The underwater skyscraper teems with sea life and had been overlooked in past surveys of the reef system.
Researchers in Australia blamed climate change for the loss, which they said could diminish critical habitats for fish and other marine life.
The tourism operators who depend on the natural wonder, already contending with climate change, have been walloped by the pandemic. The absence of visitors is bad for them — and the reef.
A recent expedition to the inky depths of the Coral Sea revealed an unknown world of creatures and geologic features.
We asked four of our contributors to write about trips that shaped who they are today, and that inspire them now, in these housebound days.