The fate of nanoflagellates in northeast coastal waters of Taiwan – a relay or the end of carbon flux in the microbial loop

• Main Authors: Chang, Wei-Lun, 張維倫
• Other Authors: Tsai, An-Yi
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/92z8vy

碩士 === 國立臺灣海洋大學 === 海洋環境化學與生態研究所 === 104 === It is clear from many studies that grazing by pigmented and heterotrophic nanoflagellates can control bacterial and Synechococcus spp. biomass by removing a substantial fraction of bacterial and Synechococcus spp. production in the coastal water of northeastern Taiwan. Little is known about the factors controlling variations in nanoflagellate growth and grazing in oceanic environments. In this study, the size-fractionation experiments (unfiltered and 10 μm filtered treatments) were performed to measure nanoflagellate growth rates, microzooplankton grazing and its effects on their role within the microbial food web. In this study, seawater samples to measure short-term (2 days) growth and grazing experiments were collected from surface waters monthly from September 2014 to August 2015. In the present study, we found that there were the clear seasonal variations in gross growth rates of pigmented and heterotrophic nanoflagellate and with the higher values in summer. In these experiments, significant impact of microzooplankton grazing were detected in January and June 2015, accounted for 50% and 60% of pigmented and heterotrophic nanoflagellate production, respectively. Beside this, the grazing dynamics of bacteria on the western coast of the subtropical Pacific were significantly influenced by ciliates between May and October in some experiments. We also found evidence for the effect of trophic cascades was significant at situations which ciliates obviously grazing on nanoflagellates in unfiltered treatments.