The harbour seal is hugely widely spread around the northern hemisphere. Indeed, it is the widely spread pinniped species, found around the north of the Atlantic, Pacific Baltic and North seas.
The global population is thought to be 350,000-500,000 (though there is a subspecies Ungava in Northern Quebec which is endangered.
Populations in Greenland, Hokkaido and the Baltic sea are reducing, and so are threatened. Here populations have been greatly reduced or eliminated.
There are 5 recognized subspecies as they are spread so widely across the world.
There are roughly 100,000 seals in Europe, and about 30% of them are in UK waters.