Optimising detection of invasive marine species by characterising eDNA particle size

Miss Kate Tuohey1, Mr Craig Sherman1, Mr Ty Matthews1, Mr  Adam Miller2, Mr Andrew Weeks3

1Deakin University, Waurn Ponds, Australia, 2Deakin University, Warrnambool, Australia, 3EnviroDNA, Brunswick, Australia

Abstract:

Capture of environmental DNA (eDNA) in water samples is an emerging method used to detect invasive marine species. Filtration of water samples to detect invasive species requires optimisation to maximise detection probability. For a given filter pore size, there is a trade-off between the volume of water that can be processed and the size of eDNA particles that can be captured, with target eDNA potentially passing through large pores. Relatively little is known about the influence of species and eDNA decay rate on the particle size fraction the eDNA signal is most strongly associated with, yet this knowledge is essential to optimise field sampling and detection probabilities. Two taxonomically distinct invasive species, the kelp (Undaria pinnatifida) and the Northern Pacific seastar (Asterias amurensis) were chosen as target species to assess the strength of the eDNA signal associated with different particle sizes. Environmental water samples from locations with known populations of U. pinnatifida and A. amurensis were collected and passed through a series of filters of descending pore size. Water samples from controlled laboratory aquariums holding the target species were also filtered. Samples were filtered each day for four days to assess the influence of decay rate on eDNA particle size. DNA collected on filters was quantified using a species-specific qPCR assay to determine the size fraction with the strongest eDNA signal. Knowledge of temporal changes in eDNA particle size distribution as well as optimised filtering procedures will advance targeted detection capability of invasive species.


Biography:

Biographies to come

Date

Mar 21 - 23 2022
Expired!