The blood flukes, Cardicola forsteri and C. orientalis, have been identified as the cause of a significant mortality increase in farmed Southern Bluefin tuna (SBT) where their impact can have a significant effect on industry productivity and profitability. Treatment with praziquantel has been successful but the industry seeks continuous improvement in health management especially as it affects productivity, and infection dynamics appear to have changed since the start of praziquantel use.

Reflecting on interesting observations around blood fluke levels in treated and untreated pontoons, the current project will:

• gather and provide detailed SBT health data with regard to praziquantel treated and untreated cages to the industry;
• attempt to understand differences between nearby praziquantel treated and untreated cages; and

• obtain a more detailed understanding of SBT pathogens in environmental samples.

  These baseline SBT health data will be valuable for future longer-term projects.