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.

Microplastics are now being monitored on beaches and in rivers and creeks in the Innisfail region as part of a larger project focused on improving the health of waterways.

Mamu Indigenous Rangers will be testing for microplastics at a number of sites, sharing their results with a national program and, where they can, looking for solutions to reduce plastic pollution.

What are microplastics?

Microplastics are plastics that have broken up into very small particles in the environment, as well as plastic products like microbeads which are used in a range of cleaning, cosmetic and personal care items, or microfibres shed from clothing and other textiles like fishing nets.

Mamu Senior Ranger Francis Joyce said plastic pollution was one of the issues listed by traditional owners at community meetings last year when planning began for the waterway health project, which is being delivered in partnership with Terrain NRM.

Rangers have recently received training from AUSMAP, the Australian Microplastic Assessment Project team which records data collected by a network of researchers and citizen scientists to create a map of microplastic pollution hotspots around Australia. The information is helping to regulate industries and enabling communities and governments to develop better waste management systems.

“We’ll be setting up sampling areas, sieving sand, counting and categorising plastics,’’ Francis said.

Tracking plastics to their source

“Hopefully, further down the track, this data can tell a story. There’s also potential to track plastics to their source if a lot of the same kind of microplastics are detected.”

The Mamu Healthy Waterways Project includes monthly water sampling across the Johnstone River catchment, testing for nutrients, pesticides and suspended solids.

The Innisfail region now has Mamu indigenous rangers caring for country – and a new water monitoring project that’s exciting both elders and the younger generation.

The first four Mamu rangers are on board.

“This is a good feeling, to be moving forward,’’ senior ranger Francis Joyce says. It’s a simple statement but one that’s loaded with passion – for the land, the animals, Mamu cultural heritage and the Mamu people’s drive to be play a bigger role in the management of land and sea.

The ranger program’s launch follows funding through the Queensland Government’s Indigenous Land and Sea Rangers Program. Rangers will be looking after cultural heritage sites, monitoring biodiversity, helping with pest plant control, and leading a new water monitoring program among other roles.

Building on water quality monitoring program

The water program, in partnership with Terrain NRM, is building on existing water quality monitoring in the region, combining cultural knowledge, values and concerns with western science.

“We’ll be doing monthly routine water sampling across the Johnstone catchment from its top to end of catchment, testing for things like nutrients, pesticides and suspended solids,’’ Francis says.

“We’ll also be monitoring impacts on the rainforest and ecosystems and looking at cultural indicators that came about through consultation with our Mamu people – things like places where there used to be yabby beds but there aren’t anymore, fish species that have disappeared from certain areas over the years…

“The information will give everyone a snapshot of waterway health and a better understanding to move towards solutions. By working together and building partnerships we can create a more sustainable future.”

The project is funded through the partnership between the Australian Government and the Great Barrier Reef Foundation. It has also involved water monitoring training for rangers and several younger traditional custodians through Terrain NRM and the Department of Environment and Science.