碩士 / 國立臺灣海洋大學 / 海洋環境與生態研究所 / 107 / Mesozooplankton are able to ingest a wide range of food sources, which prey on phytoplankton as well as on different community of protozoans (such as ciliates), connect the microbial food web with the classical phytoplankton-zooplankton-fish food chain. So far, simultaneous estimated grazing impact of mesozooplankton on microbial and classical food webs has seldom been assessed in situ and the relative important of both are remaining uncertain. The model, we assumed that phytoplankton are channeled to higher trophic levels via two ways. One is the role of mesozooplankton in predation on microphytoplankton (> 20 μm) in the grazing food chain. The other is the microbial food chain, which includes components such as pico- and nanophytoplankton (<20 μm) have stressed the importance of predation by ciliates. Four experimental treatments: unfiltered water (treatment A), 200 μm filtered water (treatment B), 20 μm filtered water (treatment C) and 50% dilution experiments (50% of 200 μm filtered water diluted with 50% GF/F filtered water (treatment D)) were incubated for 24 h in 20 liters incubation bottles for measuring the production of phytoplankton and mesozooplankton consumption rate on phytoplankton. Research was conducted aboard the R/V Ocean Research I and samples were collected from the surface waters (5 m) at an established station (Station 1A) located in the southern ECS from a pre-typhoon cruise during 4-9 July 2018 and a post-typhoon cruise during 13-17 July 2018. Our results indicated that no significant grazing effects of mesozooplankton on > 20 μm phytoplankton before and after the typhoon samplings. Furthermore, < 20 μm phytoplankton contributed 82% and 63% to total phytoplankton biomass before and after typhoon, respectively. Analysis of model flux showed that production of < 20 μm phytoplankton was 22.4 and 39.2 mgC m-3 d-1 and accounted for 10.9 and 154.2 mgC m-3 d-1 for > 20 μm phytoplankton production before and after typhoon, respectively. As for grazing effect of ciliates, prior to typhoon, ciliates grazed 52% of the < 20 μm phytoplankton production and 110% of total phytoplankton production after the typhoon sampling. Meanwhile, the results of model showed that mesozooplankton feed mostly ciliate communities, especially the consumption rate of mesozooplankton on ciliate increased after the typhoon.
| Identifer | oai:union.ndltd.org:TW/107NTOU528A001 |
| Date | January 2019 |
| Creators | Liao, Tzu-Yi, 廖子誼 |
| Contributors | Tsai, An-Yi, 蔡安益 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 39 |
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