A newly released study by UNC researchers finds that corals growing closest to the open ocean have the most trouble dealing with climate change and pollutants.

Marine scientists examined the Mesoamerican Barrier Reef off the coast of Belize in the study, which appears in the Feb. 16 issue of the PLoS One journal.

The scientists found that a distinctive type of coral on the seaward side of the reef is growing more slowly than corals closer to shore. But about 100 years ago, seaward facing corals grew most quickly.

Based on study findings, corals from the inland zone have maintained stable growth rates, while forereef corals show stunted growth.

Researchers have not determined the exact causes of the change, but findings suggest corals in the forereef zone may be more vulnerable to or human-influenced sources of stress, because they are not adapted to the stressful conditions—like fluxes in water temperature— that their inland-facing counterparts are used to.

Sediment plumes, nutrients and pollution that have been carried long distances by ocean currents from Guatemalan and Honduran watersheds may also affect coral growth.

Karl Castillo, postdoctoral research associate in the marine sciences department, Justin Ries, assistant professor of marine science, and Jack M. Weiss, adjunct assistant professor in environment and ecology co-wrote the study.