My most recent trip lasted 24 days, many of which we suffered some bad weather. The fishing master was targeting big eye tuna and sharks. As for seabirds, we had 17 species around the vessels as we worked and a single black-browed albatross was hooked during the haul.
Lines were set on 11 days during the night, but on five occasions the sun had not set. Curiously the bycatch was during a night set, which is not usually when birds are caught.
The vessel used a bird-scaring line everyday apart from one, when there was very bad weather. We also know that this captain uses the bird-scaring line whenever possible, personally deploying it and bringing it in. The vessel uses tangones (booms) that extend out approximately 10 m either side of the vessel, and from these points the bird-scaring line is deployed.
This holds the line away from the fishing gear and prevents entanglements with the hooks, even in bad weather. The bird-scaring line is 75 m long, made of 3.5 mm monofilament fishing line with 3 m long red streamers every three metres. To provide tension they are using a traffic cone, filled with expanded polyurethane and connected with a swivel and a snap connector.
During the haul there were two incidents when black-browed albatrosses were caught on hooks that returned to the ship. These birds had the hooks removed and were released live by the crew.
It should be highlighted that on this vessel the gear they use includes a swivel tied in very close to the bait, approximately 70 cm from the hook. This is interesting as this distance is often much greater. The small distance between the weighted swivel and the hook helps to sink the hook faster, giving less time for the seabirds to snatch the bait at the sea surface.