For the new study, Knowlton and colleagues visited seven locations in the Indian Ocean, the western and central Pacific, the northwestern Hawaiian Islands, and the Caribbean.
In some places, the researchers collected dead heads of coral, which house just as many crustaceans as living corals do, if not more. In other places, they planted little condominiums and waited for crustaceans to crawl in and get settled.
The team came back a year later and picked up the apartment buildings. They ended up with a total of 93 separate crustacean communities.
BIGPIC: Coral Reef Stress Map