DIRECT OBSERVATIONS OF THE MASS FLOCCULATION OF DIATOM BLOOMS - CHARACTERISTICS, SETTLING VELOCITIES AND FORMATION OF DIATOM AGGREGATES
DIRECT OBSERVATIONS OF THE MASS FLOCCULATION OF DIATOM BLOOMS - CHARACTERISTICS, SETTLING VELOCITIES AND FORMATION OF DIATOM AGGREGATES
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DOI：
10.1016/0198-0149(89)90131-3
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发表时间：
1989-02-01
期刊：
影响因子：
--
通讯作者：
GOTSCHALK, CC
中科院分区：
文献类型：
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作者：
ALLDREDGE, AL;GOTSCHALK, CC
在加州[美国]的圣巴巴拉海峡的表面沃茨中，观察到形成链的海洋硅藻在聚集成厘米大小的海洋雪絮体的过程中大量繁殖。这些聚集体由丰富的组合生活，积极光合作用硅藻占主导地位的刚毛属角毛藻和链形成菱形属。絮凝的一个水华发生在短短的24小时，和水华絮凝显然不是由氮限制引发的。硅藻起源的海洋雪也丰富在春季，夏季和初秋整个南加州湾，这表明硅藻絮凝是一个季节性的重要来源的海洋雪。休眠孢子很少发生在新形成或老化的硅藻絮凝体。现场平均沉降速度（±）标准差）新形成絮体的数量为117 . ±. 56 m d-1，比未聚集的角毛藻快两个数量级。通过大量絮凝和硅藻水华的沉降，快速、间歇性地将表层初级生产输出到海底，可能发生在远洋食草动物消费之前，并对海洋食物网、海洋通量过程和硅藻生物学产生重大影响。
Blooms of chain-forming marine diatoms were observed in the process of aggregating into centimeter-sized flocs of marine snow in surface waters of the Santa Barbara Channel, California [USA]. These aggregates were composed of a rich assemblage of living, actively photosynthesizing diatoms dominated by the setose genus Chaetoceros and by chain-forming Nitzchia spp. Flocculation of one bloom occurred in as little as 24 h, and bloom flocculation apparently was not triggered by nitrogen-limitation. Marine snow of diatom origin was also abundant during spring, summer and early autumn throughout the Southern California Bight, suggesting that diatom flocculation is a seasonally significant source of marine snow. Resting spores rarely occurred within either newly formed or aged diatom flocs. The mean in situ settling velocity (.+-. S.D.) of newly formed flocs was 117 .+-. 56 m d-1, two orders of magnitude faster than unaggregated Chaetoceros. Rapid, episodic export of surface-derived primary production to the ocean bottom via mass flocculation and settlement of diatom blooms can occur prior to consumption by pelagic grazers and significantly effects marine food webs, oceanic flux processes, and diatom biology.