Photo by Brian Skerry, National Geographic
In other parts of the world, corals have died in large numbers due to bleaching and disease, but the reefs of the South Lane Islands remain resilient. Scientists believe that the key to coral health lies in a sound ecosystem in which all native species perform their respective roles — including the brightly patterned heart-spotted spiny seabream, which feeds on plankton.
![The fourth coral bleaching will affect 850 million people! Why do corals suddenly turn white?[fig]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)