New research from the University of North Carolina at Chapel Hill compares the growth rates between nearshore and offshore corals in the Belize Mesoamerican Barrier Reef System, the world’s second-largest reef system. While nearshore corals have historically grown faster than those offshore, over the past decade there was a decline in the growth rates of two types of nearshore corals, while offshore coral growth rates in the same reef system stayed the same.

Coral reefs are a critical source of food, income and storm protection for millions of people worldwide. Nearshore corals grow in warmer and more nutrient-rich waters than their offshore counterparts and, because of their warmer temperatures, are believed to give a glimpse into the coral reefs of the future. This growth decline leads researchers to believe that any previous environmental advantage that came from corals being located closer to shore has now diminished. This is likely due to climate change and human activities, like coastal development that introduces excess sediment and nutrients to the water, subjecting corals close to shore to higher levels of stress. The findings also suggest that over time climate change will slow the growth of nearshore and offshore corals throughout the world.

“This research leaves us with troubling questions, like whether or not corals will be able to adapt to future conditions, and, if not, how that will impact the health and well-being of the millions of people around the world who rely on reefs for their food, income and protection from storms,” said Justin Baumann, a postdoctoral researcher in marine sciences and biology at the University of North Carolina at Chapel Hill. “Since we don’t know the answer to these questions, it remains crucial that we carefully manage and protect reefs so that they will have the best possible chance to acclimate, adapt, and, hopefully, survive the impacts of climate change.”

Read more at University of North Carolina at Chapel Hill

Image: Justin Baumann drills a coral core in Belize. (Credit: Hannah Aichelman)