"Their counterparts on dead coral failed to pick up the scent," one researcher said.
The study says it's unclear whether these fish just didn't respond appropriately to the hypothetical predators or if they actually failed to learn what to do in case of an attack.
Australia's Great Barrier Reef is suffering a massive bleaching event right now. If fish's survival instincts are lost with it, a lot of Australia's biodiversity is at stake.
This video includes clips from World Wildlife Fund, National Geographic, New England Aquarium and ABC Australia and images from Getty Images and Chris Mirbach.