There are two very interesting questions here.<p>The first is asking if a giant eel is possible based on known data about eels,<p>> Indeed, the probability of finding a 6-meter eel in Loch Ness is essentially zero—too low for the software used to provide a reliable estimate. Thus, while large eels may account for some eyewitness sightings of large animate objects rising to the loch surface, they are unlikely to account for “sightings” of extraordinarily large animals, which may instead be accounted for by wave phenomena, the occasional stray mammal, or other reasons.<p>The second is asking if the data used to arrive at this conclusion is well supported or not,<p>> This analysis is limited by several factors. First, the Loch Ness eel sample used was relatively small at 129. Larger samples across longer time periods may provide more accurate estimates. Second, the assumption of a skew normal distribution would not hold if, for example, a larger sample revealed a bimodal distribution of eel lengths with a small peak at higher lengths. Third, this analysis is based on purely statistical considerations; the biological mechanism behind the physiological possibility of much larger eels is beyond the scope of this study. Some authors have suggested one such mechanism as neoteny [6] (ie, uncontrolled growth of the leptocephalus larva in A. anguilla preceding subsequent stages of development [36]). Fourth, environmental conditions such as temperature and available biomass impact eel growth and length; therefore, comparisons to other environments such as Zeeschelde may not be appropriate (ie, some of the data cited may not be relevant to the relatively cold waters of Loch Ness).<p>In this scenario, the size distribution the team arrived at was based on 129 eels captured in the 1970s by the "Loch Ness Investigation Bureau." I haven't found the book online, and the article does not claim how, where, and at what depth these eels were captured. I think that is a mistake, as we can't say with any certainty if we've managed to achieve an accurate census of the loch's eel population or not.<p>As the paper itself mentions, there is a remote but slightly plausible possibility that within the 22 sq.mi. and 750' deep lake; there exists a small population of eels (at most 5 to 10 individual animals) that may be larger than a meter. But that's a <i>fairly</i> remote possibility.<p>I think it would be fruitful to constantly monitor the lake with drones and to map out all of the species within it. A lot of good science might come out of it. Because while Nessie may not be real, a sub-species of eel that has come to live within this loch might be. A bit like the Devils Hole pupfish, but Scottish.<p>We find new kinds of life everywhere all the time. The Earth is a magical place, filled to the brim with life, and we've barely scratched the surface.