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.

Need for supporting and enabling biotechnologies:

The FRDC report highlighted the need for proper genetic management in scallop enhancement ventures (FRDC 2000/190) in particular citing the key issues of genetic resource management (Blankenship and Leber, 1997). This view is further supported by proceedings from the second international stock enhancement and sea ranching conference (Leber et al., 2002b)

Determining the genetic structure of the source population is essential baseline information to design an effective genetic management protocol for restocking ventures. Although, initial allozyme work indicates that the Queensland stocks are a single genetic population and are potentially a different species to the WA (Dredge et al unpubl; FRDC 2000/190), allozyme data is not effective in discerning local genetic populations whereas microsatellites are (Kolijonen et al., 2002). The information may also be used in future environmental monitoring of genetic diversity in wild populations by providing a genetic baseline for localized allelic frequencies and provide cross generational markers of hatchery stock.

The development of appropriate genetic management protocols at an early stage of a long-term proposal such as scallop ranching in Queensland or Western Australia is both desirable and responsible. Fisheries, conservation, public and other interests will undoubtedly, and appropriately, critically scrutinize the progress of the proposed operation. The development of appropriate and responsible genetic management protocols have been identified by QSS as being a critical short-term priority, and as such may have a significant bearing on the wider public acceptance of the operation.

The current Western Australian operation have also recognized genetic management as an important factor, although they are not undertaking such work. Our proposal, which is likely to include the WA operation at some level, would therefore directly benefit both states.

Kolijonen, M.-L., Tahtinen, J., Saisa, M. and Koskiniemi, J. 2002. Maintenance of genetic diversity of Atlantic salmon (Salmo salar) by captive breeding programmes and the geographic distribution of microsatellite variation. Aquaculture 212, 69-92.

Leber, K. M., Kitada, S., Blankenship, H. L. and Svaasand, T. (2002b). Proceedding from the Second International Symposium on Stock Enhancement and Sea Ranching, Kobe, Japan.

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.

Fishery Management Plans are currently being developed for all major fisheries in Queensland. In the next few years, these plans will become the legal framework within which management practices are applied. Limit and target reference points have been developed and put forward as key assessment and management tools in all of these plans. Methods used to estimate the reference points have generally been ad hoc and based on un-standardised catch and effort data.

Clearly, there is a strong need to test these reference points.

In the Queensland Trawl Fishery Management Plan (east coast - Moreton Bay) 1998-2005, the limit reference points are based on a comparison of the average logbook catch-per-unit-effort from 1988-96 with the relevent year's catch-per-unit-effort. At present, this comparison of CPUEs takes no account of changes in effective effort.

However, effective fishing effort continually increases, even though the number of licence holders or total number of days fished each year may remain constant. This continual “effort creep” is characteristic of trawl fleets and is due to fishers adopting technological improvements in fishing practices, such as GPS and plotters. A recent study of the northern prawn fishery indicates that when GPS and plotters are used concurrently, relative fishing power increases by 7% over boats without such equipment (Robins et. al. in press).

We propose to standardise the effort of the trawl fleet, which is capital intensive and would therefore be most affected by technology advances. Two major trawl fleets operate within the Queensland region, the Torres Strait trawl and the Queensland East Coast trawl licensed fleet. In terms of value, the most important species captured by these vessels are tiger prawns, eastern king prawns and saucer scallops. AFMA and the Torres Strait Scientific Advisory Committee see a priority need that catch rate analysis of the Torres Strait tiger prawn fishery be undertaken. The prawn Working Group for Torres Strait has discussed this issue of possible changes in effective effort and the managers are of the opinion that this issue needs to be investigated. The small size of the fleet will simplify analysis compared to analysing the full Queensland tiger prawn fishery.

In summary, therefore, effective reference points must be clearly defined and relate to a management system that uses a catch-per-unit effort series adjusted for changes in fishing power.