Spatial variability in d13C and d15N of estuarine and coastal benthic consumers derived from sand goby gut contents and muscle tissue
Guelinckx, J.; Geysen, B.; De Brabandere, L.; Dehairs, F.A.; Ollevier, F.P. (2008). Spatial variability in d13C and d15N of estuarine and coastal benthic consumers derived from sand goby gut contents and muscle tissue, in: Guelinckx, J. Estuarine habitat use by a goby species: a geochemical approach = Estuarien habitatgebruik door een grondelsoort: een geochemische benadering. pp. 33-45
In: Guelinckx, J. (2008). Estuarine habitat use by a goby species: a geochemical approach = Estuarien habitatgebruik door een grondelsoort: een geochemische benadering. PhD Thesis. Katholieke Universiteit Leuven, Laboratorium voor Aquatische Ecologie: Leuven. ISBN 978-90-8649-165-0. 163 pp., more
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| Authors | | Top |
- Guelinckx, J., more
- Geysen, B., more
- De Brabandere, L., more
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- Dehairs, F.A., more
- Ollevier, F.P., more
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| Abstract |
A prerequisite to trace animal movements between two areas using stable isotopes is that food sources of the species under study are isotopically different between both areas. Additionally, for clear interpretation, it is important that the migratory source population is relatively homogeneous in isotopic composition. This preliminary study examined both conditions with the prospect of investigating sand goby Pomatoschistus minutus (Pallas, 1770) immigration patterns from the North Sea to the upper Scheldt estuary (Belgium and The Netherlands) by means of C and N isotopes (δ13C and δ15N). Stable isotope analyses on monthly gut contents (June 2003 - March 2004) demonstrated that the δ13C value of sand goby prey items was on average 6 ‰ higher in the lower estuary than in the upper estuary. From June until November, δ15N was higher in the upper estuary than in the lower estuary, but this pattern reversed during winter and early spring. Sand goby muscle tissue showed no spatial δ13C variability along the Belgian coast, but our data revealed that coastal δ13C values were depleted relative to those offshore. Coastal δ15N values, on the other hand, increased considerably with increasing distance from the estuary during summer and autumn, but an inshore-offshore δ15N gradient was not detected. In contrast to δ13C, δ15N is not an appropriate tracer to study fish migration into the Scheldt estuary due to the alternating δ15N gradient in the estuary and the spatial heterogeneity of δ15N along the Belgian coast. |
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