The Crozet Shag occurs on the Crozet Islands, the Prince Edward Islands, and Marion Island. It forms small breeding colonies on coastal cliffs and pursues fish underwater.
Breeding adults have black upperparts with a green sheen on the back and white underparts. The skin around the eye is blue, and the base of the bill is yellowish.
Small groups breed on coastal cliffs, vegetated slopes, and pebble beaches. They pursue fish underwater.
An extinction-risk assessment has not been added yet.