Longliners, black-browed albatross mortality and bait scavenging in falkland island waters: what is the relationship?

The rate of foraging attempts by black-browed albatross on baited hooks during Spanish-system (demersal) longline-setting operations, and a range of environmental and operational variables were used to investigate the relationship between their foraging behaviour and their mortality level. Logistic regression highlighted that a complex range of environmental and operational variables and black-browed albatross abundance combined to determine their mortality level. Our results suggest that, examined over a relatively short time period with minimal environmental variation, the rate of black-browed albatross foraging attempts during line-setting significantly affects their level of mortality. However, as a range of variables influence mortality, until targeted experimental studies are conducted, we suggest that caution should be exercised when using the rate of black-browed albatross foraging attempts as an index of their mortality.