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Sand Tiger Shark Mystery | JONATHAN BIRD’S BLUE WORLD

Sand Tiger Shark Mystery | JONATHAN BIRD’S BLUE WORLD


Coming up next on Jonathan Bird’s Blue World,
why do sharks hang out at shipwrecks? The blue world keeps her secrets well, and
today we’re going to attempt to solve a mystery about an amazing fish. Every spring, Sand Tiger sharks converge at
certain shipwrecks off the coast of North Carolina. Nobody knows why they visit these
wrecks or what they like about them. They don’t seem to be doing much of anything. But scientists have a theory on what they
are doing…and we’re going to see if we can confirm it. Hi, I’m Jonathan Bird and Welcome to my world! Our adventure begins in coastal North Carolina
in the United States. We have loaded piles of gear aboard a dive boat and we’re heading
way offshore…to an area of the ocean full of world war 2 shipwrecks, known as the “Graveyard
of the Atlantic.” The wrecks are located here, in a lonely part
of the open ocean, more than 15 miles from land. Eighty feet below me is the wreck of
the Carib Sea, a ship that was sunk by a German U-boat in World War two. The Carib Sea has deteriorated over 60 years
on the bottom of the ocean, but it still looks like a ship. My crew and I are suiting up to explore the
wreck and the sharks that have come here. We don our gear and jump into the water, descending
down the anchor line into the blue. What starts out as crystal clear water near
the surface, becomes more murky at the bottom. Out of the haze, a shark slowly materializes,
swimming at a leisurely pace Sand Tigers have rows of pointy teeth that
look pretty scary. These needle-like teeth are not designed for
biting divers, but in fact they are good for grabbing and holding on to slippery fish.
They aren’t good for cutting, so the Sand Tiger usually doesn’t take bites out of anything.
They usually don’t eat anything that they can’t swallow in one bite. As I swim around looking at the sharks, they
seem to be trying to act inconspicuous, as if they are just waiting for me to leave so
they can get back to what they are doing when I’m not around. But what are they doing when
I’m not around?? They could be coming to the wrecks to eat.
Afterall, there are a lot of fish here. But there are a lot of fish in lots of places.
Why would all these sharks come to the wrecks in North Carolina, all at the same time? Biologists think this is no coincidence. They
think the sharks come here to mate. One clue are the sharks teeth that can be
found on the wreck. As I look around, I find a bunch of shark’s teeth scattered on the
wreck and in the sand nearby. Sharks have a steady supply of new teeth being
regenerated because they lose their teeth every once in while when they bite something
hard. When sharks mate, the male bites onto the
female to hold on. He often loses some teeth in the process. Scientists think these teeth
are a sign that the sharks are mating at the wrecks! They sure aren’t mating while we’re around,
even if we use our super-quiet rebreathers. So the next step is to place some remote cameras
on the wreck and leave, to see if we can catch the sharks doing anything without us around. My crew and I place several remote cameras
on the shipwreck. We will record for an hour with nobody around so that the sharks won’t
be disturbed by our presence. Later we look at the tapes to see if the cameras
caught anything on tape. See now what’s surprising me about this is
that I really expected to see something different with the unmanned cameras. I mean when we’re
not down there, there’s no divers, they should be doing something now that we’re not there.
But they’re doing the same thing—which is nothing! While we got some interesting shots of the
sharks, we didn’t see any mating. In fact, they looked like they are doing the same exact
thing they do when we are down there with them I would expect a lot more action. Hmm, I think we are going to have to go back
out and see what they do at night. I think that’s the only thing we can see because if
they’re not doing it during the daytime, maybe it’s a nighttime, maybe it’s a nocturnal activity. Could the sharks be mating at night? There’s
only one way to find out, and it’s a pretty spooky option. We decide to take the boat out to the wreck
to stay overnight. We are the first film crew to attempt filming Sand Tigers on this wreck
at night. We head down into the darkness with video
lights on our cameras, hoping to see something incredible. When we reach the wreck, we don’t really see
anything except pitch darkness. Until… Out of nowhere, a dazed Sand Tiger shark suddenly
comes right at me and scares me half to death! During the day the Sand Tigers are far too
shy to come this close. They don’t seem aggressive…but they do seem
confused by the lights. They act like they are sleep-swimming, almost like a deer in
the headlights when the bright video lights get too close. After an hour looking for mating behavior
and not seeing any, we give up and head back to the boat. But we still have one last idea. And you liked the camera positions earlier? Those were good. We will try the remote cameras again, this
time at night. Alright. And the sharks do, they go through there,
they go around the front of the bow, and then when they circle around they come across that
front… But in order for the cameras to be able to
see anything, we will need at least some light. The following day, we set up a super bright
movie light over the bow of the wreck by hanging it from an air-filled lift bag. This 200 Watt
HMI light is as bright as a 1,000 watt lightbulb. If we hang it high enough over the wreck,
it should throw just enough light to provide some gentle illumination for the cameras,
but not so much that will daze the sharks. While Rick is hanging the light, Gator, Tim
and I are setting up cameras. Finally, everything is ready. Now we head
back to the surface to wait for darkness. Later, we dive back down to the wreck and
turn on both the cameras and the light. It’s a quick dive, and then we return to the boat
to wait. Whoa! I don’t know we might have just put
down the world’s largest plankton-attracter! I don’t know! But I can tell you one thing:
the sharks are around the wreck at night. Um hmm! Oh yeah, they’re there! In the morning we collect all the cameras
again. Reviewing the footage, our light above the
wreck worked out well. In fact, it worked so well that it attracted a huge school of
fish below it. I mean that big HMI light right over the bow
of the boat really causes the fish to aggregate underneath it, but it doesn’t seem to attract
the sharks, and the sharks don’t seem to be really attracted to the lights or the fish. There are very few sharks in this footage
so they’re not together by any means. Yeah, really it looks just like the day footage
all over again. We learned that the sharks are probably not
feeding on these fish because if they were, how could they not be attacking such an easy
meal? Every once in a while we see a shark or two
pass through the school, but we don’t see any mating. You might think that our entire experiment
was for nothing because we didn’t see the sharks mating. But in fact it proved that
the sharks don’t seem to be very active at night. And it showed us that they might not
be mating at the wrecks at all, though we can’t prove it either way. The ocean is filled with mysteries, many of
which will never be solved. We’re a little closer to understanding the Sand Tiger shark,
but we have a lot to learn. For now, we still have no idea why the Sand Tigers come to the
wrecks in North Carolina. This mystery will continue to remain unsolved.

100 comments on “Sand Tiger Shark Mystery | JONATHAN BIRD’S BLUE WORLD

  1. Maybe the sharks are just curious about the ship wreck – it is something that you don't find very often in the ocean world.

  2. Sand tigers dont just live on wrecks. They can also be found along rock walls, deep reefs, and other undersea structure and wreckage. I'd venture a guess that, as time went on, and the seabed began to creep over the wreck, it simply became another piece of raised undersea topography that matched the preferred habitat of the species. Great video, I've been watching your series for the last two hours, I cant stop clicking in the related videos.
    Also, I believe that fish, including elasmobranchs, cant see red light. Perhaps setting out a light with a red sheet over the bulb would have offered somewhat more insight into their behavior.

  3. Can you make a video about orcas and killer whales please? If you already did- sorry i wasn't paying attention to that.

  4. I always enjoy your video. I have dove with Aquatic Safaris out of Wilmington N.C. on the Hyde and the Markham. They we full of these awesome sharks that always seems to be in slow motion.

  5. I know why the sand tiger sharks come at the shipwrecks because to find a sucker fish. Did you see that shark with a sucker fish .

  6. Jonathan, I have wanted to ask you a question for a while. What is it like to be face to face with sharks and whales?

  7. Where are you in carolina because I go to the outer banks every summer and one time I thought I saw a shark fin and wasn't very big but it was big enough to be a sand tiger

  8. They carry the spirits of those sailors died from the german torpedo! Still protecting the ship and they always will. I think they just swimming around it cause it's huge and interesting for them! Once I dropped a toy ship in one aquarium and all fishes started to circle around it… the next day and the day after that and after that 🙂 It was very interesting for them!

  9. im in love with your channle and i just watched 4 videos😂 and i forgot to introdoos myself my name is holly and im 8 years old and one question are the sharks dangerous please respond😊

  10. i thank that sand tiger sharks go to ship reks becaus thay love sand rite ther is a lot of sand on the ship and to be curious abot what is newat the reck

  11. i thank that sand tiger sharks go to ship reks becaus thay love sand rite ther is a lot of sand on the ship and to be curious abot what is newat the reck

  12. i thank that sand tiger sharks go to ship reks becaus thay love sand rite ther is a lot of sand on the ship and to be curious abot what is newat the reck

  13. Just a random idea and I dont have any knowledge relating to aquatic life but could it be that the wreck still has some kind of electromagnetic frequency and this atracts them?

    I watched the video of the experiment of the frequencies and the Lemon Shark(I think it was) that's why it occurred to me, I know this sounds a little bit more imagination than anything else but just a thought…

  14. hi jonathan i am a diver too and i have already solved the mystery coz few weeks ago i went to a wreck and saw the sharks mating there but not all the time mostly they just roam around

  15. Hi Jonathan, I have a new hypothesis for their gathering around the shipwreck. Since it is a warship, it might still have some metal weapons or instruments that still carry magnetism and can produce electronic fields. As sharks are sensitive to electronic currents, they might be attracted by the fileds created by metal instruments in this wreck. What do you think?

  16. It's something to see, that's why. If you lived underwater would you just hang out in open water with nothing to see but more water, or would you check out all the cool shipwrecks ?

  17. They don't eat humans. They never did! They're more scared of you! If they see you, they'll flee like little girls. We're more dangerous to them, than they are to us. But it don't mean, they won't defend themselves, if harmed. These sharks only live in cold freezing water. They will die if they're in hot water.

  18. Such a shame that sharks are treated like bloodthirsty man-eaters when that is not the case, science and facts and overall compassion/empathy proves that.

  19. Are they not being cleaned there??? Other sharkies get cleaned in other places… Maybe their cleaners hate the light… If there were night cams which could film underwater it would be great…

  20. Are they not being cleaned there??? Other sharkies get cleaned in other places… Maybe their cleaners hate the light… If there were night cams which could film underwater it would be great…

  21. The sharks have a magnetic anomaly detector looking for Uboats… somebody forgot to recall them from patrol.

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