Fisheries overlap, and influence of environmental and fisheries covariates on the demography of Wandering and Grey-headed Albatrosses

Citation
Phillips RA, Pardo D, Forcada J, et al (2014) Fisheries overlap, and influence of environmental and fisheries covariates on the demography of Wandering and Grey-headed Albatrosses. ACAP Seabird Bycatch Working Group, Punta del Este, Uruguay
Abstract

We report initial results from studies of annual variation in demographic rates in relation to fisheries and climate, and maps of ring recoveries and sightings of live birds at-sea for both Wandering and Grey-headed albatrosses from South Georgia (Islas Georgias del Sur)1. We also provide a brief report on an analysis of the relative overlap between Wandering Albatrosses and fisheries in the southwest Atlantic during the chick-rearing period (May to December). Survival rates of juvenile, immature and adult Wandering Albatrosses declined in the early 1990s, although those of immatures and adults appear to have recovered in recent years; in contrast, breeding success has shown a consistent increase. Few if any of these changes could be attributed to the climatic covariates that were included in models, and the apparent links in some cases to variation in effort in particular fisheries require further investigation. Juvenile survival rates in Grey-headed Albatrosses were stable until the mid-1990s; however, values were much lower than those of adults. Immature and adult survival rates were higher than in the Wandering Albatross, but decreased slightly over the study period. Breeding success of Grey-headed Albatrosses was low, highly variable and hard to estimate in first-time breeders. Climatic and fisheries covariates explained some of the variability in demographic rates of Grey-headed Albatrosses; however, the apparent relationships with some (although not all) fisheries seem more likely to reflect coincident responses to wider environmental variation rather than direct interaction with vessels. Based on the overlap of fishing effort and bird distribution in multiple years, breeding female Wandering Albatrosses are at higher risk than males from pelagic longline fisheries in the southwest Atlantic. Mapping of ring recoveries suggested a number of potential hotspots of interaction between Wandering and Grey-headed albatrosses and fisheries in the Southern Ocean. Recommendations That ACAP consider whether advocacy, education, management advice or other activities could be focused more effectively on certain fisheries, in particular regions or management fora in ways that will more rapidly improve the conservation of Wandering and Grey-headed Albatrosses from South Atlantic colonies.