Monday, 21 May 2018

The eDNA Experiment Begins

A year since Professor Neil Gemmell of New Zealand talked of his interest in conducting eDNA tests at Loch Ness, he has organised his team and equipment and will be arriving at the loch with the improving weather and before the tourist season gets into full swing.

The subject has been covered here before, but the points are worth reiterating again as to what kind of DNA results may come out. Samples of water will be taken, the DNA strands extracted from the water, the DNA sequenced and the code compared against a database of known animals. What that shall reveal is not known to the full extent but there are things we can say in the points below.

Firstly, the experiment should detect all the indigenous species in the loch and I would hope even the rarest of those species. Whether this will be achieved is not certain but if it does not detect everything known, can it assuredly detect everything unknown?

Secondly, there is the matter of whether non-indigenous species will be detected. By that I mean animals which are not always in the loch but are there on a temporary basis dictated by seasonal, reproductive or purely random factors.

In that list we include salmon, trout and seals. The fishing season began last month and so it is possible that DNA traces of salmon may be found, though perhaps it is unlikely they would be found if the tests were conducted in mid-summer and before the second salmon run.

Seals are more interesting as they only appear in the loch every two years or so and therefore it does not seem likely they will be detected. What will also be of interest are the oft discussed catfish and sturgeon. Some believe catfish were placed in the loch decades ago and one may presume some traces will be found. Atlantic sturgeon have always been mooted as occasional visitors and so one would take that as a negative for eDNA tests.

What is the big unknown for me is finding DNA which can be mistaken for something else. I say that because it seems unlikely to me that Loch Ness Monster DNA is going to be radically different to anything else. It is going to be related to something but what? And how different will it be to its nearest relatives that have been sequenced? Let us go through the list.

Plesiosaur – the closest living relatives may be the turtle family.
Long necked seal – how different would this be from harbour or grey seals?
Paranormal Entity – No DNA expected to be found.
Giant eel – DNA difference between the local three footers and a 30 foot specimen?
Giant Invertebrates – How different would this be from the worms and mollusks in the loch?
Itinerant monster – Any DNA at all to be expected?

That is the unknown for me. How much DNA has to change to go from a five foot to a forty-foot creature? How much to extend the neck by six feet? I will leave that to the genetics experts, but I don’t expect any radical DNA to be found – Nessie has some place in an largely well known DNA tree of life.

Two more things I suggested Professor Gemmell tries is to DNA analyse core samples taken from the bottom of the loch and also take water samples from the sides of the loch.

I wish them well in their venture.

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