Giant 'Blue Hole' found in Great Barrier Reef by marine biologist

According to new satellite imagery of the area, a giant blue hole was recently discovered within Australia's Great Barrier Reef.

Marine biologist Johnny Gaskell who has since explored the spot, said,

"What we found inside was hard to believe considering 5 months ago a Category 4 cyclone went straight over the top of it."

According to Gaskell, pristine colonies of giant birdsnest corals and extremely long Staghorn corals found in the "blue hole," were completely unaffected by Cyclone Debbie, which slammed into the region as a Category 4 storm back in late March.

From Johnny Gaskell

Blue Hole mission in the Great Barrier Reef.
This Blue Hole has previously been explored and documented by geologists who suggested it could be even older than the famous Great Blue Hole, in Belize.
It's location is in one of the least explored parts Great Barrier Reef, over 200km from our home @daydreamislandresort.

Gaskell began searching for blue holes in March last year after Cyclone Debbie hit, in hope of finding coral that was spared from the storm.
The high walls that line the sinkholes tend to preserve what lies below from damaging weather. Large hurricanes can be particularly dangerous for corals, as they are smashed by swells.
The blue hole that Gaskell spotted on Google Maps was in a remote location, nearly 190 kilometres away from the nearest island.
While the specific blue hole had been previously identified, its remoteness made it difficult to access and little was known about it.
Gaskell was able to finally confirm that it was a blue hole during the diving expedition in September.

The majority of blue holes are formed from sinkholes or caves that develop slowly over time, as rock begins to erode and collapse.
Many of the world’s blue holes formed during the last Ice Age, after sea levels rose and filled existing sinkholes with water.
The term blue hole simply comes from the dark, navy waters that characterise the formations, often creating a striking contrast with the turquoise that surrounds them.

 “This Blue Hole has previously been explored and documented by geologists who suggested it could be even older than the famous Great Blue Hole, in Belize."
pictures : Johnny Gaskell 

To get there we had to travel overnight for 10 hours and time the tides perfectly...
Was well worth it! Inside the walls was similar to the site we explored a few weeks back, but this hole was deeper and almost perfectly circular.
We dived down to just over 20m yesterday, before hitting bare sediment, that slowly sloped towards the centre.
Again it was great to see big healthy coral colonies.

“Due to the sediment build-up over thousands of years, blue holes can be like time capsules for the ocean,” Gaskell said. 

We call it 'The Crack'....
Up there with the most ultimate snorkels I've ever done...

“At around 15 to 20 meters deep, there were huge Birdsnest Corals (Seriatopora) and super elongated Staghorn Corals (Acropora), both of which were among the biggest and most delicate colonies I’ve ever seen,” Mr Gaskell said.

 

After diving the Blue Hole over the weekend, we decided to move sites and check out what looked like a huge crack in the reef
 Open to the ocean at one end, and closed in by Reef at the other.
The total length was over a 1Km long, about 50m wide and the depth is still unknown.

The Crack

The strong current along the walls meant we had to drift the whole way.
This video doesn't do the site justice as most of the bigger inhabitants were not keen to come close. Only filmed fish and corals at the top on the edges.
Freediving into the depths we saw Grey Reef Sharks, Whitetip Reef sharks, Maori Wrasse, a Tawny Nurse and a 3m Lemon shark.
Seeing a huge school of Humpnose Unicornfish was definitely my highlight.
Counted over 100 in one photo.

Want to know exactly where it is? Sorry, it's still a secret.

The blue hole sits in the heart of the Great Barrier Reef off the Whitsunday Coast.
“Its location is in one of the least explored parts Great Barrier Reef, over 200 km from Daydream Island. "
Gaskell however, hasn't revealed the exact location of his discovery, so it remains a new and local secret...
"Hopefully it will be left alone.
An influx of divers would severely damage the coral colonies, as they are more delicate than usual."

Picture : nautical charts (Australia AHS) overlaid upon Google Maps imagery in the GeoGarage platform webmapping.

It's a long way offshore this spot, but hopefully we'll get back there one day.
The Crack...

 Example of another Blue Hole in the GBR found in the GeoGarage platform ?
There are a couple of known blue holes in Australia but they are quite unexplored and due to the sheer size of the Great Barrier Reef, its certain that more are out there.
Wonky Hole is 80 metres (262 feet) deep and an amazing dive teaming with sea life and covered in whip coral and gorgonians.
The Barrier Star is another hole dropping to 90 metres (295 feet) with an overhang at the sandy bottom and an abundance of reef life and coral.

Gaskell plans to continue looking for and surveying blue holes in the Great Barrier Reef.
“Some of these sites have had scientists explore them in the past, but due to the remote offshore location, there are still parts of the Great Barrier Reef that remain a mystery,” he said.

Links :

• National GeoGraphic : Peer Inside a Mysterious Blue Hole in the Great Barrier Reef
• MNN : Biologist stumbles upon massive 'blue hole' in Great Barrier Reef
• Lostateminor : See inside the Great Barrier Reef’s incredible blue hole for the first time
• National Geographic : Peer Inside a Mysterious Blue Hole in the Great Barrier Reef
• AODN : Drowned dolines - the blue holes of the Pompey Reefs, Great Barrier Reef (pdf) 
• GeoGarage blog : Image of the week : Great Blue Hole in the Belize ... / Researchers just discovered the world's deepest ...