Algae blooms said to be coral killers

UNITED NATIONS, Oct. 8 (UPI) -- A large algae bloom in the Gulf of Oman destroyed a coral reef in just three weeks, showing the threat such events can present, U.N. researchers say.

Scientists from the U.N. University Institute for Water, Environment and Health said around 95 percent of the hard coral under the rapidly growing patches of microscopic marine plants died off and 70 percent fewer fishes were observed in the area, the BBC reported.

Algae blooms can starve coral of sunlight and oxygen, leading to large die-offs, they said.

A large-scale algae bloom measuring more than 200 square miles occurred in one area of the gulf, and when researchers studied the area three weeks later they found the coral beneath the bloom had been almost completely destroyed.

"We were surprised at the extent and speed at which changes to the coral reef communities were affected," marine ecologist Andrew Bauman said.

In recent times, the increased occurrence of rapidly growing areas or "blooms" of algae have been attributed to human activities.

Eutrophication -- excess nutrients in coastal areas caused by run-off from agricultural fertilizers and human sewage -- is often cited as the trigger for these phenomena.