Foraging ecology and interactions with fisheries of wandering albatrosses ( Diomedea exulans) breeding at South Georgia

Abstract Knowledge about the areas used by the foraging wandering albatross, Diomedea exulans , its prey and overlap with longline fisheries is important information not only for the conservation of this species but also for furthering our understanding of the ecology of its prey. We attached satell...

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Bibliographic Details
Published in:Fisheries Oceanography
Main Authors: Xavier, J. C., Trathan, P. N., Croxall, J. P., Wood, A. G., Podestá, G., Rodhouse, P. G.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2004
Subjects:
Online Access:http://dx.doi.org/10.1111/j.1365-2419.2004.00298.x
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2419.2004.00298.x
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2419.2004.00298.x
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Summary:Abstract Knowledge about the areas used by the foraging wandering albatross, Diomedea exulans , its prey and overlap with longline fisheries is important information not only for the conservation of this species but also for furthering our understanding of the ecology of its prey. We attached satellite‐tracking devices and activity recorders to wandering albatrosses between May and July of 1999 and 2000 (years of differing food availability around South Georgia) in order to assess inter‐annual variation in the main foraging areas, association with oceanographic features (i.e. fronts, bathymetry), diet and interactions with fisheries. The overall foraging patterns of the tracked birds were similar in 1999 and 2000, ranging between southern Brazil (28°S) and the Antarctic Peninsula (63°S) and between the waters off Tristan da Cunha (19°W) and the Patagonian Shelf and oceanic waters south of Cape Horn (68°W) in the South Atlantic. In 1999, wandering albatrosses spent most time in sub‐Antarctic oceanic waters, their trip durations were significantly longer and they fed on fish and cephalopods (53 and 42% by mass, respectively). In contrast, in 2000, they spent more time in Antarctic waters, foraging trips were shorter and the diet was predominantly fish (84% by mass). Wandering albatrosses were associated with the sub‐Antarctic Front (SAF; both years), Subtropical Front (STF; in 1999) and the Tropical Front (TF; in 2000) suggesting that this species exploits prey concentrated at oceanic fronts. Fisheries discards also seemed to provide a very good source of food. Several fish species that are targeted (e.g. Patagonian toothfish, Dissostichus eleginoides ) or are available as offal/discards from commercial fisheries (e.g. the macrourids, Antimora rostrata and Macrourus holotrachys ) were mainly associated with the South Georgia shelf and the Patagonian Shelf, respectively. Wandering albatross foraging areas overlapped with longline fisheries in three different regions: around South Georgia, at the Patagonian Shelf ...