Tracking the prevalence of a fungal pathogen, <i>Batrachochytrium dendrobatidis</i> (chytrid fungus), using environmental DNA

Chytridiomycosis, a primary disease driving widespread and unprecedented amphibian declines, is caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). Tracking Bd through space time requires monitoring protocols that efficiently reliably assess prevalence intensity, which in turn an understanding of environment–pathogen dynamics. Environmental DNA (eDNA) was used to track intensity 95 waterbodies southern Ontario, Canada, zoospore counts relative biotic, abiotic, geographic factors. also monitored on semi-weekly basis 10 better understand patterns temporal variability. showed variable prevalence, with 47% 29% having zoospores detected May July, respectively. Patterns were markedly both within across waterbodies, indicating high spatio-temporal heterogeneity. not related environmental factors, variables, or species richness, but negatively estimated canopy cover. In intensively sampled highly time, some sites switching from detection non-detection (and vice versa) 2-week intervals. We conclude eDNA can be useful tool for wetlands emphasize need additional research into methodological factors affecting abundance before this method should widely adopted.