UOG study: Shade can mitigate impact of heat stress on corals

Staghorn corals in the reef flat off Hagåtña appear bleached as a response to stress from environmental changes. As one of Guam’s dominant reef-builders whose habitat experiences temperatures up to 97 degrees Fahrenheit, this species was used in a University of Guam study published in February that found that shade can mitigate the effects of heat stress on corals. Photo courtesy of UOG

A study by University of Guam researchers has found that shade can mitigate the effects of heat stress on corals. The study, which was funded by the university’s National Science Foundation EPSCoR grant, was published in February in the peer-reviewed Marine Biology Research journal.

“We wanted to see what role light has in coral bleaching,” said UOG Assistant Professor Bastian Bentlage, the supervisor and co-author of the study. “Usually, people talk about temperature as a cause for bleaching, but we show that both light and temperature work together.”

Previous UOG research led by Laurie J. Raymundo found that more than one-third of all coral reefs in Guam were killed from 2013 to 2017 over the course of multiple bleaching events. Coral bleaching is the process in which corals stressed by environmental changes expel the essential symbiotic algae that live in their tissues, causing them to turn white and often die.

This latest study examined the resilience of staghorn corals (<