Coral-eating fish hinder reef restoration efforts in Florida
Researchers from the University of Miami have filmed fish dining on newly out-planted corals intended to restore damaged reefs. Using underwater GoPro camera traps, footage showed Redband parrotfish, Foureye butterflyfish and Stoplight parrotfish eating 97% of the corals laid out for them at an offshore reef near Miami.
Scientists described the intense predation on newly planted corals as a “major restoration bottleneck.”
“The main goal was to address our lack of knowledge of the fish species that target corals after outplanting,” Diego Lirman, project leader and associate professor at the University of Miami’s (UM) Rosenstiel school of marine, atmospheric and earth science told The Guardian.
“Identifying the fish species responsible for coral predation would allow practitioners to avoid reef sites or areas within sites with high abundances of those species and, similarly, select the right coral species for the right outplanting site,”
“coral-baited underwater cameras provide insight into corallivore behavior and preferences and allow documentation of predation at various sites rapidly and without incurring the cost of outplanting.”
The problem
Florida has lost over 90 percent of its coral cover since the 1970s, due largely to climate change and disease. The corallivorous fish species are just doing what they’ve always done, only with far fewer corals and a much smaller area to graze. Previous efforts to protect corals have included placing straws around newly outplanted corals to act as “coral fort” physical barriers to their predators.
Parrotfish are a critical component of healthy reefs, from grazing algae and grinding coral skeletons into coral sand, to their poop having probiotic powers for reefs.
The Redband parrotfish, Sparisoma aurofrenatum, is native to the Western Atlantic and found throughout the Caribbean Sea. Males attain a maximum size of 28cm, and females, 20cm. Stoplight parrotfish, Sparisoma viride, are also native to the Western Atlantic but males can attain a maximum length of 64cm. They are known to eat corals and create sediment through bioerosion.
Foureye butterflyfish, Chaetodon capistratus, are also native to the Western Atlantic: Massachusetts, USA, Bermuda, the West Indies, northern South America, the Bahamas, Gulf of Mexico, and the Antilles. According to Fishbase, they grow to 15cm in length and eat zooantharians, gorgonians, and tunicates.
Stoplight parrotfish Image credit: James St. John, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons
