TY - JOUR

T1 - The use of stable isotopes to trace small-scale movements by small fish species

AU - Durbec, Martial

AU - Cavalli, Laurent

AU - Grey, Jonathan

AU - Chappaz, Rémi

AU - Nguyen The, B.

PY - 2010/3

Y1 - 2010/3

N2 - Valuable biological information can be obtained by monitoring the movement of organisms. However, the choice of monitoring method becomes highly restricted when following small organisms (<100 mm), especially in aquatic ecosystems. Stable isotopes are being increasingly used in this respect but rarely at the local spatial scale, i.e. 10–1000 s of metres. We sought to identify movement of small fishes between a main river channel and its tributary. Little overlap in isotope baseline was detected between the two channels despite some temporal variability in δ15N of baseline indicator organisms in the main river. The individuals of two small cyprinid fish species (Leuciscus souffia and Alburnoides bipunctatus) of all the size classes (40–100 mm) caught within the tributary showed considerable heterogeneity in δ15N values. Classification and discriminant analysis on isotope-derived data distinguished two significantly different groups. Moreover, this result was supported by further sampling of fish caught in the main river (in May and December 2006). Alternative hypotheses, such as dietary differences, biological factors, temporal shifts and spatial differences in diet, did not explain δ15N variability. This application of stable isotopes at a relatively small spatial and temporal scales further demonstrates its potential as a tool for ecologists.

AB - Valuable biological information can be obtained by monitoring the movement of organisms. However, the choice of monitoring method becomes highly restricted when following small organisms (<100 mm), especially in aquatic ecosystems. Stable isotopes are being increasingly used in this respect but rarely at the local spatial scale, i.e. 10–1000 s of metres. We sought to identify movement of small fishes between a main river channel and its tributary. Little overlap in isotope baseline was detected between the two channels despite some temporal variability in δ15N of baseline indicator organisms in the main river. The individuals of two small cyprinid fish species (Leuciscus souffia and Alburnoides bipunctatus) of all the size classes (40–100 mm) caught within the tributary showed considerable heterogeneity in δ15N values. Classification and discriminant analysis on isotope-derived data distinguished two significantly different groups. Moreover, this result was supported by further sampling of fish caught in the main river (in May and December 2006). Alternative hypotheses, such as dietary differences, biological factors, temporal shifts and spatial differences in diet, did not explain δ15N variability. This application of stable isotopes at a relatively small spatial and temporal scales further demonstrates its potential as a tool for ecologists.

KW - Baseline

KW - Carbon

KW - Nitrogen

KW - Migration

KW - Cyprinidae

KW - Leuciscus souffia

KW - Alburnoides bipunctatus

KW - River

U2 - 10.1007/s10750-009-0051-z

DO - 10.1007/s10750-009-0051-z

M3 - Journal article

VL - 641

SP - 23

EP - 31

JO - Hydrobiologia

JF - Hydrobiologia

SN - 0018-8158

IS - 1

ER -