European anchovy (Engraulis encrasicolus) inhabiting the Bay of Biscay is isolated from adjacent populations. It is assessed and managed as a single stock, even though during autumn there is almost a continuous distribution that could connect this population with the one in the North Sea (ICES 2014)(Huret et al. 2020). According to (Montes et al. 2014) two genetic populations should be considered, differentiated by their genetic adaptation to salinity. One of the populations is present in oceanic waters, and the other inhabits estuaries and river plumes. In river plumes, both populations might overlap. The ICES scientific working group considers it should be assessed and managed as a single stock, despite certain evidences of genetic heterogeneity and subpopulations, since most of the population inhabit the same areas and show homogenous recruitment pulses, in addition to having common spatial dynamics (Boyra et al. 2013).

The fishery is managed at a European level, and landings are exclusively from two countries: Spain and France. Both State Members have a purse-seine fishery, and France also has a pelagic trawler fishery, although in a decreasing trend. Nevertheless, these vessels operate mostly on the sardine and capture anchovy as an opportunistic resource (ICES 2021).