Cryptozoologists - myself included - love the idea that large undiscovered animals lurk almost at our doorsteps, in the lakes and rivers.
I no longer believe that they do. With some qualifications, I think they are mythical. I could be wrong, and I hope I am. But as decades pass with no better evidence, we ought to take a very hard look at this business.
I know there are many respectable people who are certain what they have seen in Okanagan and Champlain and Loch Ness. But there are many sources of error. And what do we make of the fact that, after decades of modern cryptozoological investigation, we have not a single piece of hard evidence from any location?
We have some suggestive things, to be sure. The Folden film from Okanagan, the Dinsdale film from Ness, that really odd piece of video like a moving underwater pipe from Champlain. Dinsdale's film still doesn't look like a boat to me, although I can't say for certain it isn't. Some of the sonar and hydrophone work in Ness and Champlain is intriguing. But "unexplained" and "proof of a large unknown animal" are not quite the same thing.
(By the way, I am making an exception for Lake Iliamna, where the creatures are clearly fish: this may prove to be the case in several other lakes as well.)
I am arguing here that the Holy Grail of lake monsters - a viable population of very large creatures unknown to science - is not going to be found.
We have lake monsters reported from around the world. All of them cannot be real. As we try to draw the line at lakes with an impressive collection of sightings and discard the rest, it's pretty fuzzy. Where do we draw it? If we dismiss seemingly solid reports from Lake X, do we have to dismiss the ones from Lake Y? No, not necessarily, but it's a difficult judgment call.
There are rare things in the world that only a few people have been lucky enough to see, like ball lightning, Mesoplodon Species B, the kouprey, the (I think this one is valid) orang-pendek. But despite the size of our lakes, we're dealing with restricted areas with increasing populations of boaters, fisherfolk, and so forth, with almost everyone in developed nations now carrying a camera-capable cell phone.
I can't give any credence, despite a handful of sightings, to the idea basilosaurids or plesiosaurs can haul out on land, so it's okay that we have not caught any lake monsters on the shore. But that also means I don't think lake monsters elude us by crossing land between lakes, where they are likely to be spotted and certain to leave evidence of their passing..
We also have no eggs or nests, so we are considering only possible animals that bear live young in the water. Again, this could be the case.
I happen to believe there is at least one large unknown, maybe two, behind "sea serpent" reports. And I grant that the occasional sea creature (be it sea elephant, shark, or unclassified giant eel) can wander far up rivers and into lakes. So some sightings may be, in fact, and individual of a species unknown to science. But if we go back to the question of a breeding colony of giant animals in a lake, the case for that eventuality does not convince me.
We're talking about creatures who have existed for centuries, and what do we have? Eyewitnesses, sincere ones to be sure. But no bodies. No fish with big unexplained teeth marks on them. No definitive film or video. Not (so far as I am aware) a single sighting from the air in any of the "major" monster lakes outside Iliamna. No scales or other residue from a collision. Some broken fishing lines and torn nets, but we can't say from what. If we could somehow, from a God's-eye view, remove all the cases caused by sturgeon, swimming moose, seiche waves, and so on, what would we have left? Some intriguing stuff, to be sure, but convincing evidence for overlooked colonies of huge animals? Again, aside from the occasional wayward sea creature, known or unknown, I don't think what's left is convincing.
Some may think me illogical, since I believe in an oceangoing unknown of which there are NO photographs (the Mary F pictures are completely unconvincing, and videotape from Chesapeake Bay is intriguing but inconclusive.) But there's a difference between a breeding population in 139 million square miles of ocean and one in a lake, even a big lake.
I salute and encourage the efforts of those who try to find creatures in such lakes. I wish you amazing success. You may find something that's wandered up form the oceans: it can happen with known animals, it can happen with unknown ones. You may find an outsized specimen of a sturgeon or other freshwater fish, But I'm not anticipating you'll find any endemic lake creatures. Years pass bringing more evidence, but never bringing hard evidence. I think it's a gap that will never be closed.
In this photo you see the Atlantic sturgeon (top) and Shortnose sturgeon (bottom) (or Acipenser oxyrinchus and Acipenser brevirostrum), both showing the ridged backs with their dermal scutes that can make these fish look, at the surface, like a row of fins or humps following a prehistoric-looking head. (NOAA)