Climate change and ocean warming threaten coral reefs and disrupt the harmonious relationship between corals and their symbiotic algae, a process known as “coral bleaching.” However, a new study conducted by scientists at the University of Hawai’i (UH) at Mānoa and the California Academy of Sciences revealed soft tissues that cover the rocky coral skeleton promote the recovery of corals following a bleaching event.

These soft tissues, which are home to beneficial algae, represent a source of energy for corals. The study, led by Chris Wall, a graduate student at the Hawai’i Institute of Marine Biology (HIMB) in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST), showed corals with thicker tissue may be better equipped to survive bleaching in a warming ocean.

Coral reefs are a vital resource to the people of Hawai’i and the state’s economy in the form of tourism, diving, and recreational fisheries, in addition to protecting shorelines from storms and coastal erosion.

When corals are stressed, they lose the colorful algae living in their tissues, resulting in bleaching and sometimes death of the corals. These events have been historically rare in the Hawaiian Islands, but heat stress is becoming more widespread as a result of climate change. Repeated bleaching events in 2014 and 2015 show that Hawai’i is not immune to the effects of ocean warming.

Source: Soft tissue makes coral tougher in the face of climate change