YTK farming is identified nationally as the greatest opportunity for new aquaculture development in the next few decades through substantial increases in farmed area and product, and use of aquafeeds, resulting in growth in regional economies and employment. Within 10 years, YTK production is expected to increase by 34,000 tonnes, worth $440 million, and using 68,000 tonnes of aquafeed worth $136 million. The key challenge to achieving this growth is for industry to diversify its focus from supplying only the relatively small volume, high price sashimi market to the larger volume, lower price Australian ‘white fish’ market, while enhancing farm productivity and reducing operating costs to maintain profitability.

This project will enable industry to grow its position by developing more cost effective, sustainable feeds and feeding strategies to enhance YTK growth and health; the industry’s highest common R&D priorities as feed and feeding strategies comprise 60% of operating costs. It will also network three key Australian YTK aquaculture companies and their aligned research institutions (SA, NSW and WA). Aquafeed companies are also likely to participate. As such, this project will meet the designated ‘Rural Research & Development for Profit Programme’ objectives:
1. “Generating knowledge, technologies, products or processes that benefit primary producers",
2. “Establishing and fostering industry and research collaborations that form the basis for ongoing innovation and growth of Australian agriculture”.

The key Activities wil address the YTK industry's common R&D priorities through three components/themes:
1. Economically sustainable feeds and improved diet formulation (NUTRITION);
2. Improved FEEDING STRATEGIES to increase profit; and
3. Improving nutritional HEALTH to boost productivity.

Once the project is initiated the Steering Committee will develop an agreed approach to engage with aquafeed companies to maximise participation in and contribution to the project.

The Australian Southern Bluefin Tuna Industry Association (ASBTIA) aims to obtain a Minor Use Permit (MUP) for praziquantel (PZQ) to treat blood fluke (Cardicola forsteri) infections in Southern bluefin tuna (SBT). Treatments to date have been undertaken under ministerial approvals pursuant to Regulation 11 of the Aquaculture Regulations 2005 (SA). The Department of Primary Industries and Regions (PIRSA) Fisheries and Aquaculture Division has indicated however, that Regulation 11 and off-label prescription is not appropriate for use of veterinary medicines used in large volumes and discharged to the marine environment. Approvals will not be continued indefinitely unless ASBTIA works towards obtaining a permit or product registration issued by the Australian Pesticides and Veterinary Medicines Authority (APVMA). Without a ministerial approval, permit or product registration, it would be illegal to use PZQ to treat SBT for blood fluke infections.

Yellowtail Kingfish (YTK) is the main cultureed finfish in SA and this industry has great potential to expand in other states of Australia. One of the major inefficiencies identified is feeds and feed management in CST’s YTK production. Henceforth, the newly formed CST RMAG has identified improving FCRs in YTK operations as an urgent priority. Upon reflection, the production efficiency of YTK by CST has been hindered by the poor understanding of feeding strategies, sea cage biomass determination, growth performance and the nutrient requirements of YTK at different life stages and water temperatures. Research in this project will specifically address each of these topics. This information is essential as YTK are exposed to sub-optimal water temperatures at most times of the year in SA. All-year round management strategies based on sound information need to be developed and implemented to maximise the production efficiency.

Despite the development of growth-ration curves for YTK by external consultants, CST is still experiencing problems establishing profitable feeding regimes that aim to reduce end of cycle FCR to less than 1.70:1.00. This level may or may not be achievable and, apart from accurate feeding, depends on many factors including diet composition, seasonal water temperature fluctuations, genetic background etc. It has also become apparent that in order for CST to gain market acceptance for their Yellowtail Kingfish products on a global basis the issue of sustainable production needs to be addressed. In order to address the issue of sustainability detailed changes to current dietary formulations for YTK, which contain high levels of fish meal and fish oil, will have to be made. Species specific information regarding nutrient availability, growth performance, fish health and maximum dietary inclusion levels of alternative sustainable ingredients for YTK cultured at fluctuating water temperatures are required in order to make these changes.

Controlling flukes of YTK is a major cost for producers, and the industry has identified improving the treatment of flukes as one of the top research priorities. Currently, the industry bathes fluke-infested YTK in hydrogen peroxide. Although this approach is currently efficacious, it is also costly, labour-intensive, and stressful for fish. An option to reduce the need to bathe frequently is to use in-feed therapeutic agents to kill or remove flukes. This project aims to develop palatable feeds containing medications that will significantly reduce burdens of flukes.

Changing bio-fouled nets is another costly practice for the industry. Antifoulants have the potential to not only reduce the frequency and cost of net-changing due to the need to maintain good water flow bringing dissolved oxygen to the caged fish, but also to potentially reduce the numbers of fluke eggs entangling on the nets, and therefore further reduce the numbers of infective fluke larvae settling on YTK within cages. The optimum compound to use from an assessment of three will be identified.

Commercial YTK may have experienced slower growth at Fitzgerald Bay than at Arno Bay; the cause is suspected to be due the higher salinity (39-42 ppt at Fitzgerald Bay, compared with 37 ppt at Arno Bay). It needs to be confirmed experimentally whether increased salinity slows growth, first in summer and, if not, then in winter.

Health issues affecting hatchery-reared, larval SBT are presently unknown. Before production begins, the development of health protocols and a surveillance program is required, as well as the collection of archival samples of larvae for future investigations. These investigations not only ensure the biosecurity of the hatchery but also the sea-based growout stage, whether associated with hatchery-produced or wild-caught stock. This project will also allocate a small amount of funds for early disease testing, if required.