The process of spreading awareness of seabird bycatch in fisheries and the work of the ATF is a topic that is very rewarding, especially when ATF instructors from other countries are able to come and share their experiences.
The ATF recently organised the first Seabird Bycatch Symposium in Chile as part of the 10th Chilean Ornithology Congress. Leo Tamini (Aves Argentinas, the BirdLife partner and host for the ATF in Argentina) travelled to take part in the symposium and share his expertise in mitigation measures.
This gave us the opportunity to present the work of the ATF in Argentina, Chile and other countries to local students, national seabird experts, visiting scientists and relevant government authorities. This kind of activity makes a huge and positive difference in support of cooperative efforts between the ATF and local stakeholders.
Pictured left to right: Leandro Tamini (Project Leader ATF-Argentina), Oliver Yates (Coordinator, Albatross Task Force) and Luis Cabezas (Project Leader ATF-Chile). Photo: Macarena Cid.
By contrast to the well-studied trawl fisheries, the level of interaction between seabirds and purse-seine fleets remains to be unknown. This type of fishery in Chile uses nets with a small mesh size and targets pelagic fish species at the surface of the water. The nets are set in a circle, forming the ‘purse’ before closing the ‘purse strings’ – a cable that runs through rings at the bottom of the net. The vessels haul the cable capturing the schooling fish in the purse and subsequently use of suction tube to transfer the fish into holding tanks.
We suspect that during the haul seabirds may become entangled in the netting as they dive down to take advantage of the trapped fish. During September we performed the first ever observations on these vessels to start exploratory monitoring of seabird interactions.
There is a lot to learn and we are currently developing the necessary onboard protocols to document any interactions. This is a great new challenge for the ATF and is extremely motivating!
Our first view of the fishery has revealed large numbers of seabirds attending the operation, especially pelicans which can be seen around the nets in the image below. Photo: Luis Cabezas.
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.