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.