Happened to read this... Australian Tuna and Billfish Longline Fisheries Bycatch and Discarding Work Plan 2011-2013 http://www.afma.gov.au/wp-content/uploads/2011/12/Bycatch-Work-Plan-2011-13-FINAL.pdf
Sunfish are largely a bycatch species in the ETBF which historically have had a low level of retention as they have no commercial value. ETBF operators generally avoid interactions with sunfish as they are likely to be tangled up in the fishing gear, which
negatively affects long line fishing operations.
Two species of Sunfish, Mola Mola and Mola Ramsayi, are rated as precautionary extremely high risk in the 2007 ERA risk assessment. This is mostly due to a high level of uncertainty in the data used for the risk assessment and their uncertain life history parameters in that they are thought to have a periodic life history strategy with late maturity, large clutches with low juvenile survivorship. More data needs to be collected on the impacts of fishing interactions on adults of these species and their life history.
Table 7 and Table 8 show that although sunfish are caught on the longlines in relatively high numbers, few are retained and between 95% and 100% of sunfish are released alive as they are mostly cut off at the line before being brought to the boat.
The ETBF and WTBF mainly catch pelagic shark species that are capable of large migrations, extending beyond the Australian EEZ. Therefore, Australia has international obligations to manage shark species under IOTC and WCPFC management measures. Excessive removal of these species from the environment can have consequences such
as altered trophic interactions. However many of these species are known to survive capture and have a high survivorship rate when released.
The tables below outline the most commonly caught and discarded shark species in the ETBF and the WTBF from observer records. In both fisheries, Blue Shark, Shortfin Mako and Crocodile sharks are commonly caught, however the majority of these sharks are released alive and vigorous."