Ms Angela Kirkegaard1, Dr Alejandro Trujillo Gonzalez1, Professor Richard Duncan1, Dr Jarrod Sopniewski1, Associate Professor Simon Clulow1
1University Of Canberra, , Australia
Biography:
Angela is a Honours Student (First Class) at the University of Canberra
Abstract:
Chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) has contributed to amphibian declines worldwide. Elevated salinity has been identified as a potential factor that minimizes Bd infections and may provide a practical disease management strategy to reduce pathogen levels in wild amphibian populations. Environmental DNA (eDNA) provides a sensitive, non-invasive approach for monitoring aquatic pathogens and may be a valuable tool for assessing whether salinity influences environmental Bd dynamics in ponds.
This study evaluated the reliability of eDNA for detecting Bd in experimental pond systems with ranging salinities designed to minimize Bd infections. Water samples were collected from 12 artificial ponds across three urban wetlands, half of which had been spiked with 5 kg pool salt to achieve a salinity of 3 ppt. Ponds were sampled six times over 4 months using a vacuum manifold with 0.45 µM filters. In the same way, frogs using the ponds were captured during monthly surveys and swabbed to compare pond salinity with environmental pathogen loads and host infection patterns. Results showed that salinity reduced Bd detection and quantification; however, naturally occurring inhibitors in pond water had a substantially greater effect on assay performance. These findings demonstrate that environmental matrix effects can strongly influence pathogen eDNA detection and highlight the importance of validating and optimising molecular workflows before using eDNA to infer disease dynamics or evaluate conservation interventions.