The role of sympagic meiofauna in Arctic and Antarctic sea-ice food webs
Both Antarctic and Arctic sympagic meiofauna investigated in this study included taxa new to sea ice. Diversity, abundance and biomass of metazoan meiofauna were significantly higher in a perennially than in a seasonally ice-covered Antarctic region. Brackish meltponds on Arctic sea ice hosted vario...
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| Other Authors: | , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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2011
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| Online Access: | https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-63534 https://macau.uni-kiel.de/receive/diss_mods_00006353 https://macau.uni-kiel.de/servlets/MCRFileNodeServlet/dissertation_derivate_00003723/diss_kramer_ipoe_2010.pdf |
| Summary: | Both Antarctic and Arctic sympagic meiofauna investigated in this study included taxa new to sea ice. Diversity, abundance and biomass of metazoan meiofauna were significantly higher in a perennially than in a seasonally ice-covered Antarctic region. Brackish meltponds on Arctic sea ice hosted various proto- and metazoans. Stable isotope and fatty acid analyses combined with grazing and predation experiments showed that most metazoan meiofauna prey on ciliates and some even on metazoans. Many of them supplement their diets with algae, bacteria and detritus. A few meiofauna taxa are mainly herbivorous, but can additionally prey on ciliates or nauplii. Ingestion rates were influenced by food density (functional response) and predator density (competition). Grazing rates and the derived grazing impact of the meiofauna community were generally low. Predation rates, in contrast, were very high in some taxa, and the derived predation impact of the meiofauna community was accordingly high. Die hier untersuchte sympagische Meiofauna der Antarktis und Arktis umfasste einige neue Meereis-Taxa. In einem ganzjährig eisbedeckten antarktischen Gebiet waren Diversität, Abundanz und Biomasse der Metazoen-Meiofauna signifikant höher als in einem saisonal eisbedeckten. Brackige Schmelztümpel auf arktischem Meereis beherbergten etliche Proto- und Metazoen. Analysen stabiler Isotope und Fettsäuren, Grazing- und Prädationsexperimente belegten, dass sich ein Großteil der Metazoen-Meiofauna räuberisch von Ciliaten und teils sogar von Metazoen ernährt. Häufig ergänzt sie ihre Nahrung mit Algen, Bakterien und Detritus. Wenige Meiofauna-Taxa sind vorrangig herbivor, können sich aber zusätzlich von Ciliaten oder Nauplien ernähren. Die Ingestionsraten wurden durch Futter- und Räuberdichte beeinflusst. Die Grazingraten und der abgeleitete Grazingdruck der Meiofauna-Gemeinschaft waren im Allgemeinen niedrig. Die Prädationsraten und der abgeleitete Prädationsdruck hingegen waren teils sehr hoch. |
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