The decline in amphibian populations is an ongoing mass extinction of amphibian species worldwide. Since the 1980s , decreases in amphibian populations, including population crashes and mass localized extinctions, have been observed in locations all over the world . These declines are known as one of the most critical threats to global biodiversity
Recent (2007) research indicates the reemergence of varieties of chrytid fungi may account for a substantial fraction of the overall decline. A more recent ( 2018 ) paper published in Science confirms this.
Several secondary causes may be involved, including other diseases, habitat destruction and modification, exploitation, pollution , pesticide use, introduced species, and ultraviolet -B radiation (UV-B). However, many of the causes of amphibian declines are still poorly understood, and the topic is currently a subject of much ongoing research . Calculations based on extinction rates suggest that the current extinctionrate of amphibians could be 211 times greater than the backgroundextinctionrate and the estimate goes up to 25,000–45,000 times if endangered species are also included in the computation.Although scientists began observing reduced populations of several Europeanamphibian species already in the 1950s , awareness of the phenomenon as a global problem and its subsequent classification as a modern- day mass extinction only dates from the 1980s . By 1993, more than 500 species of frogs and salamanders present on all five continents were in decline.
In the past three decades, declines in populations of amphibians (the class of organisms that includes frogs, toads, salamanders, newts, and caecilians) have occurred worldwide. In 2004 , the results were published of the first worldwide assessment of amphibian populations, the Global AmphibianAssessment .