In NSW, inherent variation among the characteristics of different estuarine fisheries has resulted in a range of physical modifications designed to improve the selectivity of conventional gears. While some of these designs have been effective in reducing the bycatches of unwanted species by up to 95%, rates of reduction more commonly range between 30 and 70%. Such reductions have obvious benefits for the stocks of bycatch species. considering the magnitudes of bycatches in many estuarine fisheries, and especially those targeting prawns (i.e. often 1000s of fish per haul), it is apparent that despite the use of modified gears, in nearly all cases there still remains some capture and mortality of unwanted individuals.

To augment the post-release survival of unwanted bycatch throughout nearly all of NSW estuarine fisheries (including those involving static gears, where no BRDs have been developed), ancillary options within the second category of input controls (listed above in B2) need to be investigated. The sorts of modifications that warrant examination include, defined soak times for gears, devices to limit predation on discarded bycatch, netting materials in codends that reduce damage to bycatch, the use of gloves to handle bycatch, and the utility of separating target and bycaught species in water after capture.

The majority of these operational and/or post-capture handling procedures have NOT been examined, but have the potential to significantly reduce the remaining impacts of commercial fishing gears on non-target species and sizes in NSW’s estuaries. This is one of the main research priorities detailed in the Fishery Management Strategy for the NSW Estuary General Fishery and comprises a key category within the 2004-2007 Strategic Research Plan for Fisheries, Aquaculture and Aquatic Conservation in NSW. Quantification of the utility of this category of input controls would also have benefit and application throughout all other coastal fisheries in Australia.

The research will form the basis of a PhD candidature. This approach is justified because (i) the work is new and there is sufficient intellectual content to support a PhD student, (ii) there is a paucity of researchers with higher degrees working in the applied fields of gear technology and bycatch mitigation in Australia and (iii) previous, similarly-structured FRDC projects (e.g. 93/180 and 2001/031) have resulted in successful PhD candidatures by project staff. Specifying a PhD candidature formalizes what would already occur if funding was sought for a Fisheries Technician, but at approx. 1/3 the cost, while attracting a substantial in-kind contribution from affiliated institutions (the National Marine Science Centre and University of New England).

An international review of the NPF tiger prawn assessment agreed with the conclusions of the 2001 assessment that tiger prawn stock levels were critically low, especially for brown tiger prawns. The 2002 assessment further concluded that brown tiger prawn levels were too low and also emphasized the critical need for an independent monitoring program given the confounding and complexities of the catch rate data used as the sole index of abundance in the NPF assessments. The 2003 assessment suggests that brown tiger prawn stocks are recovering but, given the high level of uncertainty in the assessment, this recovery needs to be independently tested.

The survey data used to determine the initial design for this project (see Background) was more than a decade old and did not cover the full study area. Since the first survey, changes have been made to the survey design to improve the accuracy of the abundance estimates obtained from the surveys. This design needs to be further developed and tested. Work has also begun on developing methods for incorporating the results of the surveys into stock assessments, but more research is required to overcome several technical difficulties encountered.

In this proposal, the CSIRO salaries associated with testing the survey design and with developing new methods of incorporating the results into stock assessments are seen as research. We are therefore requesting about $47,000 from FRDC’s MOU funds. For this reason, CSIRO is also supporting the project to the scale of about $86,000. The remainder of the project, some $520,000, will be underwritten by the industry as agreed in NORMAC, June 2003. The industry and NORMAC have also re-affirmed the long-term need for regular industry-funded monitoring surveys based on the output of this project.

There is a need to provide an updated design for the NPF that would work in the long-term to provide indices of abundance for key species and enhance a difficult-to-use commercial catch rate series. Furthermore, this design needs to address target, byproduct and possibly some effects-of-trawling issues to make the best use of the surveys.

An international review of the NPF tiger prawn assessment agreed with the conclusions of the 2001 assessment that tiger prawn levels are critically low, especially for brown tiger prawns. The 2002 assessment has further concluded that brown tiger prawn levels are too low but has also emphasized the critical need for an independent monitoring program given the confounding and complexities of the catch rate data used as the sole index of abundance in the NPF assessments.

The survey data used to determine the initial design for this project (see Background) is more than a decade old and does not cover the full study area. Therefore the initial surveys will be largely exploratory in nature and very much a trial to see if the proposed design is effective. Also, the survey design includes integrated components such as the assessment of long-term changes in fishing power and the contraction of the fishery over time that have not been undertaken in prawn survey designs (both nationally and internationally) before. These aspects highlight that this project has a large research component; the appropriate survey design is still being developed and methods for incorporating the results of the surveys into future stock assessments need to be developed.

In this proposal, the CSIRO salaries associated with modifying the survey design and with developing new methods of incorporating the results into stock assessments are seen as research. We are therefore requesting about $60,000 from FRDC’s MOU funds. For this reason, CSIRO is also supporting the project to the scale of about $87,000. The remainder of the project, some $510,000, will be underwriten by the industry as agreed in NORMAC, June 2003. The industry and NORMAC have also re-affirmed the long-term need for regular industry-funded monitoring surveys based on the output of this project.

There is a need to provide an updated design for the NPF that would work in the long-term to provide indices of abundance to key species and enhance a difficult-to-use commercial catch rate series. Furthermore, this design needs to address target, byproduct and possibly some effects-of-trawling issues to make the best use of the surveys, as they will be a large expense to the industry.

International

Developments in the global trade of food have exposed primary producers to a new set of opportunities and risks that are best managed with risk assessment. Estimating ‘equivalence’ is now the process used to determine whether or not Australian products can penetrate foreign markets, and whether or not products produced abroad can penetrate Australian markets. This involves an appraisal of whether the imported product presents the same or lesser magnitude of human-health risk as posed by the domestic product. Under the guidelines produced by the World Trade Organisation (WTO), the assessment of equivalence demands the conduct of a food safety risk assessment by the importing country. A country can deny the entry of a product if it fails to meet the equivalence standard. Thus exporting nations require a pool of scientific expertise to conduct their own risk assessments and also to appraise the appropriateness of those produced by their trading partners.

National

At the domestic level, state food safety legislation and food standards are increasingly based on the risk assessment approach. It is timely, therefore, for industry to (develop and) validate an integrated supply chain approach to food safety that has international standing as a basis for meeting public health and trade access requirements.

This project will provide an objective, transparent and scientifically robust basis for the management of food borne hazards and shelf life in the prawn industry. We propose to conform to the internationally accepted approach for the conduct of food safety risk assessment that is promulgated by CODEX, FAO and WHO (Anon., 2002).

Industry

This is an opportunity to work at all levels of the supply chain to ensure the safe reputation that SGWCPFA prawns enjoy is confirmed and maintained by validated quality systems. While the project develops and pre-tests a framework to validate the production of cooked prawns produced under the APPA Code it will provide industry with applied recommendations on the value of routine microbiological monitoring to support other audit verification processes.

Prawn resources underpin some of the most economically important fisheries in Australia and form the basis of very important recreational fisheries. Ecologically sustainable development of fisheries resources partly depends on catching species at optimal sizes and there is considerable concern that the gears being used in NSW’s commercial and recreational prawn fisheries catch them at sizes smaller than that which optimises biological yield.

Prawn fisheries in NSW (and the world) have attracted enormous attention in the past few decades over their by-catch of non-targeted species – especially juvenile fish. In NSW, this led to the development, implementation and legislation of various gear-based solutions like the Nordmore Grid and square mesh panels (see attached publication list). A major by-catch issue remaining for NSW’s prawn fisheries concerns the by-catch and discard of unsaleable sizes of school and king prawns. Currently, large numbers of small prawns are discarded well after capture (sometimes even after cooking) through the process of “riddling” which involves passing the prawn catch over a sieve to separate large and small individuals. This is considered a major waste of a resource – especially since it is known that, for fast-growing prawns, undersize individuals could be expected to reach a desirable size in a relatively short time. Unfortunately, virtually no research has been done on the selectivity of school and king prawns in any of the gears used to catch them (i.e. prawn trawls, haul nets, set pocket nets and snigging nets in commercial fisheries; and dragnets and scoop nets in recreational fisheries). All are thought to catch large numbers of very small school and king prawns that are discarded well after capture. If excluded from nets underwater, these prawns should, in a relatively short period of time, provide substantially improved catches of the more desirable and valuable sizes of prawns.

In 1998, Broadhurst, Larsen, Kennelly and McShane developed a codend made entirely of small square mesh to reduce the discards of small western king prawns in Gulf St Vincent, South Australia. The current application is for funds to develop full square-meshed codends and other methods to decrease the discard of small prawns throughout the many commercial and recreational prawn fisheries of NSW.