Phenology and biological traits of migrating eels sampled by trapping in the Oir river (France).

Since 1984, monitoring has been carried out to observe migration phenology and quantify the abundance of migratory eels in the Oir basin. In the downstream part of the Oir River, a trapping system controls eel migration (a descent trap since 1984 for silver eels that descend and more recently, in 2017 an upstream trap for yellow eels). On this occasion, biometric characteristics are developed to characterize the population in order to feed this data set....