Fish waste essential for coral reef sustainability: Study

TEXAS – Dirt fish turned out to play an important role to strengthen and maintain sustainability Coral reefs . Whereas previously, the presence of fish was thought to damage coral reef habitat.

The startling discovery was made during an expedition to the Mo’orea Coral Reef Long Term Ecological Research station in French Polynesia. The research team looked at coral-eating and grass-eating fish, corallivores (corallivores).

Scientists found that excrement from fish that prey on coral provides a large cargo of important microscopic organisms that strengthen coral reefs. Fish waste probiotics can also help stressed corals recover from bleaching.

This discovery proves that the excrement of coral-eating fish packed with symbiotic dinoflagellate algae is essential for coral survival. Even grass-fed fish that feed on detritus and dense algae keep coral reefs healthy.

This fact opened the door for scientists to use fecal transplants as a crutch for stressed corals. This is because fish waste contains symbionts that benefit coral reefs when they experience devastating bleaching.

“This discovery expands our way of thinking about the role of coral-eating fish in coral reefs. They not only destroy coral skeletons, they also disperse to produce symbionts that corals and other organisms need,” said Adrienne Correa, a Rice University marine biologist quoted from the NewAtlas page, Monday (17/4/2023).

From the samples found, the number of symbionts in the faeces of the ornate butterflyfish (Chaetodon ornatissimus) and the striped butterflyfish (Chaetodon reticulatus) was very large. Each species shares about 100 million living symbionts which are essential for the survival of coral reefs.

Scientists have known that the symbionts in fish waste contain many good organisms. Even the excrement of coral biting fish also leaves large lesions on the coral that contain pathogens.

“Most fish (corallivores) nibble on mature coral and do not kill the colonies they eat. This suggests some species may be important to coral reef conservation in ways we never imagined,” said Carsten Grupstra, graduate student at Rice University.

(wib)