Coral Reef Rescue: Save the Parrotfishes!

Vimeo Link:

YouTube Link:

Team Members:

Joseph Pawlik, University of North Carolina, Wilmington
Boston Dang, University of North Carolina, Wilmington


Coral reefs are important because they protect coastal shorelines from erosion, provide food for millions of people, and attract tourists. Coral reefs have declined rapidly because of climate change, disease, overfishing and pollution. On Caribbean coral reefs, this decline has been observed as a replacement of corals with seaweeds. Scientists hypothesize that this is due to overfishing of parrotfishes that eat seaweeds. The study cited in this video tested this hypothesis by counting the parrotfishes, corals, seaweeds, and other organisms on the reef across the Caribbean, focusing on sites that were strongly overfished and those that were protected from fishing. Surprisingly, there were just as many seaweeds on overfished reefs as on protected reefs, but sponges on overfished reefs were 3 times more likely to overgrow and kill corals. Because parrotfishes also eat sponges, the study showed that parrotfishes need to be protected if corals are to be protected.

Original Publication: 

Loh, T.-L., McMurray, S.E., Henkel, T.P., Vicente, J. and Pawlik, J.R., 2015. Indirect effects of overfishing on Caribbean reefs: sponges overgrow reef-building corals. PeerJ 3: e901

Link to Publication:

Support Provided by: National Science Foundation Award 1029515

By the Numbers

Over 40,000 students in 50 US states, the US Virgin Islands, and 25 countries participated as judges in the 2016 Ocean 180 Video Challenge.