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

Citation
Laich AG, Favero M, Mariano-Jelicich R, et al (2006) Environmental and operational variability affecting the mortality of Black-browed Albatrosses associated with long-liners in Argentina. EMU 106:21. https://doi.org/10.1071/MU05024
Abstract

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 plus or minus s.d. of by-catch for the analysed period (1999-2003) was 0.03 plus or minus 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.