Abalone Aquaculture Subprogram: development of an integrated management program for the control of spionid mudworms in cultured abalone

Project number: 1998-307

Project Status:

Completed

Budget expenditure: $139,008.35

Principal Investigator: Judith Handlinger

Organisation: University of Tasmania (UTAS)

Project start/end date: 28 Jun 1998 - 13 Dec 2004

Contact:

FRDC

Need

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.

Objectives

1. In general, to develop methods for the control of mudworms in farmed abalone, based on the principles of sustainable aquaculture.

2. To thoroughly investigate the ecology and reproductive biology of spionid mudworms and their interaction with abalone, through monitoring, field and laboratory experiments.

3. To gather long term data on the efficacy of the chemical treatment(s) throughout the production cycle

4. To develop a protocol of chemical treatment within the production cycle to optimise the efficiency of chemical control in relation to abalone survival, growth and marketability, cost, and responsible chemical use.

5. To gather information on the epidemiology of mudworm infestation in relation to ecological and hydrodynamic characteristics of sites, cage design and deployment and stock husbandry.

6. To use information collected to refine culture methods so as to minimise the level and consequences of mudworm infestation, preferably without the use of chemical treatments.