Nessie the Plesio-Turtle

Animal Planet re-ran the 2009 documentary "The Loch Ness Monster Revealed" recently as part of their "Monster Week". So while it is fresh in my mind, I'll review it here.

The plot is familiar, a group of experts in one or more fields came to Loch Ness in an attempt to shed some light on the 80 year old mystery. They go over the past, they do some exploratory work in the present and they predict what it might be if anyone in the future catches it.

Sometimes it works, sometimes it doesn't. The thrust of this documentary was to attempt identification with a few experiments thrown in. Three experts in marine science and paleontology were brought with Philippe Cousteau (grandson of Jacques) in order to provide some answers while Adrian Shine provided local support and expertise.

SIGHTINGS

The investigation began with what the Loch Ness Monster could look like based on eyewitness, film and video evidence. One could see them leafing through old Loch Ness Investigation Bureau reports from the 1960s. This is no easy task in general since the data set is corrupted by a subset of hoaxes and misidentifications. There is also a smaller degree of error in what people describe when they see the real Nessie.

Some of the old sceptical ground was covered as the Surgeon's Photo hoax was explained while the weak "bow wave" argument was trotted out for the MacNab photograph. To that end, some waves from passing boats were filmed and suitably zoomed in to make them look bigger (though I doubt anyone would be fooled by them).

Some vehicles of misidentification were also discussed such as the underwater currents generated when the thermoclines tilts and recovers. Then we had the ducks, logs, swans, logs and seals. Did I say logs twice? Well, you get the picture.

The Spicers' famous sighting was also discussed near the spot it happened and was discussed in a bit of a woolly manner I thought. The idea that the Spicers' long neck feature set a precedent for future Nessie stories is not tenable. It was perhaps the seventh report that made it into the newspapers. However, less than 20% of all reported sightings are head-neck, which suggests that being one of seven sightings is not statistcally significant. The more likely stance is that this is how the creature was always going to be reported.

They also mentioned the so called "King Kong" effect, of which much was made of. I covered this canard in a previous article.

CANDIDATES

Nevertheless, they came to the conclusion that a morphology not unlike our traditional plesiosaur was the best line of enquiry. So, that most familiar of Nessie candidates was examined along with some nice CGI of plesiosaur shaped Nessies swimming in a murky Loch Ness. You can always tell a Nessie programme is populist when it trots out the plesiosaur!

The speculation revolved around whether some plesiosaurs survived the great Cretaceous extinction and what form they could take today after over 65 million years of evolution. There was plenty of scope there for possible paths of modifications. But for me, plesiosaurs today could look very unlike their well known predecessors. In fact, they could bear little resemblance to their forebears.

But having decided plesiosaurs in this day and age were unlikely based on the the fossil record, they moved on. Other animals were briefly discussed but the discussion soon moved onto the modified sea-turtle theory. This basically was a sea going turtle with the shell removed, its neck extended and other additions such as blubber for the coldness of the loch and even some parthenogenesis to cope with low population numbers (it seems a Komodo Dragon performed parthenogenesis without male contact in a zoo recently).

This all seemed logical to a certain extent and I always wondered whether reptiles evolved adaptions to cope with the current ice age we are in which has so far lasted about 2.6 million years. In situations like that, your typical reptile species either dies, moves to warmer climes or adapts to the cold which exists at the fringes of the advancing and receding ice caps. Such adaptions could prove useful in the relatively warmer waters of Loch Ness.

FOOD

The matter of food stocks was addressed and attempts were made to measure the levels of plankton in the loch. Here we had a chance to see Philippe Cousteau take to the loch depths and comment on how it was like swimming in tea ... or whisky. Their estimate came out at 200 tonnes which they translated as 20 tonnes of fish and hence 2 tonnes of higher predator (monster). That doesn't seem a lot but the estimates were lowballed in my opinion.

The 20 tonnes of fish is consistent with the Loch Ness Project's estimate of 17-24 tonnes of pelagic fish but neither includes the migratory fish including salmon, trout and eels. The 10 to 1 ratio between fish and their predators (i.e. Nessie) looks more suitable for warm blooded creatures. What would a cold blooded plesio-turtle population require? How active could they be? Do they hibernate to conserve energy intake? Do they have other food sources? Crocodiles can drop to a ratio of nearly 1:1 in their domains. As you can see, not all the values in the equation were explored.

In that light, the actual Nessie tonnage could easily rise above this meagre two tonne estimate. No one, in my opinion, can be dogmatic on these numbers ... but that doesn't stop us trying!

ENTRY AND EXIT

Finally, the issue of how the monster got into the loch was explored. As said above, Scotland was in the grip of a gigantic ice sheet which temporarily receded over 10,000 years allowing the Ness valley to fill with water and let animal life come back in.

How and when a Nessie sized creature got in is no mystery. It would have swam through the River Ness to the new loch when feeding opportunities consistently presented themselves. What is not so clear is this idea of Nessie getting "land-locked" as the land rose when the icesheets melted. I don't think Nessie was and is in any sense land-locked. Doubtless, the changes to the river made with the construction of the Caledonian Canal presented challenges, but that is it.

In an experiment that looked more fun that serious investigation, our team's boat tried to get over what looked like Telford's Weir in an attempt to simulate Nessie heading into Loch Ness. They failed miserably but given the fact that Nessie goes onto land for short periods, I would reckon it would be less of a challenge to her. How often the Loch Ness Monster actually attempts this, I have no idea.

All in all, a documentary that was more entertaining that informative. Could Nessie be a plesiosaur shaped turtle? I personally doubt it, just because I would expect it to be seen more often. Put a leatherback turtle in Loch Ness and see how good it is at hiding. I am not saying you or me personally would find it from a standing start, but I am sure adequate pictures would begin to turn up in the days and weeks ahead (assuming it survives in the loch). The Loch Ness Monster is a primary water breather, so excursions to the surface are rare to say the least.