Environmental DNA: revolutionising how we investigate northern Australian aquatic life
TropWATER is leading this large-scale research programme which aims to develop rapid and cost-effective eDNA technology to identify and monitor all northern Australian aquatic species. This technology is revolutionising how we investigate life underwater and the TropWATER team are experts in using eDNA-based approaches for improving our understanding of freshwater biodiversity, and in practical monitoring and assessment applications. We are currently applying eDNA techniques to estimate the presence and distribution of aquatic invasive species (tilapia, climbing perch), rare and endangered species (sawfish, frogs, turtles), and to determine the potential effects of fish passage barriers on barramundi movements.
What is environmental DNA (eDNA) and how does it work?
Environmental DNA (eDNA) is DNA that has been released by an organism into the environment, via faeces, hair, urine, skin or gametes. This DNA can be extracted directly from environmental samples such as soil, sediment, and water without having to catch the target organism. The use of eDNA technology allows positive identification of the presence of aquatic species at any life stage and from both sexes from the collection and analysis of DNA material in water samples from different environments (freshwater, marine). In other words, surveying an aquatic field site is as easy as collecting a water sample.
What is DNA Metabarcoding?
The term “DNA barcoding” is used for species identification based on good quality DNA. The word “meta” is added when multiple species are identified from a single sample, e.g. DNA metabarcoding. DNA metabarcoding is a rapid method of biodiversity assessment that combines two powerful technologies: DNA-based identification and high-throughput DNA sequencing. DNA metabarcoding uses universal PCR primers to mass-amplify DNA barcodes from mass collections of organisms or from a single environmental sample containing degraded DNA–environmentalDNA (eDNA). The PCR product is sent to a next generation sequencer and the result is a wealth of DNA sequences which can be matched to sequences in a reference database to generate a list of species present.