[5] Recent genetic analysis indicates evidence of strong divergence between Pacific colonies relative to those in South and Western Australia, thought to be explained by philopatry and differences in foraging strategies during the breeding season.

[11] Another 500 pairs breed on St Paul Island in the Indian Ocean.

A record of birds on Astola Island of Pakistan in the Arabian Sea is unconfirmed.

The species occurs as a (boreal) summer visitor in the North Pacific Ocean,[22] where potentially large numbers are taken as bycatch in fisheries.

[23][24] The species also suffers from climate related impacts [25] and significant heavy metal contamination, the cause of which is not fully understood, but is likely due to the ingestion of significant quantities of plastic, which the birds mistake for food floating on the ocean surface.