New research shows that parrotfish excrement can build entire islands. The study was done in the Maldives and compared various sources of biogenic sand including boring sponges, sea urchins, calcifying algae (Halimeda), and parrotfish. They find that parrotfish contribute around 85% of the sand on their study island! That’s a lot of sand! It’s a good illustration of the diverse ways that organisms can contribute to basic, but very important, ecological processes.
I wonder how much of the beautiful beach sand in The Bahamas is a consequence of parrotfish poop?
Here is the press release (Link).