Okay, I see where part of the misunderstanding is coming from. Every professor and book that I've come in contact with has made differentiations in terms of anadromous--in other words, marine and anadromous are not mutually exclusive, depending on who you talk to. NOAA seems to think they are mutually exclusive, whereas when you look in much of the peer reviewed literature, they are not. For example:
http://resources.metapress.com/pdf-preview.axd?code=k4lq817u16623323&size=largest
That is part of what was confusing me as you were describing these fish. FWIW, monos and scats are actually amphidromous, moving back and forth almost daily. There are also distinctions to be made, since many anadromous fishes temporarily live in freshwater or even brackish water at a cost. It requires physiological changes that the fish may or may not be able to cope with for long periods of time. Salmon, as in your example, are a similar case. They are in rough shape by the time they spawn, since they are no longer capable of tolerating fresh water for very long. The problem with all of this is that tolerance is more along the lines of a continuum, so the lines fade quite a bit between species, making many of the terms, especially when used in certain contexts, extremely artificial. Nor do they denote preferences or in which environment a fish does better indefinitely.
Edit: In this case I think you and I both may be just spinning our wheels, so to speak