The search of Loch Ness is about so much more than mysterious water monsters. It’s about cutting edge science which will make a real difference in how we monitor and protect the world’s increasingly fragile ecosystems.
DNA sequencing technology, first developed for the Human Genome Project, finds new uses to test the surrounding environment to find out what lives there. The Super Natural History Loch Ness project and others around the world are using the messy nature of living things to analyse them in a way that is accurate and does no harm. Whether it’s as small as a marine worm or as large as a blue whale, as old as a woolly mammoth or a species new to science, it can now be studied without even being seen.
This is thanks to environmental DNA (eDNA).
WHAT IS eDNA?
Living creatures leave little bits of themselves behind wherever they go. The fur they leave behind, the skin or scales that drop off, the faeces, the urine even the drool has copies of their DNA. This DNA is different for every species living today, or that has lived in the past.
These DNA remnants can be found in the air, soil, ice and water. And now scientists can sift out the individual species’ DNA from samples taken of these environments. In some conditions, like glacial ice, this DNA can last for thousands of years. In other environments such as the ocean the DNA lasts for only a week. But by sorting out the DNA in a sample we can get a snapshot of all the creatures in the area at a moment in time.
HOW CAN WE TELL WHAT DNA BELONGS TO WHAT SPECIES?
Large databases exist with DNA records for over 100,000 different organisms. As the technology involved in genetic sequencing becomes cheaper and more available, these databases are exploding in size. The main publicly accessible database, GenBank, doubles in size about every 18 months!
It’s these databases that researchers use to match the DNA samples gathered from their environmental tests, to figure out what organisms are present. Once this process required significant computing power—now, it can be done from a laptop.
Here’s how eDNA will be collected and analysed during the search of Loch Ness. Other eDNA research follows a similar pattern.
1. All organisms in and around water leave behind DNA traces (left in skin, faeces, urine).
2. Water samples taken from The Loch.
3. Samples sent to lab for analysis.
4. DNA extracted.
5. DNA sequenced using technology originally created for human genome project.
6. DNA results compared against database of existing DNA markers for known species.
7. List shows things native, introduced, invasive and any unexpected results.