Bleached Corals, Pacific Ocean

Compare the healthy coral on the left with the bleached coral on the right. Increased water temperatures caused the bleached coral to lose the microscopic algae that give the coral color and provide it with food. Corals can recover from bleaching if there is time and space for healthy tissues to regrow, but too often other factors such as pollution or fast-growing seaweeds smother their chances. More about coral reef ecosystems can be found in the Coral Reefs section.