Zooplankton community responses to Ocean Acidification
Ocean acidification is affecting marine ecosystems directly through changes in pH, as well as indirectly, via trophic pathways. Thus, to evaluate impacts of ocean acidification on marine communities it is necessary to consider the potential pCO2 effects on population dynamics as well as community tr...
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| Other Authors: | , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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Universität Bremen
2017
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| Online Access: | https://media.suub.uni-bremen.de/handle/elib/1286 https://nbn-resolving.org/urn:nbn:de:gbv:46-00106079-12 |
| Summary: | Ocean acidification is affecting marine ecosystems directly through changes in pH, as well as indirectly, via trophic pathways. Thus, to evaluate impacts of ocean acidification on marine communities it is necessary to consider the potential pCO2 effects on population dynamics as well as community trophic interactions. Within the framework of the BIOACID II project (Biological Impacts of Ocean ACIDification), the overarching goal of this thesis was to study the effects of ocean acidification on zooplankton, focusing on copepods and jellyfish. The main results are described in four chapters (CHAPTER I to IV), each of which corresponds to a manuscript. The first part of this thesis evaluated pCO2 effects on natural mesozooplankton communities from a boreal fjord (CHAPTER I) and the subtropical Northeast Atlantic (CHAPTER II). Large-scale pelagic mesocosm units (a Kiel Off-Shore Mesocosms for Future Ocean Simulations : KOSMOS) were artificially enriched in CO2 to simulate future ocean conditions. In both experiments, we detected species-specific sensitivities to ocean acidification in copepods, as well as positive pCO2 effect on total mesozooplankton abundances under high-CO2 bloom conditions, caused by a bottom-up effect. During the Gullmar Fjord KOSMOS2013 experiment (CHAPTER I) species-specific sensitivities to CO2 were detected in copepods, as well as in hydromedusae. However, these effects on single species were not translated into the structure or the diversity of the community, likely due to the overwhelmingly dominance of Pseudocalanus acuspes, which resulted to be more abundant under acidic conditions, especially the younger (copepodite) life stage. In the Gran Canaria KOSMOS2014 study (CHAPTER II) a significant effect of pCO2 on phytoplankton succession was detected, ultimately affecting the development of the plankton community only after a simulated bloom event. The zooplankton community responded to the phytoplankton bloom in all mesocosms, although the response was delayed under high pCO2 conditions. ... |
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