Non Technical Summary

This study was done in response to management concerns over the bycatch and discarding in the overnight-set mesh net fishery of NSW. A scientific observer program was used to quantify the compositions and sizes of catches taken in mesh nets set overnight during winter 1999. A total of 55 fishing trips was sampled, which yielded 69 finfish and 3 crab species in catches. A total of 38 species were retained and 64 species discarded. Overall, discards primarily contained juveniles of target species, including luderick, bream, blue swimmer crabs and dusky flathead, and accounted for 19% of total catches by weight and 33% by number. Discards were mostly (> 82%) alive when nets were retrieved from the water but their mortality after release was not assessed. The length composition of catches generally reflected the selectivity of the different mesh sizes used in the fishery (80 to 250mm stretched mesh). The proportion of discards in catches decreased with increasing mesh size: in particular, very few undersize luderick and bream were caught in nets with 100mm mesh. It is recommended that the minimum mesh size of nets used in this fishery be raised to 100 mm to reduce discards in this fishery and this is currently being discussed by the Estuary General Management Advisory Committee.