Fungal Disease Affecting Australian Reptiles
Queensland researchers are investigating Nannizziopsis barbatae, a fungus causing concern for Australia's diverse reptile population. A long-term study of eastern water dragons in Brisbane's Roma Street Parklands observed the fungus spreading to approximately half of the population over a decade.
Characteristics and Spread
University of Queensland PhD candidate Sam Gallagher-Becker stated that the fungus causes fungal skin lesions and lethargy, potentially leading to starvation and death. The pathogen consumes keratin in reptile scales, resulting in lesions that can cause loss of limbs or digits. In severe cases, affected tissue dies, contributing to the animal's death.
Researchers noted a sharp increase in infections two to three years ago, with the infection rate stabilizing at about 50% in the parkland's water dragon population.
The disease is not confined to a single area or species. Higher infection levels have been observed in other Brisbane reptile populations, and outbreaks are documented in Dubbo and Perth. The fungus's origin, whether native to Australia or introduced, remains unknown.
An introduced origin could imply more severe effects on native species.
Broader Implications and Call for Surveillance
Associate Professor Celine Frere, the study lead, expressed concern about the potential impact on Australia's approximately 1,000 reptile species, 90% of which are endemic.
She characterized the situation as a "national emergency" due to the pathogen's lethality, lack of treatment, and potential to affect most Australian reptile species, coupled with limited knowledge about it.
Dr. Jodi Rowley, curator of Amphibian and Reptile Conservation Biology at the Australian Museum, highlighted that wildlife diseases, particularly in reptiles, are significantly understudied. She noted that the discovery of new diseases in wildlife is concerning and indicates a growing threat to Australia's biodiversity.
Dr. Rowley also indicated that climate change, extreme weather, and increased wildlife movement contribute to a global rise in fungal diseases, which can also pose threats to human populations. There is a recognized need for increased surveillance of wildlife to detect and respond to these events, especially if they originate from overseas.