Energy & Environment

Fish poop from ‘corallivorous’ fish could benefit coral reefs, Rice study shows 

Corallivorous fish, or coral-eating fish, which were previously seen as a danger to reefs are now seen in a different light after beneficial findings in their feces.


Photo by Carsten Grupstra
A coral-eating butterflyfish on a Moorea reef in July 2019.

The feces of some algae-eating fish could be deadly to coral reefs while coral-eating fish could benefit reefs, according to a new study from Rice University.

Grazers, or fish that consume algae and detritus, were previously thought to keep reefs healthy in comparison to fish who were thought to weaken reef structures through their coral-eating habits. However, this new study finds grazers have bacteria in their feces that could damage or kill living coral.

Adrienne Correa is an assistant professor in biosciences at Rice University. During their research, Correa shared a question to consider in future research to keep coral reefs thriving.

"Is there something about the fish feces from coral-eating fish that we could use to help get beneficial microorganism for coral spread around a reef?" Correa asked.

When exploring the feces of both grazers and Corallivorous fish, or coral-eating fish, researchers at Rice found microorganisms that could benefit coral in the same way probiotics benefit people.

Correa explained why researchers believed algae-eating fish were better for coral reefs in the past.

"Usually, we think that those help keep reefs healthy by eating the algae so that corals stay very abundant on reefs," Correa said.

Because the feces of corallivorous fish has found living symbiotic algae that corals depend on, they could help marine researchers looking for solutions on how to spread probiotics to keep coral reefs healthy. However, Correa warned they are still not recommended for home aquariums that have live coral.

"When coral-eating fish are out on a reef, they move around," Correa said. "They have kind of territories or ranges. But it's much bigger than the size of a typical home aquarium."

With El Niño near, the ocean will see a warmer phase in the central and east-central equatorial pacific. Correa said this could potentially lead to coral bleaching in reefs, including the Flower Garden Banks 100 miles offshore of Galveston.

Patricia Ortiz

Patricia Ortiz


Patricia Ortiz is a daily reporter for News 88.7. Her work includes a variety of topics including transportation, technology, energy, immigration and education. Patricia graduated from the University of Houston in Fall 2022 with a Bachelor's in Journalism. She spent most of her college career at the university's literary magazine,...

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