Vertical migration, entrainment and photosynthesis of the freshwater dinoflagellate Peridinium cinctum in a shallow urban lake
Vertical migration, entrainment and photosynthesis of the freshwater dinoflagellate Peridinium cinctum in a shallow urban lake
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DOI：
10.1093/plankt/fbh008
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发表时间：
2004-02
影响因子：
2.1
通讯作者：
R. Regel;J. Brookes;G. Ganf
中科院分区：
文献类型：
--
作者：
R. Regel;J. Brookes;G. Ganf
对南澳托伦斯湖多甲藻的垂直迁移、卷吸和光合作用进行了研究。细胞分布是游泳速度、剪切速度和表面混合层深度的函数。在上午，当风速较低时，细胞向上迁移，速度为2.35 × 10 ~ 4 ms ~（-1），并在0.7 m处积累（13：00 h时为827 mol m ~ 2 s ~（-1））。13：00 h后，细胞以1.85 × 10 ~ 4 ms ~（-1）的速度向下迁移至3.3-3.6 m。下午风速增大，表层混合层的切变速度超过了游泳速度，导致细胞在表层混合层中分布均匀。在表层混合层之下，深层叶绿素最大值持续存在。发现观察结果符合夹带函数（），其中如果> 1，则细胞被分离，如果< 1，则细胞被夹带。以光系统II的最大有效量子产额（F0 v/F0 m）作为衡量花背蕨光合性能的指标，以瓶（固定深度）与湖的F0 v/F0 m之比作为迁移或混合是否促进光合作用或防止光抑制的指标。在分层条件下，在瓶子和湖面样品中观察到P. cincctum的F0 v/F0 m的小（0.1-0.2单位）但显著的降低。然而，这在当天晚些时候恢复到初始值。瓶湖F0 v/F0 m的比值与环斑潜蝇的迁移模式一致。所观察到的迁移和一个理论上均匀的人口建模的每日光合速率之间的比较表明，迁移不会增加托伦斯湖内的光合速率。从黎明到黄昏，迁移和均匀分布的细胞群在水柱中的O2净生产率分别为2574和3120 mg m？2。
Vertical migration, entrainment and photosynthesis of Peridinium cinctum were investigated in the Torrens Lake, South Australia. Cell distribution was a function of swimming speed, shear velocity and the surface mixed layer depth. During the morning, when the wind speed was low, cells migrated upwards, at a velocity of 2.35 � 10 � 4 ms � 1 and accumulated at 0.7 m (827 � mol m � 2 s � 1 at 13:00 h). After 13:00 h, cells migrated downwards to 3.3-3.6 m at 1.85 � 10 � 4 ms � 1 .A s wind speed increased in the afternoon, the shear velocity of the surface mixed layer exceeded the swimming speed, leading to a homogeneous cell distribution within the surface mixed layer. Below the surface mixed layer, a deep chlorophyll maximum persisted. The observations were found to fit in an entrainment function ( ), where if > 1, cells are disentrained, and if < 1, cells are entrained. The maximum effective quantum yield of photosystem II (F 0 v/F 0 m) was used as an index to monitor the photosynthetic performance of P. cinctum and the ratio of bottle (fixed depth) to lake F 0 v/F 0 m indicated whether or not migration or mixing was enhancing photosynthesis or preventing photoinhibition. A small (0.1-0.2 units) but significant depression in F 0 v/F 0 m was observed in P. cinctum in bottle and lake surface samples during stratified conditions. However, this recovered to initial values later in the day. The ratio of bottle to lake F 0 v/F 0 m was consistent with P. cinctum migration patterns. A comparison between modelled daily photosynthetic rates of the observed migrating and a theoretical homogeneous population revealed that migration would not increase photosynthetic rates within the Torrens Lake. The net rates of O2 production in the water column from dawn to dusk for the migrating and evenly distributed cell populations were 2574 and 3120 mg m � 2 , respectively.