Fish production using various types of wastes is one of the oldest forms of aquaculture, originating in Asia around 2,000 year ago. It is still practiced in many Asian countries as an efficient means of integrating on-farm waste disposal with the production of fish for both commercial and subsistence purposes.
The severity of recent drought conditions has prompted many Victorian Water Authorities to actively pursue opportunities for water reclamation, recycling and re-use as part of their water and wastewater management strategies.
Marine and Freshwater Systems (MFS), a division of the Victorian Department of Primary Industries, received a grant to investigate the commercial viability and social acceptance of an innovative approach to the re-use of Class C recycled water – the production of fish using aquaculture technologies.
This concept differs from conventional, stand-alone aquaculture production systems as aquaculture would be integrated into the recycled water distribution system and the nutrient-rich wastewater would be the primary source of nutrition for the target culture species, rather than artificial diets.
In this aquaculture production system, known as Integrated Wastewater Aquaculture (IWA), the fish feed on plankton biomass and biosolids that are generated naturally when the recycled water is ponded and exposed to sunlight.
The project also investigated potential markets for the fish harvested from this process and identified the following product categories for analysis:
- Fishmeal and fish oil production
- Aquaculture feeds
MFS developed a series of case studies to address the main challenges to the creation of an IWA production system including:
- Socio-economic analysis, stakeholder and community engagement
- Product and market analysis
- Value chain assessment
Overall, MFS found that the viability of an IWA production system rested on a number of variables including the price of Class C recycled water, fish harvest yields and successfully tapping into existing commercial supply chains.