cabo blanco, in the atlantic ocean, is the largest surviving single population of the species, and the only remaining site that still seems to preserve a colony structure. in the summer of 1997, a disease killed more than 200 animals (two-thirds of its population) within 2 months, extremely compromising the species' viable population. while opinions on the precise causes of this epidemic remain divided, the most likely cause is a morbilivirus or a toxic algae bloom.