,35(5):147-155
基于2006年7-8月在南黄海西部 (32°~37°N,124°E以西) 进行的137个站位的浮游动物大面调查,研究了浮游动物的种类组成、丰度、生物量、优势种及生态环境指示种的分布及影响因素。结果显示,浮游动物种类组成较以往多,中华哲水蚤对浮游动物丰度贡献最高,超过50%,生物量也明显高于以往,本研究胶质性浮游动物生物量超过非胶质性浮游动物。优势种组成差别不大,中华哲水蚤存在2个丰度高值区,一个位于叶绿素a浓度较低的黄海冷水团内,一个位于海区南部;强壮滨箭虫出现频率最高,高丰度区与中华哲水蚤不同,主要位于山东半岛南岸至海州湾外侧;细足法鲹主要分布在34°N以北的冷水团范围内,在盐度低于31的海区几乎绝迹;太平洋磷虾主要分布在33°~35°N的深水区。暖水种精致真刺水蚤和肥胖软箭虫在海区南部较多,与北向的长江冲淡水和台湾暖流有关,其分布北限受到南向的苏北沿岸流和黄海冷水团的影响,这两种浮游动物在南黄海的分布可以反映上述海流的相互作用。  相似文献   

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