2010/757 Reducing the taint in Barramundi farmed in recirculating freshwater systems

By Priyantha Indrajith

Inconsistent quality of farmed Barramundi (pond or recirculation system) in the marketplace has been identified as a major issue causing buyer resistance and negative market impacts. This is limiting realisation of full revenue return for farmed Barramundi. The inconsistency in quality is mainly associated with the presence of 'earthy' or 'muddy' taints derived from planktonic and benthic algae (particularly cyanobacteria), fungi and actinomycetes which are known to produce geosmin (GSM) and 2-methyl isoborneol (MIB). These compounds impart muddy, earthy, musty odour, detectable by the human palate when present at extremely low concentrations in water and fish, and not favoured by consumers.

This project aimed to develop an algae-taint production model for recirculation systems. This innovative approach will provide clear and measurable direction for reducing taint compound levels through provision of a practical management tool. Its use will significantly improve knowledge of the balance between water quality, algicide use and purging time and conditions, and taint variability.