Foraging ranges and potential overlap with fisheries of juvenile and non-breeding black-browed and grey headed albatrosses from Diego Ramirez

Project Outline:

Diego Ramirez is the southern-most albatross breeding site in the world, lying nearly 100 km south of Cape Horne on the edge of the Chilean continental shelf. It holds globally significant populations of black-browed and grey-headed albatrosses. Previous satellite tracking research on breeding adults revealed that even though both species breed side-by-side they have totally different foraging areas. Black-brows favor the waters of the Chilean continental shelf whereas grey-heads frequent waters to the south of Chile as far as the Antarctic Polar Front. This kind of information can be used in the management of the threats albatrosses face at sea. The proposed new research is a logical extension of previous extensive research we have done on both albatross species at Diego Ramirez in the incubation and early chick rearing period.

©Graham Robertson

The new research will address these questions: 1) what are the foraging ranges of fledgling albatrosses (both species) from Diego Ramirez and to what extent do they overlap with fisheries? and 2) how do post breeding adults use the Pacific Ocean basin region in the non-breeding season and what fisheries do they interact with?

Funding for the study be used to purchase tracking devices, for logistical access to the islands and to support the participation of a Chilean university student.

The new work seeks understanding of the birds foraging whereabouts in their “off” season, how they use the Pacific Ocean basin region, and their overlap with swordfish and tuna fisheries. The fisheries interactions are important because recently the Universidad Austral de Chile, with whom I will work collaboratively in any new studies, reported significant albatross mortality in the Chilean swordfish fleet operating in the central Pacific. Any information we can gather on mortality levels and overlaps (from the proposed tracking studies) will be used in appropriate tuna commissions (with jurisdiction in the Pacific Ocean region) to improve uptake of mitigation devices and practices to reduce albatross mortality.

The project will require short visits by yacht to the colony in each of three years. Archival loggers and satellite-transmitters will be deployed in the first season, loggers will be retrieved from returning adult black-browed albatrosses (which are annual breeders) in the second season, and from returning adult grey-headed albatrosses (which breed biennially if successful) in the third season. During the course of the study our research questions may be refined and further work proposed in subsequent years. In other words, the project may evolve in stages, depending on findings and relevance to ecological understanding and management requirements.

The estimated budget for this project is $220,000 over three years.