Heterotrophic nanoflagellate and ciliate bacterivorous activity and growth in the northeast Atlantic Ocean: a seasonal mesoscale study
Heterotrophic nanoflagellate and ciliate bacterivorous activity and growth in the northeast Atlantic Ocean: a seasonal mesoscale study
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东北大西洋异养纳米鞭毛虫和纤毛虫的食菌活动和生长：季节性中尺度研究
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发表时间：
2008
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通讯作者：
M. Denis
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作者：
H. Karayanni;U. Christaki;M. Thyssen;M. Denis
2001 年冬季、春季和秋季，法国研究项目海洋多学科中阶梯状 (POMME) 项目在东北大西洋（北纬 38 至 45°，西经 16 至 22°）研究了异养纳米鞭毛虫（HNF）和纤毛虫对细菌产生（BP）及其生长率的影响。研究的不同参数的变异性似乎主要受初级生产的季节和纬度梯度控制，而不是该地区中尺度水平的强涡流活动。异养微生物丰度、生物量和原生生物摄食随时间变化，在浮游植物盛期、春季和盛期向北传播后呈现最高值。上部 100 m 的 HNF 生物量积分在春季最高（270 至 850 mg C m -2 ）。除 Tintinnus sp 外，纤毛虫综合生物量通常≤160 mg C m -2。当春季达到 637 mg C m -2 时，在北部反气旋涡流（A1）中爆发。 HNF和纤毛虫的生长速率分别为0.2至0.7 d -1 和0.2至1.4 d -1 。纤毛虫消耗的 BP 比例通常<10%，除了春季丁丁花盛开期间的反气旋涡 A1 达到 37% BP 外。总之，我们的数据表明，HNF 可以消除东北大西洋的大部分细菌产生（83 ± 27%，所有采样点和季节的平均值）。纤毛虫向较高营养级转移的碳量比 HNF 少；然而，大型食菌纤毛虫（主要是丁丁虫）的偶发性高频率增加了这些生物体作为微生物食物网中C-link的作用。
The grazing effect of heterotrophic nanoflagellates (HNF) and ciliates on bacterial pro- duction (BP), as well as their growth rates, was studied in winter, spring and autumn 2001 during the French research project Programme Ocean Multidisciplinaire Meso-Echelle (POMME) in the north- east Atlantic Ocean (38 to 45° N, 16 to 22° W). The variability of different parameters studied appears to be largely controlled by the seasonal and latitudinal gradients of primary production rather than the strong eddy activity at the mesoscale level in the area. Heterotrophic microbial abundance, bio- mass and protistan grazing varied temporally, presenting highest values during the phytoplankton bloom, during the spring period and following the northward propagation of the bloom. HNF biomass integrated over the upper 100 m was highest in spring (270 to 850 mg C m -2 ). Ciliate integrated bio- mass was generally ≤160 mg C m -2 except in a Tintinnus sp. bloom in a northern anticyclonic eddy (A1) in spring when it reached 637 mg C m -2 . HNF and ciliate growth rates varied from 0.2 to 0.7 d -1 and 0.2 to 1.4 d -1 , respectively. The fraction of BP consumed by ciliates was generally <10% except in the anticyclonic eddy A1 in spring during a tintinnid bloom when it reached 37% of BP. In conclu- sion, our data revealed that HNF can remove a large fraction of bacterial production in the northeast Atlantic Ocean (83 ± 27%, average of all sampling sites and seasons). Ciliates transferred less carbon to higher trophic levels than did HNF; however, episodic high occurrence of large bacterivorous cili- ates, primarily tintinnids, increased the role of theses organisms as C-links in the microbial food web.