Dr Sahan Jayasinghe1, Dr Cindy Bessey, Dr Lev Bodrossy, Dr Katrina West, Dr Bruce Deagle
1CSIRO, Hobart, Australia
Biography:
Sahan is an early career researcher with a passion in the experimental aspects of molecular biology and developing practical applications for the monitoring of marine ecosystems and assessing the impacts of climate change.
Abstract:
In this project, we evaluated eDNA monitoring approaches in offshore marine surveys, focussing on relatively well characterised fish fauna. eDNA samples were collected, both actively and passively, throughout the water column aboard the RV Investigator at sites from Tasmania to NSW, including sites within the South-East Marine Park Network, to establish a new baseline and provide a unique eDNA-based perspective on biodiversity in south-east marine region. The eDNA data generated by the different water filtering protocols were compared spatially (between sites and depths) and temporally (between voyages). Biodiversity data was also collected in parallel using a suite of conventional methods (i.e trawl nets, towed-cameras and acoustics) allowing direct comparisons to be made between eDNA methods and traditional surveying approaches. We found a significant difference in diversity of fish taxa between eDNA and conventional approaches, especially at deeper depths and in remote locations. We also identified significant associations between eDNA detection and environmental variables, such as temperature, salinity and oxygen. These results demonstrate the potential of eDNA as a complementary tool for marine biodiversity assessment and monitoring. The evaluation of different eDNA sampling methods will provide guidance for designing effective and scalable bio-monitoring tools for Australian marine ecosystems.