Great Barrier Reef waters spike to hottest in 400 years, study finds

FILE - Tourists snorkel above bleached and dead coral around Lizard Island on the Great Barrier Reef, located 270 kilometers (167 miles) north of the city of Cairns, Australia, on April 5, 2024. FILE - A green turtle feeds on sea grass at Lizard Island on the Great Barrier Reef near Cairns, Australia, on April 4, 2024.

Ocean temperatures in the Great Barrier Reef hit their highest level in 400 years over the past decade, according to researchers who warned that the reef likely won't survive if planetary warming isn't stopped.