Warm waters, faster growth rates and pressure on fish quality
The Atlantic Salmon farming industry in Australia is growing, and currently valued at $500 million per year. The vast majority of salmon farming is located in Tasmania, where waters are the warmest in the world for Atlantic salmon culture. Warmer temperatures mean that Tasmanian Atlantic salmon can grow to a harvestable size within 16-18 months - a faster rate of growth than in other salmon producing areas of the world. However, faster growth comes at a cost: early maturation of fish degrades flesh quality, leading to a loss in market value, and increased susceptibility to disease which can result in significant stock losses.
The Tasmanian industry was also faced with issues including a closed population and therefore a need to manage genetic diversity, and biosecurity restrictions on movement of potential broodstock from the sea back to freshwater hatcheries. There was a need to manage key commercial traits, including growth rates and disease resistance, to further expand the salmon breeding industry.
Selective Atlantic Salmon Breeding
In a joint project with Salmon Enterprises of Tasmania (SALTAS), CSIRO commenced a seven year project to establish a family- based selective breeding program in 2004. The selective breeding program focused on key performance traits in Tasmania’s Atlantic salmon stocks, including increasing seawater growth; increasing resistance to disease; decreasing early maturation in seawater; and maintaining fillet colour and oil content.
CSIRO examines the performance of the fish, selecting individuals from which to breed the next generation to ensure the best overall outcome for growers. Three age groups of fish are being grown simultaneously and about 180 salmon families (4000-5000 pedigreed individuals) are being produced each year.
Pedigree salmon breeds providing greater production efficiencies and economic returns
The partnership is delivering tens of thousands of pedigreed Atlantic salmon with performance records and estimates of their genetic values for key commercial traits. Salmon from the breeding program demonstrated greater than 10 per cent gains in growth in each generation, which equates to production efficiencies worth millions of dollars each year.
Increased disease resistance is leading to both reduced costs for growers and reduced water consumption from fewer treatments of diseased fish. Based on conservative assumptions, the net present value (NPV) of the Salmon Breeding Program is approximately $169.3 million with $78.6 million attributable to CSIRO. The benefit-cost ratio (BCR) for CSIRO is approximately 27.