There is a need to assess how bycatch reduction devices (BRDs) are likely to affect the weight and composition of bycatch in the Queensland east coast trawl fishery (QECTF). Mandatory use of the devices has been recently implemented in some sectors and further measures are proposed.

There is a need to estimate and compare the weight and composition of bycatch with- and without-BRDs to assess recent and ongoing bycatch reduction initiatives that have been legislated in the Queensland Trawl Fishery Management Plan. Deploying observers or researchers appears to be the only robust approach for undertaking these comparisons.

Current estimates of the weight and composition of bycatch from the fishery operating without-BRDs are unknown for most sectors of the QECTF. These will have to be derived in order to facilitate any comparisons with estimates obtained when the fishery is operating with-BRDs.

There is also a need for the QECTF to consider the Criteria for Assessing Sustainability of Commercial Fisheries under the Wildlife Protection Act 1984 and the project makes some headway towards addressing these criteria.

Australia’s major export market is Japan, a country in which food safety and quality are issues receiving much publicity. It is clear that Japanese consumers and, therefore, the buyers of Australian prawns will demand increasingly higher standards and assurances that quality standards are and will be maintained. The same arguments also apply to Europe where food quality and safety are seen as priority items in market access. The Australian industry must meet these demands or lose market share to competing suppliers or other products and/or suffer price reductions. Measures to ensure product integrity and safety must be implemented at the beginning of the supply chain - in this context, on board trawlers and in processing establishments - and must be seen by customers to be consistent, which requires proper training of crews and an audit system to provide assurance.

The domestic market for sea caught prawns, while less valuable, is equal in tonnage, with half the total catch (14,500 tonnes) sold on the local market. Competition from imported cooked farmed prawns and domestic farmed prawns is intense. Moreover, a large percentage of the local prawns are cooked on board boat. This is a ‘high risk’ process in food safety terms and all boats will be required to implement a food safety plan under proposed national regulations (Australia New Zealand Food Authority Proposals P145 & P160).

Further proposed changes to the Food Standards Code impact on the use of sulphur dioxide in prawns to prevent black spot. Ensuring all prawns are packed with a low residual SO2 content will be critical to avoid additional labelling.

A total quality management system for the prawn industry which is third party auditable and which links vessels and processing factories under a prawn mark will satisfy the needs of all sectors. There is a window of opportunity for the prawn industry to set the benchmark for prawn quality world wide.

An examination of which fisheries species are sustained by seagrass plant production has been highlighted as a major research priority in the recent reviews of fisheries habitat research gaps by Cappo et al. (1997) and Butler & Jernakoff (draft report to FRDC). The recommended method in Butler & Jernakoff for tracing seagrass production to fisheries species is stable isotope analysis. Coastal and fisheries managers currently consider seagrass to be valuable, nevertheless there are many seagrass meadows under threat and still being lost. An argument can be developed, supported by current scientific evidence, that many important fisheries species are not reliant on seagrass and that their numbers actually increase upon the decline of seagrass. Estuarine and offshore fisheries species that do not appear to be dependent on seagrass might actually be so, but indirectly; they may be deriving their food from animals in a trophic web that is sustained by energy (carbon) and nutrients (e.g. nitrogen) transported from seagrass meadows. Another estuarine habitat, mangrove forest, has previously been touted as generating plant production that drives food webs elsewhere in estuaries and offshore. Recent evidence from Australia and Asia suggests this is not so; mangroves seem to sustain only species living in mangrove areas. The question whether seagrass production is the major source of primary production sustaining fisheries production needs answering. The best method for tracing where fisheries species gain their nutrition is stable isotope analysis.

The proposed research will be done in Moreton Bay and Hervey Bay. These bays are of extraordinary importance to Queensland fisheries, with Moreton Bay alone comprising up to 30% of the total Queensland catch of inshore recreational and commercial species (Tibbetts & Connolly 1998). There are also important fisheries in deeper waters adjacent to these bays. Both bays have extensive areas of seagrass, but also mangroves, saltmarsh and occasional reefs offshore. They are also suffering ongoing seagrass loss.

The current assessment of the Northern tiger prawn fishery is based upon a separate analysis of the fishery for each of the two species (Wang & Die, 1996). An alternative stock modelling approach, which considered both species together (Haddon, 1997, 1998), supports the results of the first method but is somewhat more pessimistic. This alternative model provides an independent view of the status of the tiger prawn stocks and the uncertainties affecting the analysis are also different. That both approaches produce a similar conclusion (that the stocks appear to be vulnerable and fishing mortality is currently too high to be sustainable in the long term), increases confidence in the conclusion that there are serious problems with the fishery.

A weakness of the alternative model is that it is based upon commercial catch-effort data summarized over the statistical reporting areas and for each year. It is likely that this aggregation of catch and effort data is obscuring or biasing details of the stock dynamics. If the seasonal fishing behaviour of the trawl fleet, in terms of its use of the fishing grounds, has altered either in a steady manner or over shorter periods, this could have large implications for the real status of the tiger prawn stock which may have been obscured by the aggregation of the commercial catch-effort data. This may lead to the stock appearing to be more stressed than it is in reality. To test whether the alternative model is overly pessimistic, and to refine the analysis of stock dynamics, it would be necessary, using the same approaches as in the earlier model, to investigate stock and fleet dynamics at finer spatial and temporal scales.

The proposed modelling should reduce uncertainty over the present status of the tiger prawn stocks.

This development will benefit both the fishing and aquaculture industry through a better utilisation of prawn waste. It will involve taking a generally discarded seafood waste and produce a value added product. It will aid the seafood processors by reducing the costly expense of disposing of processing waste, assist in waste management and potentially produce a new market for unwanted material. Presently only small quantities of prawn heads are utilised in further processing, being sold for little or no profit. Generally prawn heads are regarded as an expense to the processor. This expense is increasing as greater pressure is being placed on manufacturers with regards to the disposal of biological waste.

This project will allow manufacturers access to detailed technical information on the processing requirements for producing a prawn stock as well as the information on the export market and the domestic market potential. This project will allow processors to investigate an additional product to manufacture without the additional costs of product development.
The success of this project is aimed at generating interest in the utilisation of prawn waste into value added food products.