After the massive bleaching in 2016, scientists discovered that the coral reefs of the Great Barrier Reef have become more resistant to last year's marine heatwave.

According to a recently published study, an international team of researchers discussed the extent of damage to the coral reefs after the major bleaching events of 1998, 2002, 2016, and 2017. They found that only 7 percent of the Great Barrier Reef has not been affected by bleaching events since 1998. Moreover, 61 percent of the individual reefs have been severely bleached at least once in the past 20 years.

Great Barrier Reef Adapting To The Changing Climate

However, here is the good news. While most of the Great Barrier Reef has at least once has been severely damaged from coral bleaching caused by a marine heatwave, the corals that have been affected are found to be more resilient. Terry Hughes, the lead author of the study, revealed that there was less bleaching in 2017 even when the temperature was higher than the year before.

"Dead corals don't bleach for a second time," he stated in a press release from the Arc Center of Excellence Coral Reef Studies. "The north lost millions of heat-sensitive corals in 2016, and most of the survivors were the tougher species. As a result of bleaching, the mix of species is changing very rapidly."

The team of researchers used the data from the National Oceanic and Atmospheric Administration's satellite-based tools to monitor the extent of the damage of last year's heatwave to the coral reef.

Hughes added that the more positive outcome last year was due to the conditions that the Great Barrier Reef experienced the year before. This is the first time that the natural wonder experienced two mass-bleaching events in a row. The reason why there was less bleaching last year was that the more susceptible species of corals died off in 2016.

Climate Change Still A Threat

This, of course, does not mean that coral reefs are no longer vulnerable to the rapid global warming. The researchers hope the new study could provide new knowledge about the cumulative impacts of climate change-driven environmental events that will become more frequent if the world fails to reduce emissions of greenhouse gases into the atmosphere.

"We need urgent global action on greenhouse emissions to save the world's coral reefs," added Hughes.

The study was published in the journal Nature.