Lethargic frogs and toads shedding thickened skin in patches, struggling with basic functions like breathing and eating, are indicative of chytridiomycosis, a deadly fungal disease known as an “epidermal epidemic” that has caused the extinction of numerous amphibian species globally. While not yet confirmed in Manitoba, Canada, the presence of the pathogen in the province is highly probable, according to Jackie Tran, a graduate student conducting extensive sampling of frogs and salamanders in southern Manitoba.
Chytridiomycosis in frogs is caused by the fungal pathogen Batrachochytrium dendrobatidis, while in salamanders, it is caused by Batrachochytrium salamandrivorans. The latter, believed to have originated in East Asia, has devastated local salamander populations in parts of Europe in recent years. Despite its absence in North America so far, the threat of its introduction remains a concern.
The disease has been directly linked to the extinction of at least 90 species and a decline in populations of over 500 others, making it one of the most devastating infectious diseases among vertebrates. Reports suggest that chytrid may have been present in Brazil and Asia for over a century before spreading worldwide, partly due to the exotic pet trade.
Research indicates that nearly half of Alberta frog populations tested between 2006-2010 were positive for chytrid, with similar findings in British Columbia, where one in ten amphibians sampled were infected, notably affecting northern leopard frogs. The decline of leopard frog populations in Manitoba, historically one of 16 amphibian species in the region, has raised suspicions that chytrid may have been responsible for a significant population decrease decades ago.
While chytrid has been confirmed in frogs in various Canadian provinces and states, its presence in Manitoba remains unconfirmed. Tran’s proactive monitoring efforts in wetland habitats are essential for early detection and mitigation of potential outbreaks, with hopes of preventing further amphibian declines. The identification of suitable habitats for the pathogen can help in implementing targeted conservation strategies to protect vulnerable amphibian populations.
Tran’s ongoing research, part of a broader pathogen monitoring program, aims to provide valuable insights into the health of wetlands and ecosystems, emphasizing the interconnectedness of biodiversity and human well-being. With the potential for proactive measures and targeted treatments, there is optimism that amphibian populations in Manitoba can be safeguarded against the devastating impacts of chytrid.