The Victorian scallop industry has decline substantially and does not appear to be recovering. Scallops have traditionally been one of Victoria's largest fisheries and the ability to resurrect a failing native fishery offers obvious benefits. Victoria has not committed time or moneys to the development of reseeding but in light of the recently successful scallop trials in Victoria it is an area that MAFRI has shown some new interest. This economic feasibility study and the potential direction for research is now very relevant to Victoria Fisheries.

There is considerable industry interest in enhancing saucer scallop populations for subsequent harvest. The Western Australian government has granted exclusive use areas off the Western Australian coastline for two companies to undertake pilot enhancement work. Neither company has developed suitable hatchery technology to support their proposed operations. There has been long-standing industry interest in enhancement in Queensland, and pilot hatchery research on saucer scallops is underway at the Bribie Island Aquaculture Research Centre.

The Queensland trawl industry is facing restructuring and considerable reduction in the area in which it can fish. Profitability in the industry appears to be generally low (Taylor Moore, pers. com.). It is not difficult to forecast that environmental pressure groups will attempt to further curtail industry activities and reduce fishing effort in and adjacent to the Great Barrier Reef World Heritage Area, and that this will further impact on the industry's economic performance. At the same time, the trawl industry is a significant generator of employment and economic wealth in regional areas where unemployment levels are far higher than the national average. Any proposals that have realistic potential to improve social and economic welfare have obvious benefit to such communities, as well as to the national interests.

Those scallop enhancement operation that been successful are now making super-normal profits. The Japanese enhancement operations, for example, are giving returns in the order of 400% profit. While this figure does not adequately address or account for previous research and development expenditure, there is no doubt enhancement operations run properly, and supported by adequate investment and infrastructure can be financially profitable. At the same time, there are numerous examples of scallop enhancement and culture operations that have been financially unsuccessful. Operations such as those in Newfoundland, Scotland, and, to a lesser extent, in Tasmania, have failed to become long production sources of scallops. Developing feasibility studies and business plans seems to be the only way to determine whether it is worth while making the considerable investments in time and money needed for a successful enhancement or culture project.

The Western Australian scallop fisheries are, as with most wild scallop fisheries, highly variable with regard to annual production, that variability being mainly due to environmental factors. The fisheries are "managed in a precautionary manner and the risk of overfishing is minimal" (Dredge et al., 2001).

A reduction in the variability of the annual production in the Western Australian scallop fisheries, and an overall increase in production, will be of major benefit to the Western Australian and Australian economies. Before any increase in production can be achieved, some further research is required.

Dredge et al. noted a need to determine the optimum size of spat release, and a need to develop transport procedures to take very large numbers of scallops from hatcheries to reseeding sites. They noted a need for a development phase in the industry to develop and translate hatchery technology to a fully commercial scale, consistent operation, and also a need to test the assumptions made in their report in respect of natural mortality rates of A. balloti at given sizes. This project will address those initial research needs.

The Dredge report noted that there would be considerable economic and social gains to be made from a successful marine ranching or enhancement operation. This project offers the first opportunity to trial commercial scallop enhancement in Australia, noting the eminent qualifications of Elmwood Holdings Pty Ltd according to the Dredge et al. report.

1. Need to evaluate current management measures

There is a need to evaluate the current management measures applied to the scallop fishery, particularly the range of minimum legal sizes, the effects of the southern closure and the rotational closures. Precisely what are these measures achieving and are they effective? Can the value of the resource be increased with alternative management measures, within the constraints of acceptable risks of overfishing? One of QFIRAC's priorities is to look at the scallop fishery and in particular the value of protected areas, sources of mortality and stock structure.

2. Need to determine discard mortality and growth by region

Some processors are requesting DPI&F abandon the rotational spawning stock closures and lower the minimum legal size of scallops with the intention of increasing the amount of scallops fishers can retain and market. To consider any of these changes in management that could possibly lead to overfishing it is imperative that we have precise estimates of key stock assessment parameters including gear selectivity, and discard mortality.

3. Need to measure fine-scale trawl intensity

The frequency with which discarded scallops are recaptured over time and space may impact on estimates of discard mortality. Using the VMS trawl track database the frequency with which an area is trawled will be determined to guide subsequent discard mortality experiments.