Development of techniques and evaluation of the potential of cage culture of silver perch for cotton farms

Silver perch (Bidyanus bidyanus) is an Australian native freshwater fish that is endemic to the Murray-Darling River System. It is a high quality, white-fleshed fish with few bones and high levels of omega oils. Research in the 1990’s demonstrated that is an excellent fish for pond culture and provided a technical basis for commercial production. A small industry based on earthen ponds currently produces around 400 tonnes annually, but development has been restricted by poor husbandry practices and production strategies on some farms, difficulties with pond management including losses to bird predation and disease, and the lack of largescale investment. Recent research at the Grafton Aquaculture Centre demonstrated that silver perch also performs very well in cages, with high survival (> 90%), good growth (1.6 – 3.5 g/fish/day) and high production rates (to 90 kg/m) at stocking densities of 100 – 200 fish/m. Potential advantages of cage culture include the elimination of bird predation and improved management including efficient feeding, grading, disease control and harvesting. Cages provide a relatively low-cost and flexible form of fish culture that can be readily adapted to existing water bodies such as storages and channels on cotton farms.