Ms Nicolette Osborne1
1Seqwater, Gold Coast, Australia
An eDNA survey to support biosecurity control measures for a noxious fish species provides a case study for using eDNA as a tool to inform environmental management decisions. A trap and haul fishway was retrofitted to an existing dam in South-East Queensland to facilitate upstream fish passage for the first time since the dam was constructed several decades prior. The presence of the declared noxious fish species Tilapia (Oreochromis mossambicus), which had established downstream of the dam since it was originally constructed, represented a significant water quality and ecosystem health threat should it be translocated upstream. Physical and procedural controls were implemented at the fishway, however there was no clear supporting information available to demonstrate whether the mitigations to prevent the upstream transfer of Tilapia were successful. Furthermore, there arose a need to justify the resourcing of the controls over time as it was not clear whether Tilapia remained absent from the waters upstream of the dam. eDNA was identified as a potential tool to inform the consideration of ongoing biosecurity and environmental management. A survey was undertaken to screen for presence/absence of Tilapia DNA upstream and downstream of the dam. Results indicated Tilapia DNA was absent in all samples collected from sites upstream of the dam, suggesting that the current controls and management approach were successfully preventing Tilapia from establishing populations upstream. The use of eDNA has been integral to informing management decisions regarding control measures to prevent impact from a noxious species on water quality and ecosystem health.
Biography:
Nicolette is an Environmental Coordinator working within the Environment, Heritage and Land Use Planning Unit at Seqwater. As the South-East Queensland bulk water supply authority, Seqwater manages infrastructure including the SEQ Water Grid and the natural catchments of the region’s water supply sources. Nicolette’s role encompasses all aspects of environmental management for a diverse array of water cycle assets, including catchments, dams, fishways, treatment plants and pipelines. Nicolette completed her undergraduate degree in science focusing on ecology, and postgraduate study concerning environmental management of water resources. With a strong interest in harnessing the benefits of innovative tools and processes to overcome practical environmental management challenges, Nicolette developed a keen interest in the benefits of eDNA to support effective and efficient decision making.