Katharina Fabricius, a coral reef ecologist at the Australian Institute of Marine Science and study co-author, told LiveScience that she has been diving and working on the reef since 1988 — and has watched the decline. "I hear of the changes anecdotally, but this is the first long-term look at the overall status of the reef.
There are still a lot of fish, and you can see giant clams, but not the same color and diversity as in the past."
To get their data, Fabricius and her colleagues surveyed 214 different reefs around the Great Barrier Reef, compiling information from 2,258 surveys to determine the rate of decline between 1985 and 2012. They estimated the coral cover, or the amount of the seafloor covered with living coral.
That overall 50-percent decline, they estimate, is a yearly loss of about 3.4 percent of the reef.
