A Comparison of Catches and Bycatches from Three Non-trawl Penaeid-Fishing Gears Used in an Australian Estuary

Abstract

The catches and bycatches from stow and trap nets and seines used by commercial fishers in Lake Illawarra, southeastern Australia, were assessed via an observer-based sampling program during the 1999/2000 fishing season. Observed retained catches included Penaeus plebejus, Metapenaeus macleayi and M. bennettae, while bycatches comprised a total of 48 species of teleosts and 9 species of invertebrate. Average daily catches and bycatches were greatest in stow nets and least in trap nets. Bycatch composition varied greatly among gear types and for trap nets, between the 1st and 2nd half of the fishing season. Gerres subfasciatus, Acanthopagrus australis, Portunus pelagicus and Sillago maculata were numerically most abundant in seines, Centropogon australis, Pomatomus saltatrix and Loligo sp. in stow nets and G. subfasciatus, Loligo sp., Hyporhamphus regularis and C. australis in trap nets. Trap and stow nets accounted for greatest (80%) and least (2%) reported fishing effort, respectively. Trap nets accounted for 82% of the estimated total penaeid catch and 69% of estimated total bycatch during the fishing season. The results are discussed in terms of differences in the selection mechanisms and spatial and temporal operations of the 3 gears and consequences for sustainable and environmentally-responsible fishing.