The populations of almost half of the world's seabirds are thought to be in decline, according to a study published in Bird Conservation International.
It found that 28 per cent of species are in the highest categories of risk. Conservationists are particularly concerned for the albatross family.
Threats include commercial fishing and damage to breeding colonies caused by rats and other invasive species. Researchers say seabirds are an important indicator of the health of the oceans.