Many species of pink coralline algae cover a reef surface in the Southern Line Islands. Often unnoticed, these pink algae crusts help to cement coral reefs together, providing extra support and habitat for animals that live on reefs. Unhealthy coral reefs are often home to fast-growing seaweeds that cover and smother the slow-growing coralline algae. In the Southern Line Islands, however, the reefs are quite pristine, with less smothering seaweed and more plant-eating fish to control the seaweed that is there. As a result, pink coralline algae are common and cover most non-coral surfaces. Read a blog post about coralline algae in the Southern Line Islands.