Effects of Herbivorous Fish on Algae, CCA, and Coral Growth

Illustration of an experiment conducted by Dr. Peter Vine to investigate the role of calcareous coralline algae (CCA), herbivory, fish grazing, filamentous algae and larval settlement on coral reefs. Pomacentrids act as “farmers,” selectively removing indigestible algae and protecting the growth of fine, filamentous algae. Thick algal mats prevent settlement of binding CCA and corals, eventually leading to mounds of loose coral rubble. Removing herbivores by other means—such as overfishing or pollution—may also leave algal growth unchecked, reducing space for CCA and corals to settle. The survival of reefs in the future may depend on the presence of a healthy population of fish.

Rendered digitally in Adobe Illustrator in a style resembling traditional pen-and-ink with watercolor. To be published in an upcoming book about Red Sea coral reef ecology by Dr. Peter Vine.