The Aquafin Co-operative Research Centre is undertaking a multi-disciplinary program of research and development, technology transfer, and education / training for the finfish aquaculture industry.  Its particular focus is on southern bluefin tuna and Atlantic salmon but it also includes smaller projects on Australian snapper, mulloway, yellowtail kingfish and striped trumpeter. The key objective of the Aquafin CRC is to create a centre of excellence in the field of sustainable finfish aquaculture with the capability of pursuing related world-class research and training.  The main partners in this CRC include the Tuna Boat Owners Association, the Tasmanian Salmonid Growers Association, the Fisheries Research and Development CSIRO, University of Tasmania, Department of Primary Industries of South Australia. NSW Department of Primary Industries is a participant in the smaller projects on snapper, mulloway and yellowtail kingfish.

The CRC has its headquarters at Adelaide and is funded until June 2008.

More information about the Aquafin CRC is available at www.aquafincrc.com.au.

NSW DPI research in the Aquafin CRC

NSW DPI lead two projects within Aquafin CRC:

Increasing the profitability of snapper farming by improving hatchery practices and diets

This project extends previous NSW DPI research, which has demonstrated the feasibility of snapper farming in both marine and inland saline waters. It seeks to reduce production costs by improving fingerling survival and growth and reducing input (feed) costs.

A reliable supply of cheap, high quality, healthy fingerlings is essential for development of viable snapper farming. Currently, industry estimates the cost of production of snapper at $1.00 per fingerling. This compares with under 35c for barramundi fingerlings and about 46c for bass. To improve profitability, there is a need to reduce the cost and improve the vigour of fingerlings and to develop cost-effective high-performance diets and feeding systems for both hatchery and grow-out. This project will improve hatchery methods and replace live feeds, such as brine shrimp (Artemia) whose supply and quality are unreliable, with alternative live feeds or artificial feeds. The project will also develop better strategies for combining intensive and extensive rearing methods so as to optimise fingerling survival and quality.  Research will have application for other species, including tuna. 

Growout diets need to produce fish with desirable marketing traits, including colour.  Fish are marketed as a “healthy” product, largely because fish fat has relatively high contents of the omega-3 highly unsaturated fatty acids.  However, while replacing fish meal and fish oil in fish diets may reduce diet cost, it will also reduce these health benefits. Minimising feed wastage through ensuring optimal pellet stability and determining the best feeding frequencies and feeding rates are critical factors in reducing pollution from fish farms. To achieve these goals, diets will be developed that satisfy but not oversupply essential nutrients and that are made from high quality, highly digestible, readily obtainable ingredients.  Diets will also be designed to stimulate maximum consumption and deliver optimal feed conversion efficiency.  Additional research is needed to build on successful results with snapper diet development under the current FRDC ADD Subprogram snapper diet development project.  The nutrition component of the current application and the existing FRDC snapper diet development project will be fully integrated.

Finally, the project will seek to reduce disease-induced mortality by developing treatment methods for common parasites and establishing a foundation for immunological approaches to fish skin diseases.

Specific objectives are:

• Improve production of snapper fingerlings by developing extensive, fertilised-pond rearing techniques for the advanced production of snapper juveniles.
• Improve production of snapper fingerlings by developing larval feeding strategies to reduce the use of live feeds, in particular Artemia, by weaning larvae at an early age onto commercial and/or experimental artificial diets.
• Improve production of snapper fingerlings by developing methods to reduce and/or treat the incidence of parasite infestation.
• Improve the skin colour of farmed snapper by reducing melanisation and improving skin pigmentation.
• Determine digestibility for, and ability of fish to utilize, new ingredients with potential for use in low-polluting snapper diets.
• Evaluate ability of snapper to utilize carbohydrate and lipid sources for energy.
• Determine optimum protein:energy ratio for fish grown at one favourable temperature.
• Provide recommendations for feeding strategies to minimise overfeeding and maximise fish production.

The planned outcomes for the project are:

• Profitable, expanding industry for snapper aquaculture in Australia.
• Viable hatcheries, breeding vigorous low-cost snapper fingerlings (for aquaculture or stock enhancement).  Our goal is to reduce fingerling costs to around 25 cents/fish.
• Development of techniques for management exclusion of ectoparasites in marine fish hatcheries.  Amyloodinium ocellatum infests many fish species in hatcherys throughout the world.  All Australian marine fish hatcheries will potentially benefit from this technology. 
• Commercially-available, cost-effective, high performance and low polluting diets for Australian snapper that help produce highly marketable fish of the desired colour.
• Increased availability of snapper for domestic (and export) markets.

Feed technology for temperate fish species

Farming of marine fish in Australia is continuing to develop and is principally based on seacage growout of tuna (Tunnus macoyii) and yellowtail (Seriola lalandi) in South Australia and Atlantic salmon (Salmo salar) in Tasmania.  –Production of yellowtail in SA was reported as 50 and 700 t in 2000/01 and 2001/02 and predicted to reach 1500 t in 2002/03 (Hutchinson, 2003).  Production of mulloway in South Australia has recently increased as farmers have sought an alternative species to culture following problems with yellowtail culture (the major problems include skin and gill flukes).  In NSW, snapper, Pagrus auratus, mulloway, Argyrosomus japonicus and silver bream (Acanthopagrus australis) are also being farmed in small quantities for domestic consumption.

In NSW, farmers also started with snapper and although they also struggled with market acceptability due to skin colour, their proximity to the market made this easier to overcome (e.g. it was easier to direct market fish to retail outlets and to sell gilled, gutted and scaled product).  Availability of sufficient numbers of fingerlings restrained production and, at least for one farm, parasite problems were experienced.  Mulloway and silver bream have been trailed as alternative species.

This shift between species is likely to remain a feature of Australian temperate marine fish culture for several reasons.  Firstly, the current small demand has meant hatchery development has been slow and inherently risky.  There are only a small number of hatcheries and this increases the risk that production of any particular species will fail.  Having more than one species to breed, especially if natural breeding seasons are offset in time, reduces the risk of failure.  Secondly, the small domestic market in Australia is particularly prone to supply driven price decreases.  Having several species available for sale mitigates this problem to some extent. 

Mulloway were first bred at Port Stephens Fisheries Centre in NSW in 1992.  This species has considerable aquaculture potential due to its almost Australian wide distribution and fast growth rates.  Commercial grow-out of this species is occurring in NSW and SA but the combined production in 2002/03 will only be several hundred tonnes. Interest in mulloway in southern states initially declined in favour of yellowtail but as mentioned above, has made somewhat of a resurgence over the last year.

Applied research is needed, especially for yellowtail and mulloway, particularly on the major cost areas of diets and feeding (for both fingerlings and grow-out fish) to help ensure profitability. This project will extend the successful research approach adopted for snapper in Aquafin CRC Project 1B.3-2001/208 (Increasing the profitability of snapper farming by improving hatchery practices and diets).  In that project, fingerling costs were reduced through systematic research to develop more cost-effective hatchery procedures including the demonstration of the feasibility of replacing live feeds including Artemia with alternative live feeds (copepods) and/or commercially available, inert pellet diets for advanced snapper larvae. This project seeks to reduce feed costs, to optimise feeding efficiency and to improve fingerling survival and growth of mulloway and yellowtail.  Deformities in marine fish larvae are often a result of inadequate nutrition during larval rearing.  This will also be investigated.

Cost of feeds and feeding for grow-out are the largest component of operating costs.  Existing diets for yellowtail and mulloway are based on generic formulations for “marine fish”.  These diets produce results but it is unknown if current diets are nutritionally adequate, especially for rapidly growing fish.  Even basic requirements, like the best protein to energy ratio, are unknown for either yellowtail or mulloway.  Both low and high energy diets are available for salmon and barramundi but even simple comparisons to find the best of these two “options” have not yet been carried out.  There is no reliable information on ingredient digestibility making it impossible for feed manufacturers to confidently formulate diets with alternative protein sources to fishmeal when fishmeal is hard to obtain and when prices are high (and, of course, fish meal prices continue to rise). 

Fingerling costs for mulloway and kingfish are currently estimated at $0.60-$2.00/fingerling. These represent well in excess of 10% of operating costs.  Growout feeds can cost in excess of $2,000/t and with the costs of feeding are usually in excess of 30% of total operating costs (>50% for some operations).  Together these represent the major areas where improvements in production technology can improve the profitability of marine fish farming.

Specific objectives are:

• to reduce costs of fingerling production.
• to improve the cost-effectiveness of grow-out diets.
• to validate improved feeds and feeding practices on a commercial scale.