While diving in Thailand in 2010, Mark Eakin, a scientist with the NOAA, saw some clownfish behaving in strange way - and for a very concerning reason.
Clown fish live in sea anemones - jellyfish-like polyps with toxic tentacles - mainly for safety reasons. But the clown fish he saw had stopped doing that.
"Instead of darting into their anemone for safety, the clown fish were going to nearby bleached corals, because something was wrong with their anemones," Eakin told The Dodo. "They didn't consider that a safe home anymore."