Grey Seals have a cold temperate to sub-Arctic distribution in North Atlantic waters over the continental shelf (Hall 2002). There are three populations isolated both geographically and by timing of reproduction (Bonner 1981); mtDNA variations are large between these three breeding areas, though the Baltic and East Atlantic populations are much closer to one another than to the West Atlantic population (Boskovic et al. 1996). In the western Atlantic, the population is centred in north-eastern North America from the Gulf of Maine to southern Labrador, including the Gulf of St Lawrence. The eastern Atlantic population is concentrated around the United Kingdom (UK) and Ireland but is also found around Iceland, the Faroe Islands, and along the European mainland coast from the Kola Peninsula south to southern Norway, and from Denmark to Brittany in France. The Baltic Sea stock is confined to the Baltic Sea (Bonner 1981, Hall 2002). Vagrants are known from as far south as New Jersey in the western Atlantic and Portugal in the eastern Atlantic (Rice 1998).