Blending traditional knowledge and science

From local rivers to Sydney’s Macquarie University – three Mamu Rangers and Terrain NRM’s Alicia Buckle recently took a deep dive into the science behind environmental DNA.

Environmental DNA (eDNA): What is it?

Environmental DNA, or eDNA, is changing the way we monitor ecosystems and it’s particularly useful in places where traditional monitoring would be dangerous (because of crocodiles) or would cause too much disturbance (in sensitive ecosystems or for rare and endangered species).

It’s being used for many things – from detecting pest fish like tilapia in our creeks and rivers or seeing whether polluted waterways are becoming healthier to monitoring endangered swordfish or finding crown-of-thorns starfish before they mature and cause major problems on the Reef.

Local waterways: How eDNA sampling helps

For Mamu Rangers, eDNA analysis is helping to monitor culturally significant species without land managers having to spend countless hours searching for them, or installing cameras and traps.

“We are using eDNA sampling to help us determine whether species like gudgeon, barramundi and mangrove jack are present or absent in waterways,’’ Mamu Ranger Francis Joyce says. “From there we’ll look at how to manage our waterways better for them.

“Being at the laboratory was amazing – it gave us more of an appreciation of all the science that happens after our sampling, and why our project’s design and sampling methods are so important.”

Fast Facts: eDNA in the laboratory

DNA is in the biological matter in samples.

Molecules called primers are released into the mixture and they attach to target sections of the DNA strands.

These sections can be used as a ‘barcode’ (like we have on products at a supermarket).

Many copies of the barcode sections are made.

These samples are sequenced to look at what species are present. Just like at the supermarket checkout, DNA barcodes can be matched to species in a database to give us a list of animals and plants found in the sample.