Temperate marine fish farmers in Australia seek to have the option to choose between several species of fish based on market price, availability and cost of fingerlings and health and feeding costs. This need was identified at the Aquafin CRC workshop held in 2002 (Allan, 2003). Most research on temperate marine finfish has been conducted on snapper (Pagrus auratus) but farmers are now concentrating more on yellowtail (Seriola lalandi) and mulloway (Argyrosomus japonicus) with significant interest in yellowfin bream (Acanthopagrus australis). Applied research is needed, particularly on the major cost areas of diets and feeding (for both fingerlings and grow-out fish) to help ensure profitability and to give farmers and feed manufacturers information so they can make informed business decisions.

Costs of feeds and feeding are usually the largest budget expense for marine fish farms and also significantly affect costs of producing fingerlings in hatcheries. In hatcheries, the global shortage of Artemia and the huge cost of weaning diets has led to a increased priority for better and cheaper live feeds, formulated weaning diets and feeding strategies. For grow-out, most farmers want high-performance, low-cost feeds. Given a choice, most farmers will pay more for diets to achieve better performance but have no real way to make decisions to achieve the most cost effective feeding strategy. There is a clear lack of information for most temperate marine species about the nutritional specifications needed for high performance diets and what physical characteristics are most desirable in the pellets (e.g. should pellets be floating or sinking, how important is pellet hardness, etc). This prevents feed manufacturers providing data-based recommendations about the best diets for farmers and prevents them from formulating and manufacturing specific diets for temperate marine finfish farmed in Australia. Unfortunately, the same lack of information is restricting choices about the ingredients being used in diets. Almost no information exists about digestibility or utilization of most of the ingredients available for use in Australia aquafeeds. Most farmers are aware of “problems” with the use of terrestrial animal protein meals in animal feeds and that use of such ingredients might negatively affect the export market for their fish. However, apart from research with snapper (Aquafin CRC; WA Fisheries) and barramundi (FRDC ADD Subprogram; WA Fisheries) there is no information about digestibility or utilization of Australian ingredients for temperate marine finfish being farmed in Australia. The immediate result of this lack of information is an increase in the proportion of expensive, imported fishmeal being used in diets.

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 by approximately 30% 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. Previous work with snapper also demonstrated a major improvement in growth of juvenile snapper when the optimal feeding frequency and day-length were identified. This project seeks to reduce feed costs, to optimise feeding efficiency and to improve fingerling survival and growth of mulloway and yellowtail. Sub-optimal performance of marine fish larvae is often a result of inadequate nutrition or sub-optimal physio-chemical variables during larval rearing. A high percentage of slow-growing or stunted fish in larval rearing runs can seriously reduce economic viability of hatcheries and increase farming costs. The performance of larvae has not been addressed in a systematic manner and although the commercial hatcheries in SA report that fingerling production is not a barrier, there are no published methods of how to optimize production of fingerlings (i.e. to to increase cost-effectiveness of fingerling production). This lack of information will reduce the chance of expanding marine fish farming in NSW and other states in Australia.

Existing grow-out diets used for marine fish such as yellowtail, mulloway and bream are based on generic formulations for “marine fish” (including salmon and barramundi). 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 yellowtail and 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). Research to provide this information is urgently needed.

There are obvious problems with a "one-species at a time" approach to diet development research. This is expensive and takes a long time. This application seeks to conduct specific research with mulloway and kingfish and to build comprehensive models of nutritional requirements for these two species that can be directly compared with other similar models now available for other marine and freshwater aquaculture species (e.g. snapper, sea bream and barramundi).

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. We aim to reduce these costs by as much as 50%. 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). Food conversion ratios of in excess of 1.5:1 are regularly reported. We aim to produce diets with FCRs of 1.2:1 with approximately 25% lower ingredient costs. Together these represent the major areas where improvements in production technology can improve the profitability of marine fish farming.

Available evidence suggests that most fish species harvested by the NSW demersal trap and recreational fisheries are taken at sizes that are too small to optimise yield and/or economic return. This is because most species taken in both of these fisheries either have MLL’s that are too small or do not have MLL's at all. There have only been stock assessments done on snapper (FRDC project No. 93/074) and silver trevally (FRDC project No. 97/125) in the trap fishery. Both studies showed that they were growth overfished and the results have been used to increase the MLL for snapper and to impose a MLL for silver trevally across all fisheries. Many other species taken by fish traps are in decline and it is highly likely that they are also growth overfished. Unfortunately, very little is known about the biology or life-history of these other species. Recreational fishers are significant harvesters of all species taken in the NSW demersal trap fishery and it is important that any MLL’s designed to reduce overfishing are applied across all fisheries.

NSW Fisheries does not currently have a policy for setting MLL's at particular sizes and the process developed during this study may form the basis for such a policy. It is important to consider several issues when setting appropriate harvest sizes and these include: (i) the size at sexual maturity; (ii) the size that will optimise yield; (iii) market requirements; (iv) an economic assessment, and (iv) public perception.

The information on biology, stock-assessment and protocols for setting appropriate harvest sizes developed during this project will directly address several key areas of importance recognized by the FRDC. The planned outcomes will lead to fisheries management being based more on the precautionary principle, will maximise the economic and social returns from harvesting these species while also providing for effective management of recreational fishing. These areas are considered to be high priorities by the NSW FRAB and by Recfish Australia in their National Research and Development plan for the recreational sector.

Aquaculture is a rapidly growing industry in Australia, and as such there are substantial issues related to resource allocation and ESD. South Australia is at the forefront of this development with a range of innovative aquaculture industries, an active group in PIRSA Aquaculture addressing policy and management issues, and another in SARDI Aquatic Sciences providing the scientific and technical background information for such matters through targeted research and development (R&D). As such, South Australia provides an ideal model for other States.

While a reasonable level of environmental information exists and, through the Aquafin CRC, continues to grow for tuna farming, this is not the case for most of the other marine aquaculture industry sectors. The purpose of this application is therefore to gather and review existing environmental information, undertake an environmental risk assessment, investigate through targeted R&D the priority environmental impact issues, establish a framework of key indicators on which to base impact assessments, and develop industry sector-based environmental monitoring programs that enable impacts to be detected. Apart from tuna, we currently have very little information on the environmental impacts of finfish farming in South Australian waters, especially for the rapidly growing Yellowtail Kingfish sector. In order to obtain public support for further development of this industry, it is essential that its environmental impacts are assessed, and strategies implemented for reducing any impacts that occur. Similarly, for shellfish farming, there is still a great deal of contention about impacts on the ecosystem, particularly seagrasses, which co-occur with the largest shellfish aquaculture industry in the state – Pacific Oysters.

This project will therefore provide background information for improving and further developing the project “Innovative solutions for aquaculture planning and management – Project 2, Spatial impacts and carrying capacity: Further developing, refining and validating existing models of shellfish and finfish carrying capacity”. Both projects will provide much of the scientific and technical data for input into the project “Innovative solutions for aquaculture planning and management – Project 1, Decision support system for aquaculture development”, where “Decision support system” is defined as a computer based, integrated method for supporting management decisions. Decision support systems must incorporate rigorous and scientifically sound decision criteria and, as such they require a good understanding of the potential environmental impacts that may result from aquaculture, as well as the characteristics of existing or future farm sites and the ecosystem in which they exist.

In response to rapid growth, PIRSA Aquaculture are also developing an environmental management policy in parallel with the AFMF ESD framework (visit www.pir.sa.gov.au/sector118.shtml). Thus, information from the present project will be important for this policy.

This project is to develop a method for policies to be developed to monitor and manage parasite burdens across an entire industry.

Yellowtail kingfish production in South Australia in 2001/2 was approximately 1100 tonnes and is expected to increase to 5000 tonnes within 5 years. The potential risks associated with a rapidly growing industry are manifest and without scientifically based, whole-industry management and auditing systems the potential for commercial, environmental and public perception problems associated with pests are significant. Some negative perceptions regarding kingfish farming have already appeared in the media (e.g. Hunt, 2003). Industry research has concentrated on the production losses associated with monogenean infestations and while on-farm management is a vital part of a pest control system, assessment systems vary between farms in stage of development and accuracy.

Marine finfish growers in South Australia have agreed in-principle to a system whereby their farms are monitored externally by the state regulatory authority (Primary Industries and Resources SA) for skin and gill fluke numbers. Two methods have been proposed; one by which individual farms will take their own fluke counts and supply them to PIRSA (with occasional auditing/checks by PIRSA) and another by which PIRSA staff will make regular farm visits to make fluke counts. Policies will be implemented through include licence conditions enforceable under the Aquaculture Act, 2001 that form an integral part of the management framework of aquaculture in South Australia. Their support for this whole-industry monitoring is derived in part from emerging negative perceptions in the media that can be countered to some extent by cooperating with government to create a scientifically based, accurate, transparent system of monitoring and managing flukes on kingfish farms throughout South Australia.

Treasurer and Pope (2001) developed a system for counting salmon lice by visual inspection, but this system is not directly applicable to parasites that have microscopic juvenile stages, do not infect their hosts externally or are unable as adults to transfer between host individuals in a pen. The confounds associated with a chemical harvesting system are different to those of visual inspection by a trained observer and this difference needs to be assessed for the method being proposed by us to be successful.

Research Management Structure
Currently the YTKF industry does not have a coordinated approach to research. This proposal identifies a need to create a structure that will allow industry to identify, prioritise, implement and manage research required to achieve sustainable development.

Strategic Research and Development Plan.
The problems associated with farming of yellowtail kingfish that have been identified need to be addressed by a management structure prepared by the stakeholders to prioritise, plan and fund research conducted to support this industry. This facility needs to have a capacity to provide a funding mechanism to address both unforeseen problems that occur (i.e. tactical research with short lead time) and identified ongoing problems (i.e. strategic research).

Foundation Projects
1. Communications Strategy
As the stakeholders are a diffuse group in relatively remote locations the benefits of modern information transfer need to be adopted to keep all parties informed of progress, results and provide a platform for ongoing comment. This facility will benefit the ability of research programs to delivery effective outcomes in a timely manner.

2. Propagation
2.1 Deformities
There is a need to identify the causes of deformities in YTKF so that methods can be adopted to minimise levels in cultured stock. This will reduce cost of fingerling production and improve final product quality. In 2001 a total of approximately 750,000 YTKF fingerlings were produced by the two commercial marine finfish hatcheries operating in South Australia, Spencer Gulf Aquaculture (SGA) at Port Augusta and Clean Seas Aquaculture Hatchery (CSAH) at Arno Bay. These hatcheries report end of nursery deformity levels between 5% and 20% that are within the range of levels reported for other commercial species farmed worldwide. This equates to lost earnings in the order of $100,000 – $300,000 pa per million fingerlings produced. Further significant costs are also attributed to the days of manual sorting of all fish prior to dispatch from the nursery; mortality of these compromised fish within the hatchery (unrecorded loss due to deformities); increased disease susceptibility during on-growing; and loss of production and value of further deformed fish that survive until harvest. As future industry production increases these costs attributed to deformities will continue to rise unless a cause is identified.

3. Environment
3.1 Assess Environmental Monitoring Methods
There is a need to initiate research for the yellowtail kingfish industry to assess the suitability of cost effect sampling strategies and PCR based environmental monitoring methods developed by the Aquafin CRC for tuna farming. The research proposed will determine if these methods can provide benefits to monitoring programs required for the YTKF industry.

3.2 Escapees
Escapement of fish is an issue of community and industry concern. There is a need to develop and monitor the effectiveness of methods used to recapture escapees.