image: This is a sub-adult black-browed albatross with discarded hake head, scavenged from a trawler. view more
Credit: Ross Wanless
The sight of seabirds following trawlers in order to feast from discarded fish is a common maritime sight, but each year many thousands of seabirds are killed by overhanging cables or in nets. New research in Animal Conservation assesses mortality figures from South Africa to show that a simple bird scaring line can reduce the mortality rate by over 90%.
The research compiled data from five years of observations to compare current and historic mortality rates. Previous research shows that in 2006 approximately 18,000 seabirds were killed each year by the South African hake trawl fishery, of which 14,000 were albatrosses.
By reviewing five years of data the team could assess the impact of bird scaring lines, streamers costing $200 that hang from a line attached to the stern of a fishing vessel. The results show that bird scaring lines alone resulted in 73 to 95% lower mortality in the winter, including a 95% reduction in albatross deaths.
Albatrosses are the most threatened group of birds on earth, with fishery-related deaths being the biggest threat to this group. Due to the many months they spend at sea, albatrosses produce few off-spring, meaning that these deaths have a disproportionately damaging impact on the global population.
Journal
Animal Conservation