European Lobster populations between the Atlantic and Mediterranean do not show major genetic differentiation between them. However, molecular markers show evidence of four major distinct groups: northern Norway; Netherlands; remaining Atlantic area; and the Mediterranean (Triantafyllidis et al. 2005; Jørstad et al. 2005).

Marine Scotland Science considers twelve assessment units, each of which assessed and managed separately (ICES, 2013; Barreto and Bailey, 2014).