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Titel |
Mesozooplankton community development at elevated CO2 concentrations: results from a mesocosm experiment in an Arctic fjord |
VerfasserIn |
B. Niehoff, T. Schmithüsen, N. Knüppel, M. Daase, J. Czerny, T. Boxhammer |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 3 ; Nr. 10, no. 3 (2013-03-01), S.1391-1406 |
Datensatznummer |
250018131
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Publikation (Nr.) |
copernicus.org/bg-10-1391-2013.pdf |
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Zusammenfassung |
The increasing CO2 concentration in the atmosphere caused by burning
fossil fuels leads to increasing pCO2 and decreasing pH in the world
ocean. These changes may have severe consequences for marine biota,
especially in cold-water ecosystems due to higher solubility of CO2.
However, studies on the response of mesozooplankton communities to elevated
CO2 are still lacking. In order to test whether abundance and taxonomic
composition change with pCO2, we have sampled nine mesocosms, which
were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted
to eight CO2 concentrations, initially ranging from 185 μatm
to 1420 μatm. Vertical net hauls were taken weekly over about one
month with an Apstein net (55 μm mesh size) in all mesocosms and
the surrounding fjord. In addition, sediment trap samples, taken every second
day in the mesocosms, were analysed to account for losses due to vertical
migration and mortality. The taxonomic analysis revealed that meroplanktonic
larvae (Cirripedia, Polychaeta, Bivalvia, Gastropoda, and Decapoda) dominated
in the mesocosms while copepods (Calanus spp., Oithona
similis, Acartia longiremis and Microsetella norvegica)
were found in lower abundances. In the fjord copepods prevailed for most of
our study. With time, abundance and taxonomic composition developed similarly
in all mesocosms and the pCO2 had no significant effect on the overall
community structure. Also, we did not find significant relationships between
the pCO2 level and the abundance of single taxa. Changes in
heterogeneous communities are, however, difficult to detect, and the exposure
to elevated pCO2 was relatively short. We therefore suggest that
future mesocosm experiments should be run for longer periods. |
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