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| Titel |
Oxygen Respiration rates of benthic foraminifera measured under laboratory conditions using oxygen microelectrodes |
| VerfasserIn |
Emmanuelle Geslin, N. Risgaard-Petersen, D. Langlet, E. Metzger, F. Jorissen |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250044073
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| Zusammenfassung |
| Oxygen respiration rates of benthic foraminifera are not well documented because of the
difficulties to measure them. However, the determination of the respiration rates of benthic
foraminifera is important in order: 1) to compare the metabolic rates of different species,
of various size, and with different microhabitats in the sediment; 2) to estimate
the contribution of benthic foraminifera in the aerobic mineralization of organic
matter.
Benthic foraminifera from 4 different natural environments were used: three species from the
intertidal rocky shore of Yeu island, two species from the muddy Bay of Aiguillon, two
species from the Bay of Biscay and eleven species from the Rhône prodelta (France). Living
foraminifera were placed in a small tube, in which oxygen gradients were determined
using oxygen microelectrodes. Respiration rates were calculated on the basis of the
oxygen fluxes measured in the vivinity of the foraminiferal specimens. Foraminiferal
biovolumes were estimated on the basis of the overall shape of the various species
(for example, Ammonia is assimilated to a half sphere) and the width of the shell
walls.
The results show a wide range of respiration rates according to the species (around
90 to 5300 pmol. cell-1.day-1) and a clear correlation with the biovolume of the
foraminifera. No clear relationship between respiration rates and microhabitat is
observed.
A comparison with previously published data shows that our estimations are generally lower
for the small size species. For example, the respiration rate estimations published recently by
Nomaki et al. (Journal of Foraminiferal Research, 37, 281-286, 2007) show a range of 900 to
10 000 pmol. cell-1.day-1.
The total contribution of benthic foraminifera in the aerobic mineralization of organic matter
is estimated for the studied areas. The first results suggest a minor role of benthic
foraminifera in this process, which strongly contrasts with their strong contribution to
anaerobic mineralisation of organic matter in the same areas (Pina-Ochoa et al., PNAS,
2009). |
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