Monitoring the salmon population in the Nivelle: for 40 years!

The overall picture is mixed. The capacity to produce juveniles in freshwater has improved, and the recent opening of the uppermost sections of the river system in Spain should help to reinforce this positive trend. At the same time, the ability to convert the juveniles produced into adult anadromous salmon returning to the Nivelle has declined. The most recent years are of particular concern, and the coming years will be crucial in determining whether this low point is temporary or whether it marks the start of an even more difficult period for the Nivelle salmon population.

The report can be accessed via this link https://hal.inrae.fr/hal-05360422v2/file/Rapport_Nivelle%287%29.html and on HAL : https://hal.inrae.fr/hal-05360422