Ge­netic hunt for Nessie

Focus-Science and Technology - - CONTENTS - WORDS: DR DAR­REN NAISH

Sci­en­tists are track­ing DNA to solve the mys­tery of Loch Ness once and for all.

For cen­turies, many have claimed that a crea­ture lurks in Loch Ness. Now, by seek­ing out mon­ster DNA from the loch’s wa­ters, UEKGPVKUVU CTG IQKPI VQ ƂPF out what’s down there

The idea that new, large an­i­mal species might be hid­ing in the world’s wilder places has al­ways been one of the most ro­man­tic and ap­peal­ing of sci­en­tific con­cepts. Even to­day, it re­mains pos­si­ble that a few big mam­mals, fish or rep­tiles await dis­cov­ery in the forests of New Guinea or South­east Asia, or in cer­tain deep-sea basins. But can we take se­ri­ously the pos­si­bil­ity, en­dorsed by a hand­ful of die-hards and be­liev­ers, that Loch Ness, Scot­land’s largest and most fa­mous lake, is home to a new species of gi­gan­tic, drag­on­like an­i­mal more than 10 me­tres long?

In May 2018, ge­neti­cist Prof Neil Gem­mell of the Uni­ver­sity of Otago, New Zealand, em­barked on a project to col­lect and test ge­netic traces of an­i­mals from the loch, and hoped to re­solve the enigma of Loch Ness once and for all. He and his team were set to use a tech­nique not pre­vi­ously used on the loch’s water. They were go­ing to hunt for en­vi­ron­men­tal DNA, or eDNA (see box, right).

ARE YOU THERE, NESSIE?

Most sci­en­tists do not think there is a mon­ster in the lake. This bold procla­ma­tion isn’t due to ar­ro­gant elitism or an in­abil­ity or un­will­ing­ness to ex­am­ine the data that ex­ists, but to the fact that the ev­i­dence put for­ward to sup­port Nessie’s re­al­ity has failed to be per­sua­sive. The photos and films are fakes, hoaxes, or mis­in­ter­pre­ta­tions of known ob­jects. Bi­o­log­i­cal ev­i­dence that might sup­port the crea­ture’s ex­is­tence – bones, car­casses, feed­ing signs or drop­pings – is non-ex­is­tent. And the large num­ber of eye­wit­ness anec­dotes pro­vides noth­ing ro­bust or con­sis­tent. Rather than mon­sters, there are in­stead as­sorted ref­er­ences to all kinds of things seen on the loch, like swim­ming deer, birds, seals, waves and wakes. Few of these things are fa­mil­iar to the aver­age loch-side vis­i­tor. A psy­cho­log­i­cal phe­nom­e­non known as ‘ex­pec­tant at­ten­tion’ is also im­por­tant in in­flu­enc­ing peo­ple’s ex­pe­ri­ences at Loch Ness. It ex­plains how peo­ple’s ob­ser­va­tions fit an ex­ist­ing ex­pec­ta­tion, in this case, that they will see a large, water-dwelling mon­ster.

Still, the idea of some­thing mysterious in the lake has none­the­less cap­tured the at­ten­tion of sci­en­tists.

“Can we take se­ri­ously the pos­si­bil­ity that Loch Ness is home to a new an­i­mal?”

There­fore, the water has been swept by ves­sels emit­ting sonar, and its depths have been ex­plored by divers, sub­mersibles and motion-de­tect­ing cam­eras. At least a few au­thors and sci­en­tists have gone on record to state their con­fi­dent be­lief in the mon­ster’s ex­is­tence, the data that con­vinced them later prov­ing in­ad­e­quate or er­ro­neous. In other words: sci­ence has searched for Nessie, and the re­sults have come back neg­a­tive.

In the 2016 book Hunt­ing Mon­sters, I noted that the abil­ity of sci­en­tists to search for and an­a­lyse the ge­netic ma­te­rial that liv­ing things leave in their en­vi­ron­ment – so-called en­vi­ron­men­tal DNA, or eDNA – might pro­vide the ul­ti­mate ar­biter of the pres­ence or ab­sence of a mys­tery crea­ture in the loch. Gem­mell was in­spired. “I was think­ing how we might use eDNA to search for and iden­tify crea­tures that live in ar­eas hard to in­ves­ti­gate us­ing tra­di­tional ap­proaches, such as deep oceans and sub­ter­ranean water sys­tems. Loch Ness seemed a per­fect fit for that sort of project,” he says. “I’m not a Nessie believer, but I’m open to the idea that I might be wrong. This project is about un­der­stand­ing the 2

2 bio­di­ver­sity of Loch Ness, with the added bonus be­ing that we might find ev­i­dence of some­thing new that may ex­plain the mon­ster leg­end.” Ac­cord­ing to Gem­mell, the study could also have ben­e­fits for our un­der­stand­ing of the health of Loch Ness and its fu­ture man­age­ment. He’s cur­rently await­ing the re­sults of the sur­vey.

SPECIES SEARCH

The study of eDNA has proved an in­valu­able tool to bi­ol­o­gists ever since it was de­vised in the 1990s. It has been used to ex­am­ine the dis­tri­bu­tion of species no longer present in an area, but whose ge­netic traces are still pre­served in sed­i­ment. It has also proved cru­cial in track­ing the spread of in­va­sive species. Asian grass carp in the North Amer­i­can Great Lakes and the New Zealand mud snail in the west­ern USA, to use just two ex­am­ples, have both had their progress mon­i­tored via eDNA.

eDNA stud­ies have also been used in the search for species that are rarely seen by peo­ple and, in some cases, not seen at all. A 2012 study of sea­wa­ter from the Baltic con­firmed the pres­ence of long-finned pilot whales in the area, a species not seen by peo­ple dur­ing the pe­riod cov­ered by the study and gen­er­ally thought to be an ex­tremely rare vis­i­tor there. More re­mark­able is a 2018 study con­cern­ing eDNA col­lected from the marine

“We could gain im­por­tant in­for­ma­tion on valu­able, rare or sen­si­tive species”

wa­ters of the New Cale­do­nian ar­chi­pel­ago in the south­west Pa­cific. This re­vealed the pres­ence of six shark species that were not picked up at all via more con­ven­tional sam­pling tech­niques, like longterm ob­ser­va­tion and the use of baited lo­ca­tions set with au­to­matic cam­eras.

It’s doubt­ful that any of the sci­en­tists in­volved in these var­i­ous eDNA projects ever con­sid­ered how ap­pli­ca­ble this work might be to the search for lake mon­sters, but it’s with this record of eDNA-based suc­cesses in mind that Gem­mell an­nounced his plans to col­lect and an­a­lyse eDNA from Loch Ness. An eDNA cen­sus of the loch could po­ten­tially re­veal the pres­ence of a large an­i­mal match­ing the ‘mon­ster’ imag­ined by wit­nesses and Nessiehunters. But it would also pro­vide a list of the many ad­di­tional species liv­ing there. Given the suc­cess of eDNA in doc­u­ment­ing the pres­ence of an­i­mals, it is quite plau­si­ble that an eDNA study could doc­u­ment fish, mol­luscs or other species not cur­rently known to be liv­ing in the loch. In­va­sive species could be among them – or­gan­isms we ur­gently need to keep track of. And we could also gain im­por­tant in­for­ma­tion on the where­abouts and move­ments of eco­nom­i­cally valu­able, rare or en­vi­ron­men­tally sen­si­tive species, like var­i­ous mem­bers of the sal­mon fam­ily, or the Euro­pean stur­geon. In short, the sci­en­tific pay-off for the study will be sub­stan­tial, whether a mon­ster is dis­cov­ered or not. “We fig­ured at the out­set that we would likely de­scribe the bio­di­ver­sity of the loch. I an­tic­i­pate find­ing ev­i­dence of all the fish species pre­vi­ously re­ported, plus per­haps some oth­ers that we think may be present,” Gem­mell says. “We also think we might find new forms of bac­te­ria and other life, par­tic­u­larly in sam­ples from around meth­ane seeps in the loch and the fridge-like depths 200m down.”

No­body re­ally ex­pects to dis­cover ev­i­dence for a crea­ture that might be re­garded as sim­i­lar to the ‘Loch Ness Mon­ster’ of pop­u­lar lore. But much re­mains to be learnt about the bi­ol­ogy and ecol­ogy of Loch Ness and its sur­round­ing lochs and lakes. If eDNA and ques­tions about a mon­ster help us to in­ves­ti­gate this sub­ject and learn more about the nat­u­ral world and how it func­tions, then this has proved a most worth­while en­deav­our.

Dr Dar­ren Naish is a palaeon­tol­o­gist and sci­ence writer. He is the au­thor of a num­ber of books on cryp­to­zo­ol­ogy, in­clud­ing Hunt­ing Mon­sters: Cryp­to­zo­ol­ogy And The Re­al­ity Be­hind The Myths. He tweets from @TetZoo.

BE­LOW: Tales of a mon­ster in Loch Ness have been around for cen­turies. Prof Neil Gem­mell is find­ing out what lurks in the murky wa­ters once and for all

ABOVE: Sonar read­ing of Loch Ness, taken by a tour boat cap­tain, re­vealed a deeper sec­tion, which some peo­ple think could be a hid­ing place for Nessie

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