Do sea monsters exist? What a fun question! It is a mixed bag, I think. Some clearly do, some are most likely myth.
There are "monsters" I would almost certainly classify as probable myths, but I want to keep an open mind. I say that because sea monsters would be very rare by virtue of their size. In nature, small fierce predators are common but large predators, especially large, fierce predators, are relatively few. The kinds of guys we are talking about here are apex predators, those at the top of their food chain. Apex predators are almost always very few and are often either far between, or clustered in even more rare packs if they are social animals, because of the scarcity of suitable, large prey. There are exceptions, of course, some whale species for instance. As an aside, I should mention that whales are such an anomaly! If I didn't already know about whales and someone told me about a pack of huge animals that feed on microscopic animals but eat only a few months out of the year, go hungry the rest of the time, and migrate thousands of miles I'd ask them what kind of drugs they'd been using.
In general terms, the bottom line is this: if you want to see a new animal of monstrous proportion, either you should feed your pet some of H. G. Wells' Food of the Gods or else you should be prepared to look for a very, very long time. But let's get down to hard facts!
Probable myth example:
The Loch Ness Monster. We've looked for it for over a century and haven't produced a well-documented, scientific encounter yet. Granted, Ness is a large lake, but come on!
1. The Colossal Squid (Mesonychoteuthis hamiltoni) is my likeliest candidate for the Kraken. We only recently discovered these critters and don't know much of anything about them, especially about their behavior. They normally stay pretty deep (2000 meters or so) but who can say what their minimum depth is or whether they'll come up that far very often? We think they are mostly dinner for sperm whales. We have encountered only a few specimens, and the current (very rough) estimates put its maximum size at 12–14 meters (39–46 feet), mostly based on parts from the stomachs of sperm whales. M. hamiltoni ranges widely in the Southern Hemisphere. The Colossal Squid qualifies in my book because it is an animal of monstrous proportion. What little we know of them is more or less documented in Wikipedia and is quite readable there, as opposed to the scientific papers which are not fun reading at all. If you care to read more, go there.
2. The Manatee (Trichechus) is a poor candidate for the mermaid but it is the best anyone has found.The name comes from the word manatí, meaning "breast." Manatí is a word from the Taíno people, a pre-Columbian civilization that was located in the Caribbean. Mistaking an animal such as the manatee for a beautiful half-woman leads me to believe that the Taíno (and sailors of old) had poor eyesight! [Hey - no comments about ... until they need glasses!] The manatee may be butt-ugly, but these harmless, almost defenseless, gentle semi-tropical aquatic herbivores are clearly real. They are not monsters, they simply suffer an image problem stemming from mistaken identity.
3. The Coelacanth (Latimeria chalumnae), on the other hand, is a monster of an entirely different sort. Coelacanths are lobe-finned fish with the pectoral and anal fins. This throwback was first noted in the fossil record in the middle Devonian and was thought to have become extinct shortly after the Cretaceous ended 65 million years ago - until some fishermen dragged one up in their nets off the coast of South Africa in the '30s. A second, related species, Latimerica enadoensis, was photographed in a fish market in 1998 just before its purchase by a customer. Several more of that one have been found and scientifically documented since. The Coelacanth is not an animal of monstrous proportion; it is a monster in the same sense a small live dinosaur would be -- it seems like a species out of its time. Why? It is kind of a "missing link" between lungfishes and tetrapods.
The Coelacanth is a Lazarus species -- one that disappears from the fossil records only to reappear much, much later -- and it isn't the only example. However, Lazarus taxons are rarely of monstrous proportion. That is not surprising because -- whether by total weight, volume, or numbers -- most species on Earth are tiny. Did you know that, by weight, 99% of Earth's biomass is single-celled or smaller? But I digress.
Can there be more Lazarus taxons in the ocean? How about undiscovered, really big animals? Could be! There are a lot of cubic miles of water and we have not explored all the oceans at all depths everywhere. So when someone tells me they saw a monster, I'm skeptical but I'm also all ears. They may be on to something exciting!
T. P. Donnelly
S/V Tranquility Base
1984 Islander 30 Bahama
Last edited by dacap06; 10-06-2010 at 06:04 AM.