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Titel |
Calcifying invertebrates succeed in a naturally CO2-rich coastal habitat but are threatened by high levels of future acidification |
VerfasserIn |
J. Thomsen, M. A. Gutowska, J. Saphörster, A. Heinemann, K. Trübenbach, J. Fietzke, C. Hiebenthal, A. Eisenhauer, A. Körtzinger, M. Wahl, F. Melzner |
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 ; 7, no. 11 ; Nr. 7, no. 11 (2010-11-26), S.3879-3891 |
Datensatznummer |
250005076
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Publikation (Nr.) |
copernicus.org/bg-7-3879-2010.pdf |
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Zusammenfassung |
CO2 emissions are leading to an acidification of the
oceans. Predicting marine community vulnerability towards acidification is
difficult, as adaptation processes cannot be accounted for in most
experimental studies. Naturally CO2 enriched sites thus can
serve as valuable proxies for future changes in community structure. Here we
describe a natural analogue site in the Western Baltic Sea. Seawater
pCO2 in Kiel Fjord is elevated for
large parts of the year due to upwelling of CO2 rich waters.
Peak pCO2 values of >230 Pa (>2300 μatm) and pHNBS values of <7.5 are encountered
during summer and autumn, average
pCO2 values are ~70 Pa (~700 μatm). In contrast to previously described naturally
CO2 enriched sites that have suggested a progressive
displacement of calcifying auto- and heterotrophic species, the macrobenthic
community in Kiel Fjord is dominated by calcifying invertebrates. We show
that blue mussels from Kiel Fjord can maintain control rates of somatic and
shell growth at a pCO2 of 142 Pa (1400 μatm, pHNBS = 7.7). Juvenile mussel recruitment
peaks during the summer months, when high water pCO2 values of ~100 Pa (~1000 μatm) prevail. Our findings indicate that calcifying keystone
species may be able to cope with surface ocean pHNBS values
projected for the end of this century when food supply is sufficient.
However, owing to non-linear synergistic effects of future acidification and
upwelling of corrosive water, peak seawater pCO2 in Kiel Fjord and many other
productive estuarine habitats could increase to values >400 Pa
(>4000 μatm). These changes will most likely affect calcification and
recruitment, and increase external shell dissolution. |
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