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.
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
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:
If there are platypus there
What sites are suitable based on habitat and water quality and
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.
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.
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.