Bleaching-level heat stress is harming 84% of the world's coral reefs in an unprecedented event that began more than a year ago, scientists say.
The most intense global coral bleaching event on record began at the start of 2023 and continues today affecting 82 nations, territories and economies, the International Coral Reef Initiative said on Wednesday.
Global coral bleaching events affected 21% of reefs in 1998, 37% in 2010 and 68% from 2014 to 2017, according to the initiative. “As an atoll nation we see our reefs damaged and livelihoods threatened," Palau's President Surangel Whipps Jr. said in urging a transition to clean energy sources. "Our oceans and the communities that depend on them cannot wait."
Rising ocean temperatures, mainly from fossil fuel burning, are damaging the world's coral reefs from bleaching events that are increasing both in frequency and magnitude. Stress from the changes in temperature, light or nutrients turns corals white as they expel the symbiotic algae that lives in their tissues and provides the corals with food and color.
'Uncharted waters'
The initiative, backed by 45 nations and 57 NGOs and international organizations, said 1 billion people benefit directly or indirectly from coral reefs, which provide $10 trillion a year in benefits like food, jobs and coastal protection.
Coral reefs occur in more than 100 countries and territories and support a quarter of all known marine life, though they cover only 0.2% of the ocean floor. The extent of ocean covered by coral reefs declined by half since the 1950s, making for an estimated loss of $500 billion a year by 2100.
Bleaching impacts commerical fisheries, but reefs have recovered with effective management, new technologies, rigorous scientific data and collaboration with Indigenous peoples. Experts aren't so sure now.
"The fact that this most recent, global-scale coral bleaching event is still ongoing, takes the world’s reefs into unchartered waters," said Britta Schaffelke, partnerships manager for the Australian Institute of Marine Science and coordinator of the Global Coral Reef Monitoring Network.
"In the past many coral reefs around the world were able to recover from severe events like bleaching or storms," she said. "We need to continue to observe and measure if and how reefs will recover and change."
