Fig. 1

Sampling localities in the North Atlantic Ocean and Mediterranean Sea. a Overview of localities in the North Atlantic and the Mediterranean Sea; b Geographical locations of the Azorean islands (in black) and seamounts (in green). Island/seamount groups in the Azores (Eastern, Central, and Western groups) are delimited by dashed orange boxes. Coastline from the Portuguese Hydrographic Institute (https://www.hidrografico.pt/op/33) and bathymetry derived from GEBCO 2020 (https://www.gebco.net/data_and_products/gridded_bathymetry_data/). Populations labelled as follows: [AZO (Azores), ICE (Iceland), KAT (Kattegat), ES (Spain), MRS (Marseille), COR (Corsica), CR (Croatia), SMA (Santa Maria), SMG (São Miguel/Sabrina), TER (Terceira), FAI (Faial), FLW (Flores), FOR (Formigas), PAB (Princess Alice Bank), ChB (Chino Bank), CB (Condor Bank), GB (Gigante Bank)]