New animations from the Pew Environment Group explain the connection between sharks and healthy coral reefs. From Pew:
Where sharks thrive, so do coral reefs. Studies in the Pacific Ocean have found that healthy coral reef systems, with abundant sea life, are dominated by sharks. Meanwhile, in areas where sharks have declined, reefs have been negatively impacted.
In the Caribbean Sea, scientists have found that declining populations of sharks may also cause a drop in parrot fish populations. Herbivorous species like parrot fish are important to the health of coral reefs because they eat algae. Overgrowth of algae harms diversity in coral reef systems. As a result, sharks need protection to maintain a diverse marine environment and healthy coral reefs.