Alaska and Loch Ness 'Monsters' huge sharks?

[Still Waters]

For years, legendary tales from Scotland and Western Alaska described large animals or monsters thought to live in Loch Ness and Lake Iliamna. But evidence has been mounting that the Loch Ness and Lake Iliamna monsters may, in fact, be sleeper sharks.

Two exceptionally large Arctic sharks ply northern waters --

and the Pacific sleeper sharks. During the last few years, scientists have documented Greenland sharks using the St. Lawrence Seaway, lending further credence to the hypothesis that some sharks can survive in freshwater. Bull sharks are also known to swim in fresh water, but this species needs warmer waters.

The idea of sharks possibly using Loch Ness is not new; that's long been one of the hypotheses explaining the Loch Ness Monster. But until now, nobody has suggested sleeper sharks, perhaps because they're secretive and so rarely seen.

http://www.alaskadis...e-sleeper-shark

[Mattshark]

It is an interesting hypothesis, but the problem is that these lakes are fresh water and Greenland sharks are not able to alter their osmoregulation.

[orangepeaceful79]

I always wondered why freshwater fish and saltwater fish couldn't just switch environments. Do fresh water and salt water have different capacities for holding oxygen?

[Blackwater]

Temperature determines how much dissolved oxygen is contained in water. Colder water holds more oxygen. As Matt stated osmoregulation is a huge factor, also salinity and food sources. A marine animals cells have adapted to having the high presence of salinity around them constantly. A freshwater animal would dehydrate in saltwater.. a marine animal would take in too much water. Not to say there aren't species who can tolerate a bit of both.

Also brackish water is another beast altogether..

Edited May 4, 2012 by Blackwater

[Farmer77]

Interesting hypothesis however the peoples of that area are extremely experienced outdoorsmen. The wild and the animals contained within are their livelihood and their recreation. I find it hard to believe that these witnesses, some of whom I have known personally, wouldn't have recognized the creature as a shark.

[Old Man Waffles]

interesting theory... (っ◕‿◕)っ ♥

[TheLostProphet14]

(^///^) I like Sharks

[Bluenose Bulwark]

Bullsharks, eels, trout, salmon, etc

Yep, no fish can cross the fresh to salt water boundary...

[Mattshark]

Bullsharks, eels, trout, salmon, etc

Yep, no fish can cross the fresh to salt water boundary...

Some fish can, most cannot and greenland shark are one of the ones that cannot.

Interesting hypothesis however the peoples of that area are extremely experienced outdoorsmen. The wild and the animals contained within are their livelihood and their recreation. I find it hard to believe that these witnesses, some of whom I have known personally, wouldn't have recognized the creature as a shark.

But witnesses are extremely unreliable, and when people see something they don't understand or cannot recognise most people's brains will produce an explanation by itself, usually not a rational one.

Edited May 5, 2012 by Mattshark

[Bluenose Bulwark]

There really hasnt been enough studies on the Greenland shark, among others, to see if they could live in fresh water for any amount of time. These sharks are hard to get to and not as common as other types, and it's already been stated by researchers that this could be a possibility (key word here).

My best bet is still on a sturgeon.

[Mattshark]

Most likely option is people actually seeing seals in Loch Ness.

Edited May 6, 2012 by Mattshark

[Rafterman]

I seem to recall seeing some images of the river that runs out of Loch Ness to the sea having some rapids that would be difficult for a canoe to get through - much less a Greenland Shark.

I know that there are bull sharks that have been observed jumping rapids salmon style in South America, but that is somewhat rare.

[95-Nasty]

Is it possible that if it is sleeper sharks, couldnt they have evolved over the years to survive in fresh ans cold water?

[Mattshark]

Is it possible that if it is sleeper sharks, couldnt they have evolved over the years to survive in fresh ans cold water?

It is beyond reasonable doubt that they haven't though, not least for the fact that people would notice such a shark going through a city such as Inverness which it would have to do and add to that the fact that there are lock gates on the water way. Additionally there is no driving force on the greenland shark to push its evolution in that direction

Edited May 6, 2012 by Mattshark

[Still Waters]

I seem to recall seeing some images of the river that runs out of Loch Ness to the sea having some rapids that would be difficult for a canoe to get through - much less a Greenland Shark.

That sounds like the weir, and there's also a series of locks to get through.

[Myles]

Growing up in the St. Louis area, it seems that every couple years a shark was caught near St. Louis. Usually bull sharks I think. That's quite a journey in fresh water. Over 700 miles.

[orangepeaceful79]

Growing up in the St. Louis area, it seems that every couple years a shark was caught near St. Louis. Usually bull sharks I think. That's quite a journey in fresh water. Over 700 miles.

The difference being that Bullsharks have adapted to be able to survive in freshwater and the journey up the mighty Mississippi is a pretty tame affair since there aren't rapids like are described in the posts above.

To me, the most likely scenario is that there are no large creatures in the Loch. Ever notice how the most likely explanation is usually the correct one? Lets see - on one hand we have the fallibility of human eyewitness reports and then on the other the possibility that a giant prehistoric fish/reptile has managed to survive millions of years with the barest minimum of population size, in a smallish lake, leaving no actual measurable traces of its existence whatsoever. Which seems more likely?

[Still Waters]

To me, the most likely scenario is that there are no large creatures in the Loch. Ever notice how the most likely explanation is usually the correct one? Lets see - on one hand we have the fallibility of human eyewitness reports and then on the other the possibility that a giant prehistoric fish/reptile has managed to survive millions of years with the barest minimum of population size, in a smallish lake, leaving no actual measurable traces of its existence whatsoever. Which seems more likely?

Just to point out, Loch Ness is not a 'smallish lake'.

Loch Ness is the second largest Scottish loch by surface area at 56.4 km² (21.8 sq mi) after Loch Lomond, but due to its great depth, it is the largest by volume. Its deepest point is 230 m (755 ft),^[1][2] deeper than the height of London's BT Tower at 189 m (620 ft) and deeper than any other loch except Loch Morar. It contains more fresh water than all the lakes in England and Wales combined,^[2] and is the largest body of water on the Great Glen Fault, which runs from Inverness in the north to Fort William in the south.

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

[orangepeaceful79]

Just to point out, Loch Ness is not a 'smallish lake'.

Loch Ness is the second largest Scottish loch by surface area at 56.4 km² (21.8 sq mi) after Loch Lomond, but due to its great depth, it is the largest by volume. Its deepest point is 230 m (755 ft),^[1][2] deeper than the height of London's BT Tower at 189 m (620 ft) and deeper than any other loch except Loch Morar. It contains more fresh water than all the lakes in England and Wales combined,^[2] and is the largest body of water on the Great Glen Fault, which runs from Inverness in the north to Fort William in the south.

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

My bad, to be sure! Thanks. still however seems unlikely to me..... The existence of Nessie, I mean.

[Mind_n_Motion]

It is an interesting concept, but I agree with everyone else that it is unlikely that whatever is being seen is a shark.

Now, the seal theory though...that is interesting. Here in the US we've had some sightings of Caribbean seals off the coast of Florida which were thought to have been wiped out decades ago. If continued research proves that these seals are not only back but have adapted to the change in water temperatures over the years...it is not unrealistic they would find their way in to other areas safe from predators, particularly enclosed lakes & possibly lochs that have underground passage ways.

I don't know how adaptable seals are to fresh vs salt water, but if sharks can adapt then in theory so too could other marine species.

But again, it is all theory. We still know so little about the marine life in our oceans & lakes & rivers....until we truly do I'm not ruling anything out, including something on the prehistoric side. I mean, have you ever seen a pic or video of a Frill Shark? They are seriously one ugly looking shark. The great white I can see staring at eye to eye but not a Frill shark.

Just in case you were curious to see one:

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