Black-browed albatross with young (Image: Chris Harbard)

Populations of three species breeding on South Georgia and outlying islands have declined by about a third in the past 30 years.

Conservation groups say the major threat to the birds' future is deep-sea fishing using a line with a number of baited hooks attached to it.

Up to 100,000 albatrosses a year drown on longline fishing hooks, they add.

Island strongholds

Three species of albatross breed in and around South Georgia - the wandering, or great albatross; the black-browed albatross and the grey-headed albatross.

Numbers of the wandering albatross are down by nearly a third since 1984, with similar losses for the other two species, according to research by the Royal Society for the Protection of Birds (RSPB) and BirdLife International.

"The albatross declines in South Georgia are the most drastic declines of albatross populations in the world," said Dr Ben Sullivan of the RSPB.

"The islands are critically important - for the wandering albatross, it's one of the world's largest populations."

Fishing threat

Dr Sullivan said the main cause of mortality was longline fishing on waters off South Africa and South America where the birds travel to feed.

"The birds are getting caught on the baited hooks of longlines and being pulled down and drowned," he said.

As part of the Save the Albatross campaign, the RSPB and BirdLife International are sending a taskforce to South Africa and South America to work with local fishermen.

Dr Sullivan said simple measures such as flying streamers behind the fishing boat or adding weights to the line so they sink more quickly would help to stop albatrosses being killed.