Ms Dana Clark1, Professor Conrad Pilditch2, Dr Joanne Ellis2, Dr John Pearman1, Dr Angel Borja3, Dr Javier Atalah1, Dr Anastasija Zaiko1,4
1Cawthron Institute, Nelson, New Zealand, 2University of Waikato, Hamilton, New Zealand, 3AZTI, Pasaia, Spain, 4University of Auckland, Auckland, New Zealand
Research demonstrating the potential of environmental DNA (eDNA) metabarcoding for biomonitoring is rapidly growing worldwide but the suitability of this approach is primarily derived from correlative studies that fail to prove causality. We carried out a seven-month manipulative experiment in two estuaries to assess the effects of nutrient loading on benthic communities. eDNA metabarcoding revealed changes in eukaryotic, diatom and bacterial communities in response to enrichment. These patterns aligned with changes in macrofaunal communities identified using traditional morphological techniques, confirming concordance between disturbance indicators detected by eDNA and current monitoring approaches. Clear shifts in eukaryotic and bacterial indicator taxa were seen in response to nutrient loading while changes in diatom communities were more subtle. Community changes were discernable in response to low levels of enrichment, suggesting that estuary health assessment tools could be developed to detect early signs of degradation. Existing eDNA-based biotic indices were able to detect these community shifts, suggesting transferability of these indices to other regions and systems. This work represents a first step towards the development of molecular-based estuary monitoring tools, which could provide a holistic and sensitive approach to ecosystem health assessment with faster turn-around times and lower costs.
Biography:
Anastasija is a member of the Biosecurity Team at the Cawthron Institute. She is involved in the development and validation of eDNA/eRNA-based tools for the routine environmental monitoring in aquatic ecosystems, ecological health indicators and a range of projects focusing on different biosecurity aspects. Currently, Anastasija co-leads the Marine Biosecurity Toolbox programme and oversees the DETECT research theme to ensure effective integration of molecular approaches into the developing biosecurity toolbox. Also, as a co-appointee at the University of Auckland, Institute of Marine Sciences, she supervises post-graduate students working in marine ecology and biosecurity research areas.