Ingestion rates of phytoplankton by copepod size fractions on a bloom associated with an off-shelf front off NW Spain
Ingestion rates of phytoplankton by copepod size fractions on a bloom associated with an off-shelf front off NW Spain
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DOI：
10.1093/plankt/20.5.957
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发表时间：
1998
影响因子：
2.1
通讯作者：
S. Barquero;J. Cabal;R. Anadón;E. Fernández;M. Varela;A. Bode
中科院分区：
文献类型：
--
作者：
S. Barquero;J. Cabal;R. Anadón;E. Fernández;M. Varela;A. Bode
食草性桡足类进行了研究，从海岸到海洋，在1994年5月的盛开关闭西北西班牙。摄食率估计肠道叶绿素含量的方法在三个大小部分。叶绿素含量表现出明显的日周期变化。描述了三种不同的水体：沿海、陆架坡折和海洋;后两个区域由热盐锋面结构分隔。浮游生物种类组成，垂直分布和生物速率的显着差异，发现区之间。最高的浮游植物生物量，占主导地位的链形成硅藻，发生在海洋区与低初级生产率。桡足类摄食对海洋浮游植物的影响很小;每天消耗高达0.2%的碳储存和<3%的碳生产。相比之下，中型和大型桡足类去除3%的碳储量和12%的初级生产力，每天在海岸附近，浮游植物占主导地位的小鞭毛虫在活跃的增长。最高的浮游生物组成和摄食率的变化被发现在货架断裂区，可能是由于位移的前。桡足类对近岸沃茨浮游植物的捕食压力适中。同时，桡足类对近海水华的影响可以忽略不计，累积的颗粒碳的命运主要取决于沉积和水动力。
Herbivory by copepods was studied from the coast towards the ocean, during a bloom in May 1994 off NW Spain. Ingestion rates were estimated by the gut chlorophyll content method in three size fractions. The chlorophyll content displayed significant daily cycles. Three different water bodies were described: coastal, shelf break and oceanic; the latter two zones separated by a thermo- haline frontal structure. Marked differences in plankton species composition, vertical distribution and biological rates were found between zones. Thehighest phytoplankton biomass, dominated by chain- forming diatoms, occurred in the oceanic zone associated with low primary production rates. Copepod feeding had a low effect on oceanic phytoplankton; up to 0.2% of carbon stock and <3% of carbon production was consumed daily. In contrast, medium-sized and large copepods removed 3% of carbon stock and 12% of primary production daily near the coast, where phytoplankton were dominated by small flagellates in active growth. The highest variability in both plankton composition and ingestion rates was found in the shelf-break zone, probably due to displacements of the front. Copepods exerted a moderate predation pressure on phytoplankton in coastal waters. Meanwhile, the impact of copepods on the offshore bloom was negligible and the fate of the accumulated particulate carbon would be mostly determined by sedimentation and water dynamics.