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| Titel |
The applicability of an 87Sr/86Sr river isoscape to fish ecological questions in the Danube catchment |
| VerfasserIn |
A. Zitek, J. Irrgeher, K. Sailer, C. Trautwein, H. Waidbacher, T. Prohaska |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250068309
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| Zusammenfassung |
| Isoscapes are spatial maps of the distribution of isotopes on Earth. As a basis for ecological
studies such as long distance migrations of animals or for determining the origin of
food these tools are increasingly being developed, until now - mainly for terrestrial
systems. In contrast, in case of aquatic systems only few maps were established up to
now.
As far as variation in the isotopic distribution in a studied area exists, the isotopic
composition bears the potential to be used as natural tracer e.g. for ecological questions or
food authentication. Above all the 87Sr/86Sr ratio taken up from the environment by
organisms without any significant fractionation is known to provide a direct link to
geologically distinct regions.
Within the ‘IsoMark’ project (www.isomark.at), a database (‘Isoscape Austria’)
containing all available spatially explicit isotope data (terrestrial and aquatic) with a focus on
isotope distributions in Austrian rivers is being developed. Water samples from different
rivers, mainly along the Danube in Austria, were collected and analyzed for their elemental
and Sr isotopic composition.
Analyses of water samples yielded several ‘Isozones’ along the Austrian part of the
Danube, indicating diverse geology in these river catchments. Studying migration phenomena
of fish using natural isotopic marks in hard parts is especially possible between
these ‘Isozones’. In geologically similar regions with little differences, element
distributions or artificial marking methods (tagging, spiking) can serve as additional
means.
A significant positive relationship between the 87Sr/86Sr ratio in river water and the
proportion of siliceous geological formations in the catchment was found on a national and
European level. These analyses proved the possibility to predict the 87Sr/86Sr ratios
in river catchments all over Europe. This relationship allows for an estimation of
the applicability of the 87Sr/86Sr ratio for fish ecological questions on a European
scale like migration, homing and dispersal that can hardly be studied with other
methods. |
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