Coral reefs host millions of bacteria, revealing Earth’s hidden biodiversity

Sampling at just 99 Pacific Ocean reefs identified half a million varieties of bacteria

Two scuba divers investigating a coral reef

Researchers collect samples from a coral reef as part of the Tara Pacific Expedition, an effort to document biodiversity in reefs across the ocean.

Pete West/Tara Ocean Foundation

Coral reefs are hot spots for more than fish.

Fish and corals in reefs across the Pacific Ocean may harbor nearly 3 million varieties of bacteria, researchers report June 1 in Nature Communications.