Bleached corals ruin fish camouflage

From an article by Matt Kaplan posted on Nature News:

No hiding place from ecosystem collapse on the reef

Fish that usually camouflage themselves among colourful coral reefs are losing their ability to hide from predators as corals are bleached by Earth's acidifying oceans.

Bleaching often leads to coral death, and is a stress response to two key factors: increasing ocean acidity, caused by uptake of carbon dioxide from the atmosphere, and a rise in ocean temperature. It's all too apparent that ecosystems near bleached corals tend to collapse, but the reasons why are not fully understood.

Some ecologists speculate that fish in bleached reefs simply move to areas where corals are still healthy, whereas others suggest that they succumb to increased predation as the corals provide less cover. To test these ideas, graduate student Darren Coker, of Australia's Centre of Excellence for Coral Reef Studies at James Cook University in Townsville, Queensland, and his colleagues have done laboratory experiments to test the effect of coral bleaching on predator evasion in reef fish.