Cousteau’s Blue Hole | JONATHAN BIRD’S BLUE WORLD


Coming up next on Jonathan Bird’s Blue World,
Jonathan explores a deep and mysterious Blue Hole in the Bahamas. Hi, I’m Jonathan Bird and welcome to my world! The Bahamas are famous in the diving world
for their natural formations called Blue Holes. A Blue Hole is typically a somewhat round
hole in the ground filled with water. They are often quite deep. Many Bahamian islands are covered in hundreds
of these Blue Holes. Blue Holes were formed during the last ice
age when sea levels were much lower than they are today. Rain, combining with carbon dioxide in the
atmosphere creates a mild acid called Carbonic Acid, otherwise known as acid rain. When rainwater collects in a small depression,
it slowly starts eating away the soft limestone of which the Bahamas islands are mostly made. Over tens of thousands of years, the hole
gets bigger and deeper. At the end of the last ice age, as the Earth
warmed, the sea levels rose, and with it, the water table. The Blue holes filled with
water. I have come to Andros in the Bahamas to dive
a little-known Blue hole called Cousteau’s Blue Hole. It’s called that because Jacques Cousteau
himself dove here! My adventure begins at Small Hope Bay Lodge
in North Andros. Today I won’t be using their dive boats…because we get to this
dive site with a truck! Small Hope Bay Lodge divemaster Dennis Burrows
is taking me on an adventure to a remote area of Andros. We drive through the mangroves to the local
highway. Then it’s into the forest on a road which
appears to be barely more than a trail. A rain storm passes through, making our journey
a little wet. But it just adds to the adventure! Small Hope Bay Lodge owner Jeff Birch has
come along to tell me a little bit about Cousteau’s Blue Hole. What do we know about Cousteau’s Blue Hole
here? Well, what we know is that Cousteau’s Blue
Hole is one of the very unique blue holes of the…of what I call the round “swimming
type” blue holes because it’s safe to dive from a recreational perspective, not
only from a cave structure perspective. And that is very very unique. I finally get my first look at Cousteau’s
Blue Hole. It looks like a small, circular pond. But this is no ordinary pond. Some of these Blue Holes are so deep, that
before scuba divers started exploring them, they thought they were bottomless. Cousteau’s Blue Hole does have a bottom,
but it’s about 400 feet below. So it’s about 4 times deeper than it is wide! The shore around the blue hole is mostly limestone,
but there are a few muddy places, and Cameraman Tim just found one! Awww! Get a shot of that! Get a shot of that
Birdman! Oh yeah, I forgot to tell you about that! Unbelievable! Once Tim has been extricated from the mud,
it’s time to carry our gear down the path from the road. It’s a lot of work, but at
least the sun came out! In the golden light of late afternoon, our
team suits up and prepares to make a dive before the sun gets too low. Todd takes a set of powerful video lights
to help lighting the wall and overhangs. Then it’s my turn to get in. Next Cameraman Tim joins us. Dennis will be our divemaster. He has done
this dive many times and knows where to find lots of interesting stuff! The water at the surface is quite green. Sunlight
near the surface allows plankton to grow, making the water murky. And the water is fresh. As we sink deeper, the sunlight drops off
quickly and we turn on our video lights. By 50 feet, there is very little light. By
70 feet there is almost no ambient light at all. Dennis leads our team along the vertical wall,
with Todd close behind lighting the place up. We have reached a layer called a halocline
where the freshwater above meets the salt water from the ocean below. In this layer, where oxygen-rich water from
above meets oxygen-poor water from below, microbial action creates clouds of fine minerals
that float in the water. Dennis leads us to a ledge with a deposit
that looks like rusty sediment. Above it on the wall are rusty looking stains
made by iron-oxidizing bacteria. They break down iron from the rock into rust, which falls
down and collects on the shelf below. This is the same kind of bacteria that makes rusty
stains in sinks and toilets. The deeper we go, the clearer the water gets.
At 90 feet, the walls are clean white limestone. At a hundred feet, we come across a layer
of sediment that looks a little bit like a chocolate layer cake. It’s called a microbial
mat, and it’s made of sulfate-reducing bacteria. These bacteria consume organic material like
leaves that fall into the Blue Hole. They operate in anaerobic conditions, meaning where
there is very little to no oxygen. In a sense, this type of bacteria essentially breathes
sulfate–which it gets from the calcium sulfate that naturally occurs in seawater. The result
is toxic hydrogen sulfide, and this thick mat of decomposed organic material. The oxygen level in the water at this depth
is very low because it is all consumed by other forms of bacteria that require oxygen
to decompose the organic matter in the water. Between that and the hydrogen sulfide in the
water, fish just can’t survive down here. Soon we start making our way up towards the
surface again. In the shallows, algae can live because there
is sunlight and no hydrogen sulfide. The algae make oxygen and fish can live here too, although
there aren’t many. I manage to find a single fish sitting on
a ledge. You have to wonder how fish ever got here in the first place! Because the limestone walls of the blue hole
are being slowly but constantly dissolved by the water, it has become quite porous.
In fact, if I touch it, it crumbles in my hand like a piece of dried toast. It’s hard
to believe that solid rock can become so fragile! Just under the surface of the water–less
than ten feet deep–the bottom is completely covered in what looks like an encrusting sponge.
But it’s not sponge at all. When I touch it, bubbles are released, potentially
indicating that there is some type of decomposition going on within it. It appears to be some
type of microbial mat that has yet to be identified by scientists. Even here in shallow water,
there are scientific discoveries to be made! We end the dive at sunset. We have seen some
amazing and weird phenomena in Cousteau’s Blue Hole. I would have never guessed there
was so much going on in a small Blue Hole like this one. It just goes to show there
is no limit to the amazing things to be seen in the Blue World.

94 thoughts on “Cousteau’s Blue Hole | JONATHAN BIRD’S BLUE WORLD

  1. I always love it when YouTube notifies me that there is a new Blue World upload.   My four year old daughter loves your show too!

  2. Yet another stunning video from the BWTV team. That place is amazing!
    Excellent job, Jonathan and team.
    Thanks for the video.

  3. Nice video 🙂 but usually you're very carreful about not touching the fragile things you come across in a dive. Why did you change your behaviour on this one ?

  4. I love your videos I awalys loved the water when I was little I am 10 year old now and I still love the water I awalys wanted to be a mermaid a pretty one ???????✌️✌️✌️✌️✌️✌️??????????????????????????????????

  5. Love your vids but I'd prefer it if you didnt touch and damage things, even if they don't seem significant. Leave it for someone else to see too !

  6. Jonathan I used the the sea of sharks whales that could swallow but you showed me what diving is like I now love the sea

  7. Across the pond in the UK – there have been several sightings of Great Whites in recent years. It would be great if Jonathan Bird's Blue World could come over here and find out if there is any truth in these stories!

  8. Hi @BlueWorldTV !! I love your videos but when are you going to make another? I can't wait till you do, I am doing a bunch of research about oceans and living things in the oceans or seas.
    These following two things don't have to be included but i would appreciate if you do.

    1. make another video about Orcas please.
    2. I am doing research so please include at least 7 facts. thanks. 🙂

  9. Fun and informative, as always and thanks for posting!

    The animated diagram was simple and very well done.  The narration through it was smooth and easy to understand, making for a seamless science lesson.  Kudos to both divers and writers . . . and a special tip of the hat to Cameraman Tim.

  10. Hey Jonathan what do you think about adding tactical pouches to weight belts. I was thinking I could buy some that airsofters use. I could put my torch in there and a few useful extras.

  11. If The Tubes Only Last 1.35 Mineutes And The Whole Is 500 Meters Down Witch Whud Of Token 2 Hours To Reach The End And Then Back Agai Witch Makes It 4 Hours How Did You Guys Really Survive.

  12. my 2 year old loves this video and he sits through the entire 10 minutes. his love for sea mammals led him here and he doesn't even finish the episodes on dolphins but this one. he likes to crack up with the old men when the cameraman Tim gets stuck in the mud. anyways, thanks for the fun

  13. So hard to believe that the "acid rain" was able to turn a small dent in the rock into a hole that's hundreds to even thousands of feet deep. Even when you consider it went from a dent to a massively deep hole in just 10,000-20,000 years. I was assuming it had to take a million+! Gotta love science! Funny that this also shuts down some of those extreme global warming nut jobs.

  14. First time I hear about blue holes. It was very interesting to know the way they were created, their vertical features and the ecology of bacteria in that kind of ecosystem.

  15. There’s a blue hole in Africa that has a monster in it that’s half squid half shark and the tentacles come from the back of it. There’s a story of three kids going swimming in it after school, and they were playing pass on the pond. And then one of them got pulled down in the water. Next both the two remaining kids swam back to shore and got out of there. They told their parents then the police. I learned this from river monsters. I don’t know if all of this is correct.

  16. Nature is amazing, the blue holes look great from the top and the water green under, looks phenomenal. Thank you Jonathan Bird for filiming and showing it for people who find the underwater world fascinating. I'm your big fan Jonathan Bird.

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