Environmental DNA (eDNA) is a useful technique for discovering what is living in or around a lake. The technology finds evidence of living organisms that we may not be able to see using our senses.
Questions for discussion
- Why does Wiremu think that kōura are in the lake?
- Why might it be difficult for Wiremu to find kōura?
- How does eDNA help people learn about the presence of living things?
- What are some of the advantages to using eDNA for lake monitoring?
- Do you think there are any disadvantages to using eDNA for lake monitoring? What are the disadvantages?
Transcript
Wiremu
My koro says our lake is filled with kōura, but I’ve never seen one.
Freshwater scientist
Small creatures can be hard to find in a big lake with only our eyes to help us.
Wiremu
Even if I look my hardest?
Freshwater scientist
Well, there might only be a few around.
Wiremu
Ae, or am I scaring them away?
Freshwater scientist
Sometimes we don’t need to see something to find out if it's there. Instead, we can use eDNA.
Wiremu
eDNA?
Freshwater scientist
All living things have DNA, and all living things shed DNA into the places they live. It can be found in scales, skin or even …
Wiremu
Ew, poop.
Freshwater scientist
When we collect DNA from the environment, it’s called eDNA. That’s it: environmental DNA. We can find DNA in water, soil or even the lake bed.
Wiremu
Wehi nā! These creatures are dropping their DNA everywhere!
Freshwater scientist
Once collected, we take the sample back to the lab and extract the eDNA. Each sequence of a DNA molecule is matched against a database of species.
Wiremu
There’s a match! Ka rawe!
Freshwater scientist
So from a single water sample, we can discover what is living in the environment.
Wiremu
So even though I can’t see the kōura in the lake, we know they’re there because we can detect their DNA.
Acknowledgements
Written, produced and animated by Iona Rachilde.
Voiced by Julius Chambers and Iona Rachilde
With special thanks to Mckayla Holloway, Jonathan Puddick, Susie Wood, John Pearman and Georgia Thomson-Laing.
