Research presented at a workshop on seabirds in Cape Town, indicated that the populations of six of the 21 albatross species have declined dramatically, BirdLife International said.
BirdLife International said that longline fishing was mainly to blame for the decline in albatross populations.
This method was responsible for the deaths - by drowning or from injuries - of more than 300 000 birds, including 100 000 albatrosses, a year, it said.
The six species are the Atlantic yellow-nosed albatross, the black-browed albatross, the black-footed albatross, the Indian yellow-nosed albatross, the Laysan albatross and the Sooty albatross.
The most threatened species is the Amsterdam albatross, which has been reduced to about 20 pairs.
"The number of seabirds killed by longlines is increasing, as is the number of albatross species in the higher categories of threat because of their continued use," said BirdLife International's Michael Rands.
