Ever since the 7th century, there have been tales about something very strange in Loch Ness. Until the early 20th century the loch was remote and few travelers ever passed that way; consequently monster sightings were very few and far between, and they were always eagerly dismissed by pragmatic skeptics in the faraway university towns of Edinburgh and Aberdeen. But then, in the 1930s, a new road was pushed through between Inverness and Fort William, which ran along the loch's northern shore, and it was then that the number of reported sightings suddenly and dramatically increased.
Well, we've all heard the stories.... a large, dark, reptilian-looking creature, very shy, aloof and elusive, haunting the deep, dark waters of the loch. Some say it is an unknown species of sea monster, in from the North Sea, others that is actually a marine plesiosaur, a type of ancient marine reptile thought to have been extinguished along with its dinosaurian cousins at the end of the Cretaceous 66 million years ago.
But can the stories really be true? Could a large animal really exist in Loch Ness? Well in common with most people I guess I for one would love the answers to these questions to be "yes!". But alas, such are the sentiments of the heart; in my case at least the head, by contrast always the realist, does not agree.
If we consider any population of animals, be they horses or bees, butterflies or fish, their actual population, plotted on a graph with time on the horizontal axis and population on the vertical axis, will not of course remain constant. Nothing in the real world ever does. Instead it will vary up and down, as the creatures proliferate in good times and wane in bad, so that their record resembles a sinuous, wavy graph which traces itself across the sheet.
Of course, the trace must never, ever come down the page so far as to touch the horizontal axis; for if it does, then the population reaches zero and the creatures are gone forever, the graph thereafter tracing flat across the page just like a hospital monitor where the patient just died.
So we know from this, then, that if the creatures are to survive at all, especially over enormous periods of time, then their trace must always generally lie so far up the page that even the worst dips in the graph never come down to touch the axis. In other words, there must be a lot of them; so many, that in the case of the Loch Ness Monster they would be very obviously apparent. One can visualise a forest of necks protruding from the misty dawn waters, as the morning sun rises over the loch.
So where are they then? Well, perhaps they are indeed very shy, and always remain submerged, or only generally pop their eyes up above the waterline. Perhaps they see us, when we do not see them.
But unfortunately this is not realistic. As we have already seen that there must either be a lot of them, or none at all, we must come to the matter of food supply. The only food in the loch which such creatures could subsist upon are the salmon which migrate there from the North Sea. These fish come up the river Ness, through the modern town of Inverness, and then through the locks which form part of the Caledonian Canal which connects Inverness with the loch itself. Unfortunately for Nessie- lovers, it has been shown, through many studies on the loch, that there aren't enough salmon in there, even at spawning season, to feed even a single monster.
Nessie's defenders usually endeavour to answer both points above, the point regarding population and that regarding food supply, by suggesting that Nessie is a single individual which usually inhabits the open sea along with many others with which she breeds, and only comes into the loch occasionally, after the salmon. This is ingenious but I'm afraid there are problems. For example, to enter the loch the creature would have to pass through the town of Inverness (and actually sit there in a line of boats waiting her turn to go through the canal locks) and it is straining things somewhat to imagine that nobody would notice her! Imagine yourself standing there, beside the long canal lock, looking first at one ship, then the one behind it, then the one behind that….. ship, ship, ship, Loch Ness Monster, ship, ship…. as they all waited in line to go through the lock. Perhaps we can also imagine Nessie sitting there very still and looking straight ahead, hoping that we haven’t noticed. And the same applies at the other end of the loch, 20 miles away in the canal locks at Fort Augustus.
Alternatively it has been suggested that the creature may access the loch not via the canal, but instead via submarine passages and tunnels which may connect Loch Ness with the Sea. But again, unfortunately, many thorough examinations by sonar have shown that there aren't any, and personally I wondered why they even bothered to look, because if there were then the level of the loch would equalise itself with the level of the sea as the water ran through the tunnel and out into the sea, whereas in reality the surface of the loch is 52 feet above sea level.
So if there are large creatures in there, then they are trapped in there, with only a fraction of the food they will need to subsist.
This looks bad. But it gets even worse.
Almost 50 times during the past 2 and a half million years, the British islands have been subjected to major episodes of glaciation (ice ages), during which the entire volume of Loch Ness, 20 miles long, by a mile wide, by 1,000 feet deep in the middle, has frozen into a single solid block of ice, in which state it has then remained for periods of up to 90,000 years at a time.
And so, in the final analysis, unless we have a hibernating, freeze-thawing, anorexic ice-dragon -- and there are actually Nordic legends of such varmints-- then the prospects look bleak indeed for the existence of Nessie.
So how then do we explain the very great number of sightings of a "large, reptilian -looking creature"? We have already seen that the only real explanation will have to be a creature which looks reptilian, which eats fish, and which could slip in and out of the loch undetected. We know that by and large these people have definitely seen something, for there exist sonar records of the odd large creature in the loch, chasing after the salmon.
And there is precisely such a creature which has known us (and us it) for a very long time, and which inhabits the cold waters of the North Sea. It is a fish called the Sturgeon.
These critters are very large by piscean standards; they can reach 9 meters in length, are very dark in colour, and despite being fish they have a very reptilian texture to their scaly hides. They usually inhabit the sea but will come far up rivers and into freshwater lochs in search of salmon. And of course, such a varmint could easily swim around under a boat inside a lock chamber, and so pass through Inverness and into Loch Ness, and back again, quite unnoticed.
It would be lovely, in this harsh world, to be able to allow ourselves, just sometimes, to really believe in such things as Nessie.
It does seem a pity therefore that such a wonderful legend, and creature, cannot realistically have any basis in true fact. And such I guess is the legacy which we all must share, in a world where our heads always seem to prevail, in the end, over the romantic requirements of our hearts.
--- Michael Alan Marshall
NOTE: In the 1970s the famous naturalist Sir Peter Scott produced a photograph allegedly from Loch Ness showing the famous "pelagic fin" of what seemed to be a plesiosaur. Jubilation erupted and the animal was duly given the name Nessiteras Rhombopteryx, which is often quoted and boasted about by monster fans. Unfortunately however this is a perfect anagram for monster hoax by sir peter s.