Bumphead Parrotfish

Photo: Mark Rosenstein · CC BY-NC

Schools of bumphead parrotfish numbering 50 or more individuals roam the Ibo Island reef crest at dawn, the rhythmic crunch of their beak-like teeth on coral audible underwater before the school comes into view. These are the largest parrotfish in the world, and Ibo's bumphead population is one of the healthiest in the western Indian Ocean — a direct consequence of the minimal fishing pressure that has protected the site for decades. Their bioerosion activity — producing up to 1 tonne of white sand per individual per year — is critical to the sediment dynamics of the entire archipelago, and beaches downstream of their feeding grounds are built partly from parrotfish-processed coral.