This project was developed by Future Fisheries Veterinary Service (FFVS) in collaboration with Australian Prawn Farms (APF), James Cook University (JCU) Aqua Path laboratory, Queensland Biosecurity Sciences Laboratory (BSL) and the University of Adelaide (UofA). Unprecedented mortality events occurred in a commercial Australian prawn industry hatchery and grow-out farm between August 2018 and January 2019. Initial investigations did not identify the consistent involvement of an infectious agent in particular. A range of potential risk factors appeared to be associated with tank- and pond-level mortality events, however subsequent mitigation of these in the hatchery, did not appear to fully resolve the mortalities. The chronology of outbreaks within the hatchery and soon after pond stocking raised alarm that this could be an Australian case of Early Mortality Syndrome. Further investigation was warranted to identify if emerging infectious agents may be involved and to determine evidence-based control and prevention methods accordingly. During 2019, a prospective grow-out pond trial and retrospective epidemiological analysis of farm data were performed, to identify potential causative agents and/or risk factors associated with the mortality events. The project outputs will help shape recommendations for reducing disease risks, improve hatchery and grow-out farm practices, and further refine disease investigation approaches. The project was funded through the Fisheries Research and Development Corporation (FRDC).