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Truly Giant Sharks

Arawn_ap_Annwn

Gone But Not Forgotten
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Aug 5, 2009
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A former housemate told me a couple of years ago he had seen footage on an American documentary (he believed it was by National Geographic) of a deep diving sub filming an enormous shark at a great depth. He remembered it as being around 50 ft long and of an unknown species, he seemed to recall the sub was manned and the occupants were scared (no s***!).

He also said he'd seen footage or heard of footage of a 50ft great white, which again he felt had been on National Geographic. I pressed him for further details but he couldn't remember any, he seemed genuine. He was Spanish and both sets of footage had been broadcast in Spain, although a part of American documentaries. The conversation began after he had seen the summer 2007 "Nessie" footage of something seeming to move at high speed under the water, he seemed very impressed by this, so maybe was the type to get excited about nothing, although he seemed sensicle enough to me.

Obviously if this were true it would have been all over the media, or at the very least the Fortean media. But he was adamant that this was the truth, so I've wondered where he got these impressions from. He must have seen some footage of some form of particularly large or unusual shark. I've tried googling this to no avail. Anyone got any ideas as to what the fire was that created this smoke? He had seen the footage comparatively recently.
 
A programme speculating on the survival of Carcharodon Megalodon perhaps?

http://en.wikipedia.org/wiki/Megalodon

One Of The Sightings:

Great white shark expert Great white shark experts Richard Ellis and John McCosker have included a rather compelling chapter on Megalodon in his definitive 1991 volume, Great White Shark. Ellis (who authored the chapter on Megalodon), notes that although all the fossilized Megalodon teeth found so far indicate that the shark is extinct, we should really get concerned about the welfare of our divers if someone ever dredges up a white Megalodon tooth. Because if we did, "we would know that the giant shark became extinct quite recently," writes Ellis, "or is flourishing somewhere in the vastness of the oceans and has simply lost a tooth."

As frightening as a notion like that may seem for anyone who doesn't live in central Nebraska, could it ever happen? Almost all who have investigated the possible existence of the great Megalodon realize that if it is extinct, it has only recently occured in the geological record. The creature lived as long ago as 50 million years (Middle and Late Tertiary Period), but Ellis confirms that scientists have concluded Megalodon probably "just" became extinct, in the late Pleistocene or early Holocene epochs. In other words, as close as 10,000 years ago! Pretty scary stuff, Mr. Cousteau.

Zoological history has proven that very large animals can remain hidden from modern science, especially in our planet's under-explored ocean depths. So if the famous coelacanth can remain undisturbed for 60 million years, why not push our giant white shark up a mere 10,000? Apparently Ellis sees no major problem with that when he writes, "Except that we have not found one, there appears to be no reason why Megalodon should not be flourishing today." Granted, Ellis feels that no concrete evidence has been found for Megalodon's current existence. "But there will always be those who keep hoping that one will appear. Let us hope we are not in the water when it does."

Or has one already appeared? Contained in Ellis's chapter on Megalodon is quite an amazing sighting report from Australia. It is taken from David G. Stead's Sharks and Rays of Australian Seas, published in 1963. Here is the now-classic monster encounter, in Stead's words:

"In the year 1918 I recorded the sensation that had been caused among the "outside" crayfish men at Port Stephens, when, for several days, they refused to go to sea to their regular fishing grounds in the vicinity of Broughton Island. The men had been at work on the fishing grounds--which lie in deep water--when an immense shark of almost unbelievable proportions put in an appearance, lifting pot after pot containing many crayfishes, and taking, as the men said, "pots, mooring lines and all." These crayfish pots, it should be mentioned, were about 3 feet 6 inches in diameter and frequently contained from two to three dozen good-sized crayfish each weighing several pounds. The men were all unanimous that this shark was something the like of which they had never dreamed of. In company with the local Fisheries Inspector I questioned many of the men very closely and they all agreed as to the gigantic stature of the beast. But the lengths they gave were, on the whole, absurd. I mention them, however, as an indication of the state of mind which this unusual giant had thrown them into. And bear in mind that these were men who were used to the sea and all sorts of weather, and all sorts of sharks as well. One of the crew said the shark was "three hundred feet long at least"! Others said it was as long as the wharf on which we stood--about 115 feet! They affirmed that the water "boiled" over a large space when the fish swam past. They were all familiar with whales, which they had often seen passing at sea, but this was a vast shark. They had seen its terrible head which was "at least as long as the roof on the wharf shed at Nelson's Bay." Impossible, of course! But these were prosaic and rather stolid men, not given to 'fish stories' nor even to talking about their catches. Further, they knew that the person they were talking to (myself) had heard all the fish stories years before! One of the things that impressed me was that they all agreed as to the ghostly whitish color of the vast fish."

In this popular account, we apparently have credible witnesses, and a knowledgeable investigator, Stead, who believed the fishermen were telling the truth (and that they may have witnessed a living Megalodon). I believe the "fact" that they did not return to sea for days could be added to their credibility, and to their loss in wages after the apparently traumatic experience (unless they were hoaxing the entire event, of course.) We also have some rather strange features in this report, including the tremendous lengths the fishermen reported, if we cannot attribute these to exaggeration due to intense fear. If we cannot, then it seems if Megalodon has survived, it may have grown bigger, and I am not sure which idea is scarier.

In his 1989 book There Are Giants in the Sea, BBC film producer and wildlife author Michael Bright concludes his sea-monster volume with mention of the giant fish:

Imagine, then, the shock when scientists dredging the bottom of the Pacific Ocean, earlier this century, discovered two 10 cm. (4 in.) long megalodon teeth that were what can only be described as geologically "fresh." One was estimated to be 24,000 years old--roughly the time of the Lascaux cave paintings. The other was just 11,000 years old and therefore belonged to a gigantic shark that swam in the Pacific Ocean at the same time as man was migrating from Asia into North America. Could this enormous predator still be lurking in the ocean depths?(4)

I suppose we'll have to see what the oceans of the world turn up for the monster hunters to hold triumphantly over the heads of skeptics. But how exciting it would be if a 70-foot shark was deposited on the shores of California, surrounded by excited vacationers with video cameras in tow. Putting child-like dreaming aside, however, leaves us with the fact that whether or not the huge Megalodon is alive today is debatable only on theoretical grounds. Despite thousands of giant, still fossilized teeth, no matter how "fresh" they might be, and the amazing (perhaps exaggerated) report from Stead, there is not much to go on.(5) However, if some shark experts can agree not to completely write off "Meg" into extinction, then we might want to ponder the possibility that Peter Benchley's imagination is not as wild as we thought it was. And we will never go deep-sea fishing in anything smaller than an aircraft carrier ever again.

http://www.monsterfishkeepers.com/forum ... hp?t=46630
 
The '2 years ago' and 'submersible' aspects are reminiscent of the Delta submersible's encounter with a six-gill shark at a depth of around 1000m in late 2007 or early 2008.

There are multiple videos of this floating around the 'Net. Here's one:

http://www.youtube.com/watch?v=pHuvs9Qqa5o
 
EnolaGaia said:
The '2 years ago' and 'submersible' aspects are reminiscent of the Delta submersible's encounter with a six-gill shark at a depth of around 1000m in late 2007 or early 2008.

There are multiple videos of this floating around the 'Net. Here's one:

http://www.youtube.com/watch?v=pHuvs9Qqa5o

That could explain it, he could easily have been confused or exagerated the length. He was more sketchy on the giant "great white", although it faintly reminiscent of the Australian story above; and I can't remember whether he said he'd seen the other footage or was just aware of it.
 
I'm not saying this is another mis-identified basking shark but not so long ago the larger ones seen were 35-45 feet and I think the record is 70 !
My only sighting was one trolling along off Charlestown beach, Cornwall back in the late 70s. The fin was about 2 and a half to 3 feet out of the water, which would make for a shark of a good 25-30 feet.
Nowadays 20 feet is about the largest reported . I think it fair to say that shark species can vary in size a lot, not just between individuals but over quite short spans of time. Perhaps it was just a biggie from a known species., or maybe a known species is suddenly getting bigger.
 
My first thought was basking shark, but do they live at great depths? I also didn't realise they got much above 35 ft.
 
The biggest measured was just over 40ft. That doesn't, of course, preclude bigger specimens swimming around. Whale Sharks are bigger though...
 
Whale sharks, to my eyes at least are readily distinguishable from most/all other sharks, but, yes that could also be an explanation.
 
6m is big for a "normal" great white but not unusual is it?

How do I edit my profile? I'd like to add an avatar.
 
we have a regular very large basking shark that comes in to one of the little bays at Mumbles, very close to the shore, at around 9 on summer mornings.
this led to reports of a great white in Swansea bay some years back.
 
Maybe the footage mentioned in the OP was from one of those "Walking with Beasts" type of mock-documentaries that the BBc and others did a few years back? They used Jurassic Park-style graphics to place presenters alongside extinct creatures.

This clip, for example, from Walking with Monsters shows Nigel Marven "meeting" a megalodon.
 
lordmongrove said:
Could be this, showing a sleper shark of around 23 feet
http://www.youtube.com/watch?v=9kVLXvDsDtQ
Or this big six gilled shark
http://www.youtube.com/watch?v=pHuvs9Qq ... L&index=22

I've seen the first video before, a friend alerted me to it saying a "megalodon" had been caught on camera. I was first aware if it on youtube around the time my Spanish housemate told me, I think I may even have shown it to him. The footage he had seen was older and I'm pretty certain it's not that film he saw.

The second clip has been posted above and is a possibility.

I don't think he had seen footage from "Walking With".
 
It's only a short clip, but this is (apparently) the largest great white caught on film.


As ever, difficult to make comparisons owing to perspective, but assuming they are not pygmies in that cage, this fish is enormous.

More. They're estimating 7m long and 50 years old:

 
An interesting case of "absence of evidence is not evidence of absence." The oceans and seas cover around 2/3 of the Earth's surface, and the deepest parts are deeper than Everest is tall. Fishing is largely confined to certain areas, and the ocean so big that an airliner can disappear with not a single ship seeing it go down. In such a vastness, it is not inconceivable that a monstrous fish, too large to be caught by anything other than a whaler, should go unnoticed.

However, that is not to assume that the megalodon exists "until proved otherwise"; it is only to say that we should not wholly discount the possibility that it exists.

The largest recorded whale shark was 41.5 ft long (12.65 metres) according to Wikipedia. The largest whale is the blue whale which grows up to 98 ft (30 metres). Therefore, we know that large sharks exist, and that 30 metre (roughly) fish-shaped creatures are viable. (Pisciform, if you prefer!) However, the largest whales and sharks are relatively slow-moving filter feeders.

That said, the largest toothed whale (the sperm whale) grows up to 20 metres, and we know that the prehistoric megalodon "only" grew up to an estimated 18 metres.

It strikes me that although we might never catch or observe a megalodon (if they are extant) we would probably find evidence of things they had bitten: whale carcasses and the like.

In response to comments above: a great white or tiger shark can swim faster than any man alive, and eat anyone it catches. Once those thresholds are crossed, it is unclear to me why a bigger shark is more frightening, as there is no evidence of them attacking boats. Wait! Are they as yet undiscovered in a triangular area of sea near Bermuda?

I would like to think the megalodon is extant, but I reserve judgement in the absence of evidence.
 
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An interesting case of "absence of evidence is not evidence of absence." The oceans and seas cover around 2/3 of the Earth's surface, and the deepest parts are deeper than Everest is tall. Fishing is largely confined to certain areas, and the ocean so big that an airliner can disappear with not a single ship seeing it go down. In such a vastness, it is not inconceivable that a monstrous fish, too large to be caught by anything other than a whaler, should go unnoticed.

However, that is not to assume that the megalodon exists "until proved otherwise"; it is only to say that we should not wholly discount the possibility that it exists.

The largest recorded whale shark was 41.5 ft long (12.65 metres) according to Wikipedia. The largest whale is the blue whale which grows up to 98 ft (30 metres). Therefore, we know that large sharks exist, and that 30 metre (roughly) fish-shaped creatures are viable. (Pisciform, if you prefer!) However, the largest whales and sharks are relatively slow-moving filter feeders.

That said, the largest toothed whale (the sperm whale) grows up to 20 metres, and we know that the prehistoric megalodon "only" grew up to an estimated 18 metres.

It strikes me that although we might never catch or observe a megalodon (if they are extant) we would probably find evidence of things they had bitten: whale carcasses and the like.

In response to comments above: a great white or tiger shark can swim faster than any man alive, and eat anyone it catches. Once those thresholds are crossed, it is unclear to me why a bigger shark is more frightening, as there is no evidence of them attacking boats. Wait! Are they as yet undiscovered in a triangular area of sea near Bermuda?

I would like to think the megalodon is extant, but I reserve judgement in the absence of evidence.

This was roughly my take a few years ago, I agree on evidence/absensce and the size of the ocean and its' relatively unexplored nature. However, most of the ocean relatively barren - the depths, the mid levels and open ocean, which means there's not much to eat and so it makes truly enormous animals comparatively rare and unknown ones very unlikely: especially in the absence of anything approaching good evidence. There are sightings but eyewitnesses are unreliable and spotting things out at sea without landscape to judge size and distance makes ocean crytpid sightings doubly so.

Obviously this doesn't preclude the existence of large and unknown species but it makes them less likely than the size of the sea might suggest. There's also the highly pollution, climate change and overfishing decimating ocean, making most oceanic life increasingly at risk, if not directly killing cryptids, it may kill their food stocks and who knows. we may have bumped off a few unknown large species in the last century or two, along with he ones we know we have.
 
This was roughly my take a few years ago, I agree on evidence/absensce and the size of the ocean and its' relatively unexplored nature. However, most of the ocean relatively barren - the depths, the mid levels and open ocean, which means there's not much to eat and so it makes truly enormous animals comparatively rare and unknown ones very unlikely: especially in the absence of anything approaching good evidence. There are sightings but eyewitnesses are unreliable and spotting things out at sea without landscape to judge size and distance makes ocean crytpid sightings doubly so.

Obviously this doesn't preclude the existence of large and unknown species but it makes them less likely than the size of the sea might suggest. There's also the highly pollution, climate change and overfishing decimating ocean, making most oceanic life increasingly at risk, if not directly killing cryptids, it may kill their food stocks and who knows. we may have bumped off a few unknown large species in the last century or two, along with he ones we know we have.
Yes, as I said, <<However, that is not to assume that the megalodon exists "until proved otherwise"; it is only to say that we should not wholly discount the possibility that it exists.>>

I think it is unlikely but not impossible. I watched a pretty well argued YouTube documentary video about this the other day. It explained the context of the "arms race" between predators and prey and how this is affected by changes of sea temperature and the resultant effects on the amount of food available at the bottom of the food chain. (A sort of "trickle up" economics... )

The ocean is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to the ocean.

(With apologies to Douglas Adams.)

However, much of the ocean is virtually desert. It is not a big wet space teeming with undiscovered megafauna swimming shoulder to shoulder.

Nevertheless, for comparison, the female giant squid can grow to about 13 metres and little as known about it until comparatively recently. There is also a species known as the "colossal squid" (yes, really) which is believed to grow up to 14 metres. This length appears to be based on projections from smaller younger specimens and comparison with other squid species.

Therefore, "scientists believe" (ahem!) that there are 14 metre long sea creatures that have never yet been captured or reliably observed.
 
Yes, as I said, <<However, that is not to assume that the megalodon exists "until proved otherwise"; it is only to say that we should not wholly discount the possibility that it exists.>>

I think it is unlikely but not impossible. I watched a pretty well argued YouTube documentary video about this the other day. It explained the context of the "arms race" between predators and prey and how this is affected by changes of sea temperature and the resultant effects on the amount of food available at the bottom of the food chain. (A sort of "trickle up" economics... )

The ocean is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to the ocean.

(With apologies to Douglas Adams.)

However, much of the ocean is virtually desert. It is not a big wet space teeming with undiscovered megafauna swimming shoulder to shoulder.

Nevertheless, for comparison, the female giant squid can grow to about 13 metres and little as known about it until comparatively recently. There is also a species known as the "colossal squid" (yes, really) which is believed to grow up to 14 metres. This length appears to be based on projections from smaller younger specimens and comparison with other squid species.

Therefore, "scientists believe" (ahem!) that there are 14 metre long sea creatures that have never yet been captured or reliably observed.

Sorry, I did not adequately acknowledge some of the nuances in your post, one of the perils of written only communications that can be sent in a split second, I'm also battling fever. Cryptozoology, is, or at least, was, my main Fortean interest, it has dwindled a lot, though by no means completely, as I have become increasingly sceptical about it.

My thinking is similar to yours, possibly a little more sceptical, or at least more sceptical than the position which you have taken in the last few posts, which are necessarily limited by space, as are mine. I was also most into big ocean cryptids, I've always liked monsters and it's an offshoot of that. The trouble with comparing unknown types of giant or colossal squid, or stating that we don't know what their maxim sizes are, with megalodon or something more mysterious, is that we know various species of giant and colossal squid are currently extant, we don't know that megalodon is still about or that any type of sea serpent exists at all, or ever has. Yes, there are oarfish and there may be extremely large eels.
 
...the "arms race" between predators and prey and how this is affected by changes of sea temperature and the resultant effects on the amount of food available at the bottom of the food chain...much of the ocean is virtually desert. It is not a big wet space teeming with undiscovered megafauna swimming shoulder to shoulder.

“...adding a factor for metabolic heat lost through the gills and not appearing as a temperature rise - allowed Carey and his co-workers to estimate the shark's metabolic rate per kilogram (2.2 pounds) of body mass at 0.2 Calories (kilocalories) per hour. This is equivalent to an oxygen consumption of 60 milligrams per kilogram per hour.

In comparison with the White Shark, we humans are energy hogs. An average, healthy 20-year-old man has a BMR of about 0.97 Calories per kilogram per hour, or about 286 milligrams of oxygen per kilogram per hour. Merely sitting comfortably at room-temperature, a person uses nearly 5 times as much energy per unit of body mass as a Great White actively swimming in a cold ocean.

If the metabolic rate for a Spiny Dogfish is scaled for size and temperature, it comes to about 20 milligrams of oxygen per kilogram of body weight per hour. Thus, a 15-foot (4.6-metre) White Shark has a metabolic rate only about three times that of a scaled-up dogfish - much less than the ten times one would predict based on body temperature alone. Thus the White Shark burns its fuel very efficiently.

Which raises an interesting question: how often does a large White Shark need to eat? Carey and his co-workers estimate that, with a metabolic rate of 0.2 Calories per kilogram per hour, 65 pounds (30 kilograms) of whale blubber would provide enough energy to maintain a 15-foot (4.6-metre), 2,075-pound (943-kilogram) White Shark about six weeks. Since the procedure used by Carey et alii would actually over-estimate the shark's metabolic rate, a large White Shark that had consumed a comparable quantity of caloric energy may be able to go two months or more between meals.

At an average cruising speed of 2 miles (3.2 kilometres) per hour, a Great White may swim more than 2,900 miles (4,600 kilometres) on a single meal. No matter how an individual animal slices its total energy pie, that's terrific fuel economy!”

http://www.elasmo-research.org/education/white_shark/metabolism.htm

maximus otter
 
An interesting case of "absence of evidence is not evidence of absence." The oceans and seas cover around 2/3 of the Earth's surface, and the deepest parts are deeper than Everest is tall. Fishing is largely confined to certain areas, and the ocean so big that an airliner can disappear with not a single ship seeing it go down. In such a vastness, it is not inconceivable that a monstrous fish, too large to be caught by anything other than a whaler, should go unnoticed.

Also consider how sensitive to electrical pulses, light and sound these creatures must be.
Any efforts to send a sub or camera down to record them - is like going birdwatching in a fire engine with sirens and lights blazing.
 
Also consider
Also consider how sensitive to electrical pulses, light and sound these creatures must be.
Any efforts to send a sub or camera down to record them - is like going birdwatching in a fire engine with sirens and lights blazing.

I'm not at all sure that you are right about that. There is plenty of good quality underwater footage of sharks, bony fish, and cetaceans.

As a canoeist, I've often had anglers complain that I will "scare the fish". As a former diver, I have often got within inches of perch, pike, roach and other species (in freshwater) and all manner of marine fish. I was using an aqualung releasing large and loud packets of air bubbles, and I was shining a torch bright enough to hurt a person's eyes from a few metres away. I had friends who used electric cameras with flash to take close ups of fish.

Small marine animals are scared of sudden movements. Large marine animals are often only scared of known predators. Yes, there is evidence that sonar and the sound of ships' propellors causes distress to whales, but those sounds can be heard for huge distances.
 
I'm not at all sure that you are right about that. There is plenty of good quality underwater footage of sharks, bony fish, and cetaceans.

As a canoeist, I've often had anglers complain that I will "scare the fish". As a former diver, I have often got within inches of perch, pike, roach and other species (in freshwater) and all manner of marine fish. I was using an aqualung releasing large and loud packets of air bubbles, and I was shining a torch bright enough to hurt a person's eyes from a few metres away. I had friends who used electric cameras with flash to take close ups of fish.

Small marine animals are scared of sudden movements. Large marine animals are often only scared of known predators. Yes, there is evidence that sonar and the sound of ships' propellors causes distress to whales, but those sounds can be heard for huge distances.
Rebreather aqualungs, such as the one I'm currently documenting, do not release clouds of air bubbles. They're ideally suited to close observation of underwater wildlife.
 
I'm not at all sure that you are right about that. There is plenty of good quality underwater footage of sharks, bony fish, and cetaceans.

As a canoeist, I've often had anglers complain that I will "scare the fish". As a former diver, I have often got within inches of perch, pike, roach and other species (in freshwater) and all manner of marine fish. I was using an aqualung releasing large and loud packets of air bubbles, and I was shining a torch bright enough to hurt a person's eyes from a few metres away. I had friends who used electric cameras with flash to take close ups of fish.

Small marine animals are scared of sudden movements. Large marine animals are often only scared of known predators. Yes, there is evidence that sonar and the sound of ships' propellors causes distress to whales, but those sounds can be heard for huge distances.
yes . . . But sparrows pigeons and starlings wouldn't be phased too much by a fire engine siren. I guess I was meaning a bird that was elusive and rarely photographed, where anything outside of its 'comfort zone' is potential danger to be avoided /evaded.
We can't surely compare the course fish of the uk with the fish evolved and highly specialised to survive in the darkness of the depths of the ocean.
 
Rebreather aqualungs, such as the one I'm currently documenting, do not release clouds of air bubbles. They're ideally suited to close observation of underwater wildlife.
Reading back on my post, I see that I got distracted. I should have added:

<<As a canoeist, I've often had anglers complain that I will "scare the fish". As a former diver, I have often got within inches of perch, pike, roach and other species (in freshwater) and all manner of marine fish. I was using an aqualung releasing large and loud packets of air bubbles, and I was shining a torch bright enough to hurt a person's eyes from a few metres away. I had friends who used electric cameras with flash to take close ups of fish.>> I have seen first hand that fish are not scared by much. You will see sharks cruising past reefs, barracuda hovering next to shoals of fish, pikes lurking by shoals of perch, and divers approaching fish of all sizes, and the fish just carry on with their normal business.

No doubt a rebreather is even less of a problem, but the simple compressed air aqualung is seldom a problem. I did my initial training in the days of twin hose demand valves with a single stage valve behind my back, but did all of my open water dives with a single hose 2 stage system.

But the point is not whether aqualungs of one kind or another scare fish. The point is that fish etc. do not scare easily, and I doubt that the electrical pulses, light and sound associated with searching for megalodon (or other species) are a major problem.
 
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