Pollock
While I guess I’m glad that McDonald’s is using a certified fish that is theoretically sustainable (although I doubt it really), I don’t know what karma the entire noble species that is pollock had in the past to deserve being harvested for such a loathsome product as the Filet-o-Fish.
Also, y’all should know what an Alaskan pollock actually looks like. Turns it is not actually a breaded, tasteless fish that swims between two awful slices of bread and a dollop of tartar sauce.