I'm a fisherman's daughter. I grew up on the boat with my father, a professional cray fisherman, eating fish as fresh as it gets. I have a shack now in the D'Entrecasteaux Channel in southern Tasmania, opposite the salmon farms. Over the years I've watched that waterway change in ways that are hard to come to terms with. That tension - between what I grew up proud of and what I see happening to those waters - is part of why I'm writing this. So is the clinical picture. The evidence on farmed Atlantic salmon has shifted considerably, and most people, including the mainland naturopaths I spoke to at a recent conference, have no idea. This is Part 1: what's actually changed in the nutritional profile of farmed salmon, and why the health case for it is weaker than it used to be.