Abundance and biological traits of fish sampled by electrofishing (except specific abundance indices) on the River Oir since 1988 (France).

Since 1988, an annual campaign is conducted to quantify by electrofishing the abundance of fishes in the Oir basin. Originally, the main target species were salmon and trout. Beginning in 2000, eels were monitored in the same way as salmonids. The inventory of the entire fish community has been carried out on a network of seven sites. It is usually done in September and october. Two sites are also monitored in May for all species The data consist of 1738 electrofishing operations and 138765 fish caught. Biological traits measured on the fish sampled are sex, maturity status, length, weight and age. Some of the salmon, trout and eels are identified individually with a pit tag. Scale sampling is carried out on a sample to estimate the age of the fish. The survey is carried out under the Research Observatory on Diadromous Fish in Coastal Streams (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.