Tasmanian salmon farmers use broad spectrum antibiotic rather than a narrow spectrum, targeted antibiotic because the causes of many salmonid diseases in the southern hemisphere are unknown. Currently, the only antibiotic registered by the Australian Pesticides and Veterinary Medicines Authority (APVMA) specifically for use in salmonids is the broad-spectrum antibiotic oxytetracycline, which has a current permit for off-label use. Some of the other antibiotics used in salmonid farming internationally have previously been approved for use in Australia for salmonid farming or are currently approved for other purposes.

Skretting Australia did not provided information on what antibiotics had been ordered for including into their feeds, rather that, ’antibiotics are only administered when the fish are sick under veterinary prescription and supervision.’ The question of what antibiotics the terrestrial animals used in aquafeed were given during their lifetime was not addressed,

The feed companies claim antibiotic use is being reported by the farming companies.