Management implications of discarding in an estuarine multi-species gill net fishery

摘要

Commercial fishers are permitted to set gill nets overnight in New South Wales (NSW) estuaries during the winter months of June, July and August. Scientific observers sampled the retained and discarded catches from 55 fishing trips sampled across six estuaries throughout the 1999 winter fishing season. A total of 69 fish and 3 invertebrate species was identified in catches, with 38 species being retained by fishers and 64 species being discarded. Discards included the juveniles of fish species of commercial and recreational importance, as well as some species of little commercial value. Discards accounted for 19% of total catches by weight and 33% by number, and were mostly alive (>82%) when nets were retrieved from the water. Subsequent mortality after release was not assessed. The mesh size of the nets observed ranged between 80 and 250 mm and the size compositions of catches generally portrayed the relative selectivity of the different mesh sizes. The data are discussed in terms of their consequences for managing the estuarine fisheries resources of NSW.