Even healthy corals have herpes, so what’s making them sick?

Coral reefs are living, breathing animals. The reefs provide shelter and habitat for other fish and plants, even algae which lives inside the coral.

But corals are disappearing. In the Carribean, coral cover has shrunk from 60% to 5%, says microbiologist Rebecca Vega Thurber. While a warming oceans and pollution play a role, Vega Thurber suspects disease is also crippling the world’s corals.

She and her team at the Oregon State University have been studying viruses that live inside the corals. Many of them carry viruses, even healthy corals, Vega Thurber explains.

“Just like in humans, almost all corals have herpes viruses,” Vega Thurber says. “This was quite a shock to us.”

Other viruses are more dangerous, like the white plague. Vega Thurber suspects that some of these viruses infect the algae within the coral. And when corals are stressed by pollution or a hurricane, these viruses erupt and the animals get sick. Science correspondent Miles O’Brien has more on what’s causing these coral diseases for the National Science Foundation series “Science Nation”.*

*For the record, the National Science Foundation is also an underwriter of the NewsHour.