Difference of planktonic ciliate communities of the tropical West Pacific,the Bering Sea and the Arctic Ocean

Ciliates are important components in planktonic food webs,but our understanding of their community structures in different oceanic water masses is limited.We report pelagic ciliate community characteristics in three seas:the tropical West Pacific,the Bering Sea and the Arctic Ocean.Planktonic ciliate abundance had"bimodal-peak","surface-peak"and"DCM(deep chlorophyll a maximum layer)-peak"vertical distribution patterns in the tropical West Pacific,the Bering Sea and the Arctic Ocean,respectively.The abundance proportion of tintinnid to total ciliate in the Bering Sea(42.6%)was higher than both the tropical West Pacific(7.8%)and the Arctic Ocean(2.0%).The abundance proportion of small aloricate ciliates(10–20μm size-fraction)in the tropical West Pacific was highest in these three seas.The Arctic Ocean had higher abundance proportion of tintinnids in larger LOD(lorica oral diameter)size-class.Proportion of redundant species increased from the Arctic Ocean to the tropical West Pacific.Our result provided useful data to further understand ecology roles of planktonic ciliates in different marine habitats.     

“底充式增氧”技术对梭子蟹养殖池塘水质环境及浮游植物群落结构的影响

于2009年6-9月在浙江省宁海县三门湾海域养殖场,选取2口水文环境相似的梭子蟹Portunus trituberculatus养殖池塘,分别采用“底充式增氧”(实验塘)和传统水车式增氧(对照塘)方式,比较研究了池塘水质环境及其浮游植物群落结构的变化.结果显示:(1)实验塘水质的溶解氧和氨氮指标均优于对照塘,其中实验塘...     

浮游植物生长上行效应的研究进展

归纳了海洋浮游植物生长营养盐限制的研究方法,综述了国内外关于海水中氮、磷、硅、铁等营养元素限制浮游植物生长的研究结果。在氮、磷营养元素限制时,海水中上述两个元素的浓度不仅限制了浮游植物的生长,而且还改变了浮游植物的种群结构,随着营养盐浓度的降低,浮游植物从小型向微型、微微型转变;而硅的缺乏,使浮游植物由硅藻向非硅藻转变;在大洋海域,铁的限制,甚至还影响到浮游植物对常量营养盐的吸收。铁施肥虽然促进了浮游植物的生长,降低了大气中CO2的浓度,缓解了温室效应,但同时也伴随着有毒藻类的生长以及DM S气体增加等带来的诸多问题。     

Interspecific competition and allelopathic interaction between <Emphasis Type="Italic">Karenia mikimotoi</Emphasis> and <Emphasis Type="Italic">Dunaliella salina</Emphasis> in laboratory culture

Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on diff erent temperature (15°C, 20°C, and 25°C) and lighting (40, 80, and 160 μmol/(m²·s)) conditions. The growth of D. salina in bi-algae culture (1:1 size/density) was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-tocell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. mikimotoi were markedly influenced by both temperature (P =0.013) and irradiance (P =0.003), resulting in diff erent growth characteristics of D. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.     

南海北部初级生产力的物理-生物海洋学耦合特征及其对固碳量的影响

通过修订的VGPM模型,利用南海北部7年平均SeaWiFS和AVHRR遥感资料,分析了该海域河口上升流及反气旋涡等生境表层叶绿素浓度和初级生产力的周年变化,结果表明,季风驱动下的物理一生物海洋学耦合过程是控制研究海域浮游植物生物量和初级生产力时空变化的主导因素.浮游植物生物量和初级生产力随着季风、环流以及中尺度涡等物理...     

Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chl a)-like type, divinyl chlorophyll a (DV Chl a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.8...     

南海北部及珠江口细菌生产力研究

2004年2~3月和2004年8~9月两个航次中对珠江口及南海北部海域的异养浮游细菌生物量、生产力及其调控机制进行了观测研究.结果表明,营养物质的供应对调查区域真光层水体内的细菌生物量和生产力起着主要控制作用,从而导致冬季航次珠江口-陆架-外海调查断面表层细菌生物量和生产力呈现沿盐度梯度向外海逐渐降低的特征.就南海北部调查区域而言,冬季真光层异养细菌生物量(C)平均为(712±290)mg/m2,夏季平均为(937±397)mg/m2;真光层细菌生产力(C)冬季平均为(65.1±42.8)mg/(m2·d),夏季平均(52.5±28.6)mg/(m2·d).本调查中,南海北部海区IBP和IPP比值范围是4%~96%,平均为26%,IBP和IPP比值与初级生产力呈负相关,其分布特征与新生产力f比的分布趋势相反,显示了异养细菌在真光层物质循环过程中所发挥的作用在南海近岸富营养海域和外海寡营养海域之间的差异.     

闽浙沿岸海域溶解态铝的分布及其影响因素

闽浙沿岸海域是我国赤潮多发区之一,为研究浮游植物对铝的清除提供了良好的场所。于2007年5月和2008年5月对该区域溶解态铝的分布进行了调查分析,讨论了水团混合、悬浮颗粒物以及浮游植物水华对溶解态铝分布的影响,结果表明,溶解态铝的分布表现为近岸高、远岸低、表层浓度低于底层的特点,统计分析显示两年观测的结果无显著差异。影响溶解态铝分布的因素主要有水团混合和底沉积物的再悬浮,此外浮游植物水华对溶解态铝也具有一定的清除作用。     

南极夏季宇航员海浮游动物群落结构及其与环境因子的关系

基于中国第36次南极科学考察期间(2019年12月至2020年1月)于南极宇航员海使用北太平洋网(0.5m~2,330μm)采集的浮游动物样品,对浮游动物的丰度、群落结构、优势种种群结构及其与环境因子之间的关系进行了研究。结果表明:2019/2020年南极夏季宇航员海浮游动物总丰度在8.93—102.00 ind./m3之间,最高丰度记录在宇航员海中部靠北区域,浮游动物主要由桡足类、磷虾、毛颚类、浮游被囊类等类群组成。调查海域桡足类丰度对浮游动物总丰度的贡献可达90%以上,其中、大中型桡足类Calanoides acutus, Metridia gerlachei, Calanus propinquus和Rhincalanus gigas分布广泛,而小型桡足类Oithona similis、Oithona frigida、Ctenocalanus citer、Oncaea conifera等在丰度上占比较高。通过聚类分析可将宇航员海浮游动物在区域上划分为5个群落,普里兹湾涡流、威德尔涡流、南极绕极流南界等物理海洋学过程是宇航员海浮游动物群落分布模式的主要控制因素。另外,生物环境匹配(Bio-env)分析显示,饵料(叶绿素a)也对该海区浮游动物的种群和群落结构具有重要影响。     

2009年春季南黄海聚球藻生长率、被摄食消亡率及其与环境因子的关系

2009年春季(3-4月)在南黄海海域采用选择性代谢抑制剂技术测定了微微型光合浮游生物--聚球藻Synechococcus spp.的生长率和被摄食消亡率,研究了其空间分布格局及其与环境因子的相关性,并根据生长率估算了聚球藻碳生物量、碳生产力及其对微微型光合浮游生物总碳生物量的贡献.结果表明,在真光层内,聚球藻平均生长...