How has chytrid fungus affected frog populations?

The fungus Batrachochytrium dendrobatidis (Bd), commonly known as the amphibian chytrid, has had a devastating impact on global frog populations by causing a pandemic disease called amphibian chytridiomycosis.1

The fungus infects the skin of frogs, where it grows and releases infectious zoospores. This infection degrades the epidermis, disrupting the animal's ability to exchange gases and maintain essential electrolyte balance, which ultimately leads to cardiac arrest and death.12

The consequences for biodiversity have been severe:
* Extinctions and Declines: Bd has been implicated in the decline of over 500 species and is attributed to approximately 90 of the modern amphibian extinctions recorded since 1980.1
* Local Devastation: In some regions, such as El Cope, Panama, the disease has caused up to a 90 percent reduction in local amphibian density.1
* Ecological Cascades: The loss of frog populations has broader environmental effects, including negative impacts on the health and biodiversity of predators that rely on them, such as snakes.1

While the fungus is now a global threat, it is considered an invasive species in most areas, having likely originated in the Korean peninsula before spreading through international trade.13