Our team have been funded via the Griffith University School of Environment and Science (ESC) ENGAGE grant scheme for the project "Impacts of fire-fighting chemicals on endangered frogs: Implications for conservation and management".
Investigators include Clare Morrison (ESC), Chantal Lanctot (Australian Rivers Institute), Laura Grogan (Environmental Futures Research Institute), David Newell (Southern Cross University), Hamish McCallum (ESC) in collaboration with Dan Ferguson (Queensland Frog Society).
The Erickson Air-Crane can fight fire with retardant or water. The pilots can select the mix as they make the drop. Red retardant is usually dropped ahead of the fire to keep flames from spreading (https://www.flyingmag.com/photo-gallery/photos/erickson-air-crane-photos/)
Wildland fires have been increasing in frequency and severity in recent years, and this trend is predicted to continue within projected climate change scenarios (Dowdy et al. 2019). Fire-fighting services use a variety of chemicals, including long-term retardants, foams and water enhancers, to aid in the suppression of fires. Until 2004, fire-fighting foams largely contained perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) as active ingredients, which have had significant impacts on the environment because of their persistence and toxicity (Squadrone et al. 2015, Zheng et al. 2019). These chemicals have since largely been phased out and replaced with less toxic and persistent alternatives. However, the impact of these new firefighting chemicals on endemic wildlife is poorly understood.
Firefighters crews battle a blaze. Picture: NIGEL HALLETT (https://www.couriermail.com.au/news/queensland/multiple-communities-under-threat-as-fires-rage-across-queensland/news-story/ed76af88b88b3158c01437a6d155f4fe)
Australia has one of the most diverse range of frogs in the world, with over 200 species. However, like many frog species around the world (IUCN 2019), populations of Australian frogs have been experiencing drastic declines since the late 1970s, and seven species have since become extinct (Scheele et al. 2017). Amphibians are known to be sensitive indicators of ecosystem health as most species are very sensitive to changes in water quality. Consequently, pollution from anthropogenic contaminants is reported as the second most important threat to amphibians after habitat loss (Chanson et al. 2008), with nearly 20% of all amphibians and 29% of threatened amphibians affected by environmental pollutants (IUCN 2019).
Fleay's barred frog tadpoles and metamorph (Mixophyes fleayi)
The recent unprecedented bushfire season that is emerging in eastern Australia this spring has seen fire-fighting chemicals being applied to otherwise pristine high-altitude forest environments, that are habitats to many native frog species, including the endangered Fleay's barred frog (Mixophyes fleayi). Given the known sensitivity of amphibians to chemical contaminants, assessing the impacts of these fire-fighting chemicals on this threatened amphibian is of high concern.
Fleay's barred frog metamorph (Mixophyes fleayi)
The project will involve a combination of field surveys and a series of laboratory-based bioassays to determine the potential acute, chronic and interactive effects of these chemicals on Fleay's barred frog. This will ultimately shed light on the impacts of current fire-fighting practices on frog populations in protected areas. The initial studies will focus on Phos-Chek, Ansulite and Blaze Tamer which are currently being used to supress wildfires throughout Australia.
Considering the recognised sensitivity of amphibians to environmental pressures, it is expected that the outcomes of the research will have profound implications for understanding how vulnerable animals cope with environmental stressors. The project will contribute towards improved guidelines for the application of aerial fire retardants, with particular relevance for the protection of threatened frog species through engagement with QLD Frog Society Inc.