Environmental and operational variability affecting the mortality of Black-browed Albatrosses associated with long-liners in Argentina

• Main Authors: Laich, A.G., Favero, M., Mariano-Jelicich, R., Blanco, G., Cañete, G., Arias, A., Rodriguez, P.S., Brachetta, H.
• Format: Journal/Newspaper
• Language: English
• Subjects: ecological impact; environmental factor; longlining; mortality; seabird; seasonal variation; Argentina; South America; Aves; Diomedea melanophris; Genypterus blacodes; Genypterus capensis; Patagonian Toothfish
• Online Access: https://hdl.handle.net/20.500.12110/paper_01584197_v106_n1_p21_Laich

The effects of different environmental and operational factors on the incidental capture of Black-browed Albatross (Thalassarche melanophris) in long-line fishing operations were analysed. This is the most commonly captured seabird by Argentine long-line fishing vessels, and significant decreases in its populations have been mainly attributed to long-line fishing practices. The estimated mean rate ± s.d. of by-catch for the analysed period (1999-2003) was 0.03 ± 0.39 birds per 1000 hooks. Black-browed Albatrosses were mainly caught during day settings. Higher capture rates were observed during autumn and winter. The effect of the length of long-lines on the incidental capture of Black-browed Albatrosses was also analysed, showing that higher capture rates occurred when short long-lines were deployed. Seasonal differences in the distribution of captures were observed, being widely distributed to the north of the shelf-break during autumn-winter (i.e. non-breeding season) and mostly concentrated in southernmost latitudes, closer to the presumed breeding area in the Malvinas (Falkland) Islands during spring-summer. Mortalities during winter were mainly associated with the Patagonian Toothfish (Dissostrichus eleginoides) fishery, while those observed during summer were associated with long-liners targeting Kingklip (Genypterus blacodes) on the Patagonian Shelf. © Royal Australasian Ornithologists Union 2006.