Estimating the impacts of the Black Summer bushfires on biodiversity using eDNA

Dr Reid Tingley¹, Ms Emily McColl-Gausden¹, Ms Emma Walker², Ms Emily Pertile², Dr Josh Griffiths², Dr Andrew Weeks²

¹Monash University, Clayton, Australia, ²EnviroDNA, Brunswick, 3056

The 2019-2020 ‘Black Summer’ bushfires highlighted an urgent need for a rapid assessment tool that can be easily deployed at landscape scales to support more traditional post-fire assessment approaches. We argue that environmental DNA (eDNA) sampling has the potential to become such a tool. In demonstrating this promise, we used eDNA sampling to assess the impacts of the Black Summer bushfires on the distributions of a broad range of aquatic and semi-aquatic taxa across Victoria, ACT and south-eastern NSW. We leveraged eDNA samples collected at 188 sites in 2018/2019 and combined these with follow-up eDNA surveys at two time points post-fire (2020, 2021) using a before-after-control-impact design. Fitting hierarchical multi-species models to these data revealed spatial and temporal shifts in species’ distributions but negligible direct impacts of the Black Summer bushfires. These findings suggest that distributions of native species that inhabit regions with rich fire histories may be surprisingly resilient to megafires, at least at the scale studied here. Our study further illustrates that eDNA sampling provides a rapid and efficient assessment methodology for understanding the landscape-scale recovery of populations following disturbance.

Biography:

Reid leads the Data Science Team at EnviroDNA and is an Adjunct Research Fellow at Monash University. He is interested in understanding the impacts of environmental change on species distributions using eDNA.