ICES | WK6ACODID; OUTPUTS FROM 2021 MEETING 2022 | 15 3.2 Summary and conclusions Heath et al. (2014) revealed two distinct spatio-genetic cod groups referred to as the “Dogger” (ICES Divisions 4.a, 4.b, 4.c, 6.a and 7.d) and “Celtic” (ICES Divisions 6.a, 7.a, 7.d, 7.e -k) units.