Just under the water lies one of the biggest mysteries of the Great Barrier Reef: blue holes. These underwater sinkholes give researchers a rare look at ocean life and how we can protect it. Until a few years ago, only two blue holes were documented in the entirety of the Great Barrier Reef — they are hard to find and even harder to get to.
With the help of Google Maps, marine biologist Johnny Gaskell and a team of researchers are finding previously unknown blue holes. In 2017, after witnessing Cyclone Debbie destroy many of the reefs in its path, he set out to find more blue holes. Home to hundreds of species of coral and serving as a protective waters for larger marine life, these formations give scientists a view of history buried in undisturbed sediment layers and clues about how to better protect coral reefs.
Using Google Maps’ satellite view, Johnny followed the cyclone’s path to pinpoint areas along the reef that might have been spared from damage. That’s when he spotted perfect circles along the reef, indicating a potential blue hole. The formation he identified was south of the Whitsundays in the Hard Line Reefs, a difficult-to-reach area of the Great Barrier Reef that’s dangerous to navigate. Despite this, Johnny and a team of divers headed out into the unknown, unsure of what — if anything — awaited them.