The first phase of the Aquaculture Nutrition Subprogram (ANS) has demonstrated a strong need for technical inputs into the strategic direction and methodology applied to the nutrition components of both species and non-species based research programs. Without a coordinated subprogram approach to this research portfolio, the FRDC would have been unable to develop a collaborative program with the Grains Research and Development Corporation to characterise and produce vegetable protein alternatives to fish meal, nor would it have been able to standardize the methodologies and research approach for aquaculture nutrition in Australia with involvement from all relevant scientists. The subprogram is also addressing “market failure” in the areas of training and communication in the field of aquaculture nutrition, with a firm emphasis on empowering end-users of aquafeeds with basic nutritional and feed processing knowledge. The ANS needs to be maintained in a similar format to the first phase in order to capitalize on many of the initiatives that were implemented during the first 3 years of the project, but with less emphasis on the facilitation and maintenance on a core of research projects.

The need for on-going research into aquaculture nutrition and the need to maintain or enhance the technical standard and direction of this research is emphasized by the fact that Australian aquaculture industries still have a heavy reliance on imported nutrition technologies, feeds and ingredients for the supply of nutrients to target species. This includes feed manufacturing technologies, ingredients such as bait fish, fish meals, crustacean meals and fish oils, and complete feeds such as those utilised by the prawn industry. Not only does this create issues in relation to imported disease risks, continuity of supply and cost, but it means that many local products are being under utilised. Given the broad range of issues associated with the provision of aquaculture diets, the real cost of aquaculture diets in Australia will only be reduced through the delivery of well-targetted, strategic research. The infancy of the Australian aquaculture industries also means that a coordinated research approach is required to maximise the outcomes from research investment in the area.

The need for on-going research into aquaculture nutrition and the need for continued inputs to how this research is conducted to ensure it is completed to the highest possible standard is emphasized by the fact that Australian aquaculture industries have a heavy reliance on imported nutrition technologies, feeds and ingredients for the supply of nutrients to target species. This includes feed manufacturing technologies, ingredients such as bait fish, fish meals, crustacean meals and fish oils, and complete feeds such as those utilised by the prawn industry. Not only does this create issues in relation to imported disease risks, continuity of supply and cost, but it means that many local products are being under utilised.

There is currently renewed interest in establishing a dedicated aquaculture nutrition research program due to the increase in cost of fishmeals and oils, their increasingly limited availability and potential contamination with antibiotic residues such as chloramphenicols if the meals are derived from some aquaculture reared products. In addition, pressure from consumers to limit the use of animal proteins in diets and limit interspecies recycling has applied new pressure to feed manufacturers and increased the need to identify and utilise alternative vegetable protein sources in aquafeeds. The increased value of the Australian dollar has also increased competition from imports and the need for the Australian sector to become increasingly efficient to remain internationally competitive with nutrition playing a key role in their capacity to achieve this.

Decreased profit margins due to reduced prawn survival and growth during suboptimal pond conditions are considerable, where a modest 3% improvement in survival in one pond would result in over $22,750 profit increase (pers.comm.,Ridley Aquafeed, at current prices)
Similarly, higher growth rates and pond yields will both improve growth efficiency for the quantity of feed fed and reduce nutrient loss to the pond environment.

While many internationals feed manufacturers operate on a least-cost formulation model, where nutrient availability and ingredient price are used to determine formulations, little attention has been placed on exploring the growth benefits of high-quality feeds to provide cost-benefits from increased production, health and performance under commercial conditions.

The overall aim of this project is to understand the role of optimised nutrition in improving growth performance under suboptimal conditions. Temperature and salinity can change drastically and suddenly on farm, and are associated with the onset of decreased prawn performance. This project would focus initially on laboratory-based experiments focused on temperature and salinity, with the view to run on farm pond trials.

Project aims are to measure:
The efficacy of a range of immunostimulants in feeds against known bacterial and viral P.monodon pathogens.
The optimal level of immunostimulants in commercial P.monodon prawn feeds for growth performance and nutrient utilisation of P.monodon and challenged with bacterial and viral pathogens.
Commercial scale pond trials of feeds containing immunostimulants compared with commercial prawn feeds.

A major problem for the culture of marine fish and crustaceans is rearing the early life stages of numerous species.. Live food is considered obligatory for success but is expensive (up to A$400-500 / kg). In recent years global harvests of Artemia cysts, particularly from Great Sale Lake USA, have decreased sharply leading to a worldwide shortage, especially for good quality cysts in terms of hatchability and nutritional content. Compounding the problem of poor supply are new AQIS regulations and biosecurity issues, which may limit future importation. The reliance of Australian hatcheries on imported Artemia is a major constraint to the sustainable development and expansion of this industry. Low cyst quality caused Artemia - related diseases throughout the world. In Australia, an additional concern is the risk of importing unknown, non-endemic pathogens into finfish and prawn hatcheries.

The need to find solutions is even greater now than 3 years ago due to the rapid development of the marine fish industry in Australia e.g. yellowtail kingfish from almost zero production to 2000 mt, and barramundi with predicted production of 4000 mt in 2003-04.

Hut Lagoon (Port Gregory, WA) where Cognis Pty Ltd is currently growing and harvesting microalgae (Dunaliella salina) for beta-carotene (supplying around 80% of global natural beta-carotene), is unique in the world in its capacity to grow high quality algae and Artemia, and for its pristine environment. The company is offering to invest significantly and estimated that the Hut Lagoon have the capacity to supply ALL the Australian needs in terms of both Artemia cysts (currently, around 5-7 mt dry cysts) and live adult Artemia and become a major export commodity capturing part of the world demand for cysts (much more than current production of 7 000 tons p.a.). An estimate of potential annual revenue for cyst production from Hut Lagoon is in the order of $ millions. Moreover, initial results shows that the waste from the algae extraction process can be used as food source for the Artemia, saving the company hundred of thousands of dollars in waste disposal fees. There is a need to properly and independently evaluate the commercial viability of Artemia production at Cognis.

Microdiets can reduce the need for live feed (and therefore costs, labour, diseases, risks) consumption in finfish hatcheries. However, with fish the poor development of digestive enzyme output is a major limitation. The prototype microdiet, developed in the current project, proved to be better than the best commercial available diet. Fish larvae microdiet prices, range between $150 and $250/kg. Commercializing the prototype microdiet together with an international feed company such as Skretting Australia (part of Nutreco – the biggest fish feed manufacture in the world) should bring in significant IP and ease pressure on Artemia supplies.