Downstream migration of radio-tagged silver eels

No abstracts are to be cited without prior reference to the author.

The catadromous eel leave the feeding grounds in fresh water during late autumn to migrate to the spawning grounds in the Sargasso Sea. During the last decades the European eel population Anguilla anguilla (L.) has decreased to a historic low population level (Dekker 2004). One of the reasons for the population decline is past anthropogenic alterations of rivers for urban and agricultural development, including building of dams for water management. While upstream obstructions to migration have been mitigated by eel passes, little attention has been paid to downstream migration and the effect of obstructions causing e.g. migration delay or increased mortality.