Project number: 2004-035
Project Status:
Budget expenditure: $310,933.00
Principal Investigator: John Stewart
Organisation: NSW Department Of Primary Industries
Project start/end date: 16 Feb 2005 - 28 Feb 2008


Available evidence suggests that most fish species harvested by the NSW demersal trap and recreational fisheries are taken at sizes that are too small to optimise yield and/or economic return. This is because most species taken in both of these fisheries either have MLL’s that are too small or do not have MLL's at all. There have only been stock assessments done on snapper (FRDC project No. 93/074) and silver trevally (FRDC project No. 97/125) in the trap fishery. Both studies showed that they were growth overfished and the results have been used to increase the MLL for snapper and to impose a MLL for silver trevally across all fisheries. Many other species taken by fish traps are in decline and it is highly likely that they are also growth overfished. Unfortunately, very little is known about the biology or life-history of these other species. Recreational fishers are significant harvesters of all species taken in the NSW demersal trap fishery and it is important that any MLL’s designed to reduce overfishing are applied across all fisheries.

NSW Fisheries does not currently have a policy for setting MLL's at particular sizes and the process developed during this study may form the basis for such a policy. It is important to consider several issues when setting appropriate harvest sizes and these include: (i) the size at sexual maturity; (ii) the size that will optimise yield; (iii) market requirements; (iv) an economic assessment, and (iv) public perception.

The information on biology, stock-assessment and protocols for setting appropriate harvest sizes developed during this project will directly address several key areas of importance recognized by the FRDC. The planned outcomes will lead to fisheries management being based more on the precautionary principle, will maximise the economic and social returns from harvesting these species while also providing for effective management of recreational fishing. These areas are considered to be high priorities by the NSW FRAB and by Recfish Australia in their National Research and Development plan for the recreational sector.


1. To develop a framework based on biological, economic and social information by which appropriate harvest sizes can be determined.
2. To recommend appropriate sizes at harvest for primary species shared by the commercial trap and recreational fisheries in NSW.
3. Where appropriate to recommend minimum legal lengths for species across all fisheries.

Final report

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