> the European smoked salmon sold here in Australia have added 'smoke [or
 > smoke flavour] and salt' the Tasmanian smoked salmon have added sugar as
 > well!  Sugar in fish!

Salt and sugar are preservation agents; both lower the Aw (water activity).
Below .94, virtually all pathogenic bacteria die or stop growing, with the
notable exception of staphylococcus aureus (a salt tolerant pathogen).

Innocently, the other, most common way of excluding pathogens by way of food
preservation techniques is to lower the pH (usually below 4.5).  Often,
reductions in Aw and pH are used in combination.

Rob