Sardines are placed in the marinating machine where they are injected with medicine for the tuna to consume. The bait is then frozen until required to treat a whole cage of fish.
Praziquantel is a medicine used in livestock and even humans, but it is expensive, needs to be administered at particular time in the life cycle, and means a wait of up to 21 days before the tuna can be harvested and sold. "When the vet writes the prescription then the medicated feed will be taken out and fed to the farm over two days to make sure we get good coverage of every fish in the pontoon," Dr Webber said.
"There are a lot of efficiencies to be gained there by being able to treat specifically at the right time for the problem instead of just going out … and treating because you think that's the right time to do it.Dr Webber said ranch mortalities had reduced to just 2 per cent because of the treatment, and those were due to causes other than blood fluke.
She said there might come a time when there were so few infected tuna that treatment might be administered in a fallow basis, but it would be impossible to wipe out the blood fluke completely."I don't think there'll ever be a time where we don't have blood fluke," she said.