According with tagging and genetic studies, it has been strongly suggested that Atlantic cod in the north Atlantic is sub-structured. The research of cod stock structure in Norwegian and Icelandic waters, and in the northwest Atlantic revealed considerable genetic differentiation between populations at localized scale (Imsland and Jónsdóttir 2003).

The Atlantic cod population in the Flemish Cap is considered a genetically distinctive population from those elsewhere in the Northwest Atlantic (Beacham 2002).