A study found higher amounts of chytrid fungus in a frog species exposed to coalmine wastewater compared to nearby unexposed sites.
Scientists said water quality monitoring programs should include factors like frog health.
Frogs in Australia's oldest national park have higher rates of a fatal fungus when exposed to wastewater from a coalmine compared to unexposed waterways, a study suggests.
The study, published in the Journal of Hazardous Materials Advances last month, looked at chytrid fungus levels in two species of frog in Royal National Park, downstream from the Metropolitan Mine, south of Sydney.
Lead author Shannon Kaiser, an ecotoxicologist from Macquarie University, said the wastewater from the mine could not be identified as the cause of the observed disease pattern.
Mr Kaiser said water quality monitoring programs should be expanded to reflect the potential disease risk to animals from environmental changes.
In response, a spokesperson for Peabody, the mine's operator, said any causal link between water chemistry changes and frog infection intensity described in the study was speculative.
The study was undertaken between December 2022 and February 2023, a few months after unlicensed discharges of coal contaminated water from Metropolitan Mine overflowed into Camp Gully Creek.
The NSW Environment Protection Authority fined the mine's operator, Peabody, more than $500,000 and issued clean-up orders along with new regulatory conditions after the incident.
The Peabody spokesperson said it had invested more than $1.5 million in upgrades since 2022 to reduce discharge risk.
Cooper Riach, from Sutherland Shire Environment Centre, raised concerns about frog health after seeing the coal waste enter Camp Gully Creek in 2022.