A targeted eDNA approach to detect and quantify Undaria pinnatifida.

Miss Jonika Edgecombe¹, Miss Gaby Keeler-May¹, Dr Anastasija Zaiko^2,3, Assoc. Prof. Xavier Pochon^2,3, Assoc. Prof Jo-Ann L. Stanton¹, Mr Jackson Treece¹, Ms Christy Rand¹, Dr. Gert-Jan Jeunen¹, Professor Chris Hepburn¹, Professor Neil Gemmell¹

¹University of Otago, Dunedin, New Zealand , ²Cawthron Institute , Nelson, New Zealand, ³Institute of Marine Science, University of Auckland, , New Zealand

Maritime transportation is an integral part of the global economy. The demand for international and transcontinental shipping, however, has accelerated the spread of invasive or non-indigenous species (NIS). International ports are high-risk areas, with ship ballast water and fouling common vectors for NIS incursions. The establishment of NIS can have economic and ecological impacts. NIS can reduce biodiversity and alter resource cycles, and are predicted to have significant negative impacts on ecosystems with high endemism, such as New Zealand. Early detection is critical to prevent further spread and establishment of NIS, and aid eradication efforts.

Environmental DNA (eDNA) bio-monitoring approaches offer solutions for the early detection of NIS, and has proven particularly powerful for detecting cryptic species in hard-to-reach environments. In a variety of scenarios, eDNA has detected and identified NIS faster and more cost-effectively than traditional methods, making routine surveillance and active preventative measures increasingly possible.

Here, we investigated the ability to extend eDNA methodology as a proxy for biomass quantification. We focus on Undaria pinnatifida (Harvey 1860) an established NIS in New Zealand, that is already perturbing coastal ecosystems. Working alongside existing controlled removal work we used species-specific qPCR assays on eDNA samples collected in parallel with biomass measurements to investigate whether quantification of a species based on eDNA sampling is feasible. We find robust correlation between eDNA and biomass measures, suggesting eDNA detection of Undaria could assist fast, targeted and cost-effective biosecurity management.

Biography:

Jonika Edgecombe is a Genetics PhD student in the Gemmell Lab Group in the Department of Anatomy at the University of Otago. She works in collaboration with the Marine Biosecurity Toolbox Programme operating within its DETECT component. She grew up around the Ocean and is passionate about its protection and preservation for future generations. Jonika loves to share her knowledge, dabbling in tutoring and teaching and focussing a large component of her work on community engagement and citizen-science.