September 12, 2024

 

Australian aquaculture firms seek sustainable alternatives in yellowtail kingfish farming

As fish oil prices continue to increase, Australian aquaculture operators are seeking more sustainable and cost-effective alternatives to support the growing commercial production of yellowtail kingfish, Phys.org reported.

 

A recent study led by Flinders University in South Australia, published in the journal Aquaculture, has assessed the potential of using canola oil and poultry oil as substitutes in farmed kingfish feed.

 

Associate Professor James Harris from Flinders University's College of Science and Engineering explained the significance of the research. "Reducing the use of wild-caught sardines and other small fish in farmed fish feed—so we can produce more fish for human consumption—will help preserve our oceans and fishery food chains," he said.

 

Fish oil, which is in high demand due to its use in both seafood production and terrestrial animal feeds, is expected to see a dramatic rise in required production levels. Current estimates suggest a 460% increase in demand by 2030, adding to the cost pressures on the aquaculture industry.

 

"We can't keep catching vast quantities of small fish to feed larger farmed fish," Harris added. "We are now focusing on reducing the amount of fish oil in their diets."

 

Fish oil is valued for its high concentrations of long-chain omega-3 polyunsaturated fatty acids, essential for the optimal growth and health of carnivorous finfish like kingfish. The study, conducted in collaboration with researchers from Primary Industries and Regions SA (PIRSA), the South Australian Research and Development Institute (SARDI), and the University of Adelaide School of Animal and Veterinary Sciences, investigated locally farmed kingfish to evaluate the effectiveness of alternative oils.

 

"We found that oil derived from canola plants and poultry can be effectively used as substitutes," Harris noted. However, he added that there were some observed changes in the kingfish livers that warrant further investigation into how these alternatives impact fat metabolism in the fish.

 

The findings provide an opportunity to refine formulated feeds to optimise growth while ensuring the health of farmed kingfish. These fish are also raised in aquaculture facilities in Japan, Europe, and the Americas.

 

Previous studies in the field of aquafeed have explored other alternatives, including soybean oil and fats from swine, bovine, or ovine sources. These have been tested to support the growth, lipid metabolism, and palatability of fish raised on alternative feeds.

 

The research underscores the ongoing efforts to balance sustainability, fish health, and the economics of aquaculture production amidst rising global demand for seafood.

 

-      Phys.org