The world’s coral reefs are in the midst of a global bleaching event, with extraordinary ocean temperatures causing widespread damage, the National Oceanic and Atmospheric Administration and international partners announced on Monday.
This marks the fourth global bleaching event on record and is expected to impact more reefs than ever before. Bleaching occurs when corals become stressed and lose the symbiotic algae they need to survive. While bleached corals can recover, prolonged exposure to high water temperatures can lead to their death.
Coral reefs are crucial ecosystems that support a quarter of ocean species at some point in their life cycles, provide food for millions of people, and protect coastlines from storms. The economic value of coral reefs is estimated at $2.7 trillion annually.
“This is scary, because coral reefs are so important,” said Derek Manzello, coordinator of NOAA’s Coral Reef Watch program.
The current bleaching event has already caused significant coral death in Florida and the Caribbean, particularly among staghorn and elk horn species. However, it is too early to estimate the full extent of global mortality.
To classify a global bleaching event, NOAA and the International Coral Reef Initiative require all three ocean basins hosting coral reefs to experience bleaching within a year, with at least 12 percent of reefs in each basin subjected to bleaching temperatures. Currently, over 54 percent of the world’s coral area has experienced bleaching-level heat stress in the past year.
The ongoing event is expected to be the most extensive global bleaching event on record, with bleaching confirmed in 54 countries, territories, and local economies. The Great Barrier Reef in Australia is experiencing severe bleaching, with a third of surveyed reefs showing extreme bleaching.
Despite the alarming situation, scientists are hopeful that urgent global action to reduce carbon emissions can help mitigate future bleaching events. Efforts are also underway to breed coral that can tolerate higher temperatures and explore other adaptation strategies.
While the challenges are significant, Dr. Ove Hoegh-Guldberg, a marine studies professor, believes that with concerted efforts, the world can still save coral reefs from further devastation.
“I think we will solve the problem if we get up and fight to solve the problem,” Dr. Hoegh-Guldberg said. “If we continue to pay lip service but not get on with the solutions, then we’re kidding ourselves.”
