Conservation of the marine ecosystem and effective management of its resources requires the ability to characterise the biodiversity present, and to monitor for changes in composition through time. Auditing environmental DNA (eDNA) present in the ocean may provide a non-destructive and highly sensitive means of detecting changes in marine communities.
DNA isolated from a variety of substrates such as seawater is collectively referred to as eDNA. When combined with next generation sequencing (NGS) and metabarcoding, eDNA can provide a wealth of information for studies of biodiversity, food web dynamics, diet analysis and invasive species monitoring. Metabarcoding eDNA has become feasible only because it is now possible to simultaneously sequence millions of copies of DNA from complex multi-species environmental samples.
Our research using eDNA isolated from seawater focuses on developing metabarcoding approaches to assess marine biodiversity. By utilising a suite of primer sets targeting different taxa and genes, our analyses enables the characterisation of the entire tree of life – from prokaryotes to mammals. To further understand the sensitivity of metabarcoding eDNA from seawater, we compare the diversity of fish recovered using this approach to the widely adopted BRUV (Baited Remote Underwater Video) methodology.
Lastly, this presentation will highlight the challenges associated with eDNA metabarcoding - false positive/negatives and contamination, detection limits, quantitativeness, DNA movement and longevity of eDNA.