Seals with non-standard fur, such as the fur seal in the photo, are relatively rare.
It is not known whether colour patterns like this are genetic (i.e. if these seals were to breed, would their offspring be similarly coloured). It is also not clear whether abnormal colouring affects the seals breeding success.
Depending on their colouring, some of these seals may not survive for long, as they may be relatively conspicuous to their predators.