The production and health performance of emerging aquaculture species, cobia and giant grouper, in former prawn farm pond and tank infrastructure is not well documented. The development of these alternative species offers flexibility and new production opportunities to WSSV affected farms in SE Queensland, and elsewhere in Australia to expand aquaculture production more generally.
Fish health problems are a common cause of aquaculture business failure. In prior pilot trials, significant health challenges were encountered that require thorough veterinary investigation and intervention. The information learnt from investigations can then form components of a health management plan for the culture of these two species in SE Queensland, in various systems. The description of health challenges through veterinary outbreak investigation allows the development and costing of interventions to prevent or treat the issue. Over the 12 month time frame of this project, surveillance strategies can be developed for early detection of disease. Such health management strategies facilitate early response actions that can minimise losses associated with infectious disease.
One metric which influences the viability of aquaculture systems is the density at which a species can be farmed. This is particularly the case in RAS, where the infrastructure capital costs are high. This project will document the impacts of stocking density on health and production in RAS, cages and ponds.
Another element that strongly influences viability of aquaculture enterprises is the growth rates of stock that are able to be achieved. Generating data from systems farmed at commercial densities can assist in determining the suitability of various sites for expansion of farming these species in Australia.
Final report
• Vaccinated and unvaccinated Giant Gropers performed similarly
• An experimental recombinant nodavirus vaccine appears to be efficacious in reducing mortalities and clinical signs in face of an outbreak.
• Giant Gropers and Cobia can be grown to market size in RAS tanks, cages within a brackish water lake, and ponds.
• Year round market placement and demand for the two species were identified.
• Cobia and Giant Groper production could be achieved in the previously affected white spot syndrome virus regions in South East Queensland.