Date:December 5, 2020

The Sad Truth Underneath The World’s Largest Sinkhole Of Belize’s Blue Hole

Easily recognizable from space, the Belize Blue Hole, sometimes known as the Great Blue Hole, is one of the most iconic dive spots in Belize.

The great blue hole remains one of the top attractions in Belize. It is not only a world-class destination for diving but also a rich habitat for a variety of marine life like nurse sharks, reef sharks, blacktip sharks, and even giant groupers.

An aerial view of the Great Blue Hole, a popular diving site that’s part of Belize’s barrier reef – Shutterstock

The tourist attraction, which has been dubbed the “Great Blue Hole,” is a collapsed cave that measures approximately 984 feet across and 410 feet deep. NASA scientist Glyn Collinson once described it as the “deepest, deep blue hole imaginable.”

So, it’s no surprise scientists are eager to learn more about the crater, which has spurred rumors of sea monsters and bizarre creatures that live inside. In November 2018, researchers with Vancouver-based Aquatica Submarines sent a three-person submarine to the site to explore the bottom of the Great Blue Hole for the first time.

Instagram | @fcousteau

“Preserved from the disturbance of time and isolated in the darkness, the hole holds clues to a very natural part of our planet’s life cycle. It’s these terraces and stalactites we set out to map,” Erika Bergman, chief submarine pilot on the recent expedition, explained in a recent blog post.

The team conducted more than 20 dives into the large sinkhole from Nov. 27 to Dec. 13, taking videos and 3-D images during each trip, Aquatica Submarines said in a news release. They even completed a two-hour live broadcast from the deep blue waters that was featured on The Discovery Channel.

One of the biggest findings of the trip was the discovery of “mysterious tracks” in the sand roughly 350 feet below the surface.

Plastic bottles lie at the bottom of one of the world’s largest sinkholes The Great Blue Hole, in Belize on the Caribbean sea. Source: Getty

In an interview with CNN Travel, Bergman said the “unidentifiable” tracks remain “open to interpretation.”

Bergman, however, wrote in a blog post that they were located near an area researchers labeled the “Conch Graveyard,” where they witnessed hundreds of dead conch that likely suffocated after becoming trapped in the oxygen-deprived base of the Blue Hole.

“Presumably, unsuspecting conchs (or other conch shell inhabitants) have been going just a little too close to the edge and falling into the hole at this entrance by the thousands. We can see each conch with little tracks back up the hill trying to escape, then a slide mark where it slid back down after presumably being asphyxiated in the anoxic environment,” Bergman explained.

Roughly 300 feet below sea level, Bergman said the crew detected toxic hydrogen sulfide gas.

Great Blue Hole sonar data – Short demo

“There is no circulation in or out of the hole and our onboard CTD and dissolved oxygen sensor revealed what we had predicted, the bottom is completely anoxic. There’s not a drop of oxygen below the H2S layer,” Bergman described, noting that sargassum seaweed could be a contributing factor.

As far as billionaire business magnate and Virgin founder Richard Branson – who joined the expedition – is concerned, there is no mythical monster hiding in the depths of the Blue Hole.

“The real monsters facing the ocean are climate change and plastic,” Branson said, according to Newsweek. “Sadly, we saw plastic bottles at the bottom of the hole, which is a real scourge of the ocean. We’ve all got to get rid of single-use plastic.”

Wikimedia Commons | U.S. Geological Survey (USGS)

They also wanted to help Ocean Unite promote ocean awareness and achieve its goal of having at least 30 percent of the world’s ocean protected by 2030.

Branson said the team spoke with Belize Prime Minister Dean Barrow about protecting 10 percent of the country’s waters and banning grill nets, “which are known as the Wall of Death and do so much damage to marine ecosystems”.
While Cousteau, Branson, and Bergman were plenty excited to explore the Blue Hole. But once the excitement wore off, the current state of this natural wonder paints a pretty grim picture for the future.

Layers of hydrogen sulfide and other gases made the trek to the bottom less straightforward than most submersible trips. But thanks to the expert guidance of Bergman, they did eventually reach the bottom.

Instagram | @fcousteau

According to Newsweek, the Great Blue Hole formed as a limestone cave hundreds of thousands of years ago, when sea levels were far lower. At the end of the last ice age, sea levels rose by around 100 m, submerging the cave to become the natural wonder it is today.

Throughout the dive, Branson broadcasted the journey on the Discovery Channel while keeping a blog. He described the Giant Blue Hole’s massive wall of giant stalactites as “breathtakingly beautiful”.

“The Blue Hole is made of a complex system of caves that once formed on dry land. It is proof how oceans can rise quickly and catastrophically.

“At 300 feet down, you could see the change in the rock where it used to be land and turned into sea. It was one of the starkest reminders of the danger of climate change I’ve ever seen,” wrote Branson.

He also described the thick layer of hydrogen sulphide that the three divers eventually reached on their dive. Further down, there was a pile of creatures that had fallen into the hole and died due to lack of oxygen.

“As for the mythical monsters of the deep? Well, the real monsters facing the ocean are climate change — and plastic. Sadly, we saw plastic bottles at the bottom of the hole, which is a real scourge of the ocean.

“We all have to get rid of single-use plastic,” he said, expressing his concern for the sustainability of the future. Branson is working alongside a scientific team to produce a 3D view of the Great Blue Hole. The team is also part of Ocean Unite, a conservation group working towards protecting 30 percent of the ocean by 2030.
Instagram | @richardbranson

“My grandchildren will be in their thirties by 2050,” Branson said.  “I don’t want them to grow up in a world without corals, without the wonders of the ocean. We need governments to act now to protect at least 30 percent of the ocean by 2030 and reduce CO2 emissions as quickly as possible with a goal of zero net emissions by 2050.”