Aquaculture health and biosecurity are complex multidisciplinary areas that require specialized human resource development (van Beek 1997). There is a wealth of lessons to be learnt from more established aquaculture industries. As each industry is unique in fish species farmed and local environmental issues, there is a need to process information into a practical biosecurity plan.

The Western Australian aquaculture industry is regionalized, with large distances between centres of activity. Ready access to veterinarians with expertise in fish and shellfish is rare, often resulting in heavy losses. There is a need to
increase/consolidate knowledge amongst fish farm managers & operational staff in aquaculture health. Involving local veterinarians will improve access to fish health services. The workshops will create greater networking allowing fish farm managers and their local veterinarians the small pool of veterinarians within Fisheries and Universities with experience in fish and shellfish health

The above need is consistent with WA industry's RDE priorities, FRDC's environmental program theme 1

The 1995 review of world aquaculture resources by the Food and Agriculture Organisation identified the major constraints to future development of aquaculture as being: the availability of feed ingredients; disease and health management; environmental impacts; and genetic and diversity issues. There are two areas in which genetics is especially important in aquaculture development: 1) Appropriate broodstock selection and breeding programs for the genetic improvement of important production traits; 2) Genetic implications of the translocation of aquaculture stocks within and outside their natural range.

Genetic improvement: The power of selective breeding in increasing productivity and efficiency has been amply demonstrated in traditional agricultural species. Aquaculture species have hardly benefited from modern developments in animal breeding, despite their typically high reproductive capacity and therefore high potential for genetic improvement. The key issues which need to be addressed are the appropriate traits for improvement and their genetic parameters (heritability, correlations with other traits); optimal selection methods (mass selection, family selection, construction of selection indexes); avoidance of inbreeding; and the role of recombinant DNA technology (transgenesis, marker-assisted selection and cytogenetic manipulation).

Understanding the power of genetics is particulary important with aquaculture species where egg supply is a limiting factor. This applies to many fish species where the first generation bred in captivity often become the broodstock for the industry. Accidental initial selection of a slow growing strain (compounded by inbreeding), or starting with a small genetic base often leads to an uncompetitive industry.

Translocation: The issue of translocation is likely to become an increasingly important constraint upon aquaculture development. Although policy guidelines are currently being produced in Western Australia and other states, their application will be hampered by a lack of genetic knowledge on two fronts. Firstly, we know very little about the genetic population structure of most endemic potential aquaculture species. Secondly, what we do know comes almost entirely from studies of neutral genetic markers, and may bear no resemblance to the genetic structure of traits of ecological importance. The issues that need to be addressed are: laboratory and analytical techniques for measuring population genetic structure; relating population genetic structure to genetic variance in traits of ecological importance; the effects of breeding for stock enhancement on inbreeding and variance effective population sizes.

These issues of genetic improvement of breeding stock and genetic effects of translocation are two sides of the same coin, because the traits which we wish to improve through breeding are in most cases precisely those traits which determine the adaptedness of local populations to their environment. Both issues need to be addressed at this early stage in the development of the aquaculture industry in Australia.

Restocking of native fish stocks is also becoming increasingly important in Australia as the political power of recreational anglers and the value of their sport to local economies increases. Restocking programs should not be undertaken without an understanding of the genetic structure and variance of existing populations or the knowledge needed to ensure that the restocked fish do not alter this balance.