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| Titel |
Reconstruction of water mass properties of the Western Mediterranean using stable isotope ratios (δ18O and δ13C) from Pinna nobilis shells |
| VerfasserIn |
Jose Rafael Garcia-March, Donna Surge, Jose Tena-Medialdea, Javi Torres, Micaela Garcia-Martinez |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250138633
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| Publikation (Nr.) |
 EGU/EGU2017-1712.pdf |
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| Zusammenfassung |
| We analysed the stable isotope ratios (δ18O and δ13C) from the calcite of the outer prismatic
layer of 8 Pinna nobilis shells at a rate of c. 12-16 samples/year for years between 1997 and
2013. These produced 8 time series between 4 and 16 years long. The empty shells had been
collected in two Spanish marine protected areas, Tabarca Island in Alicante and Columbretes
Islands in Castellón (4 specimens each). For all shells we constrained the time of death within
at least a halve year window. The present study completes previous calibrations by using
recorded seawater temperature data during at least two years for each site, coinciding with
part of the analysed periods in the shells. Our preliminary results clearly reflect the
seasonality of the signal in δ18O values for the entire ontogeny of the individuals
studied. However, one specimen from Tabarca Island sampled between years 4 and 11
(corresponding to real age) shows a clear ontogenetic change, with an abrupt reduction in
the amplitude of the signal from age 6 to 11 for both δ18O and δ13C values. We
hypothesize this pattern relates to the onset of first gonad maturation. Values of δ13C
track δ18O values in most individuals, but 3 specimens show low amplitude. For all
time series, δ13C values show a decreasing slope with ontogeny similar to previous
observations in P. nobilis and other bivalves. Estimated seawater temperature from
our δ18O time series reveals the potential of P. nobilis shells as valuable archives
of Mediterranean temperature reconstructions in the context of climate change. |
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