http://www.fishbase.org/Summary/Species ... php?id=258
Occurs in clear vegetated lakes, quiet pools and backwaters of creeks and small to large rivers (Ref. 5723). Usually solitary and highly territorial. Enters brackish water in the Baltic.
I think we can assume from this reasonably reliable source that the pike is indeed a freshwater fish with certain strains (i.e. Baltic) able to tolerate brackish waters, i.e. estuaries. I'd imagine that if fjords had a good sized river entering them, the water might be sufficiently diluted to a point where pike might be able to hack it for a time.
As regards Lumpy's source
Saltwater Flyfishing: Britain and Northern Europe. in it its says that they regurally fish for pike in the fjords in Norway.
Err, did it mention if they caught any? :lol:
