"See How Marine Heat Waves Are Spreading Across the Globe"

"Sea surface temperatures in 2024 broke records and about a quarter of the world’s oceans are experiencing temperatures that qualify as a marine heat wave." 

"Unusual heat waves have occurred in all of the major ocean basins around the planet in recent years. And some of these events have become so intense that scientists have coined a new term: super marine heat waves.

“The marine ecosystems where the super marine heat waves occur have never experienced such a high sea surface temperature in the past,” said Boyin Huang, an oceanographer at the National Oceanic and Atmospheric Administration in an email.

The seas off the coasts of the United Kingdom and Ireland experienced an unusually intense marine heat wave, one of the longest on record, starting in April and the temperature rise happened much earlier in the year than usual. Australia and its iconic coral reefs were recently struck by heat waves on two coasts."

Delger Erdenesanaa reports for the New York Times with graphics by Harry Stevens June 9, 2025. This article was produced in partnership with the Pulitzer Center’s Ocean Reporting Network.