Over the past 150 years, the interaction between humans and seabirds has become increasingly detrimental to seabird populations. Overhunting at the beginning of the 20th century decimated populations of many seabirds, including the short-tailed albatross whose numbers dropped from over one million to less than one hundred in a single thirty-year span. The introduction of invasive species such as feral cats has adversely affected seabird colonies that were previously isolated from natural predators. Land development destroyed the nesting grounds of many seabird species, affecting population size. Perhaps the greatest threat to seabirds is bycatch from commercial fishing operations. Bycatch occurs when seabirds, attracted by the offal discharge of fishing vessels, attempt to take bait from a longline or a net and become ensnared and drown as a result.

It is estimated that hundreds of thousands of seabirds are killed this way every year, making the reduction of bycatch a major target of domestic and international efforts to maintain healthy seabird populations. A number of relatively inexpensive mitigation methods have been developed to address this issue. However, the effectiveness of such methods is typically dependent on implementation throughout the geographical area encompassing seabird migratory paths.

Additional reference information: 

• Agreement on the Conservation of Albatrosses and Petrels (ACAP) offsite link, Mitigation Fact Sheets
• ACAP News Release offsite link, "Following removal of introduced cats, and nearly all the rabbits, Grey Petrels on Macquarie are doing well as the vegetation recovers." (Jan. 25, 2012)
• Seabird Islands and Introduced Predators (SEAPRE) offsite link, Seabird Islands and Introduced Predators