Saint John River, Tidal Waters?

Can anyone help me straighten this out? The lower Saint John. Does one need a licence to fish it? I always buy one (because I fish Trout lakes and streams), but I hear at least once a year from various relatives that they don't need a licence as long as they are in Tidal waters. Since the strip of the Saint John River we are one is tidal, they consider it the same as fishing out in the bay. I do remember a case a few years back of someone out fishing salmon in a river (perhaps the Restigouche) without a licence, and when stopped by the rangers he fought it, claiming they had no jurisdiction. I can't remember the outcome of that case.

Any thoughts? Where is the line between ocean fishing and river fishing? Is it at the mouth of the harbour? Reversing Falls? Oak Point (That's as far upstream as salt water penetrates) Fredericton (still tidal there, albeit not much)