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| Titel |
The potential of microchemical information in fish hard parts to study origin and migration in the Austrian Danube catchment |
| VerfasserIn |
Katherina Sailer, Andreas Zitek, Herwig Waidbacher, Johanna Irrgeher, Thomas Prohaska |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250053492
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| Zusammenfassung |
| Mainly due to the underlying geology, the Danube and its tributaries show a spatially distinct
pattern in their elemental and isotopic composition. Fish living in a certain river system store
the local chemical information in their hard parts (otoliths, scales, fin rays and vertebrae),
allowing the determination of the origin of fish and bearing the potential to answer
important ecological questions such as migration habits, which are usually difficult to
monitor.
Focusing on freshwater fish, this study is the first to be done on a typical European fish
species, the European chub (Leuciscus cephalus L.). Water and fish samples were taken
from different rivers along the course of the River Danube in Austria and based on
their microchemical composition (Ca, Mg, Sr, Na and the 87Sr/86Sr ratio), water
samples were clustered to identify isozones which represent areas with similar
chemical signatures. In a second step, the microchemical information in the fish
hard parts was analysed in order to find out whether they could be matched with
the chemical information of their origin, or respectively with the corresponding
isozones.
Furthermore, the incorporation of the chemical information was studied in more detail,
revealing the effects and influences of the time exposed to specific conditions in a river, the
season, temperature and geological background. For this purpose, E. chub and barbel (Barbus
barbus L.), were transferred from a river with calcareous background to a river with siliceous
background and vice versa. The fish were held in specially designed fish cages under
semi-natural conditions. Water chemistry was sampled before and after the exposure, while
temperature was monitored during the whole experiment. After two and a half to three
months of exposure, five fish from each location were sampled in order to investigate their
hard parts.
The analysis of water samples and fish hard parts was conducted using nebulisation-based
and laser ablation inductively coupled plasma mass spectrometry, respectively, whereby a
quadrupole instrument (ICP-QMS) was used for trace element analysis and a multiple
collector instrument for strontium isotope ratio analysis (MC-ICP-MS). The combination of
these analytical techniques provides the establishment of specific elemental and isotopic
fingerprints of individual rivers and/or isozones and is able to deliver highly precise
information about the origin and migration of fish. |
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