Performance assessment and performance improvement of two underwater line setting devices for avoidance of seabird interactions in pelagic longline fisheries.

Two underwater setting devices, the chute and the capsule were trialled at sea. These trials were undertaken in the waters off Tasmania in the presence of significant numbers of seabirds known to be vulnerable to longline fishing. Both devices adequately demonstrated their capacity to minimise seabird interactions during line setting in pelagic longline fishing. Both showed dramatically lower rates of baits taken in comparison to baited hooks set in the standard, manual way. Most, or all, bait that were taken were the direct result of tangles on board the vessel.

The chute was developed to a stage where it is now ready for more widespread testing in the industry. When in use, over 98% of baits were successfully set, irrespective of bait type, and there were no tangles.

The capsule remains in need of further development. There continues to be problems with tangling, though this was reduced so that almost 99% of hooks are set successfully. This needs further development. Excluding those occasions when tangles occurred the capsule was capable of setting hooks at sufficient depth to avoid interactions with seabirds.