Evaluation of the potential for aquaculture on cotton farms - cage culture of silver perch
Abstract
Aquaculture is the fastest growing food-producing industry in the world, and currently contributes nearly 50% of total fisheries production. It has great potential in Australia because of our limited wild fisheries, over-exploitation of some fisheries, and importation of large quantities of fish. Freshwater fish contribute around half the global aquacultural production. The native freshwater fish silver perch (Bidyanus bidyanus) has significant potential, and R&D by the NSW Government has provided a technical basis for industry development. Although around 500 tonnes are produced annually in ponds, the industry has not realised its potential to date due to difficulties with pond management, slow growth and losses to bird predation and infectious diseases during winter, the high cost of feeding and the small scale of most farms. Cages are easy to manage, facilitate efficient feeding, and protect fish from birds. Cages also enable the use of water bodies such as storages on cotton farms that are otherwise unsuitable for commercial aquaculture. Water for irrigation is a substantial and recurring cost to cotton farmers, and freshwater aquaculture may offer an opportunity to add value to the water and improve water-use efficiencies. This study demonstrated that silver perch is an excellent species for cage culture. High survival and good growth at high stocking densities lead to high production rates. Optimal stocking densities based on fish performance and welfare were identified for different production phases (e.g.100 fish/m3 for grow-out to > 500 g). Commercially-available diets with 30-45% protein and 10-17 MJ/kg energy were suitable, and the cost-effectiveness of feeding was determined principally by purchase price. A new strategy of over-wintering fingerlings at elevated temperatures in a tank-based recirculating aquaculture system (RAS) significantly improved survival and growth, and shortened the overall culture period.
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- Cotton CRC Final Reports
Final project reports from Cotton Catchment Communities CRC