Abundances and biological traits of the juveniles salmon sampled in the survey of Salmon abundance Indices in the Bresle river (France)
A survey started in 2016 is conducted every year in early autumn (September to early october) to quantify the abundance of juvenile Atlantic salmon in the Bresle In Normandy. The electrofishing protocol of Prévost and Baglinière (1995) is used. It targets Atlantic salmon young of the year (0+ parr), but older fish (juvenile salmon ≥1+) are also caught and included in this dataset. Sampling is restricted to areas with shallow running water flowing on coarse bottom substrate, i.e. the preferred habitat of young of the year salmon. The data consist of abundance indices and biological traits measured on the fish sampled: length, weight and age. The latter is ascertained from scale samples taken from the fish which size does not allow to determine their age unambiguously. The survey is carried out under the Research Observatory on Diadromes Fishes in Coastal Streamss (ERO DiaPFC) program. The data are stored in the database of the ERO. They are used to develop predictive models and tools for providing scientific advice to improve the management of this heritage species.