Complex sentence: Populations of amphibians, including the golden frog, suffered major declines possibly due to the fungal infection, chytridiomycosis, which is an invasive fungal pathogen that reached El Valle, the home of the Panamanian Golden Frog in 2006.
Split into simpler sentences: Populations of amphibians, including the golden frog, suffered major declines possibly due to the fungal infection chytridiomycosis. The infection is caused by an invasive fungal pathogen that reached El Valle, the home of the Panamanian golden frog in 2006.