This Fish Created the Beaches of Hawaii With it's Poop - And it Can Be Found in Florida!

Redband parrotfish at Conch Reef. Photo by Paul McDonald.

If you ever go snorkeling or scuba diving off the Florida Keys, you may just come across one of these guys. This is called a parrotfish - specifically, a redband parrotfish, one of about 100 species, and yes, its excretions makes up the famous white sand beaches of Hawaii (well, maybe not this fish specifically) - that's because they essentially poop sand. Parrotfish get their name from more than just their bright, exotic colors and patterns - their teeth are fused together to form a beak of sorts. They use this beak to scrape off algae from coral, and in doing so, bite off part of the coral. The coral is then ground into sand by plate-like teeth in their throats while the algae is extracted, and the sand is then excreted (and may even make it's way to the beach). While the beautiful white sand beaches of Hawaii are made of this excreted coral-sand, the white sand beaches of Florida are mostly made of quartz. Is this a good or a bad thing? You decide.

Parrotfish can be found in tropical oceans around the world; the above example was found at Conch Reef off of Key Largo, Florida, along with plenty of other colorful fish. As you're swimming around Conch Reef, you may be able to hear a sharp crunching sound - that's the sound of parrotfish biting coral! Of course, parrotfish are found at other reefs in Florida in addition to just this one - but they seemed more common here!

Queen parrotfish, another species you might see in Florida. Photo by Oceana.

And it's good that they're so common - parrotfish actually play a very important ecological role, more than just in the creation of sediment (or bio-erosion, as it's called); they are a key part of keeping coral reefs healthy. Coral reefs are constantly in a state of competition between coral and macroalgae for space and resources. A macroalgae-dominated reef doesn't provide a very good habitat for a wide a variety of animals, at least not like coral reefs do, so we want coral reefs to stay coral-dominated. Parrotfish help this happen by grazing on macroalgae, keeping its population in check and keeping it from overtaking all of those beautiful, colorful corals. So, the next time you're snorkeling or scuba diving at a coral reef (or visiting the white sand beaches of Hawaii), make sure to say thank you to any parrotfish you happen to see, because neither would be there without them!

Learn more about parrotfish here:
https://www.nationalgeographic.com/animals/fish/group/parrotfish/
https://ocean.si.edu/ocean-life/fish/tough-teeth-and-parrotfish-poop

Learn more about Conch Reef here:
https://www.florida-keys-vacation.com/Conch-Reef.html
https://floridakeys.noaa.gov/zones/spas/conchreef.html