The smelt (osmerus eperlanus) belongs to a family closely related to the salmonids. This small fish species grows to a length of 20 cm. It has a migratory form that travels from the sea upriver to spawn. In earlier times, the species was common in the Rhine, but today it is still found in the Dutch Rhine delta. The building of barrages has however resulted in the loss of estuary waters in the Rhine delta region, so the environment of the species has been drastically reduced.
