An analysis of fossilized parrotfish teeth and sea urchin spines by researchers at Scripps Institution of Oceanography at the University of California San Diego showed that when there are more algae-eating fish on a reef, it grows faster.In the new study, published in the Jan. 23 issue of the journal Nature Communication, Scripps researchers Katie Cramer and Richard Norris developed a 3,000-year record of the abundance of parrotfish and urchins on reefs from the Caribbean side of Panama to help unravel the cause of the alarming modern-day shift from coral- to algae-dominated reefs occurring across the Caribbean.“Our reconstruction of past and present reefs from fossils demonstrates that when overfishing wipes out parrotfish, reef health declines,” said Cramer, a postdoctoral researcher at Scripps and lead author of the study.