The news about the world's coral reefs has been bleak. As climate change warms the oceans and makes the water more acidic, coral reefs are dying. When coral reefs suffer, marine life suffers as well. While reefs cover just 1% of the ocean floor, they support up to 30% of all marine life.
A new study casts a hopeful light on coral reefs' dim future. Researchers have discovered that Kāne’ohe Bay in Hawaii is home to "super corals" that were nearly destroyed 30 years ago by development and sewage flowing into the bay. But the coral has rebounded rapidly — covering about 50% to 90% of the area it once did. This success comes despite warmer, more acidic water than they're used to, and despite human interference.
"We knew that the temperature and chemistry conditions in Kāne‘ohe Bay are very similar to the conditions that people predict will kill corals off globally," said Dr. Christopher Jury, lead researcher of the study and a postdoctoral researcher at the Hawaii Institute of Marine Biology at University of Hawaii. "Yet, the reefs in the bay are thriving, making the area incredibly valuable as a possible window into the future.”
The recovery process
Jury says the coral recovery came from two sources: growth in the remaining coral and recruitment of coral from other reefs. Think of coral larvae as the recruits, and as they drift through the ocean, they look for a place to settle. They landed on the reef as it was rebuilding and contributed to the healthy growth.
This means, Jury says, that "super corals" likely exist elsewhere in the ocean, both in Hawaii and beyond. However, he says it's too soon to say if transplanting the super coral into a dying reef would help the failing one rebound.
More research is needed — and soon. The United Nations Intergovernmental Panel on Climate Change (IPCC) warned in 2018 that if the planet warms up by 1.5 degrees Celsius, coral reefs would decline by 70% to 90%. If the global temperature rises by 2 degrees Celsius, virtually all coral reefs would be lost.
"It's unfortunately but inevitably true that things are going to get worse for reefs over the next 20 to 30 years, but that doesn't mean it's unstoppable," Jury told AFP. “If we ignore these problems then our generation will be the last one to see healthy, functional coral reefs. However, if we take major strides to substantially reduce the rate of climate change, conditions will start to improve.”