Disease is a significant issue for abalone aquaculture: significant mortalities result in substantial financial setbacks on some farms (Fleming, 2003). In South Australia, mass mortalities due to summer high temperatures are of serious concern. In all Australian farms some mortalities result during handling and transportation. Health is identified as a strategic research area required to develop a profitable industry in the Abalone Aquaculture Subprogram Strategic Plan. Particular needs identified were to “increase and apply knowledge of programs to survey the health status of stock on farms” and to “increase and apply knowledge of stress, its effect on production performance and strategies to minimise stress during production”. This project will contribute directly towards these aims, first by establishing normal ranges for many immunological parameters in abalone. This will allow future health monitoring programs to use these parameters. Second, we will assess the value of adding immunological parameters to the histological assessment used in the South African abalone monitoring program. Third, we will determine how stressors, nominated by farm managers as occurring in normal abalone farm processes affect the immune system. This should lead to specific recommendations for minimizing stress or maximizing health under stressful conditions.

This research will pave the way to improve health and productivity in Australian abalone aquaculture. By trialing various physiological and immunological assays we can find the most efficient and reliable set of parameters for future studies. We will also establish the natural variation in these, and thus provide the controls needed when investigating any aspect of abalone husbandry. Another goal of the FRDC subprogram strategic plan is “To improve the profitability of production”, through increased growth and survivorship. By testing the effects of genetics, environmental requirements, husbandry and nutrition on abalone immunity, we should be able to make recommendations for maximizing survivorship and productivity. Currently husbandry practices are monitored via mortality and poor growth. These are very crude measures of problems on the farm, and occur well after the event, which prevents any proactive response.

Reference:
Fleming, A. 2003. Final report of FRDC project no. 2000/200: Abalone Aquaculture Subprogram: Facilitation, administration and promotion. Appendix 1 in Proceedings of the 10th Annual Abalone Aquaculture Workshop, 19-21st November, 2003, Port Lincoln, Australia. Fleming, A.E. (Editor). Abalone Aquaculture Subprogram, Fisheries Research and Development Corporation, Canberra, Australia.

Abalone culture is a rapidly expanding industry, both in Australia and other countries, where sea-based growout systems are common. Presently the most successful commercial abalone farming operations in Australia are land based, although there is a trend towards the establishment of sea based operations in South Australia, Victoria, Western Australia and possibly New South Wales, in addition to the established operations in Tasmania. The establishment of a successful sea cage abalone culture industry depends primarily on overcoming the problems of high mortality due to mudworm. Successful establishment of this sector of the abalone culture industry, in Tasmania and elsewhere, will enhance the stability and viability of abalone culture in Australia, enabling better competitiveness with overseas producers.

Sea cage culture offers a lower capital investment strategy to a land based operation, and is therefore the best option for some small operators. In addition it represents a cost effective alternative for grow out of larger stock produced in land based operations. The involvement of three of Tasmania's largest salmon producers in sea cage abalone culture is indicative of the potentially valuable means of diversification for existing marine farmers that sea cage abalone farming represents. Additionally, sea based culture represents the most viable means of long term culture of abalone necessary for the production of large animals for products such as pearls.

Mudworm infestation also affects land based operations, causing elevated mortality levels, and reduced growth. In addition, other cultured molluscs, particularly oysters, are prone to mudworm infestation. Advances in mudworm control through improved management strategies will therefore assist the viability of these industries.

Any strategic approach to the control of mudworm, with or without the use of chemotherapeutants, will need to be based on an overall management approach. Consideration will need to be given to such factors as the ecological and hydrodynamic characteristics of sites, the design, placement and maintenance of cages, husbandry practices and management of stock. Clearly the development of such a strategy requires substantial baseline data on the epidemiology of the parasite and the biology of the host/parasite interaction, an area in which there is currently a paucity of information.

Abalone farming can be improved in Australia. The profit will be increased and the cost of production reduced:

· increased knowledge of the settlement process and development of a better settlement system resulting in low cost juvenile abalone is essential for both integrated abalone farms and for the supply of seed to growout farms;

· the development of a practical settlement protocol for abalone requires a greater understanding of microalgae requirements and their culture and reduces the cost for abalone at the growout stage;

· the project will be integrated into the abalone aquaculture sub-program and has extensive industry involvement in developing the practical aspects;

· the aquaculture industry in Victoria is developing into a major growth area and investment opportunity and production is intended to triple by the end of 2001;

· the success of the Australian abalone aquaculture industry is dependent on developing methods that reduce costs in labour and growout time;

· the project will deliver information that can result in technically advanced culture methods that will maintain the competitive edge over low labour cost countries.