There has been a distinct contrast in the background scenery to the work we have been conducting in Chile recently. Personally, I have been just as busy working at-sea on fishing vessels as I have generating awareness of our work through an ornithology congress and public talks.
The first of these has been the backbone of our work for 2011, I refer to the monitoring and experimental work we are conducting on board the industrial trawl and artisanal purse-seine fisheries. The trawl fishery targets common hake with demersal (bottom) trawl nets, while the purse-seine fleet exploits schools of common sardine and anchovy. Both fisheries are based in the central-southern zone of Chile and the interaction with seabirds is directly related to the fishing gear used in each fleet.
In the trawl fishery, the nets are set to anywhere between 50 and 500 m deep. The interactions are therefore mainly related with the trawl warp cables that tow the nets. During factory processing, fish heads and offal are released from the ship through scuppers (vents) on the side of the vessel. Albatrosses and petrels rush to feed on the fish and offal as it floats in the water. As the ship advances, the cables pass are towed past the area where the floating offal and feeding birds are gathered. Albatrosses, which forage with open wings, are struck and dragged under the water by the force of the cables.
During October we conducted the sixth and seventh sea trips to monitor this fleet and deployed the first ever tori line in trawl fisheries in Chile! This is a great first step toward mitigation implementation in Chilean trawl fisheries. We expect tori lines to cut interactions by up to 90%, which has been achieved by the ATF in other trawl fisheries.
The image below clearly shows how the tori line works, creating a physical barrier to keep the birds away from the trawl warp cables. Photo: Luis Cabezas.