Megalocytiviruses are a group of closely related viruses that cause mass mortalities in both marine and freshwater aquaculture. They are of global importance as they are listed by the World Animal Health Organization (OIE). They are difficult to control as they infect over 125 fish species and individuals can be carriers for life with sporadic disease events resulting in considerable losses at farms. This project was developed by the University of Sydney following consultation with Department of Agriculture and Water Resources (DAWR), relevant state agencies dealing with aquatic biosecurity and from advice received from native fish and ornamental fish aquaculture producers. Research has shown that imported ornamental fish are a pathway for Megalocytivirus to enter Australia. There was a critical need to develop practical and efficacious disinfection protocols for recirculating aquaculture systems. We used ISKNV freshly amplified in vivo at low passage to evaluate eight disinfection procedures using a bioassay with Murray cod (Maccullochella peelii) as a sensitive test for infectious virus. The six disinfection protocols that produced negative bioassays and were considered effective are described in this report. Further, it was demonstrated that ISKNV remained infectious in aquarium water (void of fish) at 25°C for at least 48 hours. Recommendations have been made to revise operational and disease strategy manuals as part of AQUAVETPLAN and an awareness program for increased reporting of mortality events at ornamental fish aquatic facilities for emergency disease response. The research findings will be used by biosecurity regulators and farm managers for disinfection efficacy data specific for ISKNV. These virus specific data enable interpretation of disinfection guidelines for the prevention and control of disease caused by ISKNV. The project was funded by the Australian Government Department of Agriculture and Water Resources through the Fisheries Research and Development Corporation.