As part of my surveys of Oklahoma lakes for aquatic invasive plants, I have started a project to test if environmental DNA (eDNA for short) techniques would be useful for surveying bodies of water for aquatic invasive plants.
Environmental DNA is DNA from organisms that is collected from the environment – soil, water, air – instead of directly from the organism. Organisms shed DNA into their environment all the time – in mucus, poop, hair, skin, dropped leaves, etc… By taking a sample of the environment, you do not need to find, disturb, or capture the organism. Now why is this useful? For example – Cameron Siler and his Herpetology Lab at Sam Noble Museum want to survey for rare and cryptic herps. By sampling the water of their habitat to see if the herp species DNA is in it, they don’t need to find the actual organism to know that one is living there.
Why is this useful for invasive species? My protocol for the lake surveys is to search for aquatic invasive plants at public access points, but that means most of the lake is not being sampled. While it is likely that an infestation of an invasive plant will become established near the point of entry by humans, this is not always the case. Plus we need to consider private entries and downstream invasion. You never know what is around the bend – unless you can test the water to see if the DNA is in the environment.
With the expertise of Jessa Watters and others at the Sam Noble Museum, we will be doing a small project to see if we can detect DNA from Parrotfeather, Myriophyllum aquaticum, in bodies of water that we know it infests. We are testing at what distance will we be able to get a signal from the water sample. Can we detect its presence up to 20 meters away from a known group of plants?
Priscilla H. C. Crawford 