eDNA explorers – discovering life in the lakes of Aotearoa

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.

AcknowledgementsWritten, 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.