A new study may answer the question of why some corals bleach and others do not, even when exposed to the same environmental conditions. The study suggests that the corals themselves play a role in their susceptibility to deadly coral bleaching due to the light-scattering properties of their skeletons.
A team from Northwestern University and The Field Museum of Natural History found that reef-building corals scatter light in different ways to the symbiotic algae that feed the corals. Corals that are less efficient at light scattering retain algae better under stressful conditions and are more likely to survive. Corals whose skeletons scatter light most efficiently have an advantage under normal conditions, but they suffer the most damage when stressed.
The findings could help predict the response of coral reefs to the stress of increasing seawater temperatures and acidity, helping conservation scientists preserve coral reef health and high biodiversity.
The study of nearly a hundred different species of reef-building corals, including many from the 1893 World’s Fair in Chicago, was published this week in PLOS ONE. The open-access, online journal is published by The Public Library of Science.
“We have solved a little piece of the puzzle of why coral reefs are bleaching and dying,” said Luisa A. Marcelino, who led the study. “Our research is the first to show light-scattering properties of the corals are a risk factor.”
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