Once-vibrant Caribbean coral reefs are suffering as algae smothers them and the fish disappear.

Until recently, elkhorn and staghorn corals were the main coral species in the Caribbean, but they've declined as much as 98 percent since the 1970s due to overfishing, disease and climate change.

Earthjustice is working to restore these reefs, and one of the organization's goals is to protect the parrotfish — known as the "janitor of the reef." Parrotfish graze algae off the reef, making space for coral to grow. Learn more about the group's work on the Earthjustice blog.

Related on MNN: 10 of the world's most spectacular artificial reefs