Migration of juvenile herring ( Clupea harengus ) and sprat ( Sprattus sprattus ) between the North Sea and the Schelde estuary proved by stable C en N isotopes

The temporal changes in abundance of juvenile herring ( Clupea harengus , Linnaeus, 1758) and sprat [( Sprattus sprattus , Linnaeus, 1758)] in the Schelde Estuary were examined by means of stable isotopes. Juvenile herring and sprat typically overwinter in the estuary. Herring exhibits a second, smaller density peak in the summer. A similar density peak for sprat is not observed. The temporal use of the estuary by clupeoid fish has previously been attributed to seasonal migrations of juveniles between the North Sea and the estuary. Using stable isotopes of carbon and nitrogen we have tried to... Mehr ...