Bigelow Scientist On How Environmental DNA Could Help Maine Monitor Oceans
It's called eDNA, the E stands for "environmental," and the National Science Foundation is spending $20 million in Maine to see how it can be useful.
Education and scientific institutions around the state are involved in the multiyear project, led by the University of Maine and the Bigelow Laboratory for Ocean Sciences.
Bigelow Laboratory Senior Research Scientist Dave Emerson, one of the project's co-principal investigators, talked with Maine Public's Irwin Gratz about the work being done to gather eDNA, what it reveals and how it could help monitor Maine's oceans and lakes.
This interview has been edited for clarity.
Emerson: Most organisms leave a DNA signature. We can capture that DNA from water samples and then interrogate it by sequencing it. The beauty of it is that in theory, you can go from everything from the bacteria that are there up to, say, a seal or a porpoise or a whale or a fish that was recently in that body of water and left behind a signature.
Gratz: Why is that important? I mean, there are obviously other ways to find out what creatures are in the ocean. But what can perhaps DNA help find that other forms of observation wouldn't?
It's not that easy to identify some of these organisms. Even in the larval stages of some fish and other higher organisms, it's difficult to assess just based on the larval stages what they are, whereas the DNA is a very specific signature for an organism.
I was reading, too, it has potential usefulness when examining things like red tide in water, for instance, perhaps having some predictive qualities as well.
Exactly. I think that's one of the things that we're really interested in is how well you can sort of use this kind of information to forecast the presence of potential red tides, things like that.
Talk a little bit about the project, which is funded by a $20 million grant from the National Science Foundation. What kind of work is being done out there?
There's a major research focus to it, which breaks down into several different areas of looking at things. For example, species on the move is one area that we look at, which includes both harmful algal blooms, as well as sort of changes in species compositions along the coast. Partly in response to things like climate change, Gulf of Maine warming, there's a fisheries component that's looking sort of at historical fisheries, especially alewives. We're also looking at things like blue carbon, which is another sort of buzzword that's going around these days, in terms of the ability of the ocean to sequester carbon through the growth of seaweeds, kelp, things like that. Can you use eDNA to track those kinds of processes?
Have there been any particular challenges to the techniques you need to extract eDNA and to understand what it's telling you?
It's a fairly new field. So we're still sort of grappling with some of the basic components. For example, how efficiently can you extract DNA? How well can you actually quantify or try to take a DNA sample and assess actual numbers of organisms that are in a sample or that were in a body of water, versus just knowing whether or not they're there? There's a lot of computational challenges to it. As scientists, that's what's exciting about it to us, is sort of resolving some of those problems. But that also gaining acceptance. I think that's one of the things that's really important to us and to this project is to sort of gain acceptance for eDNA as a monitoring tool. But we really would like to see Maine become a leader, not only in the science and the research, but also in the application of eDNA as a tool.