I don't think so personally, because all the northern fur seals I've seen in Europe had much paler colouration. I assume South American or South African.
@FunkyGibbon South African is the same species as the Australian Fur Seal (A. p. doriferus), I'm not sure how different they would look or if these could be they but if not this could be the source of the confusion.
The cynic in me also notes that the South American Fur Seal is Arctocephalus australis...
So, bit of a plot thickener. The part of the pool behind this one was signed Australian Fur Seal, although the sign said Cape Fur Seal. On the one hand, would be simple to believe the aquarium only has one species and these were wrongly signed in bad faith. On the other, I'm loathe to do that, and its less likely they would mislabel something as A. pusillus when they already hold it.