Saw shark and Elephant Fish Investigation
Catches of saw shark rose from 52 tonnes during 1970 to reach a peak of 359 tonnes during 1995 before beginning to decline. Catches of elephant fish rose from 10 tonnes during 1970 to peak at 118 tonnes during 1985 and then declined to 63 tonnes by 1997. These species are currently valued at about $1 million per annum to the fishermen.
Stock assessments of gummy shark and school shark are periodically updated and refined through SharkFAG, but assessments have never been made for any of the non-target species. With the fishery changing to catch quota management and with the need to ensure that the non-target species are harvested sustainably, it is essential to provide basic data needs and assessments for these species.
Because most saw shark is landed in Victoria (90%) and elephant fish is landed in Victoria (64%) and Tasmania (36%), most of the sampling will be undertaken in Bass Strait.
Bycatch and discard evaluation
Over the last decade, national and international attention has increasingly focused on fishing activities that take animals other than those intended for human consumption and other uses. There are concerns that animals might be killed and then discarded and that fishing may be depleting some of these populations.
Public perceptions of discards and bycatches associated with the use of demersal gillnets are often confused with those associated with the use of surface-set driftnets. Whilst it is understood within industry that the discard of dead fish is neglible in the SSF, there is a need to provide better information for the purpose of managing public perceptions.
Effect of high grading/discarding on the TAC setting process
One concern following the introduction of quota management in the SSF is that lower valued gummy sharks and school sharks might be discarded at sea for high grading. Large sharks or sharks damaged by sea lice or other fish often receive lower prices than smaller undamaged sharks. From onboard observations, there is a need to provide estimates of (a) quantities of sharks damaged and marketed, (b) quantities of sharks damaged and discarded, and (c) quantities of undamaged sharks discarded because of lower prices.