Platypus Landcare – Repairing Riparian in the Cattai Creek Corridor

Platypus Landcare – Repairing Riparian in the Cattai Creek Corridor

CHEN has started a new project to assist in platypus conservation efforts after finding platypus eDNA in the Cattai and Little Cattai Creek Catchment. This project will assist in the repair of the riparian zones in Cattai creek by removing the environmental weeds along the banks and planting the indigenous plants of this vegetative community, the Sydney Shale Transition Forest, an endangered ecological community.

Eroding bank. Image by Danielle Packer 2021.
Platypus Burrow within the Cattai Creek Catchment. Image by Dr. Michelle Ryan 2020.

 

 

 

 

 

 

 

 

The creek banks have become eroded due to changes in the flow regime due to stormwater release via conventional drains. They also become eroded due to weeds replacing native plants which keep the banks together with their deep roots. Platypus rely on these sturdy banks to use for their burrows which they use as shelter, protection, and to nest their young.

At the moment we have five landholders that have properties along Cattai and Blue Gum Creek and are meeting up monthly at each site to repair these riparian zones and assist in the natural regeneration of the bush.

The more volunteers we have to assist in this project the larger the area of the creek line we can cover and therefore repair more platypus habitat. If you would like to become involved, either continuously, or just for one day, we would love the help! Please email danielle@chen.org.au if you would like to be added to our mailing list. We will soon have a Facebook Group which you can be added to, to keep up to date with our events and come along to the ones you want.

We had our first Platypus Landcare day on the 6th of June 2021 in Annangrove along Cattai Creek. Conservation Volunteers Australia (CVA) assisted us in our mission as they were looking for a site to help in flood recovery efforts. Instead of five landholders, we had about 20 people show up! This big turnout really helped us make a big difference for our first day and inspired us to see the impact we can have. Dr. Michelle Ryan, Lecturer at Western Sydney University (WSU) came along to our first day to speak with all the volunteers about the platypus and how the work we are doing is helping restore platypus habitat.

You can register for our second event by registering with CVA here!

CVA Volunteers Repairing Riparian Zones. Image by Danielle 2021.
Dr Michelle Ryan talking to the volunteers about the platypuss
Dr. Michelle Ryan talking to the volunteers about the platypus. Image by Danielle 2021.

Platypus eDNA water sampling – thank you to volunteers

Platypus eDNA water sampling – thank you to volunteers

Our sampling would not have been possible without the generosity of volunteer citizen scientists (including a number of CHEN members) and students from Western Sydney University (WSU).

A couple of our eDNA testing sites were located on O’Haras Creek and Scaly Bark Creek on the outskirts of Kenthurst.  A particular thank you to Andrew Callaghan the Captain of the Kenthurst Rural Fire Service who very kindly agreed to help our eDNA water sampling team get to these sampling sites that were accessed by local fire trails.  We visited some beautiful spots and what appeared to be some good platypus habitat.

Andrew Callaghan (Captain, Kenthurst Rural Fire Service), Jacqueline Britton (Cattai Aware Project Officer) and Anja McKimmie (CHEN member) at O’Haras Creek, Kenthurst

 

Gabrielle Sabatino (WSU Undergraduate student) and Katherine Morrison (WSU PhD candidate) eDNA water sampling on Cattai Creek

 

Platypus eDNA testing results are in!!

Platypus eDNA testing results are in!!

Some very exciting news to share! The results of our eDNA tests have arrived. Western Sydney University have written all about it in their article “Evidence of platypus population found near major Sydney urban development“.

The Key Points are:

  • Citizen scientists and Western Sydney University researchers have found DNA evidence of platypus in north-west Sydney
  • The findings give credibility to historical sightings over the years
  • The discovery also comes amid major urban development of the area

Way to go CHENer’s and Western Sydney University!

Read the full article from WSU here.

We’re now going to think about how we move forward to protect this unique and iconic species in our Catchment.

Collecting an eDNA sample

Collecting an eDNA sample

How do you take and eDNA sample?

A little more on the eDNA sampling from the last post. The photos here show the filter after each syringe of water has been passed through. You can see the colour change after each syringe, the last one being quite striated and dark. As DNA is in the water, the aim is to pass as much water through the filter as you can- more water means more DNA collected to test and the greater the chance of detecting your target species (or a greater range of species if you do a broad test). 👩‍🔬

You stop filtering water through the filter when the pressure becomes too great and it is no longer possible to.

 

What does it tell us?

 The samples of DNA that we collected last about 5 days in the environment before they are too damaged to be used in testing. This means that if you get a positive results, the species has been their very recently. It can therefore be a great complement* to other types of evidence that a species is in an area, such as scats (poo), hair, scratches, rub marks, nest, egg shells, bones etc., depending on the species in question and the purpose of the research.

You can also see me doing a habitat assessment to determine how much suitable platypus habitat there is at each site. We also tested water temperature, dissolved oxygen, pH and other water quality indicators. 🔬 Oh and no, the eski is not for beers (although the location is beautiful), the samples go in an eski to stay cold and help with preservation. 

What we get overall is picture of:

  1. If there are platypus there
  2. What sites are suitable based on habitat and water quality and
  3.  If the habitat was suitable but the water quality wasn’t, we know what might be affecting them and can investigate to improve the water quality and a few other things.

All these things help inform future research, protection of area and our understanding platypi.

Watch this space for results!

 

 

       

Photos: Students from WSU sampling the creek, Habitat Assessment sheets, (far above) eDNA filters from start to finish of the filtering process.

EnviroDNA sampling – where are the platypus in the Cattai Catchment?

EnviroDNA sampling – where are the platypus in the Cattai Catchment?

Referred to as eDNA, Environmental DNA testing is process that detects species in the environment by collecting samples of DNA that animals leave behind. This can be broken down scats, broken up skin or hair cells, bodily liquids, scales etc. and it can be collected in water samples, soil and a few other ways. It is highly accurate, noninvasive & time efficient, the plus being you don’t have to actually see the animal but you can still find out if it’s there and begin protecting its habitat. Not bad at all!

Cattai Hills Environment Network in partnership with WSU students collected samples across sites in the Cattai and Little Cattai Catchment to find the platypus in the region so that we can work towards their protection. We won’t find results for a few weeks so watch this space!

Photos: Collecting water sample(s), a filter now brown full of eDNA that will be sent to the lab for testing.

 

Platypus Story

Platypus Story

Authored by Cross et al, Changeology Workshop, October 2017

Based on a true story

Two of our newly arrived residents from overseas were clearing privet on their property.  This is their story.

One crisp spring morning we finally came to the bank of the creek.  In wonder we gazed at the water running between the rocks and the cool dark pools.  Suddenly we saw a flash of fur and a rounded beak.  We had never encountered such a strange looking animal before and called our neighbour. 

It was a platypus! 


Media Release from the ABC:
We still do have platypus in some of our creeks – what can we do to ensure they survive and thrive?

Scientists have joined forces with tech giant Google to build an app that allows Australians to gather information about one of our most unique and elusive animals, the platypus.

Key points:

  • Scientists say urban sprawl and climate change are big threats to the platypus
  • The app lets people send photos and observations to an online database
  • The data will be used in the first national survey of Australia’s platypus population

It is not clear how many platypuses are living in the wild, but conservationists say the star of the 20-cent coin is facing an uncertain future due to urban sprawl and river pollution.

Read more