Assessing diversity and distribution of dinoflagellates in Australian marine waters using eDNA and High Throughput Sequencing (HTS): comparisons with traditional taxonomic methods

Dr Tahnee Manning¹, Richard Piola², Clare Grandison², Matthew Gordon², Dr Jeff  Shimeta¹, Professor Aidyn Mouradov², Arjun Venkatesh Thikagaraj¹, Dmitri Mouradov³

¹RMIT University, Bundoora, Australia, ²Maritime Division, Defence Science & Technology Group, Fishermans Bend, Australia, ³The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia

• Purpose:

A case study of eDNA sampling and high throughput sequencing (HTS). In this study, we utilised eDNA sampling and HTS for the assessment of the composition of dinoflagellate assemblages in two locations: coastal temperate Port Phillip Bay and offshore tropical waters of Davies Reef (Great Barrier Reef).

• Scope:

Dinoflagellates are an ubiquitous and ecologically important component of marine phytoplankton communities, with species including those associated with harmful algal blooms. eDNA sampling and HTS offers a novel approach compared to traditional microscopy for determining dinoflagellate diversity and distribution.

• Issue:

Taxonomic identification of dinoflagellate diversity was assessed using conventional light microscopy as well as by application of HTS of 18S rRNA amplicons of eDNA.  Although widely reported for other regions, the use of eDNA for assessing diversity and composition of dinoflagellates in Australian waters is less common. eDNA is typically utilised for detection of one species rather than for an overall assessment of dinoflagellate diversity across different locations.

• Outcome:

Application of eDNA sampling allowed for the detection of rare and less abundant taxa compared to traditional methods, with all taxa identified using microscopic techniques detected by eDNA sampling. However, approximately ninefold higher numbers of taxa were detected using eDNA compared to traditional methods. The application of eDNA and HTS techniques enabled the previously described diversity for these two locations to be expanded. The relative ease and speed of the process highlights the suitability of eDNA and HTS for future, long term surveys of Australian waters.

Biography:

Biographies to come