What do parrotfish and conservationists have in common? They’re both working to save coral reefs.
An estimated 75 percent of all coral reefs in the world are threatened and many are on the verge of complete collapse. Luckily for the reefs near Maui, several organizations are committed to preserving damaged reefs, including The Snorkel Store, a snorkel rental and adventure group. The Snorkel Store and other organizations recently discovered that they have another ally: small hermaphroditic parrotfish.
Parrotfish play a particularly important role maintaining the health of reefs by eating algae off of coral — if too much algae grows, the coral can suffocate. Parrotfish use their strong ‘beaks’ to bite off whole chunks of coral, then their big molar-like teeth (located in their throats!) grind the coral down to get at the algae. The ground-up coral gets deposited back onto the reef as brand new white coral sand. Parrotfish can produce 200 pounds of sand every year.
A reef located just off of Kaanapali Beach, a popular swimming, surfing and diving beach, is threatened by algae overgrowth, which is a result of wastewater runoff and organic materials being pumped into groundwater through injection wells. A recent study by the University of Hawaii revealed that some of this water makes its way to the ocean, which promotes algae growth.
Two key factors for coral reef conservation include reducing the amount of organic material entering the ocean and protecting parrotfish. Previous studies have highlighted the importance of parrotfish and other predatory fish and demonstrated that overfishing removes these fish, which can result in smothering of coral reefs.
Now, a new study published this week suggests that removing these fish by overfishing also alters sponge communities in the Caribbean. Without parrotfish and angelfish, coral-killing sponges become the most abundant organisms in Caribbean reefs.
Researcher Joseph Pawlik sums it up nicely in a news release: “healthy coral reefs need predatory fish…”
Copyright © 2014 by Marine Science Today, a publication of Marine Science Today LLC.