Tactical Research Fund: improved line weighting method for tuna longline fishing using live-baiting to mitigate sea bird bycatch and improve worker safety
The Commonwealth has listed the incidental capture of seabirds in oceanic longlining as a key threatening process.
Australia has a Threat Abatement Plan for the incidental catch (of bycatch) of seabirds during oceanic longline fishing operations (TAP). The TAP sets out actions that must be followed to mitigate seabird bycatch, including line weighting, catch rate triggers and management responses.
AFMA requires all Commonwealth longline fisheries to implement line weighting and other seabird bycatch mitigation measures. Despite these, in previous years there has been protracted daylight setting bans in key sub-areas of the ETBF, where live bait is used (and large economic impact), because of seabird bycatch incidents. This demonstrates that the current measures are not fully effective. Live bait increases seabird bycatch risk but are used to maintain target species catch rates.
AFMA is aware of four ‘flyback’ incidents where a crew member was hit by a line weight and hospitalised. An AFMA observer was also recently injured by a ‘flyback’ and is subject to a Comcare claim.
New line weighting regimes trialled in Australia using dead bait in 2010 showed that a ‘sliding’ 40g weight at or near the hook is potentially safer for crew, cheaper, improves sink rates and reduces risks of seabird bycatch, while maintaining fish catch rates. However, a significant proportion of fishers use live baits for which the 40g line weighting regime is insufficient.
Moving the weight to be at or near the hook dramatically increases the sink rate. However, the effects on the life status of live bait (and fish catch rates) have not yet been tested and fishers continue to prefer not to move weights nearer to the hook. This trial will investigate the impact of 60g weights within 1 meter of the hook on bait life status and catch rates.
