Identifying areas, seasons and fleets of potential highest bycatch risk to South Georgia albatrosses and petrels

This paper presents an analysis of tracking data for 4 procellariiform seabirds from South Georgia, and calculates overlap with pelagic longline fisheries in the Southern Ocean for the period 1990-2009. We used an unusually comprehensive tracking dataset from all major life-history stages (including juvenile stages), weighted according to the proportion of the population they represented (based on demographic models), in order to generate population-level distributions by month. This analysis confirms that the IOTC area is important for grey-headed and wandering albatrosses, and to a lesser extent black-browed albatrosses, with hotspots of overlap with fisheries in the southwest Indian Ocean, between the Prince Edward Islands and South Africa, and in the southeast Indian Ocean. Overlaps were particularly high with fleets from Japan and Chinese Taipei, and to a lesser extent South Korea and Spain, and highest during winter months (May–September; when fishing effort south of 30°S is greatest). The areas identified here largely match areas where high rates of bycatch have been recorded, emphasizing the need for use of bycatch mitigation measures.