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1.
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   

2.
The area of Arctic sea ice has dramatically decreased, and the length of the open water season has increased;these patterns have been observed by satellite remote sensing since the 1970 s. In this paper, we calculate the net primary productivity(NPP, calculated by carbon) from 2003 to 2016 based on sea ice concentration products,chlorophyll a(Chl a) concentration, photosynthetically active radiation(PAR), sea surface temperature(SST), and sunshine duration data. We then analyse the spatiotemporal changes in the Chl a concentration and NPP and further investigate the relations among NPP, the open water area, and the length of the open water season. The results indicate that(1) the Chl a concentration increased by 0.025 mg/m~3 per year;(2) the NPP increased by 4.29 mg/(m~2·d) per year, reaching a maximum of 525.74 mg/(m~2·d) in 2016; and(3) the Arctic open water area increased by 57.23×10~3 km~2/a, with a growth rate of 1.53 d/a for the length of the open water season. The annual NPP was significantly positively related to the open water area, the length of the open water season and the SST.The daily NPP was also found to have a lag correlation with the open water area, with a lag time of two months.With global warming, NPP has maintained an increasing trend, with the most significant increase occurring in the Kara Sea. In summary, this study provides a macroscopic understanding of the distribution of phytoplankton in the Arctic, which is valuable information for the evaluation and management of marine ecological environments.  相似文献   

3.
During a cruise of r/v ‘Oceania’ in May 2006, seven vertical dissolved organic carbon (DOC) concentration profiles were produced against a background of CTD, chlorophyll a (chl a) and phaeopigment concentration profiles. The results indicate distinct vertical and spatial DOC fluctuations, ranging from 248 ± 7 μmol C dm−3 at 70 m depth at the westernmost station G/06 to 398 ± 5 μmol C dm−3 at 5 m depth at station A/06 in the western Gulf of Gdańsk. DOC concentrations were the highest at 10 m depth, where phytoplankton activity was relatively intensive, as reflected by the active chl a concentration distribution. DOC concentrations decreased towards the sea bottom.  相似文献   

4.
Concentrations of biogenic silica(BSi) in the southern Yellow Sea were determined during four cruises(spring:April–May 2014; autumn: November 2014; summer: August–September 2015; winter: January 2016). Samples of BSi were measured using the double extraction method. Seasonal and spatial variations of BSi and the potential correlation between chlorophyll a(Chl a) content and BSi in four seasons were measured in this study. Significant spatial variability was observed in seawater BSi concentrations. The average concentration of BSi was highest in winter and lowest in spring. Furthermore, the relationships between concentrations of BSi and hydrological parameters were also discussed. There was a significant positive correlation between Chl a and BSi. The concentrations of BSi showed significant relationships with temperature and the concentrations of silicates, total inorganic nitrogen and total inorganic phosphorus, indicating that distribution of BSi was affected by temperature and nutrient level.  相似文献   

5.
2006年冬末春初,在德国POLARSTERN科学考察船执行南极威德尔海西北海域考察期间,调查了考察区海冰物理和海洋生物。本文观测了航线上钻取的27支海冰冰芯的组构和71个冰晶体薄片;分析得到393组冰温数据;348组盐度、密度数据和311组叶绿素a和脱镁叶绿素含量数据;通过302组冰内相同深度孔隙率和叶绿素a含量数据分析,发现海冰物理参数影响冰内叶绿素a含量的新证据;利用收集的雪、冰厚度数据以及环境容量制约生态平衡的规律,建立了雪、冰厚度对冰底叶绿素繁荣的影响以及;确立了南极粒状冰和柱状冰内叶绿素a上限含量同卤水体积的关系。从而表达了冰晶体对卤水排泄的效应和冰物理性质对南极春季冰底和冰-水界面叶绿素a增长的贡献。此外,还得出海冰物理性质影响冰藻,并且是南极冰区水体浮游植物繁荣的关键控制因素。  相似文献   

6.
采用HPLC-CHEMTAX方法分析了2008年春季东海近岸海域的表层浮游植物群落结构及其与环境因子的关系。结果表明,调查区表层浮游植物优势类群为硅藻和甲藻,对叶绿素a的平均贡献率分别为42%和32%。硅藻和甲藻均适于生长在低温、低盐和高氮磷比的环境,但硅藻水华发生在温度较低、盐度较高、氮磷比较高的长江冲淡水与外海水交汇的盐度锋面上,而甲藻水华发生在温度较高、盐度较低、氮磷比较低的冲淡水与台湾暖流交汇的温度锋面上。LOWESS回归表明,叶绿素a和甲藻分别随温度和盐度升高呈先增后降的趋势,硅藻随温度和盐度变化波动较大。叶绿素a和硅藻随氮磷比升高而递增,甲藻随氮磷比的变化波动较大。  相似文献   

7.
Distributions of dissolved nutrients and Chl. a were investigated in the Sangga Besar River Estuary in the well-managed Matang Mangrove Forest in West Malaysia. In the estuary, spring tide concentrations of ammonium, silicate and phosphate were higher than those in the neap tide, which suggests that these nutrients are flushed from the mangrove area by the inundation and tidal mixing of the spring tide. Ammonium comprised over 50% of the dissolved inorganic nitrogen in the spring tide, while nitrite tended to dominate in the neap tide, indicating the predominance of nitrification inside the estuary in neap tides. Nutrient concentrations in the creek water were higher than those of estuarine water, indicating the nutrient outwelling from the mangrove swamp and ammonium regeneration from mangrove litter in the creek sediments. The maximum concentration of Chl. a in spring tides reached 80 g/l while it was below 20 g/l in the neap tides. These variations in the phytoplankton biomass and nutrients probably reflect the greater nutrient availability in the spring tide due to outwelling from the mangrove swamp and creek.  相似文献   

8.
环境因素对杭州湾中型浮游动物群落结构的控制作用   总被引:1,自引:0,他引:1  
A quarterly study of mesozooplankton community structure and environmental variables in the Hangzhou Bay was conducted to examine the response of mesozooplankton community to the variation of water mass and environmental condition. The southeast coast of China is a typical region under the intensive influence of Asia monsoon and freshwater discharge from rivers. The water mass and environmental condition of the Hangzhou Bay, which were influenced by the interaction of currents, freshwater discharge of the Qiantang River and Changjiang River Plume, showed significant seasonal variation. Our results showed that both biomass and abundance were significantly higher in summer((247.7±148.8) mg/m~3 and(350.9±215.6) ind./m~3, respectively)than those in other seasons. Four eco-geographical regions were divided based on the cluster analysis of zooplankton community of the Hangzhou Bay throughout the year, except for winter. Monsoon and the dissolved inorganic nitrogen(DIN) input from freshwater discharge of the Qiantang River and Changjiang River resulted in temporal and spatial variations of environmental gradient in the Hangzhou Bay, which significantly influenced the structure of mesozooplankton community. Redundancy analysis(RDA) indicated that the mesozooplankton community structure was strictly correlated with the DIN gradient, while salinity gradient showed a weak influence in the Hangzhou Bay.  相似文献   

9.
对中国南海表层叶绿素a季节内变化的研究有助于深入认识其海洋特征,满足渔情预报等实际应用需求。利用卫星观测资料分析南海表层叶绿素a不同季节的季节内变化特征,结果表明南海表层叶绿素a季节内振荡强度冬季最高。冬季和春季的季节内振荡最强区域都位于吕宋岛西北侧海区,夏季和秋季振荡较强的区域偏向菲律宾群岛一侧。分析表明研究海区表层温度和表层叶绿素a 存在负相关,冬强夏弱,北强南弱。大部分海区海面高度和叶绿素a 相关性不显著,但南海东南边缘海区海面高度和叶绿素a在季节内存在正相关。冬季海盆尺度逆时针旋转的环流结构应是这些现象产生的原因。除南海东南边缘海区、海南岛东南海区和吕宋岛西侧海区之外,风应力大小和热通量均与叶绿素a 在季节内呈正相关。这显示非局地风场和海流等因素、海洋动力调整过程可能在吕宋海峡以西和南海东南边缘的表层叶绿素a 季节内变化中起到重要作用。  相似文献   

10.
Dimethylsulfide (DMS), chlorophyll a (Chl-a), accessory pigments (fucoxanthin, peridinin and 19-hexanoyloxyfucoxanthin), and bacterial production (BP) were measured in the surface layer (0–100 m) of the subarctic North Pacific, including the Bering Sea, during summer (14 July–5 September, 1997). In surface sewater, the concentrations of DMS and Chl-a varied widely from 1.3 to 13.2 nM (5.1 ± 3.0 nM, mean ± S.D., n = 48) and from 0.1 to 2.4 µg L–1 (0.6 ± 0.6 µg L–1, n = 24), respectively. In the subarctic North Pacific, DMS to Chl-a ratios (DMS/Chl-a) were higher on the eastern side than the western side (p < 0.0001). Below the euphotic zone, DMS/Chl-a ratios were law and the correlation between DMS and Chl-a was relatively strong (r 2 = 0.700, n = 27, p < 0.0001). In the euphotic zone, DMS/Chl-a ratios were higher and the correlation between DMS and Chl-a was weak (r 2 = 0.128, n = 50, p = 0.01). The wide variation in DMS/Chl-a ratios would be at least partially explained by the geographic variation in the taxonomic composition of phytoplankton, because of the negative correlation between DMS/Chl-a and fucoxanthin-to-Chl-a ratios (Fuc/Chl-a) (r 2 = 0.476, n = 26, p = 0.0001). Furthermore, there was a positive correlation between DMS and BP (r 2 = 0.380, n = 19, p = 0.005). This suggests that BP did not represent DMS and dimethylsulfoniopropionate (DMSP) removal by bacterial consumption but rather DMSP degradation to DMS by bacterial enzyme.  相似文献   

11.
Chlorophyll a(Chl a),particulate organic carbon(POC)and biogenic silica(BSi)were determined in coastal waters adjacent to the Zhujiang(Pearl)River Estuary(ZRE)during summer,in order to examine the C:Chl a ratio of phytoplankton and phytoplankton carbon in the plume-impacted coastal waters during summer,as well as to assess the relative contribution of diatoms to the phytoplankton biomass,by the regression between Chl a,POC and BSi.Our results showed that the C:Chl a ratio(g/g)of phytoplankton was high(up to 142),likely due to high light intensity and nutrient limitation.The river plume input stimulated phytoplankton growth,especially diatoms,resulting in higher relative contribution of phytoplankton carbon(55%)and diatoms(34%)to POC in the plume-impacted region than those(33%and 13%)in high salinity area,respectively.Phytoplankton carbon(up to 538μg/L)in the plume-impacted region was much higher than that(<166μg/L)in high salinity area.Our findings were helpful to improve the biogeochemical model in coastal waters adjacent to the ZRE.  相似文献   

12.
Temporal distributions of dimethylsulfide(DMS) and dimethylsulfoniopropionate(DMSP) were studied in the southern Yellow Sea(SYS) during April and September 2010. The mean concentrations(range) of DMS, dissolved and particulate DMSP(DMSPd and DMSPp) in the surface waters in spring are 1.69(0.48–4.92), 3.18(0.68–6.75)and 15.81(2.82–52.33) nmol/L, respectively, and those in autumn are 2.80(1.33–5.10), 5.45(2.19–11.30) and 30.63(6.24–137.87) nmol/L. On the whole, the distributions of DMS and DMSP in spring are completely different from those in autumn. In the central part of the SYS, the concentrations of DMS and DMSP in spring are obviously higher than those in autumn, but the opposite situation is found on the south of 34°N, which can be attributed to the differences in nutrients and phytoplankton biomass and composition between spring and autumn. Besides,the seasonal variations of water column stability and the Changjiang diluted water also have significant impact on the distributions of DMS and DMSP in spring and autumn on the south of 34°N. DMS and DMSPp concentrations coincide well with chlorophyll a(Chl a) levels in the spring cruise, suggesting that phytoplankton biomass may play an important role in controlling the distributions of DMS and DMSPp in the study area. Annual DMS emission rates range from 0.015 to 0.033 Tg/a(calculated by S), respectively, using the equations of Liss and Merlivat(1986) and Wanninkhof(1992). This result implies a significant relative contribution of the SYS to the global oceanic DMS fluxes.  相似文献   

13.
Phytoplankton communities can response immediately and directly to environmental changes,and thus have been applied as reliable biotic indicators in aquatic systems.This study provided insights into the relationships concerning ecological thresholds of phytoplankton communities and individual taxon in response to environmental changes in coastal waters of northern Zhejiang Province,East China Sea.Results demonstrated that there existed seasonal variations of phytoplankton community ecological thresholds of which spring being higher than those in summer.As for individual species,Prorocentrum donghaiense and Noctiluca scintillans were identified as the most tolerant and sensitive indicator species in spring and summer,respectively.They exhibited strong indications in response to environmental changes.These findings highlighted that phytoplankton community structure in this region was stable when environmental gradients were below the thresholds of sensitive species,whereas potential harmful algal blooms may occur when environmental gradients exceeded the thresholds of tolerant species.  相似文献   

14.
据2007年春季在南海西北部陆架区海域进行的网采浮游植物调查数据,分析了浮游植物群落的结构特征.此次共鉴定出浮游植物4门318种,其中硅藻类183种,甲藻类128种,蓝藻类5种,金藻类2种.大部分海域浮游植物种类数在40~70种之间,外海区域的种类数稍高于沿岸.浮游植物密度的变化范围为0.22×10。~3683.85×10。eells/m’,平均值(标准偏差)为97.49×10。(±437.38×10。)cel|s/m。.其高值区主要位于粤西近岸海域,向外海呈递减趋势.调查海域硅藻类的平均密度(标准偏差)最高,为93.82×10。(±434.34×10。)cells/m’;甲藻类的次之,为3.65×10。(±9.08×10。)cells/m’.浮游植物优势种主要有拟旋链角毛藻(Chaetocerospseudocurvisetus)、细弱海链藻(Thalassiosirasubtilis)、中肋骨条藻(Skeletonemacostatum)、劳氏角毛藻(Chaetocerosloren—zianus)和菱形海线藻(Thalassionemanitzschioides).该调查海域浮游植物多样性指数的变化范围为1.48~6.23,平均值(标准偏差)为4.70(±1.03),其分布趋势与浮游植物密度的分布趋势大致相反.将站位依等深线划分为粤西近岸海区、琼东南近岸海区和外海海区,应用非度量多维标度(nMDS)和聚类分析法分析这3个海区的浮游植物群落结构差异,并通过ANOSIM和SIMPER进行检验.结果表明3个海区之间浮游植物群落结构具有显著性差异,且粤西近岸海区与外海海区之间差异性较高.近岸种拟旋链角毛藻和中肋骨条藻在粤西近岸海区为最主要的优势种,而外海海区优势种较多,且大部分为大洋暖水性种类.  相似文献   

15.
The variability of dissolved organic carbon (DOC) over days to a multi-year time span has been investigated in the Gulf of Trieste (northern Adriatic Sea) over a period of 5 years (January 1999 to December 2003). Samples were collected in a grid of 9 to 12 stations on monthly frequency and in one station on weekly (2003) and daily (1-month) frequency. DOC samples were analyzed by the HTCO method. DOC concentration varied over the five years in the range of 50 to 194 μM with annual median values ranging from 88 to 98 μM. Over the years 1999–2002, DOC showed a clear annual periodicity with winter minima and late summer maxima, higher in 1999 and 2000. During 2003 no seasonality was detected. The absence of DOC seasonality and the lower DOC concentrations during 2003 are most likely related to the drought that characterized the whole year. Accumulation was calculated as the difference between averaged winter minima (59 ± 7 μM) and the monthly averaged integrated value. DOC that had accumulated from spring to summer totally disappeared from the water column in winter when DOC concentrations reached the background value. The Gulf of Trieste, as with the rest of the Northern Adriatic each year, seems to be able to bring back DOC concentrations at low levels despite the significant external (mainly Isonzo River inputs) and internal organic matter loads. DOC concentration exhibited quite wide fluctuations weekly and daily, suggesting there might be DOC of different turnover time through production, consumption, migration and accumulation.  相似文献   

16.
As part of a broader study on benthic-pelagic coupling in the southern North Sea, specimens of the common heart urchin Echinocardium cordatum were sampled for analyses on phytopigments and fatty acids in their guts. Results were interpreted in the context of feeding and ecological functioning of the heart urchins in the benthic system. Ingestion selection factors for both component groups were relatively high, 5 to 9 for chlorophyll a and 9 to 130 for total fatty acids. The data point to at least partially different sources of the pigments and of the fatty acids. Next to algal detritus, small infauna relatively rich in fatty acids might be preferentially co-ingested with the detritus. Due to digestive breakdown and absorption, the concentrations of pigments and fatty acids were importantly decreased, indicating a rather high digestion efficiency for this subsurface deposit feeder, up to 80%. The results indicate that E. cordatum increases its energy acquisition by strong selectivity and a high digestive efficiency. Optimal foraging is likely to apply on deposit-feeding invertebrates in relatively food-rich coastal environments as much as it does in the food-poor deep-sea environment. Using chlorophyll a as a proxy for carbon, the contribution of the urchin population to the momentary benthic carbon budget was calculated at 7% to 42%.  相似文献   

17.
本文依托2008年夏季中国第三次北极科学考察航次,对西北冰洋海盆区和楚科奇海陆架营养盐及光合色素进行了测定和分析。根据海水理化性质将研究海区分为5个区,并使用CHEMTAX软件(Mackery et al.,1996)讨论了西北冰洋不同海区浮游植物群落组成结构及其与环境因子之间的关系。结果显示在楚科奇海陆架区,太平洋入流显著影响浮游植物生物量和群落结构。高营养盐Anadyr水团以及白令陆架水控制海域,表现出高Chl a且浮游植物以硅藻为主,相反,低营养盐如阿拉斯加沿岸流控制海域,Chl a生物量低且以微型,微微型浮游植物为主。在外陆架海区,海冰覆盖情况影响着水团的物理特征及营养盐浓度水平,相应地显著影响浮游植物群落结构。在海冰覆盖区域,硅藻生物量站到总Chl a生物量的75%以上;在靠近门捷列夫深海平原海区,受相对高盐的冰融水影响(MW-HS),营养盐浓度和Chl a浓度相对海冰覆盖区略高,浮游植物结构中微型、微微型藻类比重增加,硅藻比例则降至33%;南加拿大海盆无冰海区(IfB),表层水盐度最淡,营养盐浓度最低,相应地显示出低Chl a生物量,表明海冰消退,开阔大洋持续时间延长,将导致低生物量及激发更小型浮游植物的生长,并不有利于有机碳向深海的有效输出。  相似文献   

18.
基于1998-2013年SeaWiFS和MODIS传感器的叶绿素浓度资料,本文分析了夏季南海西部叶绿素浓度高值带的年际变化规律。夏季,叶绿素及营养盐在海流的作用下离岸输送,从而在南海西部形成叶绿素浓度高值带,其分布与东向急流的流向一致。分析结果显示,高值带分布主要受13°N以南海域风场的调控,且滞后风场1周。当13°N以南海域受异常东北风(西南风)控制时,高值带位于其多年平均位置以北(南)。  相似文献   

19.
2013年4月,2014年5月,2012年6月和2015年10月在印度尼西亚北部苏拉维斯蓝碧海峡(Lembeh Strait)进行了4个航次的海洋生态调查,研究了蓝碧海峡的浮游植物种类组成,以及浮游植物群落结构的季节变化及其驱动因子。四个航次的调查中记录了5类浮游植物和416个种(类)。调查区浮游植物密度平均为2348cells/L,硅藻和甲藻种类最多。蓝藻种类最少,但丰度很高。季风转换期的4月份和10月份浮游植物丰度总量较低,东南季风期间5月份和6月份的浮游植物丰度较高。除了束毛藻(Trichodesmium)之外,常见种是浮游硅藻。浮游植物的丰度和多样性的季节性变化明显。海链藻(Thalassionema)、拟菱形藻(Pseudo-nitzschia)和蓝藻类的束毛藻对群落的不相似性贡献最大。由于蓝碧海峡南部营养盐浓度较高,南部水域的硅藻和甲藻密度稍高于海峡北部。虽然,南北两个水体中蓝藻的分布趋于均匀,但蓝碧海峡南部也有较高密度。与雅加达湾以及中国的一些海湾相比,蓝碧海峡的浮游植物丰度相当低。分析表明,SE季风期间上升流营养盐是左右浮游植物丰度月变化的重要因素。蓝碧海峡浮游生态系原始,且接近天然本底,人类活动背景噪声低,能够清晰地响应大环境的变化,是研究浮游生态系统的理想区域。  相似文献   

20.
本文基于卫星遥感的叶绿素a浓度与颗粒物后向散射系数月平均数据以及其他海洋与气象参数,详细分析了两个生物光学参量在季节尺度上的相关性及其与物理参数的耦合关系,并运用光驯化模型分析了南海表层水体浮游植物的生理学季节变化特征。结果表明,受南海地形和风场等物理参量的变化,南海叶绿素a浓度与颗粒物后向散射系数存在显著的季节和空间分布特征,具有一定的共变性和差异性。在南海近岸及浅水区,叶绿素a浓度与颗粒物后向散射系数有很好的耦合关系;而在南海深水海盆区,叶绿素a浓度冬高夏低,其季节循环过程与颗粒物后向散射系数相反,这主要是受浮游植物生理学过程的影响。"生物量控制区"与"光驯化控制区"的分界在南海与陆架-海盆分界线一致,体现了水深条件对浮游植物生理状态的影响。此外本文还发现,在吕宋海峡西部海区,叶绿素a与颗粒物后向散射系数的关系表现出"生物量-光驯化共同控制"的特点。  相似文献   

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