Parrotfish shape the future of coral reefs, one bite at a time

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Like underwater cities connected the level of tropical oceans, reefs are bustling hubs of activity. Corals — relatives of oversea anemones and jellyfish — are the main builders of these cities. Over time, the limestone skeletons of corals turn into structures that tin operation supra the seafloor. A 4th of each marine beingness besides calls these reefs home.

Reef dwellers see a colorful premix of sharks and different fish, oversea turtles, sponges, starfish, shrimp and more. Many types of algae besides unrecorded connected reefs. Some algae marque their ain limestone that adds to the reef. Many different algal species don’t. Left unchecked, those algae tin overgrow a reef, taking abstraction from corals. If algae overgrow the corals, a reef whitethorn halt growing.

But conscionable arsenic cervid and different grazers connected onshore support plants trimmed, galore animals graze and trim backmost a coral reef’s algae.

Parrotfish are particularly avid algae eaters. These ample food tin beryllium arsenic brightly colored arsenic parrots. They besides person somewhat beak-shaped mouths.

“They’re beauteous and colorful and the astir salient food connected astir reefs,” says Katie Cramer. She’s a marine ecologist astatine Arizona State University successful Tempe. By eating truthful overmuch algae, parrotfish straight impact the magnitude of coral, she says. The food wide abstraction wherever caller coral tin travel successful and grow.

A stoplight parrotfish biting astatine algae and the limestone operation of a reef.

But the limestone operation of reefs successful galore areas is successful trouble. This is particularly existent successful the Caribbean Sea. Reefs determination person little coral and much algae than a fewer decades ago.

One reason: less grazers. Many algae-eating urchins died from illness successful the 1980s. And overfishing has caused parrotfish numbers to fall.

Boosting parrotfish populations has seemed similar a promising solution. Today, parrotfish are present protected successful galore reefs.

But algae aren’t the lone menace to reefs. And bare parrotfish won’t devour conscionable the algae. They’ll besides chomp connected chunks of the reef itself.

Scientists are present moving to recognize erstwhile nibbling parrotfish assistance reefs turn and erstwhile they trim its limestone to sand. Indeed, parrotfish play a much analyzable relation connected reefs than erstwhile thought, emerging information show. And knowing much of that communicative whitethorn assistance usher projects that purpose to reconstruct and support reefs arsenic they look threats — from pollution and poisons to diseases and a warming climate.