Phenology and biological traits of adult migrating shad (Alosa sp) sampled by trapping in the survey in the Nivelle river (France)

Since 1984, monitoring has been carried out to observe migration phenology and quantify the abundance of migratory adults shad in Nivelle basin. In the Nivelle River, a trapping system controls adults shad migration by means of 2 traps, one in the downstream part and an other upstream to estimate the effectiveness. On this occasion, biometric characteristics are developed to characterize the population in order to feed this data set.