What is eDNA

My name is Robert Bajno. I'm a science research biologist with Fisheries and Oceans Canada. One of the important things we do is work to prevent the invasion and establishment of grass carp and other invasive species. If grass carp become established in Canada, it would be really devastate to our economy, our social well-being and ecosystem. The problem with grass carp is that they multiply very quickly.

Even if only a few of them invade, they can quickly expand to an unmanageable number. We definitely don't want that happening. We're conducting extensive scientific monitoring and analysis around the Great Lakes Basin. We use electro fishing, traditional netting gear, and now over the last few years, the environmental DNA.

What is environmental DNA? DNA is a molecule in living organisms.

Your DNA sequence is unique from individual to individual. So it acts very much like a genetic fingerprint that allows us to tell different species apart. Organisms release their unique DNA and skin cells, hair follicles, saliva, feces, their slime and scales. eDNA is simply DNA that's been left behind in the environment by an organism that's been in it. DNA can last in the environment for a few days to a few weeks.

So a fish, like a grass carp, can be gone for a number of days, but its DNA may still be in the water. And that gives us a window of opportunity to detect an organism of interest, very similar to crime scene investigations, where forensic police or scientists collect samples. We can take a sample of water and look for DNA evidence.

We take that water sample and we filter it through filter paper. That filter papers then preserve so that the DNA doesn't degrade or break down. And then it's sent to specialized labs for analysis. Although DNA is a very powerful tool of detection, it's not without its challenges. eDNA can move around, especially in aquatic environments. A fish swimming in a river can have its DNA float to other areas, like an adjacent bay or lake.

But quality consistent eDNA sampling still provides an excellent early warning system against invasive species. We can use DNA as a way to track their movements, and they help us find the fish itself. Fisheries and Oceans Canada has labs with dedicated teams of biologists who are experts in eDNA and its use in aquatic science. But when our lab receives an environmental DNA sample, we purify and isolate all the captured DNA to do a multitude of tests to determine if grass carp may have been present in the water body.

This same procedure can be utilized when using eDNA to search for the presence of rare or endangered species. If we do detect grass carp DNA, we return those results to our partners and that allows them to make appropriate evidence-based decisions, like conducting additional eDNA sampling, or deploying electro fishing and netting crews to those locations in which grass carp was detected.

eDNA is a very powerful tool that can be used in that fight against invasive species like grass carp. Although capturing and removing invasive grass carp is a top priority for Fisheries and Oceans Canada, finding them in a system as big as the Great Lakes is like finding a needle in a haystack. It requires a great deal of effort, but the good news is that with a little bit of guidance, anybody can collect an environmental DNA sample.

And the benefits are huge. What we've done is partnered up with indigenous communities, different federal agencies, other government departments and local communities to expand the breadth of research we do in monitoring invasive species. The involvement of these partners is critical to successfully keeping grass carp out of the Great Lakes. You can have hundreds of people collecting samples across Ontario, across the Great Lakes contributing to science. And the more people you get involved in programs like environmental DNA research, the better it is for everybody in Canada.